Acute coronary syndrome may occur with in-stent restenosis and is associated with adverse outcomes (the PRESTO trial).

Patients with de novo acute coronary syndromes (ACSs) have a higher rate of adverse cardiac events and recurrent revascularization after percutaneous coronary interventions compared with patients who have stable angina. However, it is not known if an ACS presentation in patients with in-stent restenosis (ISR) is associated with a worse prognosis. Using the large PRESTO database of patients with ISR, we compared outcomes after successful percutaneous coronary intervention in 824 patients who presented with ACS with 617 patients who had stable angina. In-hospital and 9-month follow-up for myocardial infarction, target vessel revascularization, death, and a combined outcome of major adverse cardiac events (MACEs) were obtained. Follow-up angiographic results were also compared in those patients included in the angiographic substudy (140 patients with ACS and 99 with stable angina). Patients with ISR who presented with ACS were older and less often men, with higher incidences of diabetes, hypertension, tobacco use, previous coronary artery bypass graft surgery, and congestive heart failure. In-hospital complications were rare and similar in the 2 groups. At follow-up, patients with ACS had higher incidences of target vessel revascularization (33% vs 21%, p <0.001), MACEs (35% vs 22%, p <0.001), and angiographic restenosis (> or =50% narrowing, 56% vs 42%, p = 0.043). In multivariate analysis, after adjusting for baseline differences, an ACS presentation was associated with a higher incidence of long-term MACEs (odds ratio 1.66, 95% confidence interval 1.27 to 2.18, p <0.001). In conclusion, an ACS presentation in patients with ISR is associated with a higher incidence of recurrent adverse cardiovascular events and angiographic restenosis.