Effect of Aortic Regurgitation by Cardiovascular Magnetic Resonance After Transcatheter Aortic Valve Implantation

Paravalvular Leak in Transcatheter Aortic Valve Implantation: A Review of Current Challenges and Future Directions

Transcatheter aortic valve implantation (TAVI) has emerged as a revolutionary therapeutic modality for the management of severe aortic stenosis (AS), particularly in patients who are at high or prohibitive risk for surgical aortic valve replacement (SAVR). Over the past decade, extensive clinical evidence has expanded the indications for TAVI to include intermediate- and low-risk populations, which usually represent a population of younger age, in which the most common complications of TAVI, including paravalvular leak (PVL) and pacemaker implantation, should be avoided. This review focuses on the incidence and predictors of PVL in various types of TAVI implantation, its clinical implication, and the prevention strategies to tackle this complication.

The Clinical Impact of Paravalvular Leaks With Transcutaneous Aortic Valve Implantation (TAVI) Versus Surgical Aortic Valve Replacement (SAVR): A Systematic Review and Meta-Analysis

BACKGROUND

Aortic valve stenosis is a common cardiac condition that requires intervention for symptomatic and/or prognostic reasons. The two most common interventions are surgical aortic valve replacement (SAVR) and transcatheter aortic valve implantation (TAVI). The ratio of TAVI:SAVR has increased twofold over the past few years and is now being considered in intermediate-risk patients as well. One of the significant benefits of TAVI is that it is less invasive; however, one of the drawbacks is a high paravalvular leaks (PVLs) rate compared to SAVR. To assess the impact of PVLs on survival, progression of heart failure, and the need for re-intervention.

METHOD

We conducted a comprehensive systematic literature search from the conception of TAVI 2002 until December 2022 through Embase (Ovid), MEDLINE (Ovid), Science Direct, and CENTRAL (Wiley). We followed PRISMA guidelines and checklists. Review protocol registration ID in PROSPERO: CRD42023393742.

RESULTS

We identified 28 studies that met our eligibility criteria, and only 24 studies were suitable for pooling in a meta-analysis (including their hazard ratio with a confidence interval of 95%) assessing our primary outcome (all-cause mortality). The remaining four studies were narratively synthesised. RevMan V5.4 (Version 5.4. Cochrane Collaboration, 2020) was utilised to pool meta-analysis data to assess effect estimates of PVLs in both intervention arms, using a random effect model for calculation (hazard ratio 1.14 confidence interval 95% 1.08-1.21 [p<0.0001]), with a follow-up duration between 30 days to 5 years.

CONCLUSION

Patients with mild or higher degrees of PVLs in both intervention arms incurred unfavourable outcomes. The incidence of PVLs was significantly higher with TAVI; even a mild degree led to poor quality of life and increased all-cause mortality on long-term follow-up.

Predictors and impact of low diastolic blood pressure and widened pulse pressure following transcatheter aortic valve replacement

BACKGROUND

The association between post-operative diastolic blood pressure (DBP) and pulse pressure (PP) with outcomes following transcatheter aortic valve replacement (TAVR) remains unclear. We sought to assess the prevalence, predictors, and impact of post-operative DBP and PP on presence of post-procedural aortic insufficiency (AI) and mortality in adults undergoing TAVR.

METHODS

The study population included 194 patients who underwent TAVR from 2016 to 2017 at an academic tertiary medical center, of which 176 had invasive arterial pressures available postoperatively. Low DBP and widened PP were defined as ≤40 mmHg and ≥80 mmHg respectively on invasive arterial line on post-operative day 1. Clinical outcomes of interest included post-procedural AI and 1-year all-cause mortality.

RESULTS

Post-operative low DBP and widened PP were noted in 32.4% and 58.5% of the study population. No significant association between post-operative AI and low DBP (p = 0.82) or widened PP (p = 0.32) was noted. There was a trend toward higher rates of mortality in patients with low DBP (19.3% vs 9.2%, p = 0.06) but no difference in mortality in patients with widened PP (10.7% vs 15.1%, p = 0.39) or those with ≥1+ post-procedural AI (16.7% vs 10.7%, p = 0.32). In multivariable analysis, low DBP was associated with a trend toward higher rates of 1-year mortality [odds ratio (OR) 2.43, 95% confidence interval (CI) 0.97-6.11, p = 0.06]. When excluding patients with a post-operative invasive systolic blood pressure < 80 mmHg, low DBP was associated with significantly higher risk-adjusted mortality at 1 year [OR 2.75, 95% CI (1.07-7.07), p = 0.04].

CONCLUSIONS

In this contemporary study of adults undergoing TAVR, low DBP and widened PP were widely prevalent post TAVR. Low DBP was associated with a trend toward higher rates of 1-year mortality but not with post-procedural AI.

Valve Academic Research Consortium 3: updated endpoint definitions for aortic valve clinical research

Aims 

The Valve Academic Research Consortium (VARC), founded in 2010, was intended to (i) identify appropriate clinical endpoints and (ii) standardize definitions of these endpoints for transcatheter and surgical aortic valve clinical trials. Rapid evolution of the field, including the emergence of new complications, expanding clinical indications, and novel therapy strategies have mandated further refinement and expansion of these definitions to ensure clinical relevance. This document provides an update of the most appropriate clinical endpoint definitions to be used in the conduct of transcatheter and surgical aortic valve clinical research.

