Correlation between staging classification of aortic stenosis based on the extent of cardiac damage and platelet indices.

BACKGROUND: Platelets play a key role in the natural history of aortic stenosis (AS) and after transcatheter aortic valve implantation (TAVI). An echo-based staging system stratifies patients with severe AS into 5 groups according to the associated cardiac damage phenotype. We aimed to correlate these AS stages with platelet indices in post-TAVI patients. METHODS: Patients with severe AS who underwent TAVI and were admitted to intensive cardiac care unit (ICCU) were prospectively identified and divided into 5 groups according to extra-valvular cardiac damage [no extravalvular cardiac damage (Stage 0), left ventricular damage (Stage 1), left atrial or mitral valve damage (Stage 2), pulmonary vasculature or tricuspid valve damage (Stage 3), or right ventricular damage (Stage 4)]. Baseline characteristics and complete blood count including mean platelet volume (MPV) and immature platelet fraction (IPF) were collected within 2 h after the procedure and analyzed in relation to aortic stenosis staging. RESULTS: A total of 220 patients were included. The mean age was 81 years old and 112 (50.9%) were female. Two (1%) patients were classified in stage 0; 34 (15%) in stage 1; 48 (22%) in stage 2; 49 (22%) in stage 3 and 87 (40%) in stage 4. Higher mean MPV values were correlated with higher AS staging (10.8 fL, 11 fL, 11.3 fL and 10.8 fL in stages 1, 2, 3 and 4, respectively, P = 0.02) as well as lower hemoglobin values (12 mg/dl, 11.6 mg/dl, 11 mg/dl and 11.3 mg/dl in stages 1, 2, 3 and 4, respectively P = 0.04). Mean IPF values were 5.3%, 5.58%, 5.57% and 4.83% in stage 1, 2, 3 and 4, respectively (P = 0.4). In a multivariate logistic regression model only MPV (OR = 2.6, P = 0.03) and body mass index (BMI) (OR = 1.17, P = 0.004) were correlated with higher staging (0-3) of AS. CONCLUSIONS: Although IPF and MPV levels increased in stages 0-3, there was a decrease in indices in stage 4, (probably due to bone marrow dysfunction) in this end-stage population. Higher levels of MPV and lower levels of hemoglobin were independently correlated with higher stages (0-3) of AS.

Association between triglyceride-glucose index and all-cause mortality in patients underwent transcatheter aortic valve replacement.

BACKGROUNDS: The prognosis of the triglyceride-glucose (TyG) index, a validated surrogate marker for insulin resistance, in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) remains unknown. METHODS: This study consecutively enrolled patients diagnosed with severe AS who underwent TAVR in a Chinese tertiary hospital from March 2013 to September 2023. Participants were stratified based on the TyG index cut-off value. Cox proportional hazards regression models were utilized to explore the association between the TyG index and all-cause mortality, including an assessment of interactions between the TyG index and various covariates on mortality outcomes. RESULTS: Among 1045 patients (mean age 74.7 years, 58.2% male), there was 134 all-cause mortality, resulting in a crude mortality rate of 64.3 per 1000 person-years. Adjusting for age, sex, body mass index, smoking, hypertension, diabetes mellitus, bicuspid aortic valve, atrial fibrillation, Society of Thoracic Surgeons (STS) score, and left ventricular ejection fraction, a per-unit increase in the TyG index was associated with a 41% higher all-cause mortality risk (HR 1.41, 95% CI 1.03-1.93, p = 0.030). Notably, the relationship between the TyG index and all-cause mortality was significantly modified by age (pinteraction = 0.027), sex (pinteraction = 0.007), hypertension (pinteraction = 0.030), and STS score (pinteraction = 0.002). CONCLUSIONS: A higher TyG index is significantly associated with an increased risk of all-cause mortality in AS patients after TAVR. These results underscore the importance of considering the TyG index in the prognostic evaluation of AS patients following TAVR.

Circulating Plasma Proteins in Aortic Stenosis: Associations With Severity, Myocardial Response, and Clinical Outcomes.

