Outcomes Following Transcatheter Mitral Valve Replacement Using Dedicated Devices in Patients With Mitral Annular Calcification.

BACKGROUND: Patients with mitral regurgitation (MR) and morphologic presence of relevant mitral annular calcification (MAC) represent a challenging phenotypic subset with limited treatment options. OBJECTIVES: The aim of this study was to assess the feasibility of transcatheter mitral valve replacement (TMVR) using dedicated devices for the treatment of MAC patients. METHODS: Consecutive patients with symptomatic MR receiving TMVR and with available computed tomography data from the CHOICE-MI (Choice of Optimal Transcatheter Treatment for Mitral Insufficiency) multicenter registry were stratified by the presence of none or mild mitral annular calcification (MACnone/mild) vs moderate or severe mitral annular calcification (MACmod/sev). RESULTS: Among 279 eligible patients (median age = 76.0 years [Q1-Q3: 71.0-81.0 years], EuroSCORE II = 6.2% [Q1-Q3: 3.9%-12.1%]), 222 (79.6%) presented with MACnone/mild and 57 (20.4%) with MACmod/sev. Patients with MACmod/sev had a higher prevalence of extracardiac arteriopathy (P = 0.011) and primary MR (P < 0.001). Although the technical success rate and the extent of MR elimination did not differ, TMVR treatment in MACmod/sev patients was associated with higher rates of postprocedural bleeding complications (P = 0.02) and renal failure (P < 0.001). Functional improvement at the 1- and 2-year follow-up did not differ between groups. At the 2-year follow-up, there were no differences between patients with MACmod/sev and MACnone/mild regarding all-cause mortality (38.5% vs 37.7%; P = 0.76), cardiovascular mortality (21.3% vs 24.9%; P = 0.97), and all-cause mortality or heart failure hospitalization (52.4% vs 46.7%; P = 0.28) CONCLUSIONS: TMVR in patients with MACmod/sev is associated with higher rates of postprocedural complications but similar rates of survival, MR resolution, and functional improvement compared to MACnone/mild. Further studies are necessary to define the role of dedicated TMVR devices in this population. (Choice of Optimal Transcatheter Treatment for Mitral Insufficiency Registry [CHOICE-MI]; NCT04688190).

Pulmonary arterial compliance as a measure of right ventricular loading in mitral regurgitation.

Pulmonary hypertension (PH) is a common and prognostically important complication of mitral regurgitation (MR). Mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) are traditionally used to diagnose PH, however these indices measure static rather than pulsatile load, leading to an incomplete representation of pulmonary vascular load on the right ventricle (RV). Pulmonary arterial compliance (PAC) is one method for quantifying pulsatile load, and is both a stronger predictor of prognosis in left heart failure, as well as a more sensitive measure of early pulmonary vascular dysfunction than PVR. With the expansion of transcatheter mitral and tricuspid valve therapies, there is renewed interest to more accurately define the load imposed by the pulmonary vasculature on the RV, especially in the early phase, prior to the onset of chronic PH. This review discusses the pathophysiology of pH in left heart failure and MR, the utility of PAC as a measure of RV afterload, and its calculation for clinical use and interpretation, underlining the utility of PAC as an adjunct for assessing pulmonary vascular haemodynamics.

Clinical outcomes and predictors of transapical transcatheter mitral valve replacement: the Tendyne Expanded Clinical Study.

