Objectives: We sought to analyze the very late outcomes of patients treated for in-stent restenosis (ISR) according to treatment allocation and 10 prespecified variables.
Background: Long-term results (>2 years) of patients with ISR undergoing repeat coronary interventions are not well established.
Methods: The Restenosis Intrastent: Balloon angioplasty versus elective Stenting (RIBS) randomized study compared these two strategies in 450 patients with ISR. A detailed systematic protocol was used for late clinical follow-up.
Results: At one-year follow-up (100% of patients), the event-free survival was similar in the two groups (77% stent implantation [ST] arm, 71% balloon angioplasty [BA] arm, log-rank p = 0.19). Additional long-term clinical follow-up (median 4.3 years, range 3 to 5 years) was obtained in 98.6% of patients. During this time 22 additional patients died (9 ST arm, 13 BA arm), 7 suffered a myocardial infarction (3 ST arm, 4 BA arm), 23 required coronary surgery (11 ST arm, 12 BA arm), and 9 underwent repeat coronary interventions (4 ST arm, 5 BA arm) (nonexclusive events). At four years the event-free survival was 69% in the ST arm and 64% in the BA arm (log-rank p = 0.21). Among the 10 prespecified variables, vessel size > or = 3 mm had a major influence on the clinical outcome at four years, with better results in the ST group (hazard ratio 0.51, 95% confidence interval 0.3 to 0.89, p = 0.016).
Conclusions: Patients with ISR undergoing repeat interventions have a significant event rate at late follow-up. Continued medical surveillance should be continued after one year. Patients with large vessels have a better outcome after repeat stenting.