BACKGROUND: Echocardiographic indexes of aortic stenosis may not comprehensively reflect disease morbidity. Plasma proteomic profiling may add prognostic value in these patients. METHODS AND RESULTS: Proximity extension assays (Olink) of 183 circulating cardiovascular and inflammatory proteins were performed in a prospective follow-up study of 122 asymptomatic/minimally symptomatic patients (mean±SD age, 69.1±10.9 years; 61% men) with moderate to severe aortic stenosis and preserved left ventricular ejection fraction. Protein signatures of higher-risk echocardiographic subgroups were determined. Associations of proteins with the primary composite outcome (heart failure hospitalization, progression to New York Heart Association class III-IV, or all-cause mortality) were evaluated using competing risk analyses, with aortic valve replacement being the competing risk. Network analysis unveiled mutually exclusive communities of proteins and echocardiographic parameters, connected only through NT-proBNP (N-terminal pro-B-type natriuretic peptide). Members of the tumor necrosis factor receptor superfamily (TNFRSF1A, TNFRSF1B, and TNFRSF14), and trefoil factor-3 were major hub proteins among the circulating biomarkers. Left ventricular global longitudinal strain >-15% was associated with higher levels of proteins, primarily of inflammation and immune regulation, whereas aortic valve area <1 cm2, E/e' >15, and left atrial reservoir strain <20% were associated with higher levels of NT-proBNP. Of 14 proteins associated with the primary end point, phospholipase-C, C-X-C motif chemokine-9, and interleukin-10 receptor subunit ß demonstrated the highest hazard ratios after adjusting for clinical factors (q<0.05). CONCLUSIONS: Plasma proteins involved in inflammation and immune regulation were differentially expressed in patients with aortic stenosis with reduced left ventricular global longitudinal strain, and associated with adverse clinical outcomes. Their incorporation into aortic stenosis risk stratification warrants further assessment.

Genetic causal association between lipidomic profiles, inflammatory proteomics, and aortic stenosis: a Mendelian randomization investigation.

BACKGROUND: Aortic stenosis (AS) is a prevalent and serious valvular heart disease with a complex etiology involving genetic predispositions, lipid dysregulation, and inflammation. The specific roles of lipid and protein biomarkers in AS development are not fully elucidated. This study aimed to elucidate the causal relationships between lipidome, inflammatory proteins, and AS using Mendelian randomization (MR), identifying potential therapeutic targets. METHODS: Utilizing data from large-scale genome-wide association studies (GWAS) and genome-wide protein quantitative trait loci (pQTL) studies, we conducted MR analyses on 179 plasma lipidome and 91 inflammatory proteins to assess their causal associations with AS. Our approach included Inverse Variance Weighting (IVW), Wald ratio, and robust adjusted profile score (RAPS) analyses to refine these associations. MR-Egger regression was used to address directional horizontal pleiotropy. RESULTS: Our MR analysis showed that genetically predicted 50 lipids were associated with AS, including 38 as risk factors [(9 Sterol ester, 18 Phosphatidylcholine, 4 Phosphatidylethanolamine, 1 Phosphatidylinositol and 6 Triacylglycerol)] and 12 as protective. Sterol ester (27:1/17:1) emerged as the most significant risk factor with an odds ratio (OR) of 3.11. Additionally, two inflammatory proteins, fibroblast growth factor 19 (FGF19) (OR = 0.830, P = 0.015), and interleukin 6 (IL-6) (OR = 0.729, P = 1.79E-04) were significantly associated with reduced AS risk. However, a two-step MR analysis showed no significant mediated correlations between these proteins and the lipid-AS pathway. CONCLUSION: This study reveals complex lipid and protein interactions in AS, identifying potential molecular targets for therapy. These results go beyond traditional lipid profiling and significantly advance our genetic and molecular understanding of AS, highlighting potential pathways for intervention and prevention.

Insulin-like Growth Factor-Binding Protein 2 in Severe Aortic Valve Stenosis and Pulmonary Hypertension: A Gender-Based Perspective.

