Cardiac free wall rupture in acute myocardial infarction: Ameliorative effect of coronary reperfusion

To investigate the pathophysiology of cardiac free wall rupture (cardiac rupture) following acute myocardial infarction (AMI), and to clarify whether reperfusion therapy prevents cardiac rupture, 1,329 cases of AMI (conventional therapy group: 807 cases and reperfusion therapy group: 533 cases) were studied retrospectively. The overall incidence of cardiac rupture was 2.3% (2.7% in the conventional therapy group vs. 1.7% in the reperfusion therapy group). Patients with cardiac rupture were divided into two subgroups according to the time interval from the onset of AMI to cardiac rupture (early rupture ≤72 h and late rupture ≥4 days). The indices of initial evolution of AMI was a significant risk of early cardiac rupture. The reperfusion therapy group showed significantly lower incidence of late rupture (0.4 vs. 1.5% in conventional therapy group; p<0.05). The incidence of cardiac rupture in the unsuccessful reperfusion therapy group was higher than that of the successful group (5.9% of 118 cases vs. 0.5% of 404 cases; p<0.05). It is concluded that the etiology of cardiac rupture following AMI cannot be explained by any single factor. Early rupture depends on the initial evolution of AMI, and early reperfusion and collateral flow prevent the late onset cardiac rapture.