Incidence, Trends, and Predictors of Ischemic Stroke 1 Year After an Acute Myocardial Infarction
Background and Purpose—Ischemic stroke after acute myocardial infarction is an important complication. It is unknown whether the risk has changed because the treatment of acute myocardial infarction has improved during the past decade. There is also conflicting data about predictors of stroke risk.
Methods—To obtain the 1-year incidence of stroke after acute myocardial infarction, the Register of Information and Knowledge about Swedish Heart Intensive Care Admissions database for the years 1998 to 2008 was merged with the Swedish National Patient Register (NPR). The time trend was studied by dividing the entire time period into 5 separate periods. Independent predictors were identified using a multivariable Cox proportional hazards regression model.
Results—Between 1998 and 2008, 7185 of 173 233 patients with acute myocardial infarction had an ischemic stroke within 1 year (4.1%). There was a 20% relative risk reduction during the study period (1998–2000 versus 2007–2008) relative risk 0.80 (95% confidence interval, 0.75–0.86; P<0.001. Independent predictors of stroke were age, female sex, ST-segment–elevation myocardial infarction, previous stroke, previous diabetes mellitus, heart failure at admission, angiotensin-converting enzyme inhibitor treatment and atrial fibrillation. Reperfusion treatment with fibrinolysis and percutaneous coronary intervention and treatment with aspirin, P2Y12-inhibitors, and statins predicted a reduced risk of stroke.
Conclusions—The risk of ischemic stroke within a year after myocardial infarction is substantial but has clearly been reduced during the studied time period. The major predictive factors found to correlate well with previous investigations. Reperfusion treatment, thrombocyte aggregation inhibition, and lipid lowering are the main contributors to the observed risk reduction.
- Received April 9, 2014.
- Revision received August 22, 2014.
- Accepted August 22, 2014.
- © 2014 American Heart Association, Inc.