Castelli Risk Index-II and Repeat Revascularization After PCI in Young Patients with NSTEMI: A Retrospective...

Repeat revascularization following percutaneous coronary intervention (PCI) remains an important clinical concern in young patients. We evaluated the clinical and atherogenic factors associated with repeat revascularization in patients with premature non-ST-segment elevation myocardial infarction (NSTEMI) undergoing PCI.

This retrospective, single-center observational study included 466 consecutive patients younger than 45 years who underwent PCI for NSTEMI between January 2020 and December 2024. Atherogenic markers, including the atherogenic index of plasma (AIP), triglyceride-glucose (TyG) index, remnant cholesterol inflammation index (RCII), and Castelli risk indices I and II (CRI-I and CRI-II), were analyzed. The primary endpoint was repeat revascularization only. A nested multivariable Cox model was used to evaluate the incremental prognostic value of CRI-II beyond that of a baseline model.

Repeat revascularization occurred in 73 individuals (16%) over a median follow-up of 37.2 (22.1-51.9) months, predominantly involving non-target vessel revascularization. Patients requiring repeat revascularization had significantly higher CRI-II levels (P = 0.03). CRI-II remained independently associated with repeat revascularization after adjustment, along with hypertension and bifurcation lesions (HR: 1.30, 95% CI: 1.09-1.55, P = 0.003; HR: 2.09, 95% CI: 1.27-3.45, P = 0.004; and HR: 2.26, 95% CI: 1.19-4.27, P = 0.01, respectively); the addition of CRI-II modestly improved discrimination (Harrell's C index: 0.684 to 0.694). High CRI-II was associated with significantly higher repeat revascularization rates in the Kaplan-Meier analysis (log-rank P < 0.0001).

Elevated CRI-II was independently associated with repeat revascularization, along with hypertension and bifurcation lesions, in patients with premature NSTEMI undergoing PCI. However, CRI-II showed limited discriminatory performance, and its clinical utility for risk stratification requires external validation.