Shear-Sensing by C-Reactive Protein: Linking Aortic Stenosis and Inflammation.

BACKGROUND: CRP (C-reactive protein) is a prototypical acute phase reactant. Upon dissociation of the pentameric isoform (pCRP [pentameric CRP]) into its monomeric subunits (mCRP [monomeric CRP]), it exhibits prothrombotic and proinflammatory activity. Pathophysiological shear rates as observed in aortic valve stenosis (AS) can influence protein conformation and function as observed with vWF (von Willebrand factor). Given the proinflammatory function of dissociated CRP and the important role of inflammation in the pathogenesis of AS, we investigated whether shear stress can modify CRP conformation and induce inflammatory effects relevant to AS. METHODS: To determine the effects of pathological shear rates on the function of human CRP, pCRP was subjected to pathophysiologically relevant shear rates and analyzed using biophysical and biochemical methods. To investigate the effect of shear on CRP conformation in vivo, we used a mouse model of arterial stenosis. Levels of mCRP and pCRP were measured in patients with severe AS pre- and post-transcatheter aortic valve implantation, and the presence of CRP was investigated on excised valves from patients undergoing aortic valve replacement surgery for severe AS. Microfluidic models of AS were then used to recapitulate the shear rates of patients with AS and to investigate this shear-dependent dissociation of pCRP and its inflammatory function. RESULTS: Exposed to high shear rates, pCRP dissociates into its proinflammatory monomers (mCRP) and aggregates into large particles. Our in vitro findings were further confirmed in a mouse carotid artery stenosis model, where the administration of human pCRP led to the deposition of mCRP poststenosis. Patients undergoing transcatheter aortic valve implantation demonstrated significantly higher mCRP bound to circulating microvesicles pre-transcatheter aortic valve implantation compared with post-transcatheter aortic valve implantation. Excised human stenotic aortic valves display mCRP deposition. pCRP dissociated in a microfluidic model of AS and induces endothelial cell activation as measured by increased ICAM-1 and P-selectin expression. mCRP also induces platelet activation and TGF-ß (transforming growth factor beta) expression on platelets. CONCLUSIONS: We identify a novel mechanism of shear-induced pCRP dissociation, which results in the activation of cells central to the development of AS. This novel mechanosensing mechanism of pCRP dissociation to mCRP is likely also relevant to other pathologies involving increased shear rates, such as in atherosclerotic and injured arteries.

Concomitant Left Atrial Appendage Occlusion and Transcatheter Aortic Valve Replacement Among Patients With Atrial Fibrillation.

BACKGROUND: Atrial fibrillation (AF) is common in patients undergoing transcatheter aortic valve replacement (TAVR) and is associated with increased risk of bleeding and stroke. While left atrial appendage occlusion (LAAO) is approved as an alternative to anticoagulants for stroke prevention in patients with AF, placement of these devices in patients with severe aortic stenosis, or when performed at the same time as TAVR, has not been extensively studied. METHODS: WATCH-TAVR (WATCHMAN for Patients with AF Undergoing TAVR) was a multicenter, randomized trial evaluating the safety and effectiveness of concomitant TAVR and LAAO with WATCHMAN in AF patients. Patients were randomized 1:1 to TAVR + LAAO or TAVR + medical therapy. WATCHMAN patients received anticoagulation for 45 days followed by dual antiplatelet therapy until 6 months. Anticoagulation was per treating physician preference for patients randomized to TAVR + medical therapy. The primary noninferiority end point was all-cause mortality, stroke, and major bleeding at 2 years between the 2 strategies. RESULTS: The study enrolled 349 patients (177 TAVR + LAAO and 172 TAVR + medical therapy) between December 2017 and November 2020 at 34 US centers. The mean age of patients was 81 years, and the mean scores for CHA2DS2-VASc and HAS-BLED (Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile INR, Elderly, Drugs/alcohol concomitantly) were 4.9 and 3.0, respectively. At baseline, 85.4% of patients were taking anticoagulants and 71.3% patients were on antiplatelet therapy. The cohorts were well-balanced for baseline characteristics. The incremental LAAO procedure time was 38 minutes, and the median contrast volume used for combined procedures was 119 mL versus 70 mL with TAVR alone. At the 24-month follow-up, 82.5% compared with 50.8% of patients were on any antiplatelet therapy, and 13.9% compared with 66.7% of patients were on any anticoagulation therapy in TAVR + LAAO compared with TAVR + medical therapy group, respectively. For the composite primary end point, TAVR + LAAO was noninferior to TAVR + medical therapy (22.7 versus 27.3 events per 100 patient-years for TAVR + LAAO and TAVR + medical therapy, respectively; hazard ratio, 0.86 [95% CI, 0.60-1.22]; Pnoninferiority<0.001). CONCLUSIONS: Concomitant WATCHMAN LAAO and TAVR is noninferior to TAVR with medical therapy in severe aortic stenosis patients with AF. The increased complexity and risks of the combined procedure should be considered when concomitant LAAO is viewed as an alternative to medical therapy for patients with AF undergoing TAVR. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03173534.

Major Facilitator Superfamily Domain Containing 5 Inhibition Reduces Lipoprotein(a) Uptake and Calcification in Valvular Heart Disease.

