Background: Several studies evaluating the treatment of in-stent restenosis (ISR) in native coronary vessels exist. However, only few data is available on the treatment of ISR located in saphenous vein grafts (SVG). Thus, the aim of the present study was to evaluate the outcome of patients undergoing percutaneous coronary intervention (PCI) for ISR in SVG and to compare these findings to patients with ISR located in native coronary vessels.

Methods: The ISAR-DESIRE registry is an observational study including 3,565 patients being treated for DES-ISR between January 2007 and February 2021. Of these patients, 110 patients underwent PCI for ISR in SVG. The primary endpoint was the rate of target vessel myocardial infarctions (TVMI). Furthermore, the incidences of mortality and repeat revascularization were assessed. Event rates are presented as rates per 1000 patient years. Student’s t-test and chi-square test were used for analyzing significant differences between both groups.

Results: A total of 5,593 ISR lesions were treated, 186 of which were located in SVG and 5,407 in native vessels. Patients undergoing PCI for ISR in SVG were significantly older (73.4 years vs. 69.2 years, p<0.001), were less frequently female (10.9% vs. 22.0%, p=0.008) and more frequently suffered from insulin-dependent diabetes (20.9% vs. 13.3%, p=0.032) than patients who were treated for ISR in native vessels. The rate of TVMI was significantly higher for patients who underwent PCI for ISR in SVG than for patients who were treated for ISR in native vessels (38.76 vs. 23.95 events per 1,000 patient years, HR=1.62, p=0.039), the rate of target vessel revascularizations (TVR) was significantly lower for patients after PCI of ISR in bypass grafts than for patients who were treated for ISR in native coronary arteries (40.52 vs. 81.20 events per 1000 patient years, HR=0,50, p<001). 50.9% of patients after PCI due to ISR in bypass grafts and 30.9% of patients who underwent PCI due to ISR in native vessels died (96.19 vs. 56.01 events per 1000 patient years, HR=1.72, p<0.001).

Conclusion: Patients who underwent PCI of ISR in SVG showed significantly higher rates of TVMI and higher mortality as compared to patients with ISR in native vessels. Further studies will be needed to assess the optimal treatment in these high-risk patients.