Prediction of mortality in patients with implantable defibrillator using CHADS2 score: data from a prospective observational investigation.

BACKGROUND

CHADS2 (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, previous stroke/TIA) score has been validated as a risk stratification score to predict stroke in patients with atrial fibrillation (AF). The objective of this analysis was to assess whether patient risk factors, in particular CHADS2 score, identified patients at risk of mortality.

METHODS

821 patients with an implantable cardioverter defibrillator were prospectively followed-up in 11 cardiology centers. Patients were grouped in 3 groups according to pre-specified risk classes: low (CHADS2 = 0), moderate (CHADS2 = 1, 2), and high (CHADS2 = 3-6). Information on clinical status and events, were collected during scheduled and unscheduled follow-up visits. Deaths were retrieved from medical records, or through the Regional Office of Vital Statistics.

RESULTS

Over a mean follow-up of 44±26 months, 135 deaths occurred in the overall population: 6 (7.7%) in the low-risk population, 69 (13.8%) in moderate-risk patients and 60 (24.6%) in high-risk patients. Kaplan-Meier estimated of patient survival were significantly different in 3 patients groups (93.0%, 90.1%, 78.5% in low, moderate and high risk patients respectively, at 4 years P<0.001). A sub-analysis on patients without history of AF showed similar results. Multivariate regression analysis adjusted for baseline characteristics confirmed the high risk status (HR 1.88, 95% CI 1.27-2.80; P = 0.002) as an independent predictor of mortality adjusted for the baseline characteristics.

CONCLUSIONS

In our multicenter research, the long-term mortality was higher in patients with high CHADS2 score than in those with lower risk score regardless the presence of history of AF. CHADS2 score could be considered a toll to predict all causes mortality.