Prognostic impact of in-stent restenosis in normal weight, overweight, and obese patients undergoing percutaneous coronary intervention

Background: Among patients undergoing percutaneous coronary intervention (PCI), in-stent restenosis (ISR) is related with a worse prognosis, while higher body mass index (BMI) values are associated with better outcomes. It is unclear whether the prognostic impact of ISR varies in function of BMI. Methods: Patients undergoing PCI at a large center from 2012 to 2019 not presenting with an acute myocardial infarction (MI) were included. Subjects with BMI < 18.5 kg/m² or treated with bare metal stents were excluded. Patients were stratified according to type of lesion treated (ISR vs. no-ISR) and into four BMI categories: normal weight (BMI 18.5–25 kg/m²), overweight (25.0–29.9 kg/m²), class I obesity (30.0–34.9 kg/m²), class II–III obesity (≥35.0 kg/m²). The primary outcome was major adverse cardiovascular events (MACE), a composite of all-cause death, MI, and target vessel revascularization (TVR) at 1 year. Results: Out of 16,234 patients, 3694 (23%) underwent PCI for ISR. ISR as compared to no-ISR was associated with a consistent increased risk of MACE within the normal weight (18.8% vs. 7.8%, adj. hazard ratio (HR): 1.99, 95% confidence interval [CI]: 1.51–2.64), overweight (19.1% vs. 6.4%, adj. HR: 2.35, 95% CI: 1.91–2.88), class I obesity (18.3% vs. 6.8%, adj. HR: 1.95, 95% CI: 1.47–2.57), and class II–III obesity (16.4% vs. 7.4%, adj. HR: 1.61, 95% CI: 1.09–2.37) groups (interaction p-value: 0.192). The ISR-related risks were mostly driven by an excess of TVR. Conclusions: At 1 year, ISR was associated with an increased risk of MACE irrespective of BMI, mostly due to an excess of TVR after ISR.