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.

Subphenotyping of Patients With Aortic Stenosis by Unsupervised Agglomerative Clustering of Echocardiographic and Hemodynamic Data

OBJECTIVES

The aim of this retrospective analysis was to categorize patients with severe aortic stenosis (AS) according to clinical presentation by applying unsupervised machine learning.

BACKGROUND

Patients with severe AS present with heterogeneous clinical phenotypes, depending on disease progression and comorbidities.

METHODS

Unsupervised agglomerative clustering was applied to preprocedural data from echocardiography and right heart catheterization from 366 consecutively enrolled patients undergoing transcatheter aortic valve replacement for severe AS.

RESULTS

Cluster analysis revealed 4 distinct phenotypes. Patients in cluster 1 (n = 164 [44.8%]), serving as a reference, presented with regular cardiac function and without pulmonary hypertension (PH). Accordingly, estimated 2-year survival was 90.6% (95% CI: 85.8%-95.6%). Clusters 2 (n = 66 [18.0%]) and 4 (n = 91 [24.9%]) both comprised patients with postcapillary PH. Yet patients in cluster 2 with preserved left and right ventricular structure and function showed a similar survival as those in cluster 1 (2-year survival 85.8%; 95% CI: 76.9%-95.6%), whereas patients in cluster 4 with dilatation of all heart chambers and a high prevalence of mitral and tricuspid regurgitation (12.5% and 14.8%, respectively) died more often (2-year survival 74.9% [95% CI: 65.9%-85.2%]; HR for 2-year mortality: 2.8 [95% CI: 1.4-5.5]). Patients in cluster 3, the smallest (n = 45 [12.3%]), displayed the most extensive disease characteristics (ie, left and right heart dysfunction together with combined pre- and postcapillary PH), and 2-year survival was accordingly reduced (77.3% [95% CI: 65.2%-91.6%]; HR for 2-year mortality: 2.6 [95% CI: 1.1-6.2]).

CONCLUSIONS

Unsupervised machine learning aids in capturing complex clinical presentations as observed in patients with severe AS. Importantly, structural alterations in left and right heart morphology, possibly due to genetic predisposition, constitute an equally sensitive indicator of poor prognosis compared with high-grade PH.

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.

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.

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.

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.

Prognostic impact of cancer history in patients undergoing transcatheter aortic valve implantation

BACKGROUND

The benefit of TAVI in cancer patients is currently unclear.

OBJECTIVES

The purpose of this study is to investigate prognostic impact of cancer status (active cancer or previous cancer) in severe aortic stenosis (AS) patients undergoing transcatheter aortic valve implantation (TAVI).

METHODS

Consecutive TAVI patients in the Heart Center Bonn were enrolled and we stratified the patients into three groups: current cancer (active cancer), non-current cancer (previous cancer), or no cancer. The primary outcome was all-cause death within a 5-year follow-up. We evaluated mean aortic pressure gradient (mPG) values following TAVI (baseline mPG) and at the final follow-up (follow-up mPG).

RESULTS

In total, 1568 TAVI patients were eligible and 298 patients (19.0%) had active or previous cancer. At the 5-year follow-up, cancer patients had a significantly worse prognosis than non-cancer patients (log rank, P < 0.001). In a multivariable analysis, previous cancer was a significant predictor for 5-year mortality (hazard ratio [HR], 1.56; P < 0.001). Estimated mortality rates at 5-year follow-up rates among active cancer, previous cancer, and non-cancer were 84.0%, 65.8%, and 50.2% (long-rank P < 0.001), respectively. The hazard ratios of active cancer and previous cancer for 5-year mortality were 2.79 (P < 0.001) and 1.38 (P = 0.019) compared to non-cancer patients. We found significantly higher mPG during follow-up than at baseline in cancer patients (follow-up 8.10 vs baseline 7.40 mmHg; Wilcoxon P = 0.012).

CONCLUSIONS

Active, and also previous, cancer status are associated with less beneficial long-term prognosis in TAVI patients.

