TOSCA-2: An Angiographic Substudy (Ancillary) of the Occluded Artery Trial (OAT)

BACKGROUND:

The Occluded Artery Trial (OAT) is an international study with 3200 participants. Its goal is to determine if delayed mechanical reperfusion by means of percutaneous transluminal coronary angioplasty (PTCA) and stenting reduces death, heart attacks, and hospitalization in individuals with New York Heart Association (NYHA) Class IV heart failure and a persistently occluded infarct-related artery (IRA) 3 to 28 days following a heart attack. While left ventricular (LV) function improvement has been suggested as a benefit of late reperfusion, solid evidence to support this claim is lacking. Furthermore, while stenting has reduced reocclusion rates after total occlusion PTCA, the reocclusion rate after a recent heart attack is unknown.

DESIGN NARRATIVE:

This study is a substudy of OAT and will enroll 380 participants. The primary aims of the study include the following: 1) to compare long-term patency rates between the two treatment groups (conventional medical therapy or PTCA and stenting) by means of follow-up coronary angiography one year after enrollment; and 2) to compare the change in global LV ejection fraction between the two treatment groups utilizing baseline and follow-up contrast LV angiograms. Secondary aims include the following: 1) comparison of regional wall motion and LV volumes; 2) study of the effect of reocclusion and spontaneous recanalization on LV function; and 3) study of the effect of duration of occlusion on changes in LV function after Percutaneous Coronary Intervention (PCI). The substudy will be conducted at 21 OAT study sites. The Substudy Coordinating Center (SCC) is at the University of Alberta in Edmonton, Canada. The Data Coordinating Center (DCC) is at the Maryland Medical Research Institute, which is the DCC for the OAT study. The Angiographic Core Laboratory is at the University of British Columbia.