Severe aortic valve stenosis (AS) and pulmonary hypertension (PH) are life-threatening cardiovascular conditions, necessitating early detection and intervention. Recent studies have explored the role of Insulin-like Growth Factor-Binding Protein 2 (IGF-BP2) in cardiovascular pathophysiology. Understanding its involvement may offer novel insights into disease mechanisms and therapeutic targets for these conditions. A total of 102 patients (46 female, 56 male) with severe AS undergoing a transcatheter aortic valve replacement (TAVR) in a single-center study were classified using echocardiography tests to determine systolic pulmonary artery pressure (sPAP) and the presence (sPAP ≥ 40 mmHg) or absence (sPAP < 40 mmHg) of PH. Additionally, serial laboratory determinations of IGF-BP2 before, and at 24 h, 96 h, and 3 months after intervention were conducted in all study participants. Considering the entire cohort, patients with PH had significant and continuously higher serum IGF-BP2 concentrations over time than patients without PH. After subdivision by sex, it could be demonstrated that the above-mentioned results were only verifiable in males, but not in females. In the male patients, baseline IGF-BP2 levels before the TAVR was an isolated risk factor for premature death after intervention and at 1, 3, and 5 years post-intervention. The same was valid for the combination of male and echocardiographically established PH patients. The predictive role of IGF-BP2 in severe AS and concurrent PH remains unknown. A more profound comprehension of IGF-BP2 mechanisms, particularly in males, could facilitate the earlier consideration of the TAVR as a more effective and successful treatment strategy.

Prognostic effect of the TyG index on patients with severe aortic stenosis following transcatheter aortic valve replacement: a retrospective cohort study.

BACKGROUND: The triglyceride glucose (TyG) index, as a reliable marker of insulin resistance, is associated with the incidence and poor prognosis of various cardiovascular diseases. However, the relationship between the TyG index and clinical outcomes in patients with severe aortic stenosis (AS) who underwent transcatheter aortic valve replacement (TAVR) remains unclear. METHODS: This study consecutively enrolled 1569 patients with AS underwent TAVR at West China Hospital of Sichuan University between April 2014 and August 2023. The outcomes of interest included all-cause mortality, cardiovascular mortality, and major adverse cardiovascular events (MACE). Multivariate adjusted Cox regression and restricted cubic splines (RCS) regression analyses were used to assess the associations between the TyG index and the clinical outcomes. The incremental prognostic value of the TyG index was further assessed by the time-dependent Harrell's C-index, integrated discrimination improvement (IDI) and the net reclassification improvement (NRI). RESULTS: During a median follow-up of 1.09 years, there were 146, 70, and 196 patients experienced all-cause death, cardiovascular death, and MACE, respectively. After fully adjusting for confounders, a per-unit increase of TyG index was associated with a 441% (adjusted HR: 5.41, 95% CI: 4.01-7.32), 385% (adjusted HR: 4.85, 95% CI: 3.16-7.43), and 347% (adjusted HR: 4.47, 95% CI: 3.42-5.85) higher risk of all-cause mortality, cardiovascular mortality and MACE, respectively. The RCS regression analyses revealed a linear association between TyG index and endpoints (all P for non-linearity > 0.05) with 8.40 as the optimal binary cutoff point. Furthermore, adding TyG index to the basic risk model provided a significant incremental value in predicting poor prognosis (Time-dependent Harrell's C-index increased for all the endpoints; All-cause mortality, IDI: 0.11, P < 0.001; NRI: 0.32, P < 0.001; Cardiovascular mortality, IDI: 0.043, P < 0.001; NRI: 0.37, P < 0.001; MACE, IDI: 0.092, P < 0.001; NRI: 0.32, P < 0.001). CONCLUSIONS: In patients with severe AS receiving TAVR, there was a positive linear relationship between TyG index and poor prognosis, with 8.4 as the optimal bivariate cutoff value. Our findings suggest TyG index holds potential value for risk stratification and guiding therapeutic decisions in patients after TAVR.

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.

Lipoprotein(a) and Calcific Aortic Valve Stenosis Progression: A Systematic Review and Meta-Analysis.

