Background and purpose: Ischemic stroke is an uncommon but devastating complication of myocardial infarction (MI). It is possible that delay in the acute revascularization of these patients influences the risk of peri-MI ischemic stroke independent of size of infarction or residual ventricular function. The influence of the timing and type of revascularization on risk of ischemic stroke in the patient with MI has not previously been assessed.
Methods: We used the National Registry of Myocardial Infarction 3 and 4 databases to identify 45,997 subjects who received thrombolytic therapy and 47,876 patients who were treated with primary percutaneous transluminal coronary angioplasty for MI. In-hospital ischemic stroke occurred in 248 (0.54%) and 150 (0.31%) patients in the two groups, respectively. Patients were stratified based on time from presentation to initial therapy.
Results: A statistically significant linear relationship between time to revascularization therapy and risk of in-hospital ischemic stroke was seen on univariate analysis. A multivariate model incorporating 26 other variables showed thrombolytic therapy within 15 minutes was associated with a lower risk of ischemic stroke (odds ratio, 0.58; 95% CI, 0.36-0.94). Primary angioplasty within 90 minutes of arrival was associated with a nonsignificant trend toward lower stroke risk (odds ratio, 0.68; 95% CI, 0.41-1.12). Interestingly, his benefit of early reperfusion therapy did not appear to be related to improvements in left ventricular function.
Conclusions: Risk of in-hospital ischemic stroke with MI is closely tied to the time to revascularization with both thrombolytic and percutaneous transluminal coronary angioplasty therapies. Early revascularization is independently predictive of a lower risk of ischemic stroke, but the mechanism of this does not appear to be related to improved cardiac function. The records of 45,997 subjects who received thrombolytic therapy and 47,876 patients who were treated with primary percutaneous transluminal coronary angioplasty for myocardial infarction were analyzed to determine the relationship between time to revascularization and the occurrence of ischemic stroke. A statistically significant linear relationship between time to revascularization therapy and risk of in-hospital ischemic stroke was seen on univariate analysis. A multivariate model incorporating 26 other variables showed thrombolytic therapy within 15 minutes of presentation was associated with a lower risk of ischemic stroke, and angioplasty within 90 minutes was similarly associated with a nonsignificant trend toward lower stroke risk.