BACKGROUND: High circulating levels of Lp(a) (lipoprotein[a]) increase the risk of atherosclerosis and calcific aortic valve disease, affecting millions of patients worldwide. Although atherosclerosis is commonly treated with low-density lipoprotein-targeting therapies, these do not reduce Lp(a) or risk of calcific aortic valve disease, which has no available drug therapies. Targeting Lp(a) production and catabolism may provide therapeutic benefit, but little is known about Lp(a) cellular uptake. METHODS: Here, unbiased ligand-receptor capture mass spectrometry was used to identify MFSD5 (major facilitator superfamily domain containing 5) as a novel receptor/cofactor involved in Lp(a) uptake. RESULTS: Reducing MFSD5 expression by a computationally identified small molecule or small interfering RNA suppressed Lp(a) uptake and calcification in primary human valvular endothelial and interstitial cells. MFSD5 variants were associated with aortic stenosis (P=0.027 after multiple hypothesis testing) with evidence suggestive of an interaction with plasma Lp(a) levels. CONCLUSIONS: MFSD5 knockdown suppressing human valvular cell Lp(a) uptake and calcification, along with meta-analysis of MFSD5 variants associating with aortic stenosis, supports further preclinical assessment of MFSD5 in cardiovascular diseases, the leading cause of death worldwide.

Aortic Valve Stenosis Causes Accumulation of Extracellular Hemoglobin and Systemic Endothelial Dysfunction.

BACKGROUND: Whether aortic valve stenosis (AS) can adversely affect systemic endothelial function independently of standard modifiable cardiovascular risk factors is unknown. METHODS: We therefore investigated endothelial and cardiac function in an experimental model of AS mice devoid of standard modifiable cardiovascular risk factors and human cohorts with AS scheduled for transcatheter aortic valve replacement. Endothelial function was determined by flow-mediated dilation using ultrasound. Extracellular hemoglobin (eHb) concentrations and nitric oxide (NO) consumption were determined in blood plasma of mice and humans by ELISA and chemiluminescence. This was complemented by measurements of aortic blood flow using 4-dimensional flow acquisition by magnetic resonance imaging and computational fluid dynamics simulations. The effects of plasma and red blood cell (RBC) suspensions on vascular function were determined in transfer experiments in a murine vasorelaxation bioassay system. RESULTS: In mice, the induction of AS caused systemic endothelial dysfunction. In the presence of normal systolic left ventricular function and mild hypertrophy, the increase in the transvalvular gradient was associated with elevated eryptosis, increased eHb, and increased plasma NO consumption; eHb sequestration by haptoglobin restored endothelial function. Because the aortic valve orifice area in patients with AS decreased, postvalvular mechanical stress in the central ascending aorta increased. This was associated with elevated eHb, circulating RBC-derived microvesicles, eryptotic cells, lower haptoglobin levels without clinically relevant anemia, and consecutive endothelial dysfunction. Transfer experiments demonstrated that reduction of eHb by treatment with haptoglobin or elimination of fluid dynamic stress by transcatheter aortic valve replacement restored endothelial function. In patients with AS and subclinical RBC fragmentation, the remaining circulating RBCs before and after transcatheter aortic valve replacement exhibited intact membrane function, deformability, and resistance to osmotic and hypoxic stress. CONCLUSIONS: AS increases postvalvular swirling blood flow in the central ascending aorta, triggering RBC fragmentation with the accumulation of hemoglobin in the plasma. This increases NO consumption in blood, thereby limiting vascular NO bioavailability. Thus, AS itself promotes systemic endothelial dysfunction independent of other established risk factors. Transcatheter aortic valve replacement is capable of limiting NO scavenging and rescuing endothelial function by realigning postvalvular blood flow to near physiological patterns. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifiers: NCT05603520 and NCT01805739.

Atorvastatin Effect on Aortic Dilatation and Valvular Calcification Progression in Bicuspid Aortic Valve (BICATOR): A Randomized Clinical Trial.

BACKGROUND: Ascending aorta dilation and aortic valve degeneration are common complications in patients with bicuspid aortic valve. Several retrospective studies have suggested the benefit of statins in reducing these complications. This study aimed to determine whether atorvastatin treatment is effective in reducing the growth of aortic diameters in bicuspid aortic valve and if it slows the progression of valve calcification. METHODS: In a randomized clinical trial, 220 patients with bicuspid aortic valve (43 women; 46±13 years of age) were included and treated with either 20 mg of atorvastatin per day or placebo for 3 years. Inclusion criteria were ≥18 years of age, nonsevere valvular dysfunction, nonsevere valve calcification, and ascending aorta diameter ≤50 mm. Computed tomography and echocardiography studies were performed at baseline and after 3 years of treatment. RESULTS: During follow-up, 28 patients (12.7%) discontinued medical treatment (15 on atorvastatin and 13 taking placebo). Thus, 192 patients completed the 36 months of treatment. Low-density lipoprotein cholesterol levels decreased significantly in the atorvastatin group (median [interquartile range], -30 mg/dL [-51.65 to -1.75 mg/dL] versus 6 mg/dL [-4, 22.5 mg/dL]; P<0.001). The maximum ascending aorta diameter increased with no differences between groups: 0.65 mm (95% CI, 0.45-0.85) in the atorvastatin group and 0.74 mm (95% CI, 0.45-1.04) in the placebo group (P=0.613). Similarly, no significant differences were found for the progression of the aortic valve calcium score (P=0.167) or valvular dysfunction. CONCLUSIONS: Among patients with bicuspid aortic valve without severe valvular dysfunction, atorvastatin treatment was not effective in reducing the progression of ascending aorta dilation and aortic valve calcification during 3 years of treatment despite a significant reduction in low-density lipoprotein cholesterol levels. REGISTRATION: URL: https://www.clinicaltrialsregister.eu; Unique identifier: 2015-001808-57. URL: https://www.clinicaltrials.gov; Unique identifier: NCT02679261.

mPAP/CO Slope and Oxygen Uptake Add Prognostic Value in Aortic Stenosis.