Importance: There are currently no pharmacological treatments available to slow hemodynamic progression of aortic stenosis. Plasma lipoprotein(a) concentrations predict incident aortic stenosis but its association with hemodynamic progression is controversial. Objective: To determine the association between plasma lipoprotein(a) concentrations and hemodynamic progression in patients with aortic stenosis. Design, Settings and Participants: The study included patients with aortic stenosis from 5 longitudinal clinical studies conducted from March 2001 to March 2023 in Canada and the UK. Of 757 total patients, data on plasma lipoprotein(a) concentrations and rates of hemodynamic progression assessed by echocardiography were available for 710, who were included in this analysis. Data were analyzed from March 2023 to April 2024. Exposure: Cohort-specific plasma lipoprotein(a) concentration tertiles. Main Outcomes and Measures: Hemodynamic aortic stenosis progression on echocardiography as assessed by annualized change in peak aortic jet velocity, mean transvalvular gradient, and aortic valve area. Results: Among the included patients, 497 (70%) were male and 213 (30%) were female. The mean (SD) age was 65.2 (13.1) years. Patients in the top lipoprotein(a) tertile demonstrated 41% (estimate, 1.41; 95% CI, 1.13-1.75) faster progression of peak aortic jet velocity and 57% (estimate, 1.57; 95% CI, 1.18-2.10) faster progression of mean transvalvular gradient than patients in the bottom tertile. There was no evidence of heterogeneity across the individual cohorts. Progression of aortic valve area was comparable between groups (estimate, 1.23; 95% CI, 0.71-2.12). Similar results were observed when plasma lipoprotein(a) concentrations were treated as a continuous variable. Conclusions and Relevance: In this study, higher plasma lipoprotein(a) concentrations were associated with faster rates of hemodynamic progression in patients with aortic stenosis. Lowering plasma lipoprotein(a) concentrations warrants further investigation in the prevention and treatment of aortic stenosis.

An Increase in the Ratio of Brain Natriuretic Peptide to Peak Transvalvular Pressure Gradient Suggests Coexistence of Cardiovascular Complications in Elderly Aortic Stenosis Patients.

The aim of this study was to differentiate between elderly aortic stenosis (AS) patients with and without cardiovascular complications (CCs).In total, 156 consecutive patients with AS aged ≥ 70 years were enrolled. Patients were divided into 2 groups as follows: AS without CCs (group I; n = 110) and AS with CCs (group II; n = 46). Routine electrocardiographic and echocardiographic parameters, peak and mean transvalvular pressure gradients (TPGs), aortic valve area (AVA), brain natriuretic peptide (BNP) levels, and BNP/peak TPG ratio were measured.The mean ages in groups I and II were 80.4 ± 5.5 and 82.5 ± 7.2 years. Left ventricular hypertrophy was greater in group II than in group I. Left ventricular end-diastolic and end-systolic dimensions and left ventricular fractional shortening were normal in both groups. Peak and mean TPGs were greater in group II (67.2 ± 39.3 and 40.2 ± 26.4 mmHg) than in group I (52.0 ± 23.0 and 30.2 ± 13.9, both P < 0.005); however, the AVA showed no significant difference between the 2 groups. The median BNP levels were 65.9 and 433.7 pg/mL in groups I and II (P < 0.0001). A correlation between peak TPG and BNP levels was observed in both groups. The BNP/peak TPG ratio was < 3.0 in all patients of group I and ≥ 3.0 in almost all patients of group II (P< 0.0001). The area under the curve using BNP/peak TPG ratio was 0.9883.BNP and BNP/peak TPG ratio could differentiate between AS with and without CCs in elderly patients.

Investigation of von Willebrand factor multimer abnormalities before and after aortic valve replacement using the Hydragel-5 assay.

BACKGROUND: Severe aortic stenosis (sAS) is associated with acquired von Willebrand syndrome (AVWS) by loss of high-molecular-weight multimers (HMWM) of von Willebrand factor (VWF), potentially resulting in perioperative bleeding. Analysis of VWF multimers remains challenging. Recently, the new, rapid Hydragel 5 assay has been developed, using electrophoretic protein separation for dividing VWF-multimers into low (LMWM), intermediate (IMWM), and HMWM, the hemostatically active part of VWF. Here, we evaluated its impact on predicting blood loss in presence of AVWS after surgical aortic valve replacement (SAVR). METHODS: We prospectively examined 52 patients (age: 68 ± 7 years; 54 % male) admitted to SAVR. They were divided in two groups (A: normal VWF, n = 28; B: abnormal VWF, n = 24, defined as VWF-activity/antigen (VWF:Ac/Ag)-ratio < 0.7 and/or HMWM loss). Blood samples and echocardiographic data were collected before, seven days and three months after SAVR. Blood loss and transfusions were recorded. RESULTS: Baseline characteristics and clinical data were similar in both groups. HMWM loss was present in 38.5 % of all patients. HMWM, the VWF:Ac/Ag- and HMWM/(IMWM+LMWM)-ratios were significantly decreased preoperatively in group B but normalized after SAVR. Bleeding, re-thoracotomy and transfusion rates were comparable. HMWM loss was inversely correlated with the peak aortic gradient (Pmax) and positively with the aortic valve area (AVA), while HMWM/(IMWM+LMWM)-ratio negatively correlated with the mean aortic gradient (Pmean). CONCLUSION: HMWM and HMWM/(IMWM+LMWM)-ratio inversely correlate with severity of AS and normalize after SAVR. The Hydragel-5 assay's might be valuable for routine diagnostics to assess bleeding risk and postoperative normalization of AS and VWF abnormalities in SAVR patients.