BACKGROUND: Transcatheter mitral valve replacement (TMVR) is a therapeutic option for patients with severe mitral regurgitation (MR) who are ineligible for conventional surgery. There are limited data on the outcomes of large patient cohorts treated with TMVR. AIMS: This study aimed to investigate the outcomes and predictors of mortality for patients treated with transapical TMVR. METHODS: This analysis represents the clinical experience of all patients enrolled in the Tendyne Expanded Clinical Study. Patients with symptomatic MR underwent transapical TMVR with the Tendyne system between November 2014 and June 2020. Outcomes and adverse events up to 2 years, as well as predictors of short-term mortality, were assessed. RESULTS: A total of 191 patients were treated (74.1±8.0 years, 62.8% male, Society of Thoracic Surgeons Predicted Risk of Mortality 7.7±6.6%). Technical success was achieved in 96.9% (185/191), and there were no intraprocedural deaths. At 30-day, 1- and 2-year follow-up, the rates of all-cause mortality were 7.9%, 30.8% and 40.5%, respectively. Complete MR elimination (MR <1+) was observed in 99.3%, 99.1% and 96.3% of patients, respectively. TMVR treatment resulted in consistent improvement of New York Heart Association Functional Class and quality of life up to 2 years (both p<0.001). Independent predictors of early mortality were age (odds ratio [OR] 1.11; p=0.003), pulmonary hypertension (OR 3.83; p=0.007), and institutional experience (OR 0.40; p=0.047). CONCLUSIONS: This study investigated clinical outcomes in the full cohort of patients included in the Tendyne Expanded Clinical Study. The Tendyne TMVR system successfully eliminated MR with no intraprocedural deaths, resulting in an improvement in symptoms and quality of life. Continued refinement of clinical and echocardiographic risks will be important to optimise longitudinal outcomes.

The influence of transcatheter aortic valve replacement on left atrial mechanics: a systematic review and meta-analysis.

Aims: The morphology and function of the left atrium (LA) are intimately tied to left ventricular loading conditions. Data pertaining to the effect of transcatheter aortic valve replacement (TAVR) on LA function and geometry are scarce. The aim of the study was to quantify associations between TAVR and LA remodelling by pooling available data from published observational studies. Methods and results: A systematic review and meta-analysis were performed. Studies reporting serial LA speckle-tracking echocardiographic (STE) data, before and after TAVR, were included. Other outcome data included LA area and indexed volume (LAVi) and standard chamber measurements. Outcomes were stratified by timing of follow-up echocardiography: early (<6 months) or late (≥6 months). Twelve studies were included, comprising 1066 patients. The mean reduction in LAVi was 2.72 mL/m2 [95% confidence interval (CI) 1.37-4.06, P < 0.01]. LA reservoir function improved overall by a mean difference (MD) of 3.71% (95% CI 1.82-5.6, P < 0.01), although there was significant heterogeneity within the pooled studies (I 2 = 87.3%). Significant improvement in reservoir strain was seen in both early follow-up (MD 3.1%, P < 0.01) and late follow-up studies (MD 4.48%, P = 0.03), but heterogeneity remained high (I 2 = 65.23 and 94.4%, respectively). Six studies reported a change in LA contractile function, which recovered in the early follow-up studies (MD 2.26, P < 0.01), but not in the late group (MD 1.41, P = 0.05). Pooled improvement in LA booster function was 1.96% (95% CI 1.11-2.8, P < 0.01). Conclusion: TAVR is associated with significant negative LA remodelling, and an improvement in LA mechanics, quantified by STE. The prognostic implications of these findings require further study.

Frailty and transcatheter valve intervention: A narrative review.

Frailty is a common clinical syndrome that portends poor peri-procedural outcomes and increased mortality following transcatheter valve interventions. We reviewed frailty assessment tools in transcatheter intervention cohorts to recommend a pathway for preprocedural frailty assessment in patients referred for transcatheter valve procedures, and evaluated current evidence for frailty interventions and their efficacy in transcatheter intervention. We recommend the use of a frailty screening instrument to identify patients as frail, with subsequent referral for comprehensive geriatric assessment in these patients, to assist in selecting appropriate patients and then optimizing them for transcatheter valve interventions. Interventions to reduce preprocedural frailty are not well defined, however, data from limited cohort studies support exercise-based interventions to increase functional capacity and reduce frailty in parallel with preprocedural medical optimization.

Polygenic Risk in Families With Spontaneous Coronary Artery Dissection.

