The incidence of stroke after myocardial infarction: a meta-analysis.
OBJECTIVE
While the risk of stroke after myocardial infarction (MI) is increased compared with the risk among those without MI, the magnitude of this risk remains unclear. Although numerous clinical trials have reported the incidence of stroke following MI, these are among selected populations. We reviewed cohort studies reporting the incidence of stroke after MI to better define the risk of ischemic stroke in an unselected population.


METHODS
A computerized literature search (MEDLINE and PubMed) and manual review of reference lists of identified articles were conducted. Population-based studies published from 1978-2004 with at least 100 subjects that reported number or percent of ischemic strokes experienced by MI survivors were identified. Data were extracted using standardized forms, and study quality was assessed by 2 independent reviewers. Ischemic stroke rates were reported as number of events per 1000 MI with 95% confidence intervals (CI) calculated by Poisson distribution. A combined stroke rate was calculated for in-hospital, 30 days, and 1-year post-MI using weights of 1/variance. A random-effects model also was created to estimate in-hospital stroke rate. Variability in study designs and outcome definitions limit synthesis of available data.


RESULTS
During hospitalization for the index MI, 11.1 ischemic strokes occurred per 1000 MI compared with 12.2 at 30 days and 21.4 at 1 year. Using a random-effects model, 14.5 strokes occurred per 1000 MI. Positive predictors of stroke after MI included: advanced age, diabetes, hypertension, history of prior stroke, anterior location of index MI, prior MI, atrial fibrillation, heart failure, and nonwhite race.


CONCLUSIONS
The public health implications of stroke among MI survivors, as well as the large number of MI survivors, underscore the need to be aware of this devastating complication. Further research is needed to determine the optimal stroke prevention strategies for MI survivors.
Witt
Brandi J
BJ
Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minn 55905, USA.
Ballman
Karla V
KV
Brown
Robert D
RD
Meverden
Ryan A
RA
Jacobsen
Steven J
SJ
Roger
Véronique L
VL
D016001:Confidence Intervals; D015986:Confounding Factors, Epidemiologic; D006801:Humans; D015994:Incidence; D009203:Myocardial Infarction / Q000150:complications*; D016012:Poisson Distribution; D011237:Predictive Value of Tests; D012307:Risk Factors; D012680:Sensitivity and Specificity; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology*; D014481:United States / Q000453:epidemiology