Association between serum phosphate, magnesium, calcium and aortic valve sclerosis: a propensity score-matched case-control study.

OBJECTIVES: Aortic valve sclerosis has been proposed to signify greater cardiovascular risk; the correlation between serum trace elements and aortic valve sclerosis has been reported. Therefore, an in-depth exploration of the risk factors for aortic valve sclerosis and early intervention may reduce the risk of cardiovascular disease. METHODS: In this study, Patients with aortic valve sclerosis and non-aortic valve sclerosis who underwent echocardiographic diagnosis in the People's Hospital of Xinjiang Uygur Autonomous Region during the period from 2019 to 2021 were selected for this study. The correlation between aortic valve sclerosis and serum phosphorus, calcium, and magnesium levels was explored using the propensity score matching technique by pairing the two groups of patients 1:1. RESULTS: A total of 1,533 non-aortic valve sclerosis and 1,533 aortic valve sclerosis patients were included. Logistic regression analysis showed that serum magnesium [OR: 0.346; 95%CI: 0.227, 0.528] and serum calcium [OR: 7.022; 95%CI: 4.755, 10.369] were influential factors. Patients with low, intermediate, and high serum magnesium levels had a significantly lower risk of aortic valve sclerosis compared to patients with very low micronutrient levels (p < 0.05). Comparatively, patients with low or high serum calcium levels had an elevated risk of aortic valve sclerosis (p < 0.05). CONCLUSION: Serum magnesium may have a protective role against aortic valve sclerosis, while both low and high levels of serum calcium could be risk factor for the condition. These serum micronutrients may be indications of cardiovascular disease risk prediction or prevention, and more research is required.

Post-Procedure Monocyte Count Levels Predict Major Adverse Cardiovascular Events (MACE) Following Transcatheter Aortic Valve Implantation (TAVI) for Aortic Stenosis.

BACKGROUND: Aortic stenosis has recently been characterised as having an inflammatory aetiology, beyond the traditional degenerative model. Recruitment of monocytes has been associated with inflammation contributing to progression of calcific aortic-valve disease. Prior research has demonstrated that pre-procedure inflammatory biomarkers do not consistently discriminate poorer outcomes in those with aortic stenosis. It remains, however, unclear if postprocedure inflammatory biomarkers, which are influenced by intraprocedural pro-inflammatory insults, can predict major adverse cardiovascular events (MACE) post transcatheter aortic valve implantation (TAVI). METHOD: All patients with postprocedure monocyte levels undergoing transcatheter aortic valve implantation at The Alfred Hospital, Melbourne, Australia (2008-2019) were included. The highest monocyte count from postprocedure days 1 to 3 was used. Patients were divided into "high" or "low" postprocedure monocyte count groups using the Youden Index. The incidence of 30-day MACE a composite of stroke, acute myocardial infarction, and death) was then compared. RESULTS: In total, 472 patients were included (54% men, median age 84 years). Fourteen (14) patients (3%) suffered a 30-day MACE. Those with high postprocedure monocyte count were more likely to: be hypertensive (p=0.049); have a higher Society of Thoracic Surgeons risk score (p=0.032); and, undergo non-transfemoral access (p=0.018). A high (≥0.975) postprocedure monocyte count was significantly associated with 30-day MACE (odds ratio [OR] 1.16 for each 0.1 increase in monocyte, p=0.025). This association remained present on multivariable analysis adjusted for age, sex, Society of Thoracic Surgeons risk score, and self-expanding valve prosthesis type (OR 1.17, p=0.028). CONCLUSIONS: The association between postprocedure monocytosis and 30-day MACE suggests that minimising peri-procedural inflammatory insults may improve outcomes. This inexpensive and readily available biomarker may also aid in tailored risk stratification for patients.