BACKGROUND: Recent guidelines redefined exercise pulmonary hypertension as a mean pulmonary artery pressure/cardiac output (mPAP/CO) slope >3 mm Hg·L-1·min-1. A peak systolic pulmonary artery pressure >60 mm Hg during exercise has been associated with an increased risk of cardiovascular death, heart failure rehospitalization, and aortic valve replacement in aortic valve stenosis. The prognostic value of the mPAP/CO slope in aortic valve stenosis remains unknown. METHODS: In this prospective cohort study, consecutive patients (n=143; age, 73±11 years) with an aortic valve area ≤1.5 cm2 underwent cardiopulmonary exercise testing with echocardiography. They were subsequently evaluated for the occurrence of cardiovascular events (ie, cardiovascular death, heart failure hospitalization, new-onset atrial fibrillation, and aortic valve replacement) during a follow-up period of 1 year. Findings were externally validated (validation cohort, n=141). RESULTS: One cardiovascular death, 32 aortic valve replacements, 9 new-onset atrial fibrillation episodes, and 4 heart failure hospitalizations occurred in the derivation cohort, whereas 5 cardiovascular deaths, 32 aortic valve replacements, 1 new-onset atrial fibrillation episode, and 10 heart failure hospitalizations were observed in the validation cohort. Peak aortic velocity (odds ratio [OR] per SD, 1.48; P=0.036), indexed left atrial volume (OR per SD, 2.15; P=0.001), E/e' at rest (OR per SD, 1.61; P=0.012), mPAP/CO slope (OR per SD, 2.01; P=0.002), and age-, sex-, and height-based predicted peak exercise oxygen uptake (OR per SD, 0.59; P=0.007) were independently associated with cardiovascular events at 1 year, whereas peak systolic pulmonary artery pressure was not (OR per SD, 1.28; P=0.219). Peak Vo2 (percent) and mPAP/CO slope provided incremental prognostic value in addition to indexed left atrial volume and aortic valve area (P<0.001). These results were confirmed in the validation cohort. CONCLUSIONS: In moderate and severe aortic valve stenosis, mPAP/CO slope and percent-predicted peak Vo2 were independent predictors of cardiovascular events, whereas peak systolic pulmonary artery pressure was not. In addition to aortic valve area and indexed left atrial volume, percent-predicted peak Vo2 and mPAP/CO slope cumulatively improved risk stratification.

Unraveling the Mechanisms of Valvular Heart Disease to Identify Medical Therapy Targets: A Scientific Statement From the American Heart Association.

Valvular heart disease is a common cause of morbidity and mortality worldwide and has no effective medical therapy. Severe disease is managed with valve replacement procedures, which entail high health care-related costs and postprocedural morbidity and mortality. Robust ongoing research programs have elucidated many important molecular pathways contributing to primary valvular heart disease. However, there remain several key challenges inherent in translating research on valvular heart disease to viable molecular targets that can progress through the clinical trials pathway and effectively prevent or modify the course of these common conditions. In this scientific statement, we review the basic cellular structures of the human heart valves and discuss how these structures change in primary valvular heart disease. We focus on the most common primary valvular heart diseases, including calcific aortic stenosis, bicuspid aortic valves, mitral valve prolapse, and rheumatic heart disease, and outline the fundamental molecular discoveries contributing to each. We further outline potential therapeutic molecular targets for primary valvular heart disease and discuss key knowledge gaps that might serve as future research priorities.

Cardiovascular Calcification Heterogeneity in Chronic Kidney Disease.

Patients with chronic kidney disease (CKD) exhibit tremendously elevated risk for cardiovascular disease, particularly ischemic heart disease, due to premature vascular and cardiac aging and accelerated ectopic calcification. The presence of cardiovascular calcification associates with increased risk in patients with CKD. Disturbed mineral homeostasis and diverse comorbidities in these patients drive increased systemic cardiovascular calcification in different manifestations with diverse clinical consequences, like plaque instability, vessel stiffening, and aortic stenosis. This review outlines the heterogeneity in calcification patterning, including mineral type and location and potential implications on clinical outcomes. The advent of therapeutics currently in clinical trials may reduce CKD-associated morbidity. Development of therapeutics for cardiovascular calcification begins with the premise that less mineral is better. While restoring diseased tissues to a noncalcified homeostasis remains the ultimate goal, in some cases, calcific mineral may play a protective role, such as in atherosclerotic plaques. Therefore, developing treatments for ectopic calcification may require a nuanced approach that considers individual patient risk factors. Here, we discuss the most common cardiac and vascular calcification pathologies observed in CKD, how mineral in these tissues affects function, and the potential outcomes and considerations for therapeutic strategies that seek to disrupt the nucleation and growth of mineral. Finally, we discuss future patient-specific considerations for treating cardiac and vascular calcification in patients with CKD-a population in need of anticalcification therapies.

Macrophage Migration Inhibitory Factor Promotes Thromboinflammation and Predicts Fast Progression of Aortic Stenosis.

