Very long-term outlook of acute coronary syndromes after percutaneous coronary intervention with implantation of polymer-free versus durable-polymer new-generation drug-eluting stents.

Background: Detailed long-term follow-up data on patients with acute coronary syndromes (ACS) in general, and those with ST-elevation myocardial infarction (STEMI) in particular, are limited. We aimed to appraise the long-term outlook of patients undergoing percutaneous coronary intervention (PCI) with state-of-the-art coronary stents for STEMI, other types of ACS and stable coronary artery disease (CAD), and also explore the potential beneficial impact of new-generation polymer-free drug-eluting stents (DES) in this setting.

Methods: Baseline, procedural and very long-term outcome data on patients undergoing PCI and randomized to implantation of new-generation polymer-free vs. durable polymer DES were systematically collected, explicitly distinguishing subjects with admission diagnosis of STEMI, non-ST-elevation ACS (NSTEACS), and stable CAD. Outcomes of interest included death, myocardial infarction, revascularization (i.e. patient-oriented composite endpoints [POCE]), major adverse cardiac events (MACE), and device-oriented composite endpoints (DOCE).

Results: A total of 3002 patients were included, 1770 (59.0%) with stable CAD, 921 (30.7%) with NSTEACS, and 311 (10.4%) with STEMI. At long-term follow-up (7.5±3.1 years), all clinical events were significantly more common in the NSTEACS group and, to a lesser extent, in the stable CAD group (e.g. POCE occurred in, respectively, 637 [44.7%] vs. 964 [37.9%] vs. 133 [31.5%], P<0.001). While these differences were largely attributable to adverse coexisting features in patients with NSTEACS (e.g. advanced age, insulin-dependent diabetes, and extent of CAD), the unfavorable outlook of patients presenting with NSTEACS persisted even after multivariable adjustment including several prognostically relevant factors (hazard ratio [HR] of NSTEACS vs. stable CAD 1.19 [95% confidence interval 1.03-1.38], P=0.016). Notably, even after encompassing all prognostically impactful features, no difference between polymer-free and permanent polymer drug-eluting stents appeared (HR=0.96 [0.84-1.10], P=0.560).

Conclusions: Unstable coronary artery disease, especially when presenting without ST-elevation, represents an informative marker of adverse long-term prognosis in current state-of-the-art invasive cardiology practice. Even considering admission diagnosis, and despite of using no polymer, polymer-free DES showed similar results with regards to safety and efficacy when compared with DES with permanent polymer.