Background: In survivors of acute myocardial infarction (AMI), an occluded infarct-related artery (IRA) is an important predictor of cardiac death (CD) and sudden death (SD). Early reperfusion of the IRA was associated with improved survival rate. The purpose of the present study was to assess if late IRA revascularization, performed 10-30 days after AMI, also has a beneficial effect on the incidence of CD and SD during an 18-month follow-up.
Material/methods: The study population consisted of 93 post-MI patients with occluded IRA on coronary angiography. The patients were divided into 2 groups according to IRA status at discharge -- revascularized (47 patients) or occluded (46 patients) -- and followed. Before revascularization, the two groups of patients did not differ in the prevalence of clinical and angiographic variables, or in the incidence of risk factors for SD. In patients who underwent angioplasty or bypass graft surgery of closed IRA, the markers of electrical instability demonstrated no significant improvement after revascularization.
Results: During the 18-month follow-up a significantly lower incidence of CD (0% vs 15%, p<0.01) and SD (0% vs 11%, p<0.03) was observed in the group of patients with revascularized IRA than in the group of patients with occluded IRA.
Conclusions: In survivors of AMI, late reperfusion of occluded IRA is associated with reduced 18-month cardiac mortality. The beneficial effect of this procedure on the incidence of sudden death, not associated with improvement in myocardial electrical stability, suggests that ischemia can be considered an important factor modulating the arrhythmogenic substrate.