Clinical and angiographic determinants of adverse cardiac events in patients with stent restenosis

Abstract

Patients with angiographically proven stent restenoses do not necessarily develop adverse cardiac events. Which clinical, procedural, or angiographic parameters relate to the development of adverse cardiac events among these patients has not been determined. This study included 155 patients (167 stented lesions) with angiographically proven restenosis (> or = 50% diameter stenosis) within the stent or at its margins in routine follow-up angiograms that was obtained at 6.5 +/- 3.6 months after successful stenting. Thirty-six patients (22%) had adverse cardiac events (including unstable angina necessitating target lesion revascularization, acute myocardial infarction, or cardiac death) during follow-up and 119 patients (78%) were event-free. These two groups of patients were compared to determine the parameters related to adverse cardiac events. Univariate determinants of adverse events included hypertension (P = 0.023), unstable angina at initial presentation (P = 0.002), target lesion in proximal left anterior descending artery (P = 0.041), TIMI grade 0-2 flow in follow-up angiograms (p < 0.001), impaired left ventricular function at follow-up (P = 0.002), follow-up minimal lumen diameter < or = 0.6 mm (P = 0.003), follow-up diameter stenosis > 75% (P = 0.005), late loss > 2 mm (P = 0.01), and loss index > 1.127 (P < 0.001). Multivariate analysis demonstrated hypertension (odds ratio, OR, = 3.6; P = 0.019), unstable angina at initial presentation (OR = 2.6; P = 0.007), TIMI grade 0-2 flow at follow-up (OR = 2.8; P = 0.05), impaired LV function at follow-up (OR = 4.2; P = 0.004), and loss index > 1.127 (OR = 3.6; P = 0.017) as independent risk factors for adverse cardiac events. Classification and regression tree analysis identified loss index > 1.127 and impaired LV function as the two strongest determinant of adverse cardiac event. Therefore, hypertensive patients whose initial clinical presentation were unstable angina should be managed carefully to optimize the angiographic results and, most importantly, followed up more closely for development of impaired LV function after coronary stenting in order to prevent the occurrence of adverse cardiac event at follow-up.