Abstract 2986: Did Early Hazard of PCI Offset Late Benefit in the Occluded Artery Trial (OAT)?
Background: The Occluded Artery Trial (OAT) showed no reduction in death, MI or class IV CHF with routine PCI in occluded infarct-related coronary arteries in stable patients identified up to 28 days post MI. PCI of non-acute coronary occlusions can be complex and hazardous. We report the magnitude and nature of PCI-related early hazard in OAT and its contribution to overall trial results.
Methods: All 1101 PCI and 1100 medical therapy (MED) assigned patients were examined by intention-to-treat. Pre-specified events (death, MI, class III or IV HF) and procedural complications during the first 48 hours after OAT enrollment (including at least 24 hours post protocol-driven PCI) were analyzed, and the OAT primary composite outcome (death, adjudicated MI, or new class IV HF) was examined at 5 and 30 days, and 60 months.
Results: Events or complications within 48 hours of enrollment occurred in 55 PCI patients (5.0%) versus 29 MED patients (2.6%) (p=0.01). PCI patients experienced more class III or IV HF events (5 vs. 2), coronary perforation (4 vs. 1), ventricular arrhythmias (6 vs. 2), CNS complications (3 vs. 2), major hemorrhage (8 vs. 1), and vascular complications (5 vs. 1). Cardiac rupture occurred in 4 patients; 2 in each arm. Events/complications were deemed PCI-related by sites in 35 of 55 patients, and by central review in 30 of 55. Attribution by sites and central review were generally concordant and indicate that the observed events excess was causally related to PCI procedures.
Conclusion: While there was no excess mortality in the PCI-treated group, events and complications during the first 48 hours were significantly more common in OAT patients assigned PCI than in those assigned MED. This early procedural hazard, however, was small in magnitude and was not followed by convergence of event rates through 60 months. We conclude the absence of net benefit for routine PCI in OAT cannot be explained by early hazard offsetting late benefit.