Peripheral perfusion of lower limb after transcatheter aortic valve implantation (TAVI) in patients with peripheral artery disease

BACKGROUND

In TAVI patients, peripheral arterial disease (PAD) is a common concomitant disease. Given the fact that calcified severe aortic stenosis (AS) limits the blood flow that reaches the periphery, it is conceivable that the treatment of AS may positively influence the peripheral perfusion.

AIM

To evaluate whether, and if so, how the peripheral perfusion changes after TAVI in patients with PAD comparing with patients without PAD.

METHODS

On the basis of objective vascular tests, peripheral perfusion in the lower extremities were studied in 108 TAVI patients with or without concomitant PAD.

RESULTS

108 consecutive patients with a median logistic EuroSCORE of 12.7 (IQR: 8.5 to 22.0) % underwent TAVI with an extensive pre- and post-procedural assessment of the peripheral perfusion. In patients without PAD, the time to peak flow (tPF) did not differ before (6.45 ± 5.24 s) and after (6.45 ± 5.91 s) TAVI (p = 1.000). In PAD patients, however, the tPF was significantly shortened following TAVI (9.51 ± 9.45 s vs. 8.33 ± 8.16 s, p < 0.001), thereby reflecting an improvement in peripheral blood flow. The resting arterial blood flow before and after TAVI showed the highest level at the beginning (0 s) and constantly decreased afterwards. No improvement in the peak flow was achieved.

CONCLUSIONS

In PAD patients, TAVI led to improved peripheral blood flow as reflected by shortened time to peak flow measurements.

P918Tricuspid regurgitation in patients undergoing transcatheter aortic valve implantation

Background

Transcatheter aortic valve implantation (TAVI) has become the treatment of choice in elderly patients with severe aortic stenosis and increased surgical risk. A significant number of these elderly patients have concomitant tricuspid valve regurgitation. The impact on outcome, however, is still matter of debate.

Objectives

In this prospective observational study, we investigated the impact of concomitant tricuspid regurgitation (TR) on outcome in patients undergoing transcatheter aortic valve implantation.

Methods

Between February 2008 and May 2018, 1411 patients with severe symptomatic aortic stenosis and increased operative risk underwent TAVI at the Heart Center Bonn and participated in this study, after written informed consent was obtained.

Before TAVI procedure, all patients underwent a careful cardiac evaluation and interdisciplinary discussion within the local, institutional Heart Team.

The pre-interventional 3D echocardiography was used to determine the degree of tricuspid valve regurgitation. According to the severity of TR, patients were divided into two groups; patients with TR < II and patients with moderate to severe TR ≥ II andcompared regarding rates of mortality after 1 year of follow-up between the two groups.

Results

Out of 1411 TAVI patients, 802 (56.8%) had tricuspid regurgitation < II, 610 (43.2%) patients suffered from tricuspid regurgitation ≥ II.

The mean age of our study population was 81.1 (±6.5). The baseline characteristics did not differ significantly between the two groups, such as extracardiac arteriopathy (TR < II: 44% vs TR ≥ II: 41.6%; p=0.37), diabetes (TR < II: 27.5% vs TR ≥ II: 27.7%; p=0.92) or arterial hypertension (TR < II: 91% vs TR ≥ II: 93.2%; p=0.64). However, patients with concomitant TR ≥ II had significantly more often NYHA class IV (TR < II: 5.0% vs TR ≥ II: 15.4%; p<0.001) and a higher logistic EuroSCORE (TR < II: 12.9 (8.8/21.2) vs TR ≥ II: 20.6 (13.1/33.4); p<0.001). Additionally, patients with a TR ≥ II had significantly more often a concomitant mitral regurgitation ≥ II (TR < II: 43.3% vs TR ≥ II: 60.4%; p<0.001). Comparing rates of mortality, we found a significant association between the degree of tricuspid regurgitation and 1-year mortality in patients undergoing TAVI (TR < II: 85 (10.6%) vs. TR ≥ II: 136 (22.3%); p<0.001), as presented in Figure 1.

