Transmitral Gradients Following Transcatheter Edge-to-Edge Repair: Are Mean Gradients Meaningful?

Impact of Intraprocedural Mitral Regurgitation and Gradient Following Transcatheter Edge-to-Edge Repair for Primary Mitral Regurgitation

BACKGROUND

The impact of intraprocedural results following transcatheter edge-to-edge repair (TEER) in primary mitral regurgitation (MR) is controversial.

OBJECTIVES

This study sought to investigate the prognostic impact of intraprocedural residual mitral regurgitation (rMR) and mean mitral valve gradient (MPG) in patients with primary MR undergoing TEER.

METHODS

The PRIME-MR (Outcomes of Patients Treated With Mitral Transcatheter Edge-to-Edge Repair for Primary Mitral Regurgitation) registry included consecutive patients with primary MR undergoing TEER from 2008 to 2022 at 27 international sites. Clinical outcomes were assessed according to intraprocedural rMR and mean MPG. Patients were categorized according to rMR (optimal result: ≤1+, suboptimal result: ≥2+) and MPG (low gradient: ≤5 mm Hg, high gradient: > 5 mm Hg). The prognostic impact of rMR and MPG was evaluated in a Cox regression analysis. The primary endpoint was 2-year all-cause mortality or heart failure hospitalization.

RESULTS

Intraprocedural rMR and mean MPG were available in 1,509 patients (median age = 82 years [Q1-Q3: 76.0-86.0 years], 55.1% male). Kaplan-Meier analysis according to rMR severity showed significant differences for the primary endpoint between rMR ≤1+ (29.1%), 2+ (41.7%), and ≥3+ (58.0%; P < 0.001), whereas there was no difference between patients with a low (32.4%) and high gradient (42.1%; P = 0.12). An optimal result/low gradient was achieved in most patients (n = 1,039). The worst outcomes were observed in patients with a suboptimal result/high gradient. After adjustment, rMR ≥2+ was independently linked to the primary endpoint (HR: 1.87; 95% CI: 1.32-2.65; P < 0.001), whereas MPG >5 mm Hg was not (HR: 0.78; 95% CI: 0.47-1.31; P = 0.35).

CONCLUSIONS

Intraprocedural rMR but not MPG independently predicted clinical outcomes following TEER for primary MR. When performing TEER in primary MR, optimal MR reduction seems to outweigh the impact of high transvalvular gradients.

Prognosis of Elevated Mitral Valve Pressure Gradient After Transcatheter Edge-to-Edge Repair: Systematic Review and Meta-Analysis

Elevation in mitral valve pressure gradient (MVPG) after mitral valve transcatheter edge-to-edge repair (M-TEER) is common, however, evidence on its prognosis is scarce and debatable. Thus, this study aims to investigate the impact of increased MVPG after M-TEER on outcomes. Studies reporting the associations between the elevated MVPG after M-TEER and outcomes were identified in a systematic search of published literatures. Associations were pooled by meta-analysis using a random-effects model. The primary outcome was the composite of all-cause mortality and heart failure (HF) hospitalization. Seven observational studies with 2,730 patients (mean age, 77.7 ± 9.3 years; male, 64.4%; functional mitral regurgitation [MR], 65.2%) were eligible for the present analysis. M-TEER was performed entirely using the MitraClip system (Abbott), followed by 29.7% of patients having increased MVPG. Elevated postprocedural MVPG was not associated with a higher risk of the primary outcome, compared to low MVPG [hazard ratio (HR) = 1.22; 95% confidence interval (CI) 0.95-1.58; p = 0.12; I2 = 53.5%). However, the prognosis of elevated MVPG was observed in degenerative MR patients (HR = 1.37; 95% CI 1.03-1.84; p = 0.03; I2 = 0%), whereas not in functional MR patients. Patients with low MVPG + high residual MR had a higher risk of the primary outcome than those with high MVPG + low residual MR after M-TEER (HR = 1.50; 95% CI 1.10-2.03; p = 0.01; I2 = 13%). In conclusion, elevated MVPG seems to predict adverse outcomes mainly in patients with degenerative MR. Future studies are needed to prove these findings.

Impact of Mitral Regurgitation Etiology on Mitral Surgery After Transcatheter Edge-to-Edge Repair: From the CUTTING-EDGE Registry

BACKGROUND

Although >150,000 mitral TEER procedures have been performed worldwide, the impact of MR etiology on MV surgery after TEER remains unknown.

OBJECTIVES

The authors sought to compare outcomes of mitral valve (MV) surgery after failed transcatheter edge-to-edge repair (TEER) stratified by mitral regurgitation (MR) etiology.