Importance: Spontaneous coronary artery dissection (SCAD) is a poorly understood cause of acute coronary syndrome that predominantly affects women. Evidence to date suggests a complex genetic architecture, while a family history is reported for a minority of cases. Objective: To determine the contribution of rare and common genetic variants to SCAD risk in familial cases, the latter via the comparison of a polygenic risk score (PRS) with those with sporadic SCAD and healthy controls. Design, Setting, and Participants: This genetic association study analyzed families with SCAD, individuals with sporadic SCAD, and healthy controls. Genotyping was undertaken for all participants. Participants were recruited between 2017 and 2021. A PRS for SCAD was calculated for all participants. The presence of rare variants in genes associated with connective tissue disorders (CTD) was also assessed. Individuals with SCAD were recruited via social media or from a single medical center. A previously published control database of older healthy individuals was used. Data were analyzed from January 2022 to October 2023. Exposures: PRS for SCAD comprised of 7 single-nucleotide variants. Main Outcomes and Measures: Disease status (familial SCAD, sporadic SCAD, or healthy control) associated with PRS. Results: A total of 13 families with SCAD (27 affected and 12 unaffected individuals), 173 individuals with sporadic SCAD, and 1127 healthy controls were included. A total of 188 individuals with SCAD (94.0%) were female, including 25 of 27 with familial SCAD and 163 of 173 with sporadic SCAD; of 12 unaffected individuals from families with SCAD, 6 (50%) were female; and of 1127 healthy controls, 672 (59.6%) were female. Compared with healthy controls, the odds of being an affected family member or having sporadic SCAD was significantly associated with a SCAD PRS (where the odds ratio [OR] represents an increase in odds per 1-SD increase in PRS) (affected family member: OR, 2.14; 95% CI, 1.78-2.50; adjusted P = 1.96 × 10-4; sporadic SCAD: OR, 1.63; 95% CI, 1.37-1.89; adjusted P = 5.69 × 10-4). This association was not seen for unaffected family members (OR, 1.03; 95% CI, 0.46-1.61; adjusted P = .91) compared with controls. Further, those with familial SCAD were overrepresented in the top quintile of the control PRS distribution (OR, 3.70; 95% CI, 2.93-4.47; adjusted P = .001); those with sporadic SCAD showed a similar pattern (OR, 2.51; 95% CI, 1.98-3.04; adjusted P = .001). Affected individuals within a family did not share any rare deleterious variants in CTD-associated genes. Conclusions and Relevance: Extreme aggregation of common genetic risk appears to play a significant role in familial clustering of SCAD as well as in sporadic case predisposition, although further study is required.

Outcomes After Transcatheter Mitral Valve Replacement According to Regurgitation Etiology.

BACKGROUND: Whether transcatheter mitral valve replacement (TMVR) devices perform similarly with respect to the underlying mitral regurgitation (MR) etiology remains unknown. The aim of the present analysis was to assess outcomes of TMVR according to the MR underlying etiology among the CHoice of OptImal transCatheter trEatment for Mitral Insufficiency (CHOICE-MI) registry. METHODS: Of 746 patients, 229 patients (30.7%) underwent TMVR. The study population was subdivided according to primary, secondary, or mixed MR. Patients with mitral annular calcification were excluded. The primary study endpoint was a composite endpoint of all-cause mortality or hospitalization for heart failure at 1 year. Secondary study endpoints were all-cause and cardiovascular mortality at 1 year, New York Heart Association functional class, and residual MR, both at discharge and 1 year. RESULTS: The predominant MR etiology was secondary MR (58.4%), followed by primary MR (28.7%) and mixed MR (12.9%). Technical success and procedural mortality were similar according to MR etiology. Discharge echocardiography revealed residual MR 2+ in 11.3%, 3.7%, and 5.3% of patients with primary, secondary, and mixed MR, respectively (P = .1). MR elimination was similar in all groups up to the 1-year follow-up. There was no difference in terms of primary combined outcome occurrence according to MR etiology. One-year all-cause mortality was reported in 28.8%, 24.2%, and 32.1% of patients with primary, secondary, and mixed MR, respectively (P = .07). CONCLUSIONS: In our study we did not find differences in short-term and 1-year outcomes after TMVR according to MR etiology.

Machine learning prediction of progressive subclinical myocardial dysfunction in moderate aortic stenosis.