Figure 1

Conclusion

Moderate to severe tricuspid valve regurgitation is associated with higher rates of mortality in patients undergoing transcatheter aortic valve implantation. Our results are hypothesis-generating and it has to be elucidated whether the severity of TR is only a surrogate for more advanced stage of aortic stenosis or whether it is causative so that mortality could be reduced by its treatment.

Acknowledgement/Funding

None

P5574Prognostic impact of left atrial function following transcatheter mitral valve repair

Background

Left atrial (LA) function predicts clinical outcome in a variety of cardiovascular diseases. However, limited data is available in the setting of mitral regurgitation (MR).

Purpose

The aim of the present study was to assess potential changes in LA ejection fraction (LA-EF) and its prognostic value in patients following transcatheter mitral valve repair using the mitraclip.

Methods

A total of 88 consecutive patients undergoing mitraclip implantation with complete echocardiography at baseline and follow-up between 3 and 6 months post-procedure were enrolled.

Results

LA-EF improved in 58% of the population. Change in LA-EF was associated with residual MR, residual transmitral gradient and left ventricular ejection fraction (LV-EF) changes. Compared to their counterparts, patients with residual MR ≥ grade 2 (−6% [−9 to 1%] vs. 4% [−5 to 15%]; p=0.05) and with residual transmitral gradient ≥5 mmHg (−2% [−9 to 9%] vs. 5% [−4 to 16%]; p=0.03) showed a decline in LA-EF, respectively. Furthermore, LA-EF significantly correlated with changes in LV-EF (r=0.40; p=0.001). With regards to clinical outcome, heart failure symptoms as assessed by NYHA class were more severe in patients with worsened LA-EF at follow-up. Finally, LA-EF change was identified as independent predictor of all-cause mortality (HR 0.94 [0.90–0.98]; p=0.008).

Kaplan-Meier estimates for survival

Conclusion

The present analysis showed changes in LA function in patients undergoing mitraclip implantation to be associated with important measures including residual MR, elevated transmitral gradient and LV function. Importantly, LA function alterations represent a strong predictor for all-cause mortality.

Early versus newer generation transcatheter heart valves for transcatheter aortic valve implantation: Echocardiographic and hemodynamic evaluation of an all-comers study cohort using the dimensionless aortic regurgitation index (AR-index)

Aims

More than mild paravalvular aortic regurgitation (pAR) negatively impacts prognosis after transcatheter aortic valve implantation (TAVI). “Newer generation” transcatheter heart valves (THVs) including Direct Flow Medical, Medtronic Evolut R, Boston Lotus, and Edwards SAPIEN 3 valve system promise to improve outcome by reducing the rate of TAVI-related issues such as pAR. Aim was to evaluate and compare the hemodynamic performance with AR index of “early” vs. “newer generation” THVs and its impact on outcome.

Methods and results

In 805 patients undergoing TAVI, the degree of pAR was assessed using imaging modalities (angiography, echocardiography) and hemodynamic measurements (aortic regurgitation index, ARI ratio). Severity of pAR and outcome were assessed according to the VARC-2 criteria.

805 patients underwent TAVI with use of the CoreValve (n = 400), SAPIEN XT (n = 48), Direct Flow Medical (n = 38), Evolut R (n = 114), Lotus (n = 104), or SAPIEN 3 (n = 101) prosthesis. TTE post TAVI revealed that a total of 7.3% of the patients showed moderate/severe pAR. The occurrence of greater than mild pAR occurred less frequently in patients treated with “newer generation” THVs (p<0.001): CoreValve (11.3%), SAPIEN XT (12.5%), Direct Flow Medical (5.3%), Evolut R (5.3%), Lotus (0.0%), and SAPIEN 3 (0.0%). The AR index was significantly higher (p<0.001) in patients receiving “newer generation” prostheses compared to those in whom “earlier generation” THVs were used. However, the ARI was only predictive of cumulative all-cause mortality at 1 and 3 years in “early generation”, but not in “newer generation” THVs. In the overall cohort, 30-day and 1-year mortality was 4.8% and 20.1%, respectively. In patients treated with “newer generation” devices, the respective mortality rates remained substantially below those of patients treated with “earlier generation” THVs (30-day mortality: 2.5% vs. 6.7%, p< 0.001; 1-year mortality: 11.2% vs. 27.2%, p<0.001).

