The CHA2DS2-VASc Score and Its Association with Long-Term Outcome in a Cardiac Resynchronization Therapy Population

BACKGROUND: Cardiac resynchronization therapy (CRT) is commonly used in patients with heart failure and left ventricular dyssynchrony. Several scoring systems have been tested in order to predict long-term outcome. Although intended for use in patients with atrial fibrillation, we sought to assess the performance of the CHA2DS2-VASc score in a CRT population. METHODS: Data on 796 consecutive CRT patients were retrospectively gathered from hospital records and healthcare registries. CHA2DS2-VASc scores were calculated, as well as other stratification scores for comparison. The outcomes were crude mortality, time to first heart failure hospitalization, and a composite of the 2. CHA2DS2-VASc score was evaluated against the end points with survival analyses and compared to other risk stratification scores. RESULTS: The CHA2DS2-VASc score was significantly correlated with both outcomes in univariable and multivariable analysis adjusting for other known predictors of CRT outcome (unadjusted HR 1.28, 95% CI 1.21-1.36 and HR 1.19, 95% CI 1.13-1.25 for the mortality and heart failure hospitalization end points, respectively). Its performance compared well to other validated scores for the mortality end point (Harrell's C: 0.61, range for other scoring systems: 0.57-0.65), as well as the heart failure hospitalization end point (Harrell's C: 0.57, range of other scoring systems: 0.58-0.62). It correlated to 5- and 10-year survival with an area under the curve of 0.63 and 0.73, respectively. CONCLUSION: When tested for association with outcome in a CRT population, the CHA2DS2-VASc score correlates to increased mortality and risk of heart failure hospitalization. It performs similarly to CRT-specific scores. However, the results of this study indicate that all tested scores should be used with caution in CRT patients.