Abstract
BACKGROUND: Non-ST-elevation myocardial infarction (NSTEMI) is a prevalent acute coronary syndrome among the elderly, a population often underrepresented in clinical trials. Frailty, a marker of physiologic vulnerability, may influence the risks and benefits of percutaneous coronary intervention (PCI) in these patients. AIM: To evaluate the impact of frailty status on in-hospital outcomes among patients aged ≥ 75 years with NSTEMI undergoing PCI. METHODS: We conducted a retrospective cohort study using the 2021-2022 National Inpatient Sample to evaluate the impact of frailty on in-hospital outcomes among NSTEMI patients aged ≥ 75 years undergoing PCI. Patients were stratified into three frailty categories using the Hospital Frailty Risk Score. Multivariable logistic and generalized linear models with interaction terms assessed the association between frailty and clinical outcomes. RESULTS: Among 456690 NSTEMI admissions, 37.95%, 50.71%, and 11.34% were categorized as low, intermediate, and high frailty, respectively. PCI use declined with increasing frailty (35.0% in low vs 7.5% in high; P < 0.001). Adjusted mortality was lower with PCI across all frailty levels [odds ratios (OR): 0.27 (low), 0.37 (intermediate), 0.43 (high); all P < 0.001]. However, the mortality benefit was attenuated with increasing frailty (interaction OR: 1.56 and 1.83 for intermediate and high vs low frailty; P < 0.001). Frailty was independently associated with higher odds of complications, including acute kidney injury, respiratory failure, delirium, and bleeding. PCI was associated with shorter hospital stays in low (-0.90 days) but longer in the high-frail category (+2.47 days; P < 0.001), and increasing frailty correlated with significantly higher hospital charges. CONCLUSION: In elderly NSTEMI patients, PCI conferred a survival benefit across all frailty strata, although with a diminishing magnitude as frailty increased. Frailty correlated with increased complications and healthcare resource utilization.