BACKGROUND: Aortic stenosis (AS) is driven by progressive inflammatory and fibrocalcific processes regulated by circulating inflammatory and valve resident endothelial and interstitial cells. The impact of platelets, platelet-derived mediators, and platelet-monocyte interactions on the acceleration of local valvular inflammation and mineralization is presently unknown. METHODS: We prospectively enrolled 475 consecutive patients with severe symptomatic AS undergoing aortic valve replacement. Clinical workup included repetitive echocardiography, analysis of platelets, monocytes, chemokine profiling, aortic valve tissue samples for immunohistochemistry, and gene expression analysis. RESULTS: The patients were classified as fast-progressive AS by the median ∆Vmax of 0.45 m/s per year determined by echocardiography. Immunohistological aortic valve analysis revealed enhanced cellularity in fast-progressive AS (slow- versus fast-progressive AS; median [interquartile range], 247 [142.3-504] versus 717.5 [360.5-1234]; P<0.001) with less calcification (calcification area, mm2: 33.74 [27.82-41.86] versus 20.54 [13.52-33.41]; P<0.001). MIF (macrophage migration inhibitory factor)-associated gene expression was significantly enhanced in fast-progressive AS accompanied by significantly elevated MIF plasma levels (mean±SEM; 6877±379.1 versus 9959±749.1; P<0.001), increased platelet activation, and decreased intracellular MIF expression indicating enhanced MIF release upon platelet activation (CD62P, %: median [interquartile range], 16.8 [11.58-23.8] versus 20.55 [12.48-32.28], P=0.005; MIF, %: 4.85 [1.48-9.75] versus 2.3 [0.78-5.9], P<0.001). Regression analysis confirmed that MIF-associated biomarkers are strongly associated with an accelerated course of AS. CONCLUSIONS: Our findings suggest a key role for platelet-derived MIF and its interplay with circulating and valve resident monocytes/macrophages in local and systemic thromboinflammation during accelerated AS. MIF-based biomarkers predict an accelerated course of AS and represent a novel pharmacological target to attenuate progression of AS.

Valvular Prostaglandins Are Elevated in Severe Human Aortic Valve Stenosis.

BACKGROUND: Aortic valve stenosis (AVS) is the most common valvular disease in the developed world. AVS involves the progressive fibrocalcific remodeling of the aortic valve (AV), which impairs function and can ultimately lead to heart failure. Due to gaps in our understanding of the underlying mechanisms of AVS, there are no pharmacological treatments or dietary interventions known to slow AVS progression. Recent studies have begun to suggest oxylipins-a class of bioactive lipids-may be dysregulated in the valves of patients with AVS. METHODS: We utilized high-performance liquid chromatography-tandem mass spectrometry to conduct a targeted oxylipin analysis on human AV tissue and plasma from a cohort of 110 patients undergoing AV surgery. RESULTS: We identified 36 oxylipins in human AV tissue with all showing significant increase in patients with severe AVS. A multivariate model including patient characteristics and valvular oxylipins identified the arachidonic acid-COX (cyclooxygenase) pathway-derived prostanoids to be the most associated with AVS severity. Plasma oxylipin levels were measured in a subset of AV surgery patients and compared with a control group of healthy participants, showing distinct oxylipin profiles between control and disease. CONCLUSIONS: Our comprehensive analysis of oxylipins in the human AV identified the inflammatory and osteogenic regulating prostanoids to be positively correlated with AVS severity. This elucidation of prostanoid dysregulation warrants further research into COX inhibition to mitigate AVS.

Severe aortic stenosis: secular trends of incidence and outcomes.

BACKGROUND AND AIMS: Severe aortic stenosis (AS) is the guideline-based indication for aortic valve replacement (AVR), which has markedly increased with transcatheter approaches, suggesting possible increasing AS incidence. However, reported secular trends of AS incidence remain contradictory and lack quantitative Doppler echocardiographic ascertainment. METHODS: All adults residents in Olmsted County (MN, USA) diagnosed over 20 years (1997-2016) with incident severe AS (first diagnosis) based on quantitatively defined measures (aortic valve area ≤ 1 cm2, aortic valve area index ≤ 0.6 cm2/m2, mean gradient ≥ 40 mmHg, peak velocity ≥ 4 m/s, Doppler velocity index ≤ 0.25) were counted to define trends in incidence, presentation, treatment, and outcome. RESULTS: Incident severe AS was diagnosed in 1069 community residents. The incidence rate was 52.5 [49.4-55.8] per 100 000 patient-year, slightly higher in males vs. females and was almost unchanged after age and sex adjustment for the US population 53.8 [50.6-57.0] per 100 000 residents/year. Over 20 years, severe AS incidence remained stable (P = .2) but absolute burden of incident cases markedly increased (P = .0004) due to population growth. Incidence trend differed by sex, stable in men (incidence rate ratio 0.99, P = .7) but declining in women (incidence rate ratio 0.93, P = .02). Over the study, AS clinical characteristics remained remarkably stable and AVR performance grew and was more prompt (from 1.3 [0.1-3.3] years in 1997-2000 to 0.5 [0.2-2.1] years in 2013-16, P = .001) but undertreatment remained prominent (>40%). Early AVR was associated with survival benefit (adjusted hazard ratio 0.55 [0.42-0.71], P < .0001). Despite these improvements, overall mortality (3-month 8% and 3-year 36%), was swift, considerable and unabated (all P ≥ .4) throughout the study. CONCLUSIONS: Over 20 years, the population incidence of severe AS remained stable with increased absolute case burden related to population growth. Despite stable severe AS presentation, AVR performance grew notably, but while declining, undertreatment remained substantial and disease lethality did not yet decline. These population-based findings have important implications for improving AS management pathways.

Transcatheter aortic valve implantation in low-risk tricuspid or bicuspid aortic stenosis: the NOTION-2 trial.

