Right ventricular function and outcome in patients undergoing transcatheter mitral valve repair

Objectives

This study sought to assess the impact of right ventricular dysfunction (RVD) on event-free survival after transcatheter mitral valve repair (TMVR) for severe mitral regurgitation.

Background

The prognostic value of left and RV global longitudinal strain (LV- and RV-GLS) on cardiovascular magnetic resonance feature tracking (CMR-FT) in patients undergoing TMVR is unknown.

Methods

Consecutive TMVR patients underwent pre-procedural and follow-up CMR-FT analysis. Kaplan-Meier estimates and multivariable Cox-regression analyses were performed, using a composite endpoint of heart failure hospitalization (HFH) and death.

Results

62 patients (78.3±7.0y/o, 45% female, EuroSCORE-II: 9.6±7.1%) underwent CMR-FT prior to TMVR, 24% had concomitant tricuspid edge-to-edge repair (TTVR). On presentation, 23 (37%) patients suffered RVD, defined as RV-GLS >−20% on CMR-FT. RVD was associated with reduced LV and RV ejection fraction (LVEF: 39.2 vs. 48.7%, p=0.008, RVEF: 35.1 vs. 46.7%, p<0.001), as well as impaired LV-GLS (−14.0 vs. −19.5%, p=0.012).

Eighteen events (12 deaths, 6 HFH) occurred during follow-up (11.4±9.1 months). On multivariable Cox-regression adjusted for baseline, procedural, imaging, and biomarker data, RV but not LV-GLS was significantly associated with outcome (adj.HR 2.50, 95% CI: 1.29–4.86, p=0.007 and 1.46, 95% CI: 0.50–4.28, p=0.491, respectively). Among various definitions of RVD on echocardiography and CMR, only RV-GLS on CMR-FT was significantly associated with outcome (RV-GLS >−20%: adj.HR 7.53, 95% CI: 2.07–27.42, p=0.002), but not RVEF on CMR or echo-indices of RV function (Central Illustration).

Follow-up CMR-FT was performed in 21 (34%) patients and RV-GLS significantly improved after TMVR (−20.6 to −25.2%, p=0.016), irrespective of additional TTVR.

Conclusions

RV-GLS, as determined on CMR-FT, rather than LV-GLS or RVEF, is an independent predictor of outcome in patients undergoing TMVR.

Funding Acknowledgement

Type of funding sources: None.

A streamlined, machine learning-derived approach to risk-stratification in heart failure patients with secondary tricuspid regurgitation

Background

Secondary tricuspid regurgitation (sTR) is the most frequent valvular heart disease and has significant impact on mortality. A high burden of comorbidities often worsens the already dismal prognosis of sTR, while tricuspid interventions remain underused and initiated too late.

Objectives

To examine the most powerful predictors of all-cause mortality in moderate and severe sTR using machine learning techniques and to provide a streamlined approach to risk-stratification using readily available clinical, echocardiographic and laboratory parameters.

Methods

This large-scale, long-term observational study included 3359 moderate and 1509 severe sTR patients encompassing the entire heart failure spectrum (preserved, mid-range and reduced ejection fraction). A random survival forest was applied to investigate the most important predictors and group patients according to their number of adverse features (Figure 1).

Results

The identified predictors and thresholds, that were associated with significantly worse mortality were higher age (≥75 in moderate and ≥70 years in moderate and severe sTR respectively), higher NT-proBNP (≥4000 pg/ml), increased high sensitivity C-reactive protein (≥1.0 mg/dl), serum albumin <40 g/L and hemoglobin <13 g/dL. Additionally, grouping patients according to the number of adverse features yielded important prognostic information, as patients with 4 or 5 adverse features had a sevenfold risk increase in moderate sTR (7.11 [2.27–4.30] HR 95% CI, P<0.001) and fivefold risk increase in severe sTR (5.08 [3.13–8.24] HR 95% CI, P<0.001) (Figure 2: A moderate sTR derivation, B moderate sTR validation, C severe sTR derivation, D severe sTR validation).

Conclusion

This study presents a streamlined, machine learning-derived and internally validated approach to risk-stratification in patients with moderate and severe sTR, that adds important prognostic information to aid clinical decision-making.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Austrian Science Fund

Right ventricular longitudinal strain on cardiovascular magnetic resonance imaging predicts outcome in patients undergoing transcatheter mitral valve repair

Background

The prognostic value of left and right ventricular global longitudinal strain (LV and RV GLS) derived from cardiovascular magnetic resonance (CMR) feature tracking in patients with severe mitral regurgitation (MR) undergoing transcatheter mitral valve repair (TMVR) is unknown.

Methods

Consecutive patients scheduled for TMVR underwent pre-procedural and follow-up CMR imaging including feature tracking strain analysis. Kaplan-Meier estimates and multivariate Cox-regression analyses were used to identify the prognostic impact of LV and RV GLS on CMR using a composite of heart failure hospitalization and death.

