Transcatheter Mitral Valve Implantation Systematic Review: Focus on Transseptal Approach and Mitral Annulus Calcification

INTRODUCTION

This systematic review was performed to evaluate the results of transcatheter mitral valve implantation (TMVI) in the native mitral valve.

EVIDENCE ACQUISITION

Medline, EMBASE, and the Cochrane Central register were systematically searched for studies that reported results of TMVI in mitral valve regurgitation and/or stenosis and mitral annular calcification. To improve the sensitivity of the literature search, we performed citation chasing in Google Scholar, Scopus, and Web of Science.

EVIDENCE SYNTHESIS

Twelve studies reporting results of TMVI in mitral regurgitation were retrieved and included 347 patients. The transseptal approach represented 28% of cases. Secondary mitral regurgitation was the predominant indication in 63% of cases. Thirty-day mortality was 11% and was lowered with the transseptal approach (7%). Technical success was 92%. Surgical conversion was needed in 5% of patients. Only one patient presented moderate to severe mitral regurgitation. These hemodynamic results were sustainable up to one year of follow-up. Three series focused on results of TMVI in mitral annulus calcification including 167 patients. Only nine patients were treated with TMVI dedicated prosthesis. Eighty-seven patients had their prosthesis delivered through a transseptal approach. Mitral stenosis was present in 63% of cases. Thirty-day mortality was 24%, and none with TMVI prosthesis. Technical success was achieved in 71% of cases and was improved by using TMVI prosthesis (89%). The main complication was left ventricular outflow tract obstruction (20%). Post procedural moderate to severe mitral regurgitation was observed in 4% of cases.

CONCLUSION

TMVI seems to be feasible, achieving good technical success and predictable and durable MR reduction.

Comparison of Mitral Valve Replacement and Repair for Degenerative Mitral Regurgitation: a Meta-analysis and Implications for Transcatheter Mitral Procedures

PURPOSE OF REVIEW

Surgical mitral valve repair is considered superior to replacement to treat primary mitral regurgitation. However, the heterogeneity of cohorts and the lack of consideration of confounding in the published literature raise potential biases. The aim of this study was to pool all available matched data comparing outcomes of mitral valve repair and replacement in the setting of primary mitral regurgitation.

RECENT FINDINGS

We searched Medline, Embase and the Cochrane Library Central Register of Controlled Trials to identify propensity-matched studies or reports with multivariable adjustment comparing repair and replacement in patients with primary mitral regurgitation. The primary outcome was all-cause mortality. DerSimonian and Laird random effects were used to perform the meta-analysis. Eight observational studies were selected including 4599 patients (3064 mitral repairs and 1535 replacements). Mean age ranged from 62 to 69 years, and the mean follow-up duration ranged between 3 and 9 years. Replacement was associated with an increased risk of long-term all-cause mortality compared to repair (HR of 1.68, 95% confidence interval 1.35-2.09, p < 0.001, τ² = 0.03). Surgical era and atrial fibrillation impacted the risk of mortality but not mitral anatomy. Neither repair nor replacement impacted significantly on the risk of re-operation after mitral surgery (HR 1.18, 95% CI 0.85-1.63, p = 0.33, τ² < 0.01). Mitral valve replacement is possibly associated with higher long-term mortality than mitral valve repair in primary mitral regurgitation but often used as a bailout option in more complex anatomy. Despite this observation, both techniques have similar risk of re-operation.

Hemodynamic Instability in Heart Failure Intensifies Age-Dependent Cognitive Decline

This review attempts to examine two key elements in the evolution of cognitive impairment in the elderly who develop heart failure. First, major left side heart parts can structurally and functionally deteriorate from aging wear and tear to provoke hemodynamic instability where heart failure worsens or is initiated; second, heart failure is a major inducer of cognitive impairment and Alzheimer's disease in the elderly. In heart failure, when the left ventricular myocardium of an elderly person does not properly contract, it cannot pump out adequate blood to the brain, raising the risk of cognitive impairment due to the intensification of chronic brain hypoperfusion. Chronic brain hypoperfusion originates from chronically reduced cardiac output which progresses as heart failure worsens. Other left ventricular heart parts, including atrium, valves, myocardium, and aorta can contribute to the physiological shortfall of cardiac output. It follows that hemodynamic instability and perfusion changes occurring from the aging heart's blood pumping deficiency will, in time, damage vulnerable brain cells linked to specific cognitive regulatory sites, diminishing neuronal energy metabolism to a level where progressive cognitive impairment is the outcome. Could cognitive impairment progress be reversed with a heart transplant? Evidence is presented detailing the errant hemodynamic pathways leading to cognitive impairment during aging as an offshoot of inefficient structural and functional heart parts and their contribution to heart failure.