Early coronary revascularization diminishes the risk of ischemic stroke with acute myocardial infarction.

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.

Point-of-care determination of baseline platelet function as a predictor of clinical outcomes in patients who present to the emergency department with chest pain.

BACKGROUND: Increased platelet reactivity can identify patients at high risk for thrombotic events, but its clinical use has been impractical due to technical limitations. The purpose of the present study is to determine if a point-of-care measurement of platelet function in patients presenting to an emergency room with chest pain can identify those at high risk of adverse cardiac events. METHODS: Platelet function was measured using the Ultegra-RPFA in 201 patients presenting to the emergency department with the primary complaint of chest pain and either known coronary disease or at least one cardiac risk factor. The primary endpoint was any major adverse cardiac events (MACE) [cardiac death, myocardial infarction (MI), re-admission for coronary revascularization] 6 months post-enrollment. RESULTS: Platelet function at baseline ranged from 44 to 315 platelet activation units (PAU) (mean 175+/-6). Seventy-six patients experienced MACE (37.8%) by 6 months post-enrollment. Mean PAU was significantly lower in the group experiencing MACE (166+/-9 vs. 181+/-9; p=0.026). By univariate analysis, admission PAU was a significant predictor of MACE at 6 months (p=0.028). However, when adjusted for age, gender, cardiac risk factors, and a history of coronary artery disease (CAD) using multivariate logistic regression analysis, PAU was no longer significantly predictive of MACE (p=0.268). CONCLUSIONS: Point-of-care testing of platelet function deserves further study for risk assessment and individualized therapy in the future.