Abstract 17647: Superiority of Strain over Ejection Fraction in Predicting Adverse Outcomes in Chronic Heart Failure
Background: The relevance of myocardial deformation in determining prognosis in chronic heart failure, particularly in comparison to ejection fraction (EF), remains unknown. We sought to comprehensively evaluate the relationships between strain and strain rate in multiple dimensions (longitudinal, circumferential, and radial) and adverse clinical outcomes in patients with heart failure.
Methods: In 416 patients with chronic systolic heart failure, we performed quantitative echocardiography measures of EF and longitudinal, circumferential, and radial strain and strain rate using speckle-tracking imaging. The association between these parameters and all-cause mortality, cardiac transplantation, and ventricular-assist device (VAD) placement was assessed using Cox regression models. The area under the ROC curve (AUC) was calculated at 1 year and 5 years to quantify both short-term and long-term prognostic accuracy.
Results: Over a maximum follow-up of 8 years, there were 138 events, including 80 deaths, 46 transplants, and 12 VADs. In unadjusted models, all strain and strain rate parameters were associated with adverse outcomes (Table 1). In fully adjusted models, all parameters with the exception of radial strain rate remained significantly associated. Patients in the lowest tertile of strain or strain rate parameter had an approximately 2-fold increased risk of adverse outcomes compared to the reference group (Table 1). Addition of strain to EF led to a significantly improved AUC at 1 year (0.697 versus 0.633, p=0.032) and 5 years (0.700 versus 0.638, p=0.001). In contrast, strain rate did not provide incremental value to EF.
Conclusions: Longitudinal, circumferential, and radial strain and strain rate are independently associated with prognosis in chronic heart failure. Strain, but not strain rate, provides incremental value to EF in the prediction of adverse clinical outcomes.
- © 2013 by American Heart Association, Inc.