METHODS

Data from the CUTTING-EDGE registry were retrospectively analyzed. Surgeries were stratified by MR etiology: primary (PMR) and secondary (SMR). MVARC (Mitral Valve Academic Research Consortium) outcomes at 30 days and 1 year were evaluated. Median follow-up was 9.1 months (IQR: 1.1-25.8 months) after surgery.

RESULTS

From July 2009 to July 2020, 330 patients underwent MV surgery after TEER, of which 47% had PMR and 53.0% had SMR. Mean age was 73.8 ± 10.1 years, median STS risk at initial TEER was 4.0% (IQR: 2.2%-7.3%). Compared with PMR, SMR had a higher EuroSCORE, more comorbidities, lower LVEF pre-TEER and presurgery (all P < 0.05). SMR patients had more aborted TEER (25.7% vs 16.3%; P = 0.043), more surgery for mitral stenosis after TEER (19.4% vs 9.0%; P = 0.008), and fewer MV repairs (4.0% vs 11.0%; P = 0.019). Thirty-day mortality was numerically higher in SMR (20.4% vs 12.7%; P = 0.072), with an observed-to-expected ratio of 3.6 (95% CI: 1.9-5.3) overall, 2.6 (95% CI: 1.2-4.0) in PMR, and 4.6 (95% CI: 2.6-6.6) in SMR. SMR had significantly higher 1-year mortality (38.3% vs 23.2%; P = 0.019). On Kaplan-Meier analysis, the actuarial estimates of cumulative survival were significantly lower in SMR at 1 and 3 years.

CONCLUSIONS

The risk of MV surgery after TEER is nontrivial, with higher mortality after surgery, especially in SMR patients. These findings provide valuable data for further research to improve these outcomes.

Three-year outcomes for transcatheter repair in patients with mitral regurgitation from the CLASP study

BACKGROUND

Mitral valve transcatheter edge-to-edge repair (M-TEER) is an effective option for treatment of mitral regurgitation (MR). We previously reported favorable 2-year outcomes for the PASCAL transcatheter valve repair system.

OBJECTIVES

We report 3-year outcomes from the multinational, prospective, single-arm CLASP study with analysis by functional MR (FMR) and degenerative MR (DMR).

METHODS

Patients with core-lab determined MR ≥ 3+ were deemed candidates for M-TEER by the local heart team. Major adverse events were assessed by an independent clinical events committee to 1 year and by sites thereafter. Echocardiographic outcomes were evaluated by the core laboratory to 3 years.

RESULTS

The study enrolled 124 patients, 69% FMR; 31% DMR (60% NYHA class III-IVa, 100% MR ≥ 3+). The 3-year Kaplan-Meier estimate for survival was 75% (66% FMR; 92% DMR) and freedom from heart failure hospitalization (HFH) was 73% (64% FMR; 91% DMR), with 85% reduction in annualized HFH rate (81% FMR; 96% DMR) (p < 0.001). MR ≤ 2+ was achieved and maintained in 93% of patients (93% FMR; 94% DMR) and MR ≤ 1+ in 70% of patients (71% FMR; 67% DMR) (p < 0.001). The mean left ventricular end-diastolic volume (181 mL at baseline) decreased progressively by 28 mL [p < 0.001]. NYHA class I/II was achieved in 89% of patients (p < 0.001).

CONCLUSIONS

The 3-year results from the CLASP study demonstrated favorable and durable outcomes with the PASCAL transcatheter valve repair system in patients with clinically significant MR. These results add to the growing body of evidence establishing the PASCAL system as a valuable therapy for patients with significant symptomatic MR.

Prognostic Value of Tricuspid Valve Gradient After Transcatheter Edge-to-Edge Repair: Insights From the TriValve Registry

BACKGROUND

Data regarding the impact of the tricuspid valve gradient (TVG) after tricuspid transcatheter edge-to-edge repair (TEER) are scarce.

OBJECTIVES

This study sought to evaluate the association between the mean TVG and clinical outcomes among patients who underwent tricuspid TEER for significant tricuspid regurgitation.

METHODS

Patients with significant tricuspid regurgitation who underwent tricuspid TEER within the TriValve (International Multisite Transcatheter Tricuspid Valve Therapies) registry were divided into quartiles based on the mean TVG at discharge. The primary endpoint was the composite of all-cause mortality and heart failure hospitalization. Outcomes were assessed up to the 1-year follow-up.