Conclusion

TAVI with use of “newer generation” THVs showed significantly reduced pAR and improved outcomes compared to “early generation” devices that could at least in part be explained by more favorable hemodynamics

Prognostic Impact of Left Atrial Function Following Transcatheter Mitral Valve Repair

Background

Left atrial (LA) function predicts clinical outcome in a variety of cardiovascular diseases. However, limited data are available in the setting of mitral regurgitation. The aim of the present study was to assess potential changes in LA ejection fraction (LAEF) and its prognostic value in patients following transcatheter mitral valve repair using the MitraClip.

Methods and Results

A total of 88 consecutive patients undergoing MitraClip implantation with complete echocardiography at baseline and follow‐up between 3 and 6 months postprocedure were enrolled. LAEF improved in 58% of the population. Change in LAEF was associated with residual mitral regurgitation, residual transmitral gradient and left ventricular ejection fraction changes. Compared with their counterparts, patients with residual mitral regurgitation ≥grade 2 (change in LAEF, −6% [Interquartile [IQR], −9–1%] versus 4% [IQR, −5–15%]; P=0.05) and with residual transmitral gradient ≥5 mm Hg (change in LAEF, −2% [IQR, −9–9%] versus 5% [IQR, −4–16%]; P=0.03) showed a decline in LAEF, respectively. Furthermore, LAEF significantly correlated with changes in left ventricular ejection fraction (r=0.40; P=0.001). With regards to clinical outcome, heart failure symptoms as assessed by New York Heart Association class were more severe in patients with worsened LAEF at follow‐up. Finally, LAEF change was identified as an independent predictor of all‐cause mortality (hazard ratio, 0.94; 95% CI, 0.90–0.98 [P=0.008]).

Conclusions

The present analysis showed that changes in LA function in patients undergoing MitraClip implantation are associated with important measures including residual mitral regurgitation, elevated transmitral gradient, and left ventricular function. Importantly, LA function alterations represent a strong predictor for all‐cause mortality.

Reverse Cardiac Remodeling After Transcatheter Treatment of Severe Tricuspid Regurgitation Using the Edge-to-Edge MitraClip Technique

OBJECTIVES

In recent years, transcatheter treatment techniques for tricuspid regurgitation (TR) have rapidly evolved. Cardiac remodeling analysis beyond clinical outcome assessment following transcatheter tricuspid repair is still lacking. The aim of the present case series was to analyze cardiac remodeling after tricuspid valve repair using the edge-to-edge MitraClip technique.

METHODS

Echocardiographic analysis was performed prior to MitraClip implantation and at 3-month and 6-month follow-up exams.

RESULTS

Six consecutive patients undergoing MitraClip implantation between April 2017 and March 2018 at our institution were enrolled. During follow-up, TR reduction was durable in all patients, without recurrence of severe TR. Compared to baseline, right ventricular function improved in 5 out of 6 patients. Reduction in right ventricular area was observed in the majority of patients and reduction in right atrial volume was observed in all subjects. Patients also experienced beneficial left cardiac remodeling.

CONCLUSION

The present series indicates that transcatheter treatment of severe TR using the edge-to-edge MitraClip technique can lead to reverse cardiac remodeling, which is not commonly seen in surgically treated patients.

