BACKGROUND: The magnitude of ST segment elevation resolution is a marker of myocardial reperfusion in patients presenting with acute myocardial infarction (AMI). Incomplete ST segment elevation resolution (ISTSR) was identified as a predictor of unfavorable outcomes in AMI patients after reperfusion therapy. The aims of our study were to describe the frequency of ISTSR in a contemporary registry of primary angioplasty (PCI) and compare the in-hospital outcomes with patients with complete ST segment elevation resolution (CSTSR). METHOD: From July 2008 to February 2009, we included 183 consecutive patients with AMI (< 24hs) from eight centers in Argentina to a prospective ST-segment elevation myocardial infarction (STEMI) registry. ISTSR was defined as a decrease < 70% of ST elevation between the baseline electrocardiogram and the electrocardiogram carried out 60 minutes after PCI. Clinical, angiographic and procedural related variables were analyzed, as well as a composite endpoint of in-hospital cardiac events (CE) including mortality, reinfarction, shock, mechanical complications and urgent target vessel revascularization. RESULTS: Incomplete resolution of ST-segment elevation 60 minutes after angioplasty was observed in 89 patients (51.5%) whereas complete resolution was evident in 84 patients (48.5%). Patients with suboptimal myocardial reperfusion had a higher rate of Killip class >1 at presentation (33.7% vs. 19%; P = 0.04), left anterior descending artery as the infarct related artery (52.8% vs. 30.9%; P = 0.005), and diffuse disease in the infarct related artery (23.6% vs. 10.7%; P = 0.008), with a trend towards higher incidence of in-hospital cardiac events (14.6% vs. 5.9%; P = 0.08) and in-hospital mortality (11.2% vs. 3.6%; P = 0.08). Multivariate analysis showed that the presence of Killip class >1 at presentation (OR 7.6; CI 95% 2.32-25.2; P = 0.0008) and complete ST segment resolution (OR 0.23; CI 95% 0.06-0.8; P = 0.02) were independent predictors of in-hospital cardiac events. CONCLUSIONS: In spite of the drugs and devices currently available there is a significant proportion of patients who do not achieve complete myocardial reperfusion after primary angioplasty as expressed by an incomplete resolution of ST segment elevation. This phenomenon is associated with a worse in-hospital outcome. The presence of hemodynamic compromise at presentation, anterior infarction, and diffuse disease in the culprit vessel are associated with suboptimal myocardial reperfusion.
Myocardial infarction; Angioplasty, transluminal percutaneous coronary; Myocardial reperfusion; Thrombolytic therapy; Electrocardiography; Argentina