BACKGROUND AND AIMS: Transcatheter aortic valve implantation (TAVI) has become the first choice to treat older patients with severe symptomatic aortic stenosis (AS). This study aimed to compare TAVI with surgery in low-risk patients ≤75 years of age, including both tricuspid and bicuspid AS. METHODS: The Nordic Aortic Valve Intervention (NOTION)-2 trial enrolled and 1:1 randomized low-risk patients aged ≤75 years with severe symptomatic AS to TAVI or surgery. The primary endpoint was a composite of all-cause mortality, stroke, or rehospitalization (related to the procedure, valve, or heart failure) at 12 months. RESULTS: A total of 370 patients were enrolled with a mean age of 71.1 years and a median Society of Thoracic Surgeons risk score of 1.1%. A total of 100 patients had bicuspid AS. The 1-year incidence of the primary endpoint was 10.2% in the TAVI group and 7.1% in the surgery group [absolute risk difference 3.1%; 95% confidence interval (CI), -2.7% to 8.8%; hazard ratio (HR) 1.4; 95% CI, 0.7-2.9; P = .3]. Patients with TAVI, when compared to surgery, had lower risk of major bleeding and new-onset atrial fibrillation and higher risk of non-disabling stroke, permanent pacemaker implantation, and moderate or greater paravalvular regurgitation. The risk of the primary composite endpoint was 8.7% and 8.3% in patients with tricuspid AS (HR 1.0; 95% CI, 0.5-2.3) and 14.3% and 3.9% in patients with bicuspid AS (HR 3.8; 95% CI, 0.8-18.5) treated with TAVI or surgery, respectively (P for interaction = .1). CONCLUSIONS: Among low-risk patients aged ≤75 years with severe symptomatic AS, the rate of the composite of death, stroke, or rehospitalization at 1 year was similar between TAVI and surgery. Transcatheter aortic valve implantation outcomes in young bicuspid AS patients warrant caution and should be further investigated. (NOTION-2, ClinicalTrials.gov, NCT02825134). TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT02825134.

Transcatheter or surgical aortic valve implantation: 10-year outcomes of the NOTION trial.

BACKGROUND AND AIMS: Transcatheter aortic valve implantation (TAVI) has become a viable treatment option for patients with severe aortic valve stenosis across a broad range of surgical risk. The Nordic Aortic Valve Intervention (NOTION) trial was the first to randomize patients at lower surgical risk to TAVI or surgical aortic valve replacement (SAVR). The aim of the present study was to report clinical and bioprosthesis outcomes after 10 years. METHODS: The NOTION trial randomized 280 patients to TAVI with the self-expanding CoreValve (Medtronic Inc.) bioprosthesis (n = 145) or SAVR with a bioprosthesis (n = 135). The primary composite outcome was the risk of all-cause mortality, stroke, or myocardial infarction. Bioprosthetic valve dysfunction (BVD) was classified as structural valve deterioration (SVD), non-structural valve dysfunction (NSVD), clinical valve thrombosis, or endocarditis according to Valve Academic Research Consortium-3 criteria. Severe SVD was defined as (i) a transprosthetic gradient of 30 mmHg or more and an increase in transprosthetic gradient of 20 mmHg or more or (ii) severe new intraprosthetic regurgitation. Bioprosthetic valve failure (BVF) was defined as the composite rate of death from a valve-related cause or an unexplained death following the diagnosis of BVD, aortic valve re-intervention, or severe SVD. RESULTS: Baseline characteristics were similar between TAVI and SAVR: age 79.2 ± 4.9 years and 79.0 ± 4.7 years (P = .7), male 52.6% and 53.8% (P = .8), and Society of Thoracic Surgeons score < 4% of 83.4% and 80.0% (P = .5), respectively. After 10 years, the risk of the composite outcome all-cause mortality, stroke, or myocardial infarction was 65.5% after TAVI and 65.5% after SAVR [hazard ratio (HR) 1.0; 95% confidence interval (CI) 0.7-1.3; P = .9], with no difference for each individual outcome. Severe SVD had occurred in 1.5% and 10.0% (HR 0.2; 95% CI 0.04-0.7; P = .02) after TAVI and SAVR, respectively. The cumulative incidence for severe NSVD was 20.5% and 43.0% (P < .001) and for endocarditis 7.2% and 7.4% (P = 1.0) after TAVI and SAVR, respectively. No patients had clinical valve thrombosis. Bioprosthetic valve failure occurred in 9.7% of TAVI and 13.8% of SAVR patients (HR 0.7; 95% CI 0.4-1.5; P = .4). CONCLUSIONS: In patients with severe AS and lower surgical risk randomized to TAVI or SAVR, the risk of major clinical outcomes was not different 10 years after treatment. The risk of severe bioprosthesis SVD was lower after TAVR compared with SAVR, while the risk of BVF was similar.

PALMD haploinsufficiency aggravates extracellular matrix remodeling in vascular smooth muscle cells and promotes calcification.