Background: Moderate severity aortic stenosis (AS) is poorly understood, is associated with subclinical myocardial dysfunction, and can lead to adverse outcome rates that are comparable to severe AS. Factors associated with progressive myocardial dysfunction in moderate AS are not well described. Artificial neural networks (ANNs) can identify patterns, inform clinical risk, and identify features of importance in clinical datasets. Methods: We conducted ANN analyses on longitudinal echocardiographic data collected from 66 individuals with moderate AS who underwent serial echocardiography at our institution. Image phenotyping involved left ventricular global longitudinal strain (GLS) and valve stenosis severity (including energetics) analysis. ANNs were constructed using two multilayer perceptron models. The first model was developed to predict change in GLS from baseline echocardiography alone and the second to predict change in GLS using data from baseline and serial echocardiography. ANNs used a single hidden layer architecture and a 70%:30% training/testing split. Results: Over a median follow-up interval of 1.3 years, change in GLS (≤ or >median change) could be predicted with accuracy rates of 95% in training and 93% in testing using ANN with inputs from baseline echocardiogram data alone (AUC: 0.997). The four most important predictive baseline features (reported as normalized % importance relative to most important feature) were peak gradient (100%), energy loss (93%), GLS (80%), and DI < 0.25 (50%). When a further model was run including inputs from both baseline and serial echocardiography (AUC 0.844), the top four features of importance were change in dimensionless index between index and follow-up studies (100%), baseline peak gradient (79%), baseline energy loss (72%), and baseline GLS (63%). Conclusions: Artificial neural networks can predict progressive subclinical myocardial dysfunction with high accuracy in moderate AS and identify features of importance. Key features associated with classifying progression in subclinical myocardial dysfunction included peak gradient, dimensionless index, GLS, and hydraulic load (energy loss), suggesting that these features should be closely evaluated and monitored in AS.

Clinical outcomes of transcatheter mitral valve replacement: two-year results of the CHOICE-MI Registry.

BACKGROUND: Transcatheter mitral valve replacement (TMVR) using dedicated devices is an alternative therapy for high-risk patients with symptomatic mitral regurgitation (MR). AIMS: This study aimed to assess the 2-year outcomes and predictors of mortality in patients undergoing TMVR from the multicentre CHOICE-MI Registry. METHODS: The CHOICE-MI Registry included consecutive patients with symptomatic MR treated with 11 different dedicated TMVR devices at 31 international centres. The investigated endpoints included mortality and heart failure hospitalisation rates, procedural complications, residual MR, and functional status. Multivariable Cox regression analysis was applied to identify independent predictors of 2-year mortality. RESULTS: A total of 400 patients, median age 76 years (interquartile range [IQR] 71, 81), 59.5% male, EuroSCORE II 6.2% (IQR 3.8, 12.0), underwent TMVR. Technical success was achieved in 95.2% of patients. MR reduction to ≤1+ was observed in 95.2% at discharge with durable results at 1 and 2 years. New York Heart Association Functional Class had improved significantly at 1 and 2 years. All-cause mortality was 9.2% at 30 days, 27.9% at 1 year and 38.1% at 2 years after TMVR. Chronic obstructive pulmonary disease, reduced glomerular filtration rate, and low serum albumin were independent predictors of 2-year mortality. Among the 30-day complications, left ventricular outflow tract obstruction, access site and bleeding complications showed the strongest impact on 2-year mortality. CONCLUSIONS: In this real-world registry of patients with symptomatic MR undergoing TMVR, treatment with TMVR was associated with a durable resolution of MR and significant functional improvement at 2 years. Two-year mortality was 38.1%. Optimised patient selection and improved access site management are mandatory to improve outcomes.

Genome-wide association meta-analysis of spontaneous coronary artery dissection identifies risk variants and genes related to artery integrity and tissue-mediated coagulation.

