Objectives. In a prospective study we evaluated whether late recanalization of the left anterior descending coronary artery (LAD) affects ventricular volume and function after anterior myocardial infarction. Background. Rersistent coronary occlusion after anterior myocardial infarction leads to ventricular dilation and heart failure. Methods. We studied 73 consecutive patients with acute anterior myocardial infarction as a first cardiac event; all had an isolated lesion or occlusion of the proximal LAD. Six patients died before hospital discharge. The 67 survivors were classified into two groups: group I (patent LAD and good distal flow, n = 40) and group II (LAD occlusion or subocclusion, n = 27). The 20 patients in group I who had significant residual stenosis and all patients in group II underwent elective percutaneous transluminal coronary angioplasty (PTCA) within 18 days of myocardial infarction. The procedure was successful in 17 patients in group I (group IB) and in 16 patients in group II (group IIA): in the remaining 11 patients of group II, patency could not be reestablished (group IIB). Left ventricular volumes, ejection fraction and a dysfunction score were measured by echocardiography on admission, before PTCA, at discharge and after 3 and 6 months. Results. Although cumulative ST segment elevation was similar in groups I and II, ejection fraction and dysfunction score were significantly worse in group II. However, ventricular function and volumes progressively improved in group IIA, whereas group IIB exhibited progressive deterioration of function (dysfunction score [mean ± SD] increased from 21 ± 6 to 25 ± 8, p <0.05; ejection fraction decreased from 43 ± 10% to 37 ± 11%, p <0.05); and end-systolic volume increased from 34 ± 10 to 72 ± 28 ml/m2, p <0.05). Patients in group IIB also had worse effort tolerance, higher heart rate at rest, lower blood pressure and significantly greater prevalence of chronic heart failure. Conclusions. Delayed PTCA of an occluded LAD can frequently restore vessel patency. Success appears to be associated with better ventricular function and a lack of chronic dilation. Large randomized studies are warranted to evaluate the effect of delayed PTCA on late mortality.
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