MedWire News: Patients who undergo percutaneous coronary intervention (PCI) more than 12 hours after suffering an acute myocardial infarction (AMI) have improved cardiac function and survival compared with those who receive medical management, a meta-analysis indicates.
"This analysis includes the largest cohort to date and shows a statistically significant survival and remodeling advantage in favor of PCI of the infarct-related artery late after AMI," say the authors.
They add that the clinical implications of this are "potentially very significant," as the number of patients treated within 12 hours of onset of symptoms "is still disappointing, with 8.5% to 40.0% of patients presenting beyond 12 hours."
Antonio Abbate (Virginia Commonwealth University Medical Center, Richmond, USA) and colleagues conducted a systematic review and meta-analysis of randomized trials comparing PCI of the infarct-related artery with conservative medical management in patients presenting more than 12 hours and up to 60 days after an AMI.
The benefits of early PCI (<12 hours after MI) are accepted, but late (>12 hour) reperfusion remains controversial, they explain, particularly as two recent large randomized trials provided contradictory results.
The analysis included 10 trials enrolling 3560 patients who were randomly assigned to PCI (n=1779) or medical therapy (n=1781) a median of 12 days after AMI, and followed-up for a mean of 2.8 years.
As reported in the Journal of the American College of Cardiology, 112 (6.3%) of the PCI group and 149 (8.4%) of the medical-therapy group died, representing a 51% lower relative risk for dying in the PCI group compared with the medical therapy group (p=0.03).
Furthermore, the PCI group had improved cardiac remodeling compared with patients who received medical management only, as reflected by greater improvements in left ventricular (LV) ejection fraction (+4.4%, p=0.009) and LV end-diastolic ( -7.0 ml/m2, p=0.008) and end-systolic (-7.5 ml/m2, p=0.004) volume indices.
The authors comment: "The available evidence from individual trials examining the effects of late PCI has not been able to establish a clear benefit. The data from our meta-analysis suggests that a survival benefit may indeed exist."
They add: "Patient selection and adequate length of follow-up may prove to be essential in determining who is likely to benefit the most from late PCI."
In an accompanying editorial, Manel Sabaté (Saint Paul University Hospital, Barcelona, Spain) noted that most (84%) patients in the analysis showed total infarct-related artery occlusion, patients with relevant ischemia were excluded from six trials, and the degree of angiographic success was variable, as were rates of stent and glycoprotein IIb/IIIa inhibitor use.
"In this heterogeneous scenario, poorly representative of current PCI technology and outcomes, late PCI was still able to significantly reduce all-cause mortality," he wrote.
He said that the results provide the "last remaining piece of evidence in the field of total occluded infarct-related artery," and that gaps in recommendations can now be filled.
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