Reduced PALMD expression is strongly associated with the development of calcified aortic valve stenosis; however, the role of PALMD in vascular calcification remains unknown. Calcified arteries were collected from mice to detect PALMD expression. Heterozygous Palmd knockout (Palmd+/-) mice were established to explore the role of PALMD in subtotal nephrectomy-induced vascular calcification. RNA sequencing was applied to detect molecular changes in aortas from Palmd+/- mice. Primary Palmd+/- vascular smooth muscle cells (VSMCs) or PALMD-silenced VSMCs by short interfering RNA were used to analyze PALMD function in phenotypic changes and calcification. PALMD haploinsufficiency aggravated subtotal nephrectomy-induced vascular calcification. RNA sequencing analysis showed that loss of PALMD disturbed the synthesis and degradation of the extracellular matrix (ECM) in aortas, including collagens and matrix metalloproteinases (Col6a6, Mmp2, Mmp9, etc.). In vitro experiments revealed that PALMD-deficient VSMCs were more susceptible to high phosphate-induced calcification. Downregulation of SMAD6 expression and increased levels of p-SMAD2 were detected in Palmd+/- VSMCs, suggesting that transforming growth factor-ß signaling may be involved in PALMD haploinsufficiency-induced vascular calcification. Our data revealed that PALMD haploinsufficiency causes ECM dysregulation in VSMCs and aggravates vascular calcification. Our findings suggest that reduced PALMD expression is also linked to vascular calcification, and PALMD may be a potential therapeutic target for this disease. NEW & NOTEWORTHY We found that PALMD haploinsufficiency causes extracellular matrix dysregulation, reduced PALMD expression links to vascular calcification, and PALMD mutations may lead to the risk of both calcific aortic valve stenosis and vascular calcification.

Multiomics of Tissue Extracellular Vesicles Identifies Unique Modulators of Atherosclerosis and Calcific Aortic Valve Stenosis.

BACKGROUND: Fewer than 50% of patients who develop aortic valve calcification have concomitant atherosclerosis, implying differential pathogenesis. Although circulating extracellular vesicles (EVs) act as biomarkers of cardiovascular diseases, tissue-entrapped EVs are associated with early mineralization, but their cargoes, functions, and contributions to disease remain unknown. METHODS: Disease stage-specific proteomics was performed on human carotid endarterectomy specimens (n=16) and stenotic aortic valves (n=18). Tissue EVs were isolated from human carotid arteries (normal, n=6; diseased, n=4) and aortic valves (normal, n=6; diseased, n=4) by enzymatic digestion, (ultra)centrifugation, and a 15-fraction density gradient validated by proteomics, CD63-immunogold electron microscopy, and nanoparticle tracking analysis. Vesiculomics, comprising vesicular proteomics and small RNA-sequencing, was conducted on tissue EVs. TargetScan identified microRNA targets. Pathway network analyses prioritized genes for validation in primary human carotid artery smooth muscle cells and aortic valvular interstitial cells. RESULTS: Disease progression drove significant convergence (P<0.0001) of carotid artery plaque and calcified aortic valve proteomes (2318 proteins). Each tissue also retained a unique subset of differentially enriched proteins (381 in plaques; 226 in valves; q<0.05). Vesicular gene ontology terms increased 2.9-fold (P<0.0001) among proteins modulated by disease in both tissues. Proteomics identified 22 EV markers in tissue digest fractions. Networks of proteins and microRNA targets changed by disease progression in both artery and valve EVs revealed shared involvement in intracellular signaling and cell cycle regulation. Vesiculomics identified 773 proteins and 80 microRNAs differentially enriched by disease exclusively in artery or valve EVs (q<0.05); multiomics integration found tissue-specific EV cargoes associated with procalcific Notch and Wnt signaling in carotid arteries and aortic valves, respectively. Knockdown of tissue-specific EV-derived molecules FGFR2, PPP2CA, and ADAM17 in human carotid artery smooth muscle cells and WNT5A, APP, and APC in human aortic valvular interstitial cells significantly modulated calcification. CONCLUSIONS: The first comparative proteomics study of human carotid artery plaques and calcified aortic valves identifies unique drivers of atherosclerosis versus aortic valve stenosis and implicates EVs in advanced cardiovascular calcification. We delineate a vesiculomics strategy to isolate, purify, and study protein and RNA cargoes from EVs entrapped in fibrocalcific tissues. Integration of vesicular proteomics and transcriptomics by network approaches revealed novel roles for tissue EVs in modulating cardiovascular disease.

Association Between Type 2 Diabetes and Changes in Myocardial Structure, Contractile Function, Energetics, and Blood Flow Before and After Aortic Valve Replacement in Patients With Severe Aortic Stenosis.