Methods and results 

Several years after the publication of the VARC-2 manuscript, an in-person meeting was held involving over 50 independent clinical experts representing several professional societies, academic research organizations, the US Food and Drug Administration (FDA), and industry representatives to (i) evaluate utilization of VARC endpoint definitions in clinical research, (ii) discuss the scope of this focused update, and (iii) review and revise specific clinical endpoint definitions. A writing committee of independent experts was convened and subsequently met to further address outstanding issues. There were ongoing discussions with FDA and many experts to develop a new classification schema for bioprosthetic valve dysfunction and failure. Overall, this multi-disciplinary process has resulted in important recommendations for data reporting, clinical research methods, and updated endpoint definitions. New definitions or modifications of existing definitions are being proposed for repeat hospitalizations, access site-related complications, bleeding events, conduction disturbances, cardiac structural complications, and bioprosthetic valve dysfunction and failure (including valve leaflet thickening and thrombosis). A more granular 5-class grading scheme for paravalvular regurgitation (PVR) is being proposed to help refine the assessment of PVR. Finally, more specific recommendations on quality-of-life assessments have been included, which have been targeted to specific clinical study designs.

Conclusions 

Acknowledging the dynamic and evolving nature of less-invasive aortic valve therapies, further refinements of clinical research processes are required. The adoption of these updated and newly proposed VARC-3 endpoints and definitions will ensure homogenous event reporting, accurate adjudication, and appropriate comparisons of clinical research studies involving devices and new therapeutic strategies.

Valve Academic Research Consortium 3: Updated Endpoint Definitions for Aortic Valve Clinical Research

AIMS

The Valve Academic Research Consortium (VARC), founded in 2010, was intended to (i) identify appropriate clinical endpoints and (ii) standardize definitions of these endpoints for transcatheter and surgical aortic valve clinical trials. Rapid evolution of the field, including the emergence of new complications, expanding clinical indications, and novel therapy strategies have mandated further refinement and expansion of these definitions to ensure clinical relevance. This document provides an update of the most appropriate clinical endpoint definitions to be used in the conduct of transcatheter and surgical aortic valve clinical research.

METHODS AND RESULTS

Several years after the publication of the VARC-2 manuscript, an in-person meeting was held involving over 50 independent clinical experts representing several professional societies, academic research organizations, the US Food and Drug Administration (FDA), and industry representatives to (i) evaluate utilization of VARC endpoint definitions in clinical research, (ii) discuss the scope of this focused update, and (iii) review and revise specific clinical endpoint definitions. A writing committee of independent experts was convened and subsequently met to further address outstanding issues. There were ongoing discussions with FDA and many experts to develop a new classification schema for bioprosthetic valve dysfunction and failure. Overall, this multi-disciplinary process has resulted in important recommendations for data reporting, clinical research methods, and updated endpoint definitions. New definitions or modifications of existing definitions are being proposed for repeat hospitalizations, access site-related complications, bleeding events, conduction disturbances, cardiac structural complications, and bioprosthetic valve dysfunction and failure (including valve leaflet thickening and thrombosis). A more granular 5-class grading scheme for paravalvular regurgitation (PVR) is being proposed to help refine the assessment of PVR. Finally, more specific recommendations on quality-of-life assessments have been included, which have been targeted to specific clinical study designs.

CONCLUSIONS

Acknowledging the dynamic and evolving nature of less-invasive aortic valve therapies, further refinements of clinical research processes are required. The adoption of these updated and newly proposed VARC-3 endpoints and definitions will ensure homogenous event reporting, accurate adjudication, and appropriate comparisons of clinical research studies involving devices and new therapeutic strategies.

Hemodynamic performance of the balloon-expandable SAPIEN 3 valve as assessed by cardiac magnetic resonance

BACKGROUND

Scarce data exist on transcatheter heart valve (THV) performance evaluated by cardiac magnetic resonance (CMR) in newer generation THV patients. Furthermore, it has been suggested that echocardiographic evaluation after TAVR may inaccurately assess residual AR in some patients. This study aimed to determine the incidence and severity of aortic regurgitation (AR) assessed by CMR in patients undergoing TAVR with the SAPIEN 3 valve, and evaluate the agreement between CMR and transthoracic echocardiography (TTE) on the assessment of AR severity in such patients.

METHODS

This multicentric observational study included 146 SAPIEN 3 patients with TTE and CMR within the month following their procedure. According to the CMR regurgitation fraction (RF), AR was considered mild and moderate-severe if the RF was 15-<30% and ≥ 30%, respectively. TTE exams followed VARC-2 recommendations.

RESULTS

By CMR, SAPIEN 3 recipients displayed a mean RF of 5.0 ± 6.1%, and mild and moderate-severe AR rates of 3.4% and 0.7%, respectively. The agreement between CMR-TTE was modest (weighted κ = 0.2640, p<0.001), due to an overestimation of AR severity by TTE. A historical cohort of 139 SAPIEN XT patients with a post-procedure CMR, displayed a mean RF of 9.6 ± 10.7% and mild and moderate-severe AR rates of 18.7% and 3.6%, respectively (p < .001 vs. SAPIEN 3 group).

CONCLUSIONS

SAPIEN 3 recipients exhibited very low rates of residual AR by CMR, suggesting a surgical-like performance regarding AR with this newer generation THV. TTE tended to overestimate the severity of AR, particularly among mild AR patients.