Spontaneous coronary artery dissection (SCAD) is an understudied cause of myocardial infarction primarily affecting women. It is not known to what extent SCAD is genetically distinct from other cardiovascular diseases, including atherosclerotic coronary artery disease (CAD). Here we present a genome-wide association meta-analysis (1,917 cases and 9,292 controls) identifying 16 risk loci for SCAD. Integrative functional annotations prioritized genes that are likely to be regulated in vascular smooth muscle cells and artery fibroblasts and implicated in extracellular matrix biology. One locus containing the tissue factor gene F3, which is involved in blood coagulation cascade initiation, appears to be specific for SCAD risk. Several associated variants have diametrically opposite associations with CAD, suggesting that shared biological processes contribute to both diseases, but through different mechanisms. We also infer a causal role for high blood pressure in SCAD. Our findings provide novel pathophysiological insights involving arterial integrity and tissue-mediated coagulation in SCAD and set the stage for future specific therapeutics and preventions.

Transcatheter Mitral Valve Replacement Versus Medical Therapy for Secondary Mitral Regurgitation: A Propensity Score-Matched Comparison.

BACKGROUND: Transcatheter mitral valve replacement (TMVR) is an emerging therapeutic alternative for patients with secondary mitral regurgitation (MR). Outcomes of TMVR versus guideline-directed medical therapy (GDMT) have not been investigated for this population. This study aimed to compare clinical outcomes of patients with secondary MR undergoing TMVR versus GDMT alone. METHODS: The CHOICE-MI registry (Choice of Optimal Transcatheter Treatment for Mitral Insufficiency) included patients with MR undergoing TMVR using dedicated devices. Patients with MR pathogeneses other than secondary MR were excluded. Patients treated with GDMT alone were derived from the control arm of the COAPT trial (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation). We compared outcomes between the TMVR and GDMT groups, using propensity score matching to adjust for baseline differences. RESULTS: After propensity score matching, 97 patient pairs undergoing TMVR (72.9±8.7 years; 60.8% men; transapical access, 91.8%) versus GDMT (73.1±11.0 years; 59.8% men) were compared. At 1 and 2 years, residual MR was ≤1+ in all patients of the TMVR group compared with 6.9% and 7.7%, respectively, in those receiving GDMT alone (both P<0.001). The 2-year rate of heart failure hospitalization was significantly lower in the TMVR group (32.8% versus 54.4%; hazard ratio, 0.59 [95% CI, 0.35-0.99]; P=0.04). Among survivors, a higher proportion of patients were in the New York Heart Association functional class I or II in the TMVR group at 1 year (78.2% versus 59.7%; P=0.03) and at 2 years (77.8% versus 53.2%; P=0.09). Two-year mortality was similar in the 2 groups (TMVR versus GDMT, 36.8% versus 40.8%; hazard ratio, 1.01 [95% CI, 0.62-1.64]; P=0.98). CONCLUSIONS: In this observational comparison, over 2-year follow-up, TMVR using mostly transapical devices in patients with secondary MR was associated with significant reduction of MR, symptomatic improvement, less frequent hospitalizations for heart failure, and similar mortality compared with GDMT. REGISTRATION: URL: https://clinicaltrials.gov; Unique identifier: NCT04688190 (CHOICE-MI) and NCT01626079 (COAPT).

Transcatheter mitral valve replacement or repair for secondary mitral regurgitation: a propensity score-matched analysis.

