Changes of Right Ventricular Function After Transcatheter Aortic Valve Replacement and Association With Outcomes.

BACKGROUND: Baseline right ventricular (RV) dysfunction represents a predictor for poor outcome in patients undergoing transcatheter aortic valve replacement (TAVR). However, RV function may improve after TAVR, which could have important implications on outcomes. The aim of the present study was to assess changes in RV function after TAVR and its prognostic value regarding clinical outcome. METHODS AND RESULTS: Patients undergoing TAVR at our institution were consecutively enrolled and categorized into 4 groups according to changes in RV function during echocardiographic follow-up at 6 months. A total of 188 patients were included. Of those showing normal function at baseline, 87% (130/149) had preserved RV function at follow-up (group 1), whereas 13% (19/149) developed new RV dysfunction (group 2). Of those with RV dysfunction at baseline (39 patients), RV function normalized in 46% (18/39) (group 3) and remained impaired in 54% (21/39) (group 4). The Kaplan-Meier estimated survival at 3 years was highest in patients in group 1 (83%), intermediate in group 2 (65%) and 3 (69%), whereas group 4 had the worst survival (37%; P < .001). Furthermore, new or persistent RV dysfunction was identified to be independently associated with mortality during follow-up (hazard ratio 2.55; interquartile range 1.03-6.47, P = .004). CONCLUSIONS: Patients with preserved RV function have a high 3-year survival. Normalization of RV function showed improved survival compared with patients with persistent RV dysfunction, who had a dismal prognosis despite TAVR.

The effect of transcatheter aortic valve implantation approaches on mortality.

OBJECTIVES: We aimed to evaluate the effect of transcatheter aortic valve implantation (TAVI) approaches on mortality and identify effect modifiers and predictors for mortality. BACKGROUND: Alternative access routes to transfemoral (TF) TAVI include the surgical intra-thoracic direct-aortic (DA) and transapical (TA) approach. TA TAVI has been associated with a higher mortality rate. We hypothesized that this is related to effect modifiers, in particular the left ventricular ejection fraction (LVEF). METHODS: This multicentre study derived its data from prospective registries. To adjust for confounders, we used propensity-score based, stabilized inverse probability weighted Cox regression models. RESULTS: In total, 5,910 patients underwent TAVI via TF (N = 4,072), DA (N = 524), and TA (N = 1,314) access. Compared to TF, 30-day mortality was increased among DA (HR 1.87, 95%CI 1.26-2.78, p = .002) and TA (HR 3.34, 95%CI 2.28-4.89, p < .001) cases. Compared to TF, 5-year mortality was increased among TA cases (HR 1.50, 95%CI 1.24-1.83, p < .001). None of the variables showed a significant interaction between the approaches and mortality. An impaired LVEF (≤35%) increased mortality in all approaches. CONCLUSIONS: The surgical intra-thoracic TA and DA TAVI are both associated with a higher 30-day mortality than TF TAVI. TA TAVI is associated with a higher 5-year mortality than TF TAVI. The DA approach may therefore have some advantages over the TA approach when TF access is not feasible.

Influence of diagnosis of venous thromboembolism on immature platelets, absolute platelet count and platelet aggregation over time.

The extent of the involvement of platelets in venous thromboembolisms (VTE) is still not fully understood. Immature platelets are large, RNA-rich, prothrombotic platelets. They are involved in arterial thromboembolisms and are associated with adverse cardiovascular events. Their role in VTE has not been investigated before. The aim of this study was to assess different platelet parameters including immature platelet fraction (IPF), immature platelet count (IPC), absolute platelet count and platelet aggregation (PA) over time in patients with VTE at time of diagnosis, as well as at 3-10 days and at 90-110 days after diagnosis. 50 healthy volunteers similar in age and sex to patients served as controls at diagnosis. IPF was measured by the Sysmex XE-5000 analyzer, PA was assessed using the Multiplate analyzer. Diagnosis of VTE had no relevant effect on IPF and IPC whereas absolute platelet count and PA were significantly decreased compared to controls. In the course of VTE, IPF decreased significantly, whereas IPC, absolute platelet count and PA increased. In conclusion, VTE was associated with relevant changes of the absolute platelet count and PA at diagnosis, as well as changes in IPF and IPC over time reflecting a relevant and measurable platelet consumption in VTEs.

TAVR outcome after reclassification of aortic valve stenosis by using a hybrid continuity equation that combines computed tomography and echocardiography data.

