Frailty and outcomes after percutaneous coronary intervention: a systematic review and dose–response meta-analysis

Background Frailty is a multidimensional geriatric syndrome that may amplify procedural risk and attenuate recovery after percutaneous coronary intervention, yet reported prevalence and prognostic magnitude vary across frailty instruments and clinical settings. Purpose To quantify (1) frailty prevalence by assessment instrument, (2) associations between frailty and mortality and bleeding after percutaneous coronary intervention, and (3) the dose–response relationship across frailty severity. Methods PubMed and ScienceDirect were searched from inception to 30 September 2025 for observational studies enrolling adults undergoing contemporary percutaneous coronary intervention with outcomes reported by frailty status using a defined instrument. Random-effects meta-analysis (inverse-variance) pooled adjusted relative risks; subgroup analyses were prespecified by instrument type (bedside phenotype/functional tools, Clinical Frailty Scale, and administrative/deficit scores). Dose–response analyses compared robust, pre-frail/vulnerable, and frail strata when available. Results Fifteen cohort studies comprising 14,716,621 patients were included. In bedside-assessed cohorts, the pooled frailty prevalence was 19.4% (range 7.7%–32.6%), whereas administrative coding algorithms identified high-risk frailty in 0.03%. Frailty was consistently associated with higher all-cause mortality. In studies using the Clinical Frailty Scale, frailty conferred a threefold higher mortality risk (hazard ratio 3.40, 95% confidence interval 2.23–5.16); phenotype/functional instruments showed a similar direction of effect (hazard ratio 2.18, 95% confidence interval 1.52–3.11), while administrative/deficit scores produced larger estimates (hazard ratio >7). Eight studies provided severity strata, demonstrating a graded relationship: pre-frail/vulnerable patients had intermediate risk (adjusted hazard ratios 1.70–3.82 vs robust), with further escalation in frail patients (2.37–7.81). Frailty was also associated with major bleeding after percutaneous coronary intervention (hazard ratio 3.14, 95% confidence interval 2.00–4.94). Conclusion(s) Frailty is common when measured at the bedside and is a strong, graded predictor of mortality and bleeding after percutaneous coronary intervention. Routine pre-procedure frailty assessment may improve risk stratification, shared decision-making, and tailoring of peri-procedural and post-discharge care.