Identifying People at High Risk for Severe Aortic Stenosis: Aortic Valve Calcium Versus Lipoprotein(a) and Low-Density Lipoprotein Cholesterol.

BACKGROUND: Aortic valve calcification (AVC), Lp(a) [lipoprotein(a)], and low-density lipoprotein cholesterol (LDL-C) are associated with severe aortic stenosis (AS). We aimed to determine which of these risk factors were most strongly associated with the risk of incident severe AS. METHODS: A total of 6792 participants from the MESA study (Multi-Ethnic Study of Atherosclerosis) had computed tomography-quantified AVC, Lp(a), and LDL-C values at MESA visit 1 (2000-2002). We calculated the absolute event rate of incident adjudicated severe AS per 1000 person-years and performed multivariable adjusted Cox proportional hazards regression. RESULTS: The mean age was 62 years old, and 47% were women. Over a median 16.7-year follow-up, the rate of incident severe AS increased exponentially with higher AVC, regardless of Lp(a) or LDL-C values. Participants with AVC=0 had a very low rate of severe AS even with elevated Lp(a) ≥50 mg/dL (<0.1/1000 person-years) or LDL-C ≥130 mg/dL (0.1/1000 person-years). AVC >0 was strongly associated with severe AS when Lp(a) <50 mg/dL hazard ratio (HR) of 33.8 (95% CI, 16.4-70.0) or ≥50 mg/dL HR of 61.5 (95% CI, 7.7-494.2) and when LDL-C <130 mg/dL HR of 31.1 (95% CI, 14.4-67.1) or ≥130 mg/dL HR of 50.2 (95% CI, 13.2-191.9). CONCLUSIONS: AVC better identifies people at high risk for severe AS compared with Lp(a) or LDL-C, and people with AVC=0 have a very low long-term rate of severe AS regardless of Lp(a) or LDL-C level. These results suggest AVC should be the preferred prognostic risk marker to identify patients at high risk for severe AS, which may help inform participant selection for future trials testing novel strategies to prevent severe AS.

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.

Immature Surfactant Protein B Increases in the Serum of Patients with Calcific Severe Aortic Stenosis.

Valvular disease is a complex pathological condition that impacts countless individuals around the globe. Due to limited treatments, it is crucial to understand its mechanisms to identify new targets. Valve disease may result in pulmonary venous hypertension, which is linked to compromised functioning of the alveolar and capillary membranes and hindered gas exchange. Nonetheless, the correlation between surfactant proteins (SPs) and valve disease remains unexplored. A total of 44 patients were enrolled in this study, with 36 undergoing aortic valve replacement and 8 needing a second aortic valve substitution due to bioprosthetic valve degeneration. Ten healthy subjects were also included. The results showed that patients who underwent both the first valve replacement and the second surgery had significantly higher levels of immature SP-B (proSP-B) compared to control subjects. The levels of the extra-lung collectin SP-D were higher in patients who needed a second surgery due to bioprosthetic valve degeneration, while SP-A levels remained unchanged. The research also showed that there was no reciprocal relationship between inflammation and SP-D as the levels of inflammatory mediators did not differ between groups. The present study demonstrates that circulating proSP-B serves as a reliable marker of alveolar-capillary membrane damage in patients with valvular heart disease.

Association between red blood cell distribution width and the all-cause mortality of patients with aortic stenosis: A retrospective study.

