Routine microaxial left ventricular support during nonemergent high-risk PCI: an updated systematic review and meta-analysis with Bayesian and grade methodologies.

INTRODUCTION: Microaxial left ventricular support (MLVS; Impella, Abiomed) is increasingly used during nonemergent high-risk percutaneous coronary intervention (HR-PCI), although randomized evidence remains limited and device-related complications are a concern. METHODS: PubMed/MEDLINE, Scopus, Web of Science, and the Cochrane Library were searched from inception through March 2026 for randomized and comparative observational studies of MLVS versus control during nonemergent HR-PCI. Random-effects meta-analysis, subgroup and sensitivity analyses, Bayesian modeling, risk-of-bias assessment, and GRADE were performed. RESULTS: Ten studies including 7,875 patients were analyzed. MLVS was not associated with lower all-cause mortality overall (RR 1.17, 95% CI 0.81-1.67; I2 = 82.1%). Exploratory analyses showed higher mortality estimates in randomized trials (RR 1.44, 95% CI 1.05-1.97) and studies of planned pre-PCI support (RR 1.52, 95% CI 1.17-1.97). Bayesian analysis yielded a median RR of 1.14 (95% CrI 0.80-1.65; Pr[RR > 1]=77.2%). Myocardial infarction, stroke/cerebrovascular events, and MACE/MACCE were not significantly different, while major bleeding was increased (RR 1.92, 95% CI 1.14-3.23). CONCLUSIONS: Current evidence does not support routine prophylactic MLVS during nonemergent HR-PCI. Selective use may remain appropriate, but further adequately powered randomized trials are needed. PROTOCOL REGISTRATION: PROSPERO CRD420261358349.