Frailty as an independent predictor for midterm adverse outcomes in the elderly undergoing primary percutaneous coronary intervention: A longitudinal cohort study.

Background: Frailty is associated with poor health outcomes in elderly population. However, its effect on midterm outcomes in elderly patients undergoing primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) remains unknown.

Aims: This study aimed to evaluate the association between frailty, as classified by the Clinical Frailty Scale (CFS), and midterm adverse outcomes in elderly STEMI patients after primary PCI.

Methods: In this prospective, observational, multicenter cohort study, frailty status of 426 STEMI patients aged ≥60 years undergoing primary PCI was determined using the nine-point CFS 2 weeks before the occurrence of STEMI. Patients scoring at least four points on the CFS were considered frail. The primary outcome was a composite of cardiovascular death or readmission. Secondary outcomes included cardiovascular death, cardiovascular readmission, heart failure-related death or readmission, and myocardial reinfarction. Follow-up data were collected through medical record reviews and/or telephone interviews.

Results: Of 426 elderly patients, 116 were frail. The median follow-up period was 15 months (interquartile range 5-19 months). Primary outcome events occurred in 87 (75.0%) frail and 75 (24.2%) nonfrail patients. The adjusted hazard ratio was 3.278 after model selection using the Bayesian Model Averaging approach (95% confidence interval 2.372-4.531). Multivariate Cox proportional hazard survival analysis showed that frailty was significantly associated with a higher prevalence of all secondary outcome events after adjusting for TIMI, PAMI, and CADILLAC risk scores.

Conclusions: Frailty, as defined by the CFS, was independently associated with midterm adverse outcomes in elderly patients undergoing primary PCI for STEMI.