Atrial fibrillation during acute myocardial infarction: association with all-cause mortality and sudden death after 7-year of follow-up

Abstract

Atrial fibrillation/flutter (AF/FL) is a common complication of acute myocardial infarction (AMI). Indeed, the determinants of AF/FL in AMI-patients and the association of AF/FL with mortality are not well-known. The purpose of the present study was to investigate the relationship between presence of AF/FL and mortality in patients with AMI and to report on predictors of AF/FL. We studied 505 patients enrolled in three intensive care units with definite AMI and followed up for 7 years. No patient was lost to follow-up. Patients with AF/FL during the 1st week of hospitalisation were compared with those with steady sinus rhythm. End-points were all-cause mortality and modes of death. At multivariable logistic regression analysis, elderly, body mass index, congestive heart failure (CHF), history of hypertension and plasma cholesterol (in a negative fashion) were independently associated with the presence of AF/FL. At survival analysis, after full adjustment, AF/FL was not associated with in-hospital mortality. After 7 years of follow-up, AF/FL was found to be associated with all-cause mortality [adjusted odds ratio (OR) = 1.6; 95% confidence interval (CI) = 1.2-2.3], together with age, diabetes mellitus, creatine kinase-MB isoenzyme (CK-MB) peak, CHF, estimated glomerular filtration rate and thrombolysis. At adjusted logistic polynomial regression analysis, AF/FL was found to be associated with an excess of mortality for reasons of sudden death (SD) (adjusted OR = 2.7; 95% CI = 1.2-6.4). No interaction was observed between AF/FL and medications on in-hospital mortality. For 7-year mortality, angiotensin-converting enzyme (ACE)-inhibitors and digitalis showed an independent negative (protective) interaction chiefly on SD (adjusted OR = 0.06; 95% CI = 0.01-0.74, and RR = 0.10; 95% CI = 0.02-0.58, respectively). Patients with AMI and AF/FL portend a poor prognosis in the long-term chiefly because of an excess of SD. Treatment with ACE-inhibitors and digitalis may have long-term beneficial effects on SD.