Percutaneous coronary intervention of the infracted-related artery performed late (from 12 hours to 60 days) after acute myocardial infarction is associated with significant improvements in cardiac function and survival, according to a study in the February issue of the Journal of the American College of Cardiology.
Antonio Abbate, MD, from the Virginia Commonwealth University Pauley Heart Center in Richmond, Va., and colleagues from several European institutions, performed a systematic review and meta-analysis of randomized trials comparing percutaneous coronary intervention (PCI) of the infarct-related artery (IRA) with medical therapy in patients randomized more than 12 hours after acute myocardial infarction (AMI).
“There is ongoing uncertainty about the risk–benefit ratio of late PCI in stable patients with AMI,” the authors wrote.
Researchers retrieved 10 studies that enrolled 3,560 patients, with median time from AMI to randomization of 12 days (range 1 to 26 days), and follow-up of 2.8 years (42 days to 10 years). Randomization allocated 1,779 subjects to PCI and 1,781 to medical treatment.
There were 112 (6.3 percent) and 149 (8.4 percent) deaths in the two groups, respectively, yielding significantly improved survival in the PCI group. These benefits were associated with similarly favorable effects on cardiac remodeling, such as improved left ventricular ejection fraction in the PCI group (+4.4 percent change).
“Abbate et al have provided us with the last remaining piece of evidence in the field of total occluded IRA,” wrote Manel Sabaté, MD, PhD, an interventional cardiologist at Saint Paul University Hospital in Barcelona, Spain, in an accompanying commentary.
“Finally, all gaps can be filled in by a homogenous recommendation and level of evidence. Successful PCI of the nonreperfused IRA -- beyond 12 hours after the onset of symptoms -- with or without the presence of ischemia is associated with improved long-term survival and improved cardiac function and remodeling parameters,” Sabaté said.
Current evidence (and guidelines) support recanalization of the IRA not only acutely after MI but also in the chronic phase (greater than three months) if symptoms, ischemia, or viability of the occluded vessel are present.
“It is, therefore, questioned whether an invasive strategy may also be indicated on a continuum for latecomers after MI – more than 12 hours but less than three months,” Sabaté reasoned.
Both U.S. and European guidelines do not cover all possible scenarios and clinical situations in this time frame. In this regard, Abbate et al should be commended for their meta-analysis that has contributed to shed light on this controversial topic, he said.
The findings of a beneficial effect of late PCI proposes that revascularization of the IRA by means of PCI occurring late and beyond the window of myocardial salvage can be favorable in terms of post-AMI cardiac remodeling and all-cause mortality, according to the study.
“The clinical implications of such findings are potentially very significant. The number of patients treated within 12 hours of the onset of symptoms is still disappointing, with 8.5 percent to 40 percent of patients presenting beyond that timeframe,” the authors concluded.