BACKGROUND: Type 2 diabetes (T2D) is associated with an increased risk of left ventricular dysfunction after aortic valve replacement (AVR) in patients with severe aortic stenosis (AS). Persistent impairments in myocardial energetics and myocardial blood flow (MBF) may underpin this observation. Using phosphorus magnetic resonance spectroscopy and cardiovascular magnetic resonance, this study tested the hypothesis that patients with severe AS and T2D (AS-T2D) would have impaired myocardial energetics as reflected by the phosphocreatine to ATP ratio (PCr/ATP) and vasodilator stress MBF compared with patients with AS without T2D (AS-noT2D), and that these differences would persist after AVR. METHODS: Ninety-five patients with severe AS without coronary artery disease awaiting AVR (30 AS-T2D and 65 AS-noT2D) were recruited (mean, 71 years of age [95% CI, 69, 73]; 34 [37%] women). Thirty demographically matched healthy volunteers (HVs) and 30 patients with T2D without AS (T2D controls) were controls. One month before and 6 months after AVR, cardiac PCr/ATP, adenosine stress MBF, global longitudinal strain, NT-proBNP (N-terminal pro-B-type natriuretic peptide), and 6-minute walk distance were assessed in patients with AS. T2D controls underwent identical assessments at baseline and 6-month follow-up. HVs were assessed once and did not undergo 6-minute walk testing. RESULTS: Compared with HVs, patients with AS (AS-T2D and AS-noT2D combined) showed impairment in PCr/ATP (mean [95% CI]; HVs, 2.15 [1.89, 2.34]; AS, 1.66 [1.56, 1.75]; P<0.0001) and vasodilator stress MBF (HVs, 2.11 mL min g [1.89, 2.34]; AS, 1.54 mL min g [1.41, 1.66]; P<0.0001) before AVR. Before AVR, within the AS group, patients with AS-T2D had worse PCr/ATP (AS-noT2D, 1.74 [1.62, 1.86]; AS-T2D, 1.44 [1.32, 1.56]; P=0.002) and vasodilator stress MBF (AS-noT2D, 1.67 mL min g [1.5, 1.84]; AS-T2D, 1.25 mL min g [1.22, 1.38]; P=0.001) compared with patients with AS-noT2D. Before AVR, patients with AS-T2D also had worse PCr/ATP (AS-T2D, 1.44 [1.30, 1.60]; T2D controls, 1.66 [1.56, 1.75]; P=0.04) and vasodilator stress MBF (AS-T2D, 1.25 mL min g [1.10, 1.41]; T2D controls, 1.54 mL min g [1.41, 1.66]; P=0.001) compared with T2D controls at baseline. After AVR, PCr/ATP normalized in patients with AS-noT2D, whereas patients with AS-T2D showed no improvements (AS-noT2D, 2.11 [1.79, 2.43]; AS-T2D, 1.30 [1.07, 1.53]; P=0.0006). Vasodilator stress MBF improved in both AS groups after AVR, but this remained lower in patients with AS-T2D (AS-noT2D, 1.80 mL min g [1.59, 2.0]; AS-T2D, 1.48 mL min g [1.29, 1.66]; P=0.03). There were no longer differences in PCr/ATP (AS-T2D, 1.44 [1.30, 1.60]; T2D controls, 1.51 [1.34, 1.53]; P=0.12) or vasodilator stress MBF (AS-T2D, 1.48 mL min g [1.29, 1.66]; T2D controls, 1.60 mL min g [1.34, 1.86]; P=0.82) between patients with AS-T2D after AVR and T2D controls at follow-up. Whereas global longitudinal strain, 6-minute walk distance, and NT-proBNP all improved after AVR in patients with AS-noT2D, no improvement in these assessments was observed in patients with AS-T2D. CONCLUSIONS: Among patients with severe AS, those with T2D demonstrate persistent abnormalities in myocardial PCr/ATP, vasodilator stress MBF, and cardiac contractile function after AVR; AVR effectively normalizes myocardial PCr/ATP, vasodilator stress MBF, and cardiac contractile function in patients without T2D.

Multiancestry Genome-Wide Association Study of Aortic Stenosis Identifies Multiple Novel Loci in the Million Veteran Program.

BACKGROUND: Calcific aortic stenosis (CAS) is the most common valvular heart disease in older adults and has no effective preventive therapies. Genome-wide association studies (GWAS) can identify genes influencing disease and may help prioritize therapeutic targets for CAS. METHODS: We performed a GWAS and gene association study of 14 451 patients with CAS and 398 544 controls in the Million Veteran Program. Replication was performed in the Million Veteran Program, Penn Medicine Biobank, Mass General Brigham Biobank, BioVU, and BioMe, totaling 12 889 cases and 348 094 controls. Causal genes were prioritized from genome-wide significant variants using polygenic priority score gene localization, expression quantitative trait locus colocalization, and nearest gene methods. CAS genetic architecture was compared with that of atherosclerotic cardiovascular disease. Causal inference for cardiometabolic biomarkers in CAS was performed using Mendelian randomization and genome-wide significant loci were characterized further through phenome-wide association study. RESULTS: We identified 23 genome-wide significant lead variants in our GWAS representing 17 unique genomic regions. Of the 23 lead variants, 14 were significant in replication, representing 11 unique genomic regions. Five replicated genomic regions were previously known risk loci for CAS (PALMD, TEX41, IL6, LPA, FADS) and 6 were novel (CEP85L, FTO, SLMAP, CELSR2, MECOM, CDAN1). Two novel lead variants were associated in non-White individuals (P<0.05): rs12740374 (CELSR2) in Black and Hispanic individuals and rs1522387 (SLMAP) in Black individuals. Of the 14 replicated lead variants, only 2 (rs10455872 [LPA], rs12740374 [CELSR2]) were also significant in atherosclerotic cardiovascular disease GWAS. In Mendelian randomization, lipoprotein(a) and low-density lipoprotein cholesterol were both associated with CAS, but the association between low-density lipoprotein cholesterol and CAS was attenuated when adjusting for lipoprotein(a). Phenome-wide association study highlighted varying degrees of pleiotropy, including between CAS and obesity at the FTO locus. However, the FTO locus remained associated with CAS after adjusting for body mass index and maintained a significant independent effect on CAS in mediation analysis. CONCLUSIONS: We performed a multiancestry GWAS in CAS and identified 6 novel genomic regions in the disease. Secondary analyses highlighted the roles of lipid metabolism, inflammation, cellular senescence, and adiposity in the pathobiology of CAS and clarified the shared and differential genetic architectures of CAS with atherosclerotic cardiovascular diseases.

Economic Outcomes of Transcatheter Versus Surgical Aortic Valve Replacement in Patients with Severe Aortic Stenosis and Low Surgical Risk: Results from the PARTNER 3 Trial.