AIMS: This study aimed to compare outcomes after transcatheter mitral valve replacement (TMVR) and mitral valve transcatheter edge-to-edge repair (M-TEER) for the treatment of secondary mitral regurgitation (SMR). METHODS AND RESULTS: The CHOICE-MI registry included 262 patients with SMR treated with TMVR between 2014 and 2022. The EuroSMR registry included 1065 patients with SMR treated with M-TEER between 2014 and 2019. Propensity score (PS) matching was performed for 12 demographic, clinical and echocardiographic parameters. Echocardiographic, functional and clinical outcomes out to 1 year were compared in the matched cohorts. After PS matching, 235 TMVR patients (75.5 years [70.0, 80.0], 60.2% male, EuroSCORE II 6.3% [interquartile range 3.8, 12.4]) were compared to 411 M-TEER patients (76.7 years [70.1, 80.5], 59.0% male, EuroSCORE II 6.7% [3.9, 12.4]). All-cause mortality was 6.8% after TMVR and 3.8% after M-TEER at 30 days (p = 0.11), and 25.8% after TMVR and 18.9% after M-TEER at 1 year (p = 0.056). No differences in mortality after 1 year were found between both groups in a 30-day landmark analysis (TMVR: 20.4%, M-TEER: 15.8%, p = 0.21). Compared to M-TEER, TMVR resulted in more effective mitral regurgitation (MR) reduction (residual MR ≤1+ at discharge for TMVR vs. M-TEER: 95.8% vs. 68.8%, p < 0.001), and superior symptomatic improvement (New York Heart Association class ≤II at 1 year: 77.8% vs. 64.3%, p = 0.015). CONCLUSION: In this PS-matched comparison between TMVR and M-TEER in patients with severe SMR, TMVR was associated with superior reduction of MR and superior symptomatic improvement. While post-procedural mortality tended to be higher after TMVR, no significant differences in mortality were found beyond 30 days.

Pulsatile energy consumption as a surrogate marker for vascular afterload improves with time post transcatheter aortic valve replacement in patients with aortic stenosis.

The effect of arterial stiffening on elevated pulsatile left ventricular afterload patients with aortic stenosis (AS) is pronounced beyond systemic hypertension. Circulatory afterload pulsatile efficiency (CAPE) is a marker of vascular function, defined as the ratio of steady state energy consumption (SEC) to maintain systemic circulation and pulsatile energy consumption (PEC). Twenty patients aged 80 ± 7 years were assessed at baseline and a median of 60 days post transcatheter aortic valve replacement (TAVR), with pulsatile vascular load calculated using simultaneous radial applanation tonometry derived aortic pressure and cardiac magnetic resonance phase-contrast imaging derived ascending aortic flow. Eight out of 20 patients had a reduction in PEC post TAVR, and the reduction of PEC correlated strongly with the number of days post TAVR (R = 0.62, P < 0.01). Patients assessed within the 100 days of TAVR had a rise in their PEC when compared to baseline (0.19 ± 0.09 vs 0.14 ± 0.08 W, P = 0.04). Baseline PEC correlated moderately with baseline SEC (R = 0.49, P = 0.03), and a high baseline PEC was predictive of post TAVR PEC reduction (R = 0.54, P =0.01). Overall, no significant differences were found between baseline and post TAVR for systolic aortic pressure (131 ± 20 vs 131 ± 20 mmHg), systemic vascular resistance (1894 ± 493 vs 2015 ± 519 dynes.s/cm5), aortic valve ejection time (337 ± 22 vs 324 ± 34 ms) or aortic characteristic impedance (120 ± 48 vs 107 ± 41 dynes.s/cm5). Improved flow profiles after TAVR likely unmask the true vascular properties by altering ventriculo-valvulo-arterial coupling, leading to downstream vascular remodelling secondary to flow conditioning, and results in eventual improvement of pulsatile afterload as reflected by our proposed index of CAPE.

Peri-procedural management of transcatheter mitral valve replacement in patients with heart failure.

Over the past decade, transcatheter mitral valve replacement (TMVR) technologies have evolved with the objective of improving outcomes for patients with severe mitral regurgitation (MR) deemed unsuitable for conventional mitral valve surgery. Although the safety and efficacy of transcatheter edge-to-edge mitral valve repair (TEER) is well-established, there is a sense amongst innovators that a major advantage of TMVR may be to offer a more complete solution for the correction of MR in patients whose complex anatomy means that the likelihood of achieving grade 0 or 1 MR with TEER is low. However, abrupt correction of MR in a poorly prepared left ventricle poses a number of unique haemodynamic challenges, particularly when sudden elimination of regurgitant flow causes a relative increase in left ventricular (LV) afterload. Rapid reduction in LV cavity size following MR elimination may itself result in relative LV outflow tract obstruction (LVOTO), irrespective of the intrinsic risk of LVOTO associated with TMVR. Nevertheless, TMVR on a beating heart affords the opportunity to study real-time invasive cardiac indices in high-risk patients with acute reversal of severe MR.

