Long-Term Risk of Stroke in Myocardial Infarction Survivors: Thirty-Year Population-Based Cohort Study.
Improved survival after myocardial infarction (MI) has increased the number of patients at risk of post-MI stroke. We examined risks of ischemic stroke, intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH) in patients with MI compared with the general population.



We conducted a nationwide population-based cohort study using Danish medical registries. During 1980 to 2009, we identified all patients with a first-time inpatient diagnosis of MI and formed a sex- and age-matched comparison cohort. We computed cumulative stroke risks and adjusted stroke rate ratios with 95% confidence intervals (CIs).



We identified 258 806 patients with an MI and 1 244 773 individuals from the general population. For patients with MI, the cumulative stroke risks after 1 to 30 years were 12.6% for ischemic stroke, 1.2% for ICH, and 0.24% for SAH. During the first 30 days after MI, the adjusted stroke rate ratio was 30-fold increased for ischemic stroke (31.9; 95% CI, 28.4-35.8), 20-fold for ICH (21.8; 95% CI, 16.6-28.5), and 15-fold for SAH (16.6; 95% CI, 8.7-32.0). The adjusted stroke rate ratio remained increased during 31 to 365 days (3-fold for ischemic stroke, 2-fold for ICH, and 1.5-fold for SAH). During the ensuing 1 to 30 years, the risks remained increased for ischemic stroke (1.6; 95% CI, 1.6-1.6) but decreased to near unity for ICH (1.1; 95% CI, 1.0-1.2) and SAH (1.1; 95% CI, 0.94-1.2).



MI was a risk factor for all stroke subtypes during the first year of follow-up, but only for ischemic stroke thereafter.
From the Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark (J.S., E.H.P., M.S., L.P., V.W.H.); Department of Cardiology, Aarhus University Hospital, Skejby, Aarhus N, Denmark (J.S., M.S., H.E.B.); and Departments of Health Research and Policy (Epidemiology) (V.W.H., H.T.S.) and Neurology and Neurological Sciences (V.W.H.), Stanford University, Stanford, CA. jens.sundboll@clin.au.dk.
Jens
J
Sundbøll
From the Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark (J.S., E.H.P., M.S., L.P., V.W.H.); Department of Cardiology, Aarhus University Hospital, Skejby, Aarhus N, Denmark (J.S., M.S., H.E.B.); and Departments of Health Research and Policy (Epidemiology) (V.W.H., H.T.S.) and Neurology and Neurological Sciences (V.W.H.), Stanford University, Stanford, CA.
Erzsébet
E
Horváth-Puhó
From the Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark (J.S., E.H.P., M.S., L.P., V.W.H.); Department of Cardiology, Aarhus University Hospital, Skejby, Aarhus N, Denmark (J.S., M.S., H.E.B.); and Departments of Health Research and Policy (Epidemiology) (V.W.H., H.T.S.) and Neurology and Neurological Sciences (V.W.H.), Stanford University, Stanford, CA.
Morten
M
Schmidt
From the Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark (J.S., E.H.P., M.S., L.P., V.W.H.); Department of Cardiology, Aarhus University Hospital, Skejby, Aarhus N, Denmark (J.S., M.S., H.E.B.); and Departments of Health Research and Policy (Epidemiology) (V.W.H., H.T.S.) and Neurology and Neurological Sciences (V.W.H.), Stanford University, Stanford, CA.
Lars
L
Pedersen
From the Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark (J.S., E.H.P., M.S., L.P., V.W.H.); Department of Cardiology, Aarhus University Hospital, Skejby, Aarhus N, Denmark (J.S., M.S., H.E.B.); and Departments of Health Research and Policy (Epidemiology) (V.W.H., H.T.S.) and Neurology and Neurological Sciences (V.W.H.), Stanford University, Stanford, CA.
Victor W
VW
Henderson
From the Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark (J.S., E.H.P., M.S., L.P., V.W.H.); Department of Cardiology, Aarhus University Hospital, Skejby, Aarhus N, Denmark (J.S., M.S., H.E.B.); and Departments of Health Research and Policy (Epidemiology) (V.W.H., H.T.S.) and Neurology and Neurological Sciences (V.W.H.), Stanford University, Stanford, CA.
Hans Erik
HE
Bøtker
From the Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N, Denmark (J.S., E.H.P., M.S., L.P., V.W.H.); Department of Cardiology, Aarhus University Hospital, Skejby, Aarhus N, Denmark (J.S., M.S., H.E.B.); and Departments of Health Research and Policy (Epidemiology) (V.W.H., H.T.S.) and Neurology and Neurological Sciences (V.W.H.), Stanford University, Stanford, CA.
Henrik Toft
HT
Sørensen
D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000453:epidemiology* / Q000209:etiology; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications*; D012042:Registries; D012306:Risk; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology
myocardial infarction; risk factor; stroke; subarachnoid hemorrhage