Brief report - Telomere length is a poor biomarker to predict 1-year mortality or cardiovascular comorbidity in patients with transcatheter aortic valve replacement

Background

Transcatheter aortic valve replacement (TAVR) is a therapeutic option for patients with aortic valve stenosis at increased surgical risk. Telomeres are an established marker for cellular senescence and have served to evaluate cardiovascular diseases including severe aortic valve stenosis. In our study, we hypothesized that telomere length may be a predictor for outcome and associated with comorbidities in patients with TAVR.

Methods and results

We analyzed leucocyte telomere length from 155 patients who underwent TAVR and correlated the results with 1-year mortality and severe comorbidities. The cohort was subdivided into 3 groups according to telomere length. Although a trend for a positive correlation of telomere length with a lower EuroSCORE could be found, telomere length was not associated with survival, aortic valve opening area or cardiovascular comorbidities (peripheral, coronary or cerebrovascular disease). Interestingly, long telomeres were significantly correlated to a reduced left ventricular ejection fraction (LVEF).

Conclusion

In elderly patients with severe aortic valve stenosis, leucocyte telomere length did not predict post-procedural survival. The correlation between long telomere length and reduced LVEF in these patients deserves further attention.

Long-term follow-up after stent graft placement for access-site and access-related vascular injury during TAVI - The Bonn-Copenhagen experience

AIMS

Stent graft placement is a safe and effective treatment option for vascular complications in the context of transcatheter aortic valve implantation (TAVI). This study aimed to provide long-term angiological follow-up of stent grafts used for this indication.

METHODS AND RESULTS

Seventy-one patients (64.8% female, log EuroScore 14.7 ± 6.8%) who had undergone TAVI between March 2010 and October 2015 with implantation of a Viabahn or Fluency stent graft to treat access-site or access-related vascular injury (ASARVI) were analyzed. Implantations were mostly due to access-site bleeding complications (83.1%) in the common femoral artery (97.1%). Follow-up was performed with duplex sonography in all patients after a median of 3.9 years after TAVI (interquartile range [IQR]: 895-1749 days). Ultrasound revealed tri- or biphasic flow patterns in 16.9% and 77.6%, respectively. Stent graft patency was 100% without signs of stent graft stenosis (mean peak velocity ratio 1.0 ± 0.2). Pseudo-aneurysms or endoleaks were diagnosed in 5.6% of patients. Additional fluoroscopic and/or computed tomography (CT)-imaging was available in 36.6% of patients and did not reveal any stent fracture.

CONCLUSION

Self-expanding stent grafts provide excellent long-term function with few complications when implanted in the context of TAVI-related ASARVI.

Soluble ST2 for Risk Stratification and the Prediction of Mortality in Patients Undergoing Transcatheter Aortic Valve Implantation

This study aimed to assess the prognostic value of soluble ST2 (sST2) for risk stratification in patients undergoing transcatheter aortic valve implantation (TAVI). In 461 patients undergoing TAVI, sST2 was determined at baseline and categorized into quartiles. An optimum cutoff of 29 ng/ml was calculated. Primary end point was 1-year all-cause mortality. Results were validated in an independent cohort. Patients with sST2 >29 ng/ml had an increased 30-day (9.7% vs 4.6%, p = 0.043) and 1-year mortality (38.1% vs 21.8%, p = 0.001). In accordance, patients with N-terminal pro-brain natriuretic peptide (NT-proBNP) >8145 pg/ml revealed a comparable 30-day mortality (7.9% vs 4.7%, p = 0.189) and 1-year mortality (39.5% vs 21.0%, p <0.001). In univariate regression analysis, sST2 and NT-proBNP were associated with increased mortality risk. In multivariate regression analysis, independent predictors of mortality were logistic EuroSCORE, chronic renal failure, left ventricular ejection fraction, and sST2. In receiver operating characteristic curve analysis, sST2 did not provide incremental prognostic information beyond that obtained from surgical risk scores such as the STS-PROM or NT-proBNP. Similar findings could be achieved in an independent validation cohort. In conclusion, sST2 is independently associated with adverse outcome after TAVI but was not superior to NT-proBNP or surgical risk scores for the prediction of postprocedural outcomes.

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.