Patients with atrial fibrillation and hyperthyroidism 14 or hypertrophic cardiomyopathy 15 have also been reported to be at high risk for stroke. Several studies evaluated the use of clinical and echocardiographic features for predicting stroke. These studies, which include secondary analyses of data from placebo-assigned patients in large clinical trials, have identified several high risk factors . 16 SPAF-I investigators performed an extensive analysis of baseline clinical and echocardiographic features for subsequent thromboembolism. Independent clinical risk factors identified include a history of hypertension, prior thromboembolism, and recent heart failure.
Atrial fibrillation leads to further stasis and development of left atrial thrombus.
19 Precordial echocardiographic predictors of stroke have also been identified. Global left ventricular dysfunction and left atrial size were independent thromboembolism risk factors in the SPAF-I Study. Using echocardiography, AFI identified moderate to severe left ventricular dysfunction as the only independent echocardiographic predictor of stroke. Prior to SPAF-III, however, the validity of secondarily derived risk stratification had not been proven in a prospective study. This analysis was the basis for the SPAF-III Study.