BACKGROUND: In patients with severe symptomatic aortic stenosis at low surgical risk, transfemoral transcatheter aortic valve replacement (TAVR) with the SAPIEN 3 valve has been shown to reduce the composite of death, stroke, or rehospitalization at 2-year follow-up compared with surgical aortic valve replacement (SAVR). Whether TAVR is cost-effective compared with SAVR for low-risk patients remains uncertain. METHODS: Between 2016 and 2017, 1000 low-risk patients with aortic stenosis were randomly assigned to TAVR with the SAPIEN 3 valve or SAVR in the PARTNER 3 trial (Placement of Aortic Transcatheter Valves). Of these patients, 929 underwent valve replacement, were enrolled in the United States, and were included in the economic substudy. Procedural costs were estimated using measured resource use. Other costs were determined by linkage with Medicare claims or by regression models when linkage was not feasible. Health utilities were estimated using the EuroQOL 5-item questionnaire. With the use of a Markov model informed by in-trial data, lifetime cost-effectiveness from the perspective of the US health care system was estimated in terms of cost per quality-adjusted life-year gained. RESULTS: Although procedural costs were nearly $19 000 higher with TAVR, total index hospitalization costs were only $591 more with TAVR compared with SAVR. Follow-up costs were lower with TAVR such that TAVR led to 2-year cost savings of $2030/patient compared with SAVR (95% CI, -$6222 to $1816) and a gain of 0.05 quality-adjusted life-years (95% CI, -0.003 to 0.102). In our base-case analysis, TAVR was projected to be an economically dominant strategy with a 95% probability that the incremental cost-effectiveness ratio for TAVR would be <$50 000/quality-adjusted life-year gained (consistent with high economic value from a US health care perspective). These findings were sensitive to differences in long-term survival, however, such that a modest long-term survival advantage with SAVR would render SAVR cost-effective (although not cost saving) compared with TAVR. CONCLUSIONS: For patients with severe aortic stenosis and low surgical risk similar to those enrolled in the PARTNER 3 trial, transfemoral TAVR with the SAPIEN 3 valve is cost saving compared with SAVR at 2 years and is projected to be economically attractive in the long run as long as there are no substantial differences in late death between the 2 strategies. Long-term follow-up will be critical to ultimately determine the preferred treatment strategy for low-risk patients from both a clinical and economic perspective.

Th1 cells reduce the osteoblast-like phenotype in valvular interstitial cells by inhibiting NLRP3 inflammasome activation in macrophages.

BACKGROUND AND AIMS: Inflammation is initiates the propagation phase of aortic valve calcification. The activation of NLRP3 signaling in macrophages plays a crucial role in the progression of calcific aortic valve stenosis (CAVS). IFN-γ regulates NLRP3 activity in macrophages. This study aimed to explore the mechanism of IFN-γ regulation and its impact on CAVS progression and valve interstitial cell transdifferentiation. METHODS AND RESULTS: The number of Th1 cells and the expression of IFN-γ and STAT1 in the aortic valve, spleen and peripheral blood increased significantly as CAVS progressed. To explore the mechanisms underlying the roles of Th1 cells and IFN-γ, we treated CAVS mice with IFN-γ-AAV9 or an anti-IFN-γ neutralizing antibody. While IFN-γ promoted aortic valve calcification and dysfunction, it significantly decreased NLRP3 signaling in splenic macrophages and Ly6C+ monocytes. In vitro coculture showed that Th1 cells inhibited NLPR3 activation in ox-LDL-treated macrophages through the IFN-γR1/IFN-γR2-STAT1 pathway. Compared with untreated medium, conditioned medium from Th1-treated bone marrow-derived macrophages reduced the osteogenic calcification of valvular interstitial cells. CONCLUSION: Inhibition of the NLRP3 inflammasome by Th1 cells protects against valvular interstitial cell calcification as a negative feedback mechanism of adaptive immunity toward innate immunity. This study provides a precision medicine strategy for CAVS based on the targeting of anti-inflammatory mechanisms.

Balloon-expandable transcatheter heart valves for treatment of aortic valve stenosis in patients with large aortic annuli: Evaluation of deployment balloon overfilling strategies.

OBJECTIVES: Transcatheter aortic valve implantation (TAVI) using balloon-expandable (BE) transcatheter heart valves (THV) in aortic annuli above 29 mm includes particular procedural steps, mainly involving overfilling of the deployment balloon. Data on overfilling strategies in clinical daily practice is scarce. We herein aimed for a retrospective description of utilized overfilling strategies in those patients. METHODS: Between January 2016 and December 2022, 45 patients (100% male, 76.9 ± 6.1 years) received TAVI in aortic annuli above 29 mm using a BE THV. Overfilling volumina of the deployment balloon were left to operators' discretion. Clinical and multislice computed tomography data were retrospectively collected. Clinical endpoints were adjudicated in accordance with the updated standardized VARC-3 definitions. RESULTS: Profound overfilling (+4/5 mL) was used in patients with a mild calcium burden (˂750 mm³) even in aortic annuli of 29.0-30.0 mm. Nominal/slight overfilling (+1 mL) was used in aortic annuli up to 32.5 mm but an intermediate to severe calcific burden (>750-3200 mm³). Accordingly, a low calcification group (˂750 mm³, n = 17) compared to a significant calcification group (≥750 mm³, n = 28), presented with higher overfilling volumina (2.1 ± 1.4 vs. 0.8 ± 1.0; p ˂ 0.001), although aortic annulus diameter was not different (29.8 ± 0.8 vs. 29.9 ± 0.9 mm; p = 0.7). All-cause 30-day mortality was 0%. Device success was 97.8%. Transvalvular mean pressure gradient at discharge was 9.5 ± 3.6 mmHg. No case of PVL >mild was documented. CONCLUSION: Extent of overfilling of the deployment balloon largely depends on calcification burden in addition to aortic annulus diameter with significant and profound overfilling particularly in patients with a calcification burden of the aortic valve complex ˂750 mm³.