Prevalence of Spontaneous Coronary Thrombolysis and its Relation to Left Ventricular Function

The prevalence of spontaneous recanalisation (SR) of the infarct-affected coronary artery and the subsequent effect on left ventricular and functional reserve was assessed in 50 patients 35 ± 10 days after acute myocardial infarction and compared to control patients without angiographic evidence of SR but with permanent coronary occlusion. The clinical characteristics of both groups were similar. None of the patients in either group received thrombolytic therapy. The prevalence of SR at the time of the study was 44% versus 56% permanent occlusion. The degree of residual stenosis in the SR group varied widely, from < 50% to subtotal. Neither radionuclide global left ventricular ejection fraction and left ventricular functional reserve nor cineangiographic analysis of wall motion abnormalities 35 ± 10 days post-infarction could significantly separate the SR group from patients with permanent coronary occlusion, comparable in variables such as age, history and site of infarction. Patients with inferior wall infarction, however, revealed a tendency to SR-related preservation of left ventricular function. In patients with anterior infarction no such trend was detectable. We conclude that SR occurs too late to salvage a significant amount of myocardium at risk and thus to limit infarct size when compared to permanent occlusion of the infarct-affected vessel.