Fluid structure computational model of simulating mitral valve motion in a contracting left ventricle.

BACKGROUND: Fluid structure interaction simulations h hold promise in studying normal and abnormal cardiac function, including the effect of fluid dynamics on mitral valve (MV) leaflet motion. The goal of this study was to develop a 3D fluid structure interaction computational model to simulate bileaflet MV when interacting with blood motion in left ventricle (LV). METHODS: The model consists of ideal geometric-shaped MV leaflets and the LV, with MV dimensions based on human anatomical measurements. An experimentally-based hyperelastic isotropic material was used to model the mechanical behaviour of the MV leaflets, with chordae tendineae and papillary muscle tips also incorporated. LV myocardial tissue was prescribed using a transverse isotropic hyperelastic formulation. Incompressible Navier-Stokes fluid formulations were used to govern the blood motion, and the Arbitrary Lagrangian Eulerian (ALE) method was employed to determine the mesh deformation of the fluid and solid domains due to trans-valvular pressure on MV boundaries and the resulting leaflet movement. RESULTS: The LV-MV generic model was able to reproduce physiological MV leaflet opening and closing profiles resulting from the time-varying atrial and ventricular pressures, as well as simulating normal and prolapsed MV states. Additionally, the model was able to simulate blood flow patterns after insertion of a prosthetic MV with and without left ventricular outflow tract flow obstruction. In the MV-LV normal model, the regurgitant blood flow fraction was 10.1 %, with no abnormality in cardiac function according to the mitral regurgitation severity grades reported by the American Society of Echocardiography. CONCLUSION: Our simulation approach provides insights into intraventricular fluid dynamics in a contracting LV with normal and prolapsed MV function, as well as aiding in the understanding of possible complications after transcatheter MV implantation prior to clinical trials.

Extracorporeal Membrane Oxygenation-Supported Transcatheter Mitral Valve-in-Valve Replacement and Paravalvular Plugging for Critical Prosthetic Mitral Stenosis.

We present the case of a patient with rapidly progressive bioprosthetic mitral valve stenosis in the setting of end-stage renal failure. Critical valve stenosis led to cardiogenic shock requiring full hemodynamic support. Emergent extracorporeal membrane oxygenation-supported transcatheter mitral valve-in-valve implantation was successfully undertaken as a life-saving measure with an excellent final result. (Level of Difficulty: Advanced.).

Exploring the Genetic Architecture of Spontaneous Coronary Artery Dissection Using Whole-Genome Sequencing.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is a cause of acute coronary syndrome that predominantly affects women. Its pathophysiology remains unclear but connective tissue disorders (CTD) and other vasculopathies have been observed in many SCAD patients. A genetic component for SCAD is increasingly appreciated, although few genes have been robustly implicated. We sought to clarify the genetic cause of SCAD using targeted and genome-wide methods in a cohort of sporadic cases to identify both common and rare disease-associated variants. METHODS: A cohort of 91 unrelated sporadic SCAD cases was investigated for rare, deleterious variants in genes associated with either SCAD or CTD, while new candidate genes were sought using rare variant collapsing analysis and identification of novel loss-of-function variants in genes intolerant to such variation. Finally, 2 SCAD polygenic risk scores were applied to assess the contribution of common variants. RESULTS: We identified 10 cases with at least one rare, likely disease-causing variant in CTD-associated genes, although only one had a CTD phenotype. No genes were significantly associated with SCAD from genome-wide collapsing analysis, however, enrichment for TGF (transforming growth factor)-ß signaling pathway genes was found with analysis of 24 genes harboring novel loss-of-function variants. Both polygenic risk scores demonstrated that sporadic SCAD cases have a significantly elevated genetic SCAD risk compared with controls. CONCLUSIONS: SCAD shares some genetic overlap with CTD, even in the absence of any major CTD phenotype. Consistent with a complex genetic architecture, SCAD patients also have a higher burden of common variants than controls.