RESULTS

A total of 308 patients were included from 24 centers. Patients were divided into quartiles of the mean TVG as follows: quartile 1 (n = 77), 0.9 ± 0.3 mm Hg; quartile 2 (n = 115), 1.8 ± 0.3 mm Hg; quartile 3 (n = 65), 2.8 ± 0.3 mm Hg; and quartile 4 (n = 51), 4.7 ± 2.0 mm Hg. The baseline TVG and the number of implanted clips were associated with a higher post-TEER TVG. There was no significant difference across TVG quartiles in the 1-year composite endpoint (quartiles 1-4: 35%, 30%, 40%, and 34%, respectively; P = 0.60) or the proportion of patients in New York Heart Association class III to IV at the last follow-up (P = 0.63). The results were similar after adjustment for clinical and echocardiographic characteristics (composite endpoint quartile 4 vs quartile 1-quartile 3 adjusted HR: 1.05; 95% CI: 0.52-2.12; P = 0.88) or exploring post-TEER TVG as a continuous variable.

CONCLUSIONS

In this retrospective analysis of the TriValve registry, an increased discharge TVG was not significantly associated with adverse outcomes after tricuspid TEER. These findings apply for the explored TVG range and up to the 1-year follow-up. Further investigations on higher gradients and longer follow-up are needed to better guide the intraprocedural decision-making process.

Transcatheter edge-to-edge mitral valve repair in mitral regurgitation: current status and future prospects

INTRODUCTION

Mitral regurgitation (MR) is associated with substantial morbidity and mortality. Within the past 15 years, mitral valve edge-to-edge repair (M-TEER) has developed from an experimental approach to a guideline-recommended, safe, and effective treatment option for patients with severe primary or secondary mitral regurgitation.

AREAS COVERED

This review covered relevant publications of M-TEER and summarizes the development of M-TEER devices within the last 15 years. It outlines anatomical challenges which drove the evolution of M-TEER devices, provides an overview about the current state of clinical application and research, and offers an outlook into the future of transcatheter mitral valve treatment.

EXPERT OPINION

The development and refinement of new M-TEER device generations offer the possibility to treat a wide range of mitral valve anatomies. Choosing the best device for the individual anatomic properties of the patients and considering comorbidities is the key to maximized MR reduction, minimalized complication rates, and thus optimized postinterventional prognosis. Independent from prognostic implications, quality of life has become an important patient-centered outcome that can be improved by M-TEER in virtually all patients treated.

Outcomes in Patients With High Transmitral Gradient After Mitral Valve Transcatheter Edge-to-Edge Repair for Mitral Regurgitation

Despite being highly effective in reducing residual mitral regurgitation and improving outcomes, mitral valve transcatheter edge-to-edge repair (MV-TEER) may be associated with high postprocedural residual mitral gradient (rMG). Conflicting results have been reported regarding the relation between rMG and adverse events. This study aimed to evaluate the predictors and the impact of elevated rMG after MV-TEER on clinical events in patients with functional mitral regurgitation (FMR) at 2 years follow-up. We selected a cohort of 864 patients with FMR who were treated with MV-TEER enrolled in the multicentre Italian Society of Interventional Cardiology (GISE) registry of transcatheter treatment of mitral valve regurgitation (GIOTTO). Patients were stratified into tertiles according to rMG. The primary clinical end point was a composite of all-cause death and hospitalization because of heart failure at 2-year follow-up. Overall, 269 patients (31.5%) with an rMG <3 mm Hg, 259 (30.3%) with an rMG ≥3/<4 mm Hg, and 326 (38.2%) with an rMG ≥4 mm Hg were considered. At multivariate logistic regression, ischemic FMR etiology, baseline MG, and the number of implanted clips were independent predictors of an rMG ≥4 mm Hg. Clinical follow-up was available in 570 patients (63.2%). Patients with an rMG ≥4 mm Hg experienced higher rates of the composite end point than patients of the other tertiles (51.1%, vs 42.3% vs 40.8% log-rank test: p = 0.033). In multivariate Cox's regression, both rMG ≥4 mm Hg (hazard ratio 1.54, 95% confidence interval 1.14 to 2.08) and residual mitral regurgitation ≥2+ (hazard ratio 1.36, 95% confidence interval 1.01 to 1.83) were independent predictors of adverse events at 2-year follow-up. In conclusion, we demonstrated that real-world patients who underwent MV-TEER who show an rMG ≥4 mm Hg are at higher risk of death or hospitalization because of heart failure during a 2-year follow-up. Further studies will be needed to confirm our results.

Transcatheter Mitral Valve Repair or Replacement: Competitive or Complementary?

Over the last two decades, transcatheter devices have been developed to repair or replace diseased mitral valves (MV). Transcatheter mitral valve repair (TMVr) devices have been proven to be efficient and safe, but many anatomical structures are not compatible with these technologies. The most significant advantage of transcatheter mitral valve replacement (TMVR) over transcatheter repair is the greater and more reliable reduction in mitral regurgitation. However, there are also potential disadvantages. This review introduces the newest TMVr and TMVR devices and presents clinical trial data to identify current challenges and directions for future research.