Late acute myocardial infarction with the previous by-pass surgery

pp 268-272

Abstract

Objectives: 1) Identify the responsable mechanism of late acute myocardial infarction in patients with previous by-pass surgery (graft occlusion or native artery). 2) General analysis of the population and type of acute myocardial infarction. 3) Consider the results of thrombolytic therapy in these patients. Methods: 111 patients with previous by-pass surgery (a year or more) enrolled in a consecutive form, with diagnosis of acute myocardial infarction who underwent coronary angiography within 3 hours and 8 days of the acute event. Results: General characteristics: sex: 103 male patients, 8 female patients; age: 43-82 years (middle 65.3); risk factors: 77 patients were smoking at the time of the infarction (42 smoked more than 30 cigarettes); 56 patients had hypertension and 21 were diabetics. The time of by-pass surgery was between one and 16 years. The type of acute myocardial infarction was Q in 68 patients (66.7 %); no Q in 43 (33.3 %); gilty vessel: 82 patients had graft occlusion (74.5 %), 19 (17.2 %) occlusion of the native artery (distal to the graft or not revascularize vessel). In 10 patients we could not identify clearly the mechanism. Thrombolytics: 14 patients; intravenous in 9 (reperfusion in 3 -30 %-), 4 intragraft (reperfusion in 2 -50 %-). Conclusions: 1) In patients with previous by-pass surgery acute myocardial infarction is frequently caused by graft occlusion (74.5 %). 2) High incidence of no Q infarction (33.3 %). 3) A very high percentage of patients smoke all though they had previous by-pass surgery. 4) All though the number of patients that received thrombolytic therapy is low, intravenous thrombolysis seems less effective in this population