Role of Polymer-Free Drug-Eluting Stents in Insulin-Dependent Diabetic Patients Undergoing Percutaneous Coronary Intervention: An Observational Study

Background/Objectives: Diabetes mellitus (DM), especially insulin-dependent DM (IDDM), is strongly associated with adverse outcomes following percutaneous coronary intervention (PCI) failure. Polymer-free drug-eluting stents (PF-DESs) have emerged as a promising strategy to mitigate long-term coronary inflammation. This study aimed to evaluate the role of PF-DES, as compared to permanent-polymer DES (PP-DES) and biodegradable-polymer DES (BP-DES), in a real-world cohort of IDDM patients with obstructive coronary artery disease (CAD) undergoing PCI. Methods: IDDM patients with CAD who underwent PCI with DES at Parma University Hospital were divided into two study groups: PF-DES group vs. BP/PP-DES group. The primary endpoint was target vessel failure (TVF) at the 4-year follow-up. Survival analyses and propensity score matching (PSM) were performed to account for baseline differences. Results: A total of 170 IDDM patients with 215 treated lesions (31.6% PF-DES; 68.4% BP/PP-DES) were included. The PF-DES group experienced significantly lower rates of TVF (10.3% vs. 27.2%, p < 0.01, log rank p = 0.0072) compared with the BP/PP-DES group. PSM analysis confirmed the good clinical performance of PF-DES (HR 0.27, p < 0.01). Conclusions: In this PSM-based observational study, PF-DESs were associated with significantly lower rates of TVF compared with BP/PP-DESs in IDDM patients undergoing PCI for CAD. These suggest that PF-DES may represent a personalized PCI strategy for IDDM patients, with prognostic benefits that become increasingly pronounced as the clinical and anatomical risk profile worsens.