BACKGROUND: It is essential to assess the risk stratification of patients with aortic stenosis (AS). OBJECTIVE: To clarify the predictive value of red blood cell distribution width (RDW) in AS patients using a large cohort from the MIMIC-IV database. METHODS: Restricted cubic spline, the Kaplan-Meier method, and logistic and Cox regression analyses were used to explore the association between RDW and all-cause mortality in AS patients. Multivariate adjustments, propensity score matching and weighting, and subgroup analysis were conducted to exclude confounding factors. Receiver operating characteristic (ROC) and decision curve analysis (DCA) curves were drawn to evaluate the predictive performance of RDW. RESULTS: 1,148 patients with AS were included. Their death risks gradually increased with the elevation of RDW. Multivariate-adjusted 90-day (OR: 2.12; HR: 1.90; p = 0.001) and 1-year (OR: 2.07; HR: 1.97; p < 0.001) all-cause mortalities were significantly higher in patients with RDW≥14.7 %, which remained robust after propensity score matching and subgroup analysis. For AS patients with high RDW, those < 75 years old had higher death risks than those ≥ 75 years old. The area under the ROC curve of RDW were 0.741 and 0.75 at 90-day and 1-year follow-ups, respectively, exhibiting comparable performance to acute physiology score III and outperforming other critical illness scores in predicting the prognosis of AS patients. DCA curves also illustrated that RDW had a wide range of net benefits. CONCLUSIONS: High RDW was independently associated with increased 90-day and 1-year all-cause mortalities of AS patients, with strong predictive capability of prognosis.

Human epididymis protein 4 is a useful predictor of post-operative prognosis in patients with severe aortic stenosis.

AIMS: The human epididymis protein 4 (HE4), a novel fibrosis marker, is expressed only in activated fibroblasts and is thought to reflect ongoing left ventricular (LV) fibrosis. LV fibrosis is a feature of severe aortic stenosis (AS) and is related to the post-operative outcome of patients with AS. We investigated the relationship between serum levels of HE4 and the post-operative prognosis of patients with severe AS. METHODS AND RESULTS: We measured the serum HE4 levels of 55 participants (80.8 ± 8.0 years old, male n = 26, 46%) with severe AS prior to surgical aortic valve replacement (n = 31, 56%) or transcatheter aortic valve implantation (n = 24, 44%) at Kumamoto University Hospital in 2018. We followed them for cardiovascular (CV) death or hospitalization for heart failure (HF) for 3 years. Serum HE4 levels were positively correlated with computed tomography-extracellular volume (CT-ECV) values (r = 0.53, P = 0.004). Kaplan-Meier curves demonstrated a significantly higher probability of hospitalization for HF or CV-related death in the patients with high HE4 (greater than the median HE4 value) compared with the patients with low HE4 (lower than the median HE4 value) (log-rank P = 0.003). Multivariate analysis showed HE4 (log(HE4)) to be an independent prognostic factor [hazard ratio (HR): 7.50; 95% confidence interval (CI): 1.81-31.1; P = 0.005]. Receiver operating characteristic (ROC) curve analysis suggested that HE4 is a marker of increased risk of CV-related death or hospitalization for HF at 3 years after surgery, with an area under the curve (AUC) of 0.76 (95% CI: 0.62-0.90; P = 0.003). CONCLUSIONS: We found that HE4 is a potentially useful biomarker for predicting future CV events in patients scheduled for AS surgery. Measuring serum HE4 values could help consider AS surgery.

Extracellular Vesicles to Predict Outcomes After Transcatheter Aortic Valve Implantation - a Prospective, Multicenter Cohort Study.

INTRODUCTION: Transcatheter aortic valve implantation (TAVI) is an established treatment for aortic stenosis (AS) in patients at intermediate and high surgical risk. Circulating extracellular vesicles (EVs) are nanoparticles involved in cardiovascular diseases. We aimed to (i) determine the effect of TAVI on plasma concentrations of five EV subtypes and (ii) evaluate the predictive value of EVs for post-TAVI outcomes. METHODS: Blood samples were collected 1 day before TAVI and at hospital discharge. Concentrations of EVs were evaluated using flow cytometry. RESULTS: Concentration of leukocytes EVs decreased after TAVI, compared to the measurement before (p = 0.008). Among 123 patients discharged from the hospital, 19.5% experienced MACCE during the median of 10.3 months. Increased pre-TAVI concentration of phosphatidylserine-exposing EVs was an independent predictor of MACCE in multivariable analysis (OR 5.313, 95% CI 1.164-24.258, p = 0.031). CONCLUSIONS: Patients with increased pre-TAVI concentration of procoagulant, PS-exposing EVs have over fivefold higher odds of adverse outcomes.