Incidence and predictors of early recurrent ischemia after successful percutaneous transluminal coronary angioplasty for acute myocardial infarction

Abstract

Two hundred forty consecutive patients with acute myocardial infarction treated within 48 hours by successful percutaneous transluminal coronary angioplasty (PTCA) were analyzed to determine the incidence and predictors of recurrent ischemic events during hospitalization. Thirty-nine patients had recurrent ischemia: 20 patients had chest pain or electrocardiographic changes requiring repeat PTCA or bypass surgery, or resulting in a second creatine kinase elevation suggestive of myocardial infarction; 12 had total occlusion of the dilated artery on follow-up angiography; and 7 had exercise-induced ischemia and ≥ 70% diameter stenosis that required PTCA or bypass surgery before hospital discharge. In-hospital mortality was 15% in the recurrent ischemia group, compared to 1% in the group without recurrent myocardial ischemia (p < 0.001). Angiographic follow-up before hospital discharge was obtained in 198 patients, including 38 of the 39 patients with ischemic events. Thus, the true incidence of recurrent ischemic events was between 39 of 199 and 39 of 240, or 16 and 20%. In multivariate analyses, recurrent ischemia was predicted by translesional gradient >25 mm Hg (p = 0.001), dissection (p = 0.01) and post-PTCA Thrombolysis in Myocardial Infarction 2 flow pattern (p = 0.016). However, even in the absence of these risk factors recurrent ischemic events occurred in 13% of patients. Post-PTCA percent diameter stenosis (whether assessed by objective or visual assessment), degree of the early systemic fibrinolytic state, post-PTCA residual minimal diameter and concomitant use of thrombolytic agents were not predictive. Thus, recurrent ischemia after successful PTCA for acute myocardial infarction occurs in 16 to 20% of patients, is significantly more common with post-PTCA translesional gradient ≥ 25 mm Hg, dissection or Thrombolysis in Myocardial Infarction 2 flow, but may also occur unpredictably.