BACKGROUND: In the continuity equation, assumption of a round-shaped left ventricular outflow tract (LVOT) leads to underestimation of the true aortic valve area in two-dimensional echocardiography. The current study evaluated whether inclusion of the LVOT area, as measured by computed tomography (CT), reclassifies the degree of aortic stenosis (AS) and assessed the impact on patient outcome after transcatheter aortic valve replacement (TAVR). METHODS AND RESULTS: Four hundred and twenty-two patients with indexed aortic valve area index (AVAi) of <0.6 cm2 /m2 , assessed by using the classical continuity equation (mean age: 81.5 ± 6.1 years, 51% female, mean left ventricular ejection fraction: 53.2 ± 13.6%), underwent TAVR and were included. After inclusion of the CT measured LVOT area into the continuity equation, the hybrid AVAi led to a reclassification of 30% (n = 128) of patients from severe to moderate AS. Multivariate predictors for reclassification were male sex, lower mean aortic gradient, and lower annulus/LVOT ratio (all p < .01). Reclassified patients had significantly higher sST2 at baseline and higher NT-proBNP values at baseline and 6 months follow-up compared to non-reclassified patients. Acute kidney injury was experienced more frequently after TAVR by reclassified patients, but no significant mortality difference occurred during 2 years of follow-up. CONCLUSION: The hybrid AVAi reclassifies a significant portion of low-gradient severe AS patients into moderate AS. Reclassified patients showed increased fibrosis and heart failure markers at baseline compared to non-reclassified patients. But reclassification had no significant impact on mortality up to 2 years after TAVR. Routine assessment of hybrid AVAi seems not to improve further risk stratification of TAVR patients.

Risk scores and biomarkers for the prediction of 1-year outcome after transcatheter aortic valve replacement.

BACKGROUND: Up to 50% of the patients still die or have to be rehospitalized during the first year after transcatheter aortic valve replacement (TAVR). This emphasizes the need for more strategic patient selection. The aim of this prospective observational cohort study was to compare the prognostic value of risk scores and circulating biomarkers to predict all-cause mortality and rehospitalization in patients undergoing TAVR. METHODS: We calculated the hazard ratios and C-statistics (area under the curve [AUC]) of 4 risk scores (logistic European System for Cardiac Operative Risk Evaluation [EuroSCORE], EuroSCORE II, Society of Thoracic Surgeons predicted risk of mortality, and German aortic valve score) and 5 biomarkers of inflammation and/or myocardial dysfunction (high-sensitivity C-reactive protein, growth differentiation factor (GDF)-15, interleukin-6, interleukin-8, and N-terminal pro-B-type natriuretic peptide) for the risk of death (n = 80) and the combination of death or rehospitalization (n = 132) during the first year after TAVR in 310 consecutive TAVR patients. RESULTS: The EuroSCORE II and GDF-15 had the strongest predictive value for 1-year mortality (EuroSCORE II, AUC 0.711; GDF-15, AUC 0.686) and for the composite end point (EuroSCORE II, AUC 0.690; GDF-15, AUC 0.682). When added to the logistic EuroSCORE and EuroSCORE II, GDF-15 enhanced the prognostic performance of the score and enabled substantial reclassification of patients. Combinations of increasing tertiles of the logistic EuroSCORE or EuroSCORE II and GDF-15 allowed the stratification of the patients into subgroups with mortality rates ranging from 4.0% to 49.1% and death/rehospitalization rates ranging from 15.3% to 68.4%. CONCLUSIONS: Our study identified GDF-15 in addition to the logistic EuroSCORE and the EuroSCORE II as the most promising predictors of a poor outcome after TAVR.

Elucidation of the genetic causes of bicuspid aortic valve disease.

AIMS: The present study aims to characterize the genetic risk architecture of bicuspid aortic valve (BAV) disease, the most common congenital heart defect. METHODS AND RESULTS: We carried out a genome-wide association study (GWAS) including 2236 BAV patients and 11 604 controls. This led to the identification of a new risk locus for BAV on chromosome 3q29. The single nucleotide polymorphism rs2550262 was genome-wide significant BAV associated (P = 3.49 × 10-08) and was replicated in an independent case-control sample. The risk locus encodes a deleterious missense variant in MUC4 (p.Ala4821Ser), a gene that is involved in epithelial-to-mesenchymal transformation. Mechanistical studies in zebrafish revealed that loss of Muc4 led to a delay in cardiac valvular development suggesting that loss of MUC4 may also play a role in aortic valve malformation. The GWAS also confirmed previously reported BAV risk loci at PALMD (P = 3.97 × 10-16), GATA4 (P = 1.61 × 10-09), and TEX41 (P = 7.68 × 10-04). In addition, the genetic BAV architecture was examined beyond the single-marker level revealing that a substantial fraction of BAV heritability is polygenic and ∼20% of the observed heritability can be explained by our GWAS data. Furthermore, we used the largest human single-cell atlas for foetal gene expression and show that the transcriptome profile in endothelial cells is a major source contributing to BAV pathology. CONCLUSION: Our study provides a deeper understanding of the genetic risk architecture of BAV formation on the single marker and polygenic level.

Artificial intelligence-enabled phenotyping of patients with severe aortic stenosis: on the recovery of extra-aortic valve cardiac damage after transcatheter aortic valve replacement.

