Residual or recurrent mitral regurgitation predicts mortality following transcatheter edge-to-edge mitral valve repairCentral MessagePerspective

Objective: Although regurgitant mitral valves can be repaired through surgical or transcatheter approaches, contemporary comparative outcomes are limited with the impact of residual and recurrent mitral regurgitation (MR) on clinical outcomes being poorly defined. We hypothesized that moderate (2+) or greater residual or recurrent (RR) MR—regardless of type of repair—predicts worse clinical outcomes. Methods: Our institutional experience of 660 consecutive patients undergoing mitral valve repair (2015-2021) consisting of 393 surgical mitral valve repair (SMVr) and 267 transcatheter edge-to-edge mitral valve repair (TEER) was studied. The echocardiographic impact of RRMR (2+) following both SMVr and TEER on death and reintervention was evaluated. Results: Patients averaged 67.8 ± 14.2 years (SMVr = 63.8 ± 13.3 vs 73.6 ± 13.6, P < .0001) and 62.1% were male. Baseline clinical and demographic data were vastly different between the 2 groups. Residual or recurrent 2+ or greater MR developed in 25% (n = 68) of patients who received TEER compared with 6% (n = 25) of SMVr (P < .0001). Reintervention (9.3% vs 2.4%, P = .002) and death (37.9% vs 10.4%, P < .0001) rates at 3-years were greater among the TEER group versus SMVr group. Given the heterogeneity in baseline characteristics and difference in survival, each cohort was analyzed separately, stratified by RRMR, using multivariable modeling to identify predictors of repeat reintervention and death. There were too few events of RRMR in the SMVr cohort for evaluation. For the TEER subgroups, we observed greater long-term mortality, but not reintervention among those with RRMR., Hypertension was the strongest predictor of death and obesity was for reintervention. Conclusions: Patients undergoing SMVr and TEER are vastly different with respect to baseline patient characteristics and clinical outcomes, with patients who undergo TEER being much greater risk with poorer prognosis. Moderate or greater RRMR predicted worse long-term survival but not reintervention among patients who received TEER. Given the difference in survival among patients with RRMR following TEER, care must be taken to ensure that patients entering clinical trials and receiving TEER should have a high probability of achieving mild or less MR as seen in contemporary surgical results

Evidence of Glycolysis Up-Regulation and Pyruvate Mitochondrial Oxidation Mismatch During Mechanical Unloading of the Failing Human Heart

This study sought to investigate the effects of mechanical unloading on myocardial energetics and the metabolic perturbation of heart failure (HF) in an effort to identify potential new therapeutic targets that could enhance the unloading-induced cardiac recovery. The authors prospectively examined paired human myocardial tissue procured from 31 advanced HF patients at left ventricular assist device (LVAD) implant and at heart transplant plus tissue from 11 normal donors. They identified increased post-LVAD glycolytic metabolites without a coordinate increase in early, tricarboxylic acid (TCA) cycle intermediates. The increased pyruvate was not directed toward the mitochondria and the TCA cycle for complete oxidation, but instead, was mainly converted to cytosolic lactate. Increased nucleotide concentrations were present, potentially indicating increased flux through the pentose phosphate pathway. Evaluation of mitochondrial function and structure revealed a lack of post-LVAD improvement in mitochondrial oxidative functional capacity, mitochondrial volume density, and deoxyribonucleic acid content. Finally, post-LVAD unloading, amino acid levels were found to be increased and could represent a compensatory mechanism and an alternative energy source that could fuel the TCA cycle by anaplerosis. In summary, the authors report evidence that LVAD unloading induces glycolysis in concert with pyruvate mitochondrial oxidation mismatch, most likely as a result of persistent mitochondrial dysfunction. These findings suggest that interventions known to improve mitochondrial biogenesis, structure, and function, such as controlled cardiac reloading and conditioning, warrant further investigation to enhance unloading-induced reverse remodeling and cardiac recovery