Real-time physiologic biomarker for prediction of atrial fibrillation recurrence, stroke, and mortality after electrical cardioversion: A prospective observational study

Background Left atrial appendage emptying flow velocity (LAAEV) depends largely on left atrioventricular compliance and may play a role in mediating the perpetuation of atrial fibrillation (AF) and AF-related outcomes. Methods We identified 3,251 consecutive patients with sustained AF undergoing first-time successful transesophageal echocardiography (TEE)-guided electrical cardioversion who were enrolled in a prospective registry between May 2000 and March 2012. Left atrial appendage emptying flow velocity was stratified into quartiles: ≤20.2, 20.3-33.9, 34-49.9, and ≥50 cm/s. Multivariate Cox regression models were used to identify independent predictors of AF recurrence, ischemic stroke, and all-cause mortality. Results The mean (SD) age was 69 (12.6) years and 67% were men. Compared with the fourth quartile, patients in the first-third quartiles were significantly older, had higher CHA;bsubesubbsubesub-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke/transient ischemic attack [TIA], vascular disease, age 65-74 years, sex category) scores, greater frequency of atrial spontaneous echo contrast, and AF of longer duration. Kaplan-Meier analysis showed a decreased probability of event-free survival with decreasing quartiles of LAAEV. Five-year cumulative event rates across first-fourth quartiles were 83%, 80%, 73%, and 73% (P <.001) for first AF recurrence; 7.5%, 7.0%, 4.1%, and 4.0%, for stroke (P =.01); and 31.3%, 26.1%, 24.1%, and 19.4%, for mortality (P <.001), respectively. Multivariate Cox regression analysis revealed an independent association of the first and second quartiles with AF recurrence (P <.001 and P <.001, respectively) and stroke (P =.03, and P =.04, respectively), and of the first quartile with mortality (P =.003). Conclusions Patients with decreased LAAEV have an increased risk of AF recurrence, stroke, and mortality after successful electrical cardioversion. Real-time measurement of LAAEV by TEE may be a useful physiologic biomarker for individualizing treatment decisions in patients with AF.