OBJECTIVE: A novel artificial intelligence-based phenotyping approach to stratify patients with severe aortic stenosis (AS) prior to transcatheter aortic valve replacement (TAVR) has been proposed, based on echocardiographic and haemodynamic data. This study aimed to analyse the recovery of extra-aortic valve cardiac damage in accordance with this novel stratification system following TAVR. METHODS: The proposed phenotyping approach was previously established employing data from 366 patients with severe AS from a bicentric registry. For this consecutive study, echocardiographic follow-up data, obtained on day 147±75.1 after TAVR, were available from 247 patients (67.5%). RESULTS: Correction of severe AS by TAVR significantly reduced the proportion of patients suffering from concurrent severe mitral regurgitation (from 9.29% to 3.64%, p value: 0.0015). Moreover, pulmonary artery pressures were ameliorated (estimated systolic pulmonary artery pressure: from 47.2±15.8 to 43.3±15.1 mm Hg, p value: 0.0079). However, right heart dysfunction as well as the proportion of patients with severe tricuspid regurgitation remained unchanged. Clusters with persistent right heart dysfunction ultimately displayed 2-year survival rates of 69.2% (95% CI 56.6% to 84.7%) and 74.6% (95% CI 65.9% to 84.4%), which were significantly lower compared with clusters with little or no persistent cardiopulmonary impairment (88.3% (95% CI 83.3% to 93.5%) and 85.5% (95% CI 77.1% to 94.8%)). CONCLUSIONS: This phenotyping approach preprocedurally identifies patients with severe AS, who will not recover from extra-aortic valve cardiac damage following TAVR and whose survival is therefore significantly reduced. Importantly, not the degree of pulmonary hypertension at initial presentation, but the irreversibility of right heart dysfunction determines prognosis.

Harnessing feature extraction capacities from a pre-trained convolutional neural network (VGG-16) for the unsupervised distinction of aortic outflow velocity profiles in patients with severe aortic stenosis.

Aims: Hypothesizing that aortic outflow velocity profiles contain more valuable information about aortic valve obstruction and left ventricular contractility than can be captured by the human eye, features of the complex geometry of Doppler tracings from patients with severe aortic stenosis (AS) were extracted by a convolutional neural network (CNN). Methods and results: After pre-training a CNN (VGG-16) on a large data set (ImageNet data set; 14 million images belonging to 1000 classes), the convolutional part was employed to transform Doppler tracings to 1D arrays. Among 366 eligible patients [age: 79.8 ± 6.77 years; 146 (39.9%) women] with pre-procedural echocardiography and right heart catheterization prior to transcatheter aortic valve replacement (TAVR), good quality Doppler tracings from 101 patients were analysed. The convolutional part of the pre-trained VGG-16 model in conjunction with principal component analysis and k-means clustering distinguished two shapes of aortic outflow velocity profiles. Kaplan-Meier analysis revealed that mortality in patients from Cluster 2 (n = 40, 39.6%) was significantly increased [hazard ratio (HR) for 2-year mortality: 3; 95% confidence interval (CI): 1-8.9]. Apart from reduced cardiac output and mean aortic valve gradient, patients from Cluster 2 were also characterized by signs of pulmonary hypertension, impaired right ventricular function, and right atrial enlargement. After training an extreme gradient boosting algorithm on these 101 patients, validation on the remaining 265 patients confirmed that patients assigned to Cluster 2 show increased mortality (HR for 2-year mortality: 2.6; 95% CI: 1.4-5.1, P-value: 0.004). Conclusion: Transfer learning enables sophisticated pattern recognition even in clinical data sets of limited size. Importantly, it is the left ventricular compensation capacity in the face of increased afterload, and not so much the actual obstruction of the aortic valve, that determines fate after TAVR.

Dose-Dependent Effect of Renin-Angiotensin System Blockade Following Transcatheter Aortic Valve Replacement.

BACKGROUND: There is growing body of evidence from retrospective studies that renin-angiotensin system (RAS) blockade is associated with improved outcome after transcatheter aortic valve replacement (TAVR). However, it remains unknown whether the effect of RAS blockade is dose dependent. The current study sought to assess the dose-dependent effect of RAS blockade on survival and left-ventricular (LV) remodelling after TAVR. METHODS: Patients who were enrolled into our observational TAVR study at our institution were retrospectively assessed according to different doses of RAS blockade: group 1 (no RAS blockade), group 2 (25% of maximum daily dose), group 3 (50% of maximum daily dose), and group 4 (full daily dose). RESULTS: A total of 323 patients between January 2015 and September 2019 were included. Patients with higher doses of RAS blockade showed a trend toward higher overall survival at 3-year follow-up (56% with no RAS blockade vs 66% with the 25% dose vs 79% with the 50% dose vs 78% with the full dose; P = 0.063). After adjustment for baseline characteristics, the difference in survival was significant (P = 0.042). Besides New York Heart Association class and left-ventricular ejection fraction (LVEF), RAS blockade dose was identified as independent predictor for all-cause mortality (hazard ratio [HR] 0.72; 95% confidence interval [CI], 0.54-0.97; P = 0.03). With respect to LV remodelling, a significantly larger reduction of LV mass index was observed during the follow-up with higher doses of RAS blockade. CONCLUSIONS: The current study showed that the impact of RAS blockade treatment on clinical outcome and LV remodelling after TAVR is dose dependent.