Stasis Imaging Predicts the Risk of Cardioembolic Stroke Related to Acute Myocardial Infarction

Background In the setting of ST-segment elevation myocardial infarction (STEMI), imaging-based biomarkers could be useful for guiding oral anticoagulation for primary prevention of stroke. Objectives To test the efficacy of intraventricular blood stasis imaging for predicting a composite primary endpoint of cardioembolic risk during the first 6 months after STEMI. Methods The Imaging Silent Brain Infarct in Acute Myocardial Infarction (ISBITAMI, NCT02917213 ) was a prospective clinical study including patients with a first STEMI, an EF ≤ 45% and without atrial fibrillation. Patients underwent ultrasound-based stasis imaging at enrollment followed by heart and brain magnetic resonance at 1-week and at 6-month visits. From the stasis maps, we calculated the average residence time, R T , of blood inside the LV and assessed its performance to predict the primary endpoint. Apical longitudinal strain was quantified by speckle tracking. Results A total of 68 patients were univocally assigned to the primary endpoint. Of them, 19 patients suffered one or more events: 3 strokes, 5 silent brain infarctions, and 15 mural thromboses. No systemic embolisms were observed. R T (OR: 3.28, 95% CI: 1.61-6.67, p=0.001) and apical strain (OR: 1.48, 95% CI: 1.14-1.92, p= 0.002) showed complementary prognostic value. The bivariate model showed a c-index= 0.84 (0.73-0.95) a negative predictive value of 1.00 (0.93-1.00) and positive predictive value of 0.45 (0.39 - 0.80). Results were confirmed in a multiple imputation sensitivity analysis. Conventional ultrasound-based metrics were of limited predictive value. Conclusions In patients with STEMI and LV systolic dysfunction in sinus rhythm, the risk of cardioembolic stroke can be accurately predicted by echocardiography combining stasis and strain imaging.