Late percutaneous coronary intervention for the totally occluded infarct-related artery: A meta-analysis of the effects on cardiac function and remodeling

Background: Late percutaneous coronary intervention (PCI) of a totally occluded infarct-related artery (IRA) in stable patients is currently not recommended based on the lack of clear clinical benefits in randomized controlled trials. We sought to perform a systematic review and meta-analysis of randomized controlled trials comparing PCI with optimal medical therapy in patients with IRA occlusion more than 12 hr after onset of acute myocardial infarction (AMI), focusing on left ventricular function and remodeling. Methods and Results: PubMed, CENTRAL, and mRCT were searched for eligible studies. Studies were included in the analysis if they were randomized controlled trials comparing conservative medical management with PCI performed at least 12 hr after the onset of symptoms of AMI, and data on left ventricular ejection fraction (LVEF) at baseline and follow-up were available. Studies were excluded if randomization occurred less than 12 hr after symptom onset, or if patients were hemodynamically unstable. Change in LVEF was the primary outcome of interest, with changes in left ventricular end-diastolic volume index (LVEDVI) and end-systolic volume index (LVESVI) analyzed as secondary endpoints. We retrieved five studies in which baseline and follow up LVEF data were available enrolling a total of 648 patients: 342 patients randomized to PCI and 306 to medical treatment. There was a statistically significant difference in LVEF changes over time favoring PCI (+3.1%, 95% CI +1.0 to +5.2, P = 0.0004). In addition, there were statistically significant differences changes in both LVEDVI (-5.1 ml in favor of PCI, 95% CI of -9.4 to -0.8, P = 0.020) and LVESVI (-5.3 ml in favor in PCI, 95% CI of -8.3 to -2.4, P = 0.0005). Conclusions: This meta-analysis suggests that late revascularization of an occluded IRA may improve left ventricular systolic function and remodeling, supporting the "open artery hypothesis." The reason why these changes have not resulted in clinical benefits in large clinical trials is subject to debate. © 2008 Wiley-Liss, Inc