Results

A total of 62 patients (78.3±7.0y/o, 45% female, EuroSCORE II: 9.7±7.2%) with severe MR underwent CMR prior to TMVR. 23 (37%) patients presented with right ventricular dysfunction (RVD) defined by RV GLS >−20% on CMR. At baseline, RVD was associated with NT-proBNP levels (9510 vs. 4064pg/mL, p=0.030). On CMR, RVD was associated with reduced left and RV ejection fraction (LVEF: 39.2 vs. 48.7%, p=0.011, RVEF: 35.1 vs. 46.7%, p<0.001), as well as increased LV GLS (−14.0 vs. −19.5%, p=0.003).

A total of 18 events (12 deaths, 6 hospitalizations for heart failure) occurred during follow-up (mean 11.4±9.1months). While LV GLS was not significantly associated with outcome (HR 0.95, 95% CI: 0.90–1.01, p=0.082), RV GLS showed a strong and independent association with event-free survival by multivariate Cox-regression analysis (adj.HR 0.91, 95% CI: 0.83–0.99, p=0.033) after adjustment for relevant baseline and procedural data (EuroSCORE II, post-procedural residual MR), imaging parameters (TAPSE, LV and RVEF on CMR), and cardiac biomarkers (NT-proBNP). When compared with the “gold standard” RVEF on CMR (RVEF <45%: adj.HR 0.86, 95% CI: 0.23–3.20, p=0.825) and TAPSE on echo (TAPSE <17mm: adj.HR: 2.77, 95% CI: 0.72–10.70, p=0.140), only RVD (RV GLS >−20%: adj.HR 5.05, 95% CI: 1.23–20.63, p=0.024) was significantly associated with the composite endpoint (Figure 1). Follow-up CMR was performed in 21 (34%) patients. RV GLS significantly improved after TMVR (−20.6 to −25.2%, p=0.016, Figure 2).

Conclusions

RV rather than LV GLS, as determined on CMR, is an important predictor of outcome in patients undergoing TMVR. At 1 year follow-up, RV function significantly improved, and thus might add useful prognostic information on top of established risk factors.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Prevalence of cardiac amyloidosis in patients undergoing transcatheter edge-to edge mitral valve repair

Introduction

Cardiac amyloidosis (CA) is associated with severe aortic stenosis, however, its prevalence in patients with severe mitral regurgitation in elderly patients is unknown.

Methods

Patients scheduled for transcatheter edge-to edge mitral valve repair (TMVR) were prospectively screened for CA using 99m technetium-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) bone scintigraphy and subsequent serum as well as urine free light-chain quantification in case of a positive DPD scan, defined as visual cardiac update based on the Perugini grading scale.

Results

Out of 100 patients undergoing TMVR, 28 patients (28.0%) had a positive DPD-scan (DPD+). 14 patients (14.0%) showed Perugini grade I enhancement, 9 patients (9.0%) grade II enhancement, and in 5 patients (5.0%), grade III enhancement was present. 28 patients suffered from TTR and two from AL- amyloidosis (one patient had a combination of TTR and AL-amyloidosis). When compared to patients with a negative scan (DPD-), DPD+ patients presented with similar baseline characteristics such as age (DPD- vs DPD+ 76y/o vs 77y/o, p=0.44), gender (female; 62.7% vs 50.0%, p=0.25), coronary artery disease (59.7% vs 42.9%, p=0.13), previous valve surgery (25.4% vs 14.3%, p=0.24) and atrial fibrillation (68.7% vs 78.6%, p=0.33). Also, NYHA functional class and EuroScore II were similar (NYHA ≥ III; 85.1% vs 82.1%, p=0.72, and EuroScore II 9.9±9.8% vs 7.0±4.8%, p=0.21, respectively). On echocardiography, DPD+ patients presented with more pronounced left and right ventricular hypertrophy (interventricular septum: 15mm vs 13mm, p<0.01) but similar left ventricular ejection fraction (44.9% vs 42.3%, p=0.34). At 3-months after TMVR, DPD+ patients showed significant improvement in BNP serum levels when compared to DPD- patients (DPD+ vs DPD-: +315±2569pg/ml vs −2404±8696pg/ml, p=0.03), while NYHA functional class remained unchanged (NYHA improvement ≥1 class: 57.6% vs 50.0%, p=0.52)

Conclusions

In this single centre experience, CA was highly prevalent among elderly patients with severe mitral regurgitation scheduled for TMVR. TMVR in CA patients resulted in significant improvement of NT-pro BNP levels. Future studies need to clarify the prognostic relevance of CA in this specific patient population.

Funding Acknowledgement

Type of funding sources: None.