Surgical treatment for life-threatening acute myocardial infarction: A prospective protocol

Objective: In this paper we describe the preliminary results of a prospective operative protocol designed in order to define the role of emergent myocardial revascularization in extensive acute myocardial infarction and in post-infarction cardiogenic shock. Methods: Entry criteria are: age < 75 years; anterior acute myocardial infarction with ST segment elevation > 4 leads, infero-postero-lateral or inferior and right ventricular, within 6 h from onset of chest pain; post-infarction cardiogenic shock within 3 h from onset of shock. From November 1994 to July 1995, after emergency coronary arteriography, 23 patients were treated by coronary artery bypass grafting. Fifteen were operated for extensive acute myocardial infarction (group A, mean age 54.1 ± 9.4 years) and eight for post-infarction cardiogenic shock (group B mean age 65.0 ± 8.7 years). Mean time from onset was 4.4 ± 1.3 h in group A and 2.2 ± 0.8 h in group B. Mean left ventricular ejection fraction was 39.3 ± 12.7% in group A and 22.6 ± 3.5% in group 13. Six out of eight group B patients needed intraaortic balloon counterpulsation preoperatively, and 2/8 cardiopulmonary resuscitation. Results: Myocardial revascularization consisted in 3.4 ± 1.1 grafts in group A (vein grafts, except for 8 patients who also received a left internal thoracic artery graft) and 3.3 ± 1.1 vein grafts in group B. All patients in group B and 3/15 (20%) in group A underwent intraortic balloon counterpulsation. In-hospital death occurred in 1/15 (6.7%) patients of group A and in 4/8 (50%) patients of group B. At a mean follow-up of 4.1 ± 3.4 months for group A and of 3.9 ± 2.2 months for group B left ventricular ejection fraction was 43.4 ± 9.0% in group A and 35.7 ± 13.1% in group B. Conclusions: Experience of 9 months with this prospective protocol showed its effectiveness in the management of critically ill patients with acute coronary occlusion leading to low mortality rate in acute myocardial infarction and improved survival rate in post-infarction cardiogenic shock.