Long-Term Risk of Myocardial Infarction Compared to Recurrent Stroke After Transient Ischemic Attack and Ischemic Stroke: Systematic Review and Meta-Analysis

Abstract

Background: Uncertainties remain about the current risk of myocardial infarction (MI) after ischemic stroke or transient ischemic attack.

Methods and results: We undertook a systematic review to estimate the long-term risk of MI, compared to recurrent stroke, with temporal trends in ischemic stroke/transient ischemic attack patients. Annual risks and 95% confidence intervals (95% CI) of MI and recurrent stroke were estimated using random-effect meta-analyses. We calculated incidence ratios of MI/recurrent stroke, for fatal and nonfatal events, using similar analyses. Rate ratios for MI in patients with potential risk factors compared to those without were calculated using Poisson regression.A total of 58 studies (131 299 patients) with a mean (range) follow-up of 3.5 (1.0-10.0) years were included. The risk of MI was 1.67%/y (95% CI 1.36-1.98, P_het<0.001 for heterogeneity) and decreased over time (P_int=0.021); 96% of the heterogeneity between studies was explained by study design, study period, follow-up duration, mean age, proportion of patients on antithrombotic therapy, and incident versus combined ischemic stroke/transient ischemic attack. The risk of recurrent stroke was 4.26%/y (95% CI 3.43-5.09, P_het<0.001), with no change over time (P_int=0.63). The risk of fatal MI was half the risk of recurrent strokes ending in fatality (incidence ratio=0.51, 95% CI 0.14-0.89, P_het=0.58). The risk of nonfatal MI was 75% smaller than the risk of recurrent nonfatal stroke (incidence ratio=0.25, 95%CI 0.02-0.50, P_het=0.68). Male sex, hypertension, coronary and peripheral artery diseases were associated with a doubled risk of MI.

Conclusions: After ischemic stroke/transient ischemic attack, the risk of MI is currently <2%/y, and recurrent stroke is a more common cause of death than MI.

Keywords: ischemic; myocardial infarction; stroke.

Figure 1

Evolution of the annual risks of myocardial infarction (MI) and cardiac death in IS/TIA patients over time. The size of the plot is inversely proportional to the within‐study variance. IS indicates ischemic stroke; TIA, transient ischemic attack.

Figure 2

Evolution of the annual risks of myocardial infarction (MI) and cardiac death in IS/TIA patients with the duration of study follow‐up. The size of the plot is inversely proportional to the within‐study variance. IS indicates ischemic stroke; TIA, transient ischemic attack.

Figure 3

Evolution of the annual risks of recurrent stroke and vascular death in IS/TIA patients over time. The size of the plot is inversely proportional to the within‐study variance. IS indicates ischemic stroke; TIA, transient ischemic attack.

Figure 4

Evolution of the annual risks of recurrent stroke and vascular death in IS/TIA patients with the duration of study's follow‐up. The size of the plot is inversely proportional to the within‐study variance. IS indicates ischemic stroke; TIA, transient ischemic attack.

Figure 5

Evolution of the incidence ratio of fatal and nonfatal myocardial infarction (MI)/recurrent stroke over time and with the duration of study's follow‐up. The size of the plot is inversely proportional to the within‐study variance.

Figure 6

Evolution of the incidence ratio of cardiac death/fatal recurrent stroke against study's duration of follow‐up and over time. The size of the plot is inversely proportional to the within‐study variance.

Figure 7

Forest plots of the meta‐analyses of potential risk factors for myocardial infarction (MI) in IS/TIA patients. The size of the square is proportional to the sample size of the study. CAD indicates coronary artery disease; CI, confidence interval; IS, ischemic stroke; M‐H, Mantel‐Haenszel; MI, myocardial infarction; N, number of patients; n, number of studies; P _het, P value for heterogeneity; PAD, peripheral artery disease; RR, rate ratio; TIA, transient ischemic attack.