How previous angina influences early prognosis of patients with acute myocardial infarction

Background There is little information about how previous angina influences the complications of myocardial infarction and also contradictory results have been reported. Objective To compare the risk factors for myocardial infarction, complicati ons, performance of left ventricle, and coronary angiography findings of pa tients who had suffered acute myocardial infarction with those for patients who had not. Methods We studied 600 patients diagnosed to have suffered acute myocardial infarction. Patients are grouped into those having previously had angina f or at least 1 month preceding acute myocardial infarction (group I, n=308 p atients; 223 men and 85 women, mean age 60.4 +/- 10.6 years) and those who had not had angina (group II, n = 292 patients; 221 men and 71 women, mean age 58 +/- 9 years). The risk factors, complications (cardiogenic shock, he art failure, disturbances of rhythm and conduction, cardiac rupture and dea th), left-ventricle ejection fraction, and echocardiography and coronary an giographic findings during hospitalization are compared. Results There was no difference with respect to localization of myocardial infarction (anterior, inferior, and non-Q) between groups I and II (P > 0.0 5). Hypertension in members of group I was higher (P < 0.05). There was no statistically significant difference with respect to diabetes mellitus, hyp ercholesterolemia and cigarette smoking (P > 0.05). Heart failure (P < 0.05 ), cardiogenic shock (P < 0.01), incidence of ventricular premature systole > 3/min (P < 0.001) and atrial fibrillation (P < 0.05) were seen more prev alently in group Il than they were in group I. There was no difference betw een the two groups with respect to bundle-branch blockage and third-degree atrioventricular blockage. Incidences of ventricular fibrillation, rupture of interventricular septum (IVS) and death in hospital were higher in group II (6.2 versus 3.6%, 6.2 versus 3.2%, 2.1 versus 0.6%) but were not statis tically significant. Coronary angiography detected no statistically signifi cant difference with respect to disease in left main coronary artery, and o ne-vessel and two-vessel disease; but three-vessel disease was significantl y more prevalent in group II (P < 0.01). Conclusion Heart failure, cardiogenic shock, arrhythmia (more than three VP S within 1 min and atrial fibrillation), and three-vessel disease detected by coronary angiography were found more often in the myocardial infarct pat ients without previous angina and these differences were statistically sign ificant. In-hospital mortality and cardiac rupture were also found more com monly in this group and ejection fractions measured by echocardiography wer e found to be less, but these differences were statistically insignificant. J Cardiovasc Risk 7:135-139 (C) 2000 Lippincott Williams & Wilkins.