EAARN score, a predictive score for mortality in patients receiving cardiac resynchronization therapy based on pre-implantation risk factors

Abstract

Aims: The beneficial effects of CRT in patients with advanced heart failure, wide QRS, and low LVEF have been clearly established. Nevertheless, mortality remains high in some patients. The aims of our study were to identify the predictors of mortality in patients treated with CRT and to design a risk score for mortality.

Methods and results: A cohort of 608 consecutive patients treated with CRT from 2000 to 2011 in our centre was prospectively analysed. Baseline clinical and echocardiography variables were analysed and mortality data were collected. During a mean follow-up of 36.2 ± 29.2 months, 174 patients died: 123/174 (71%) due to cardiovascular causes, 25/174 (14%) non-cardiac causes, and 26/174 (15%) unknown aetiology. In a multivariate analysis the predictors of mortality were NYHA class IV [hazard ratio (HR) 2.54, 95% confidence interval (CI) 1.7-3.7, P < 0.001], glomerular filtration rate (GFR) <60 mL/min/1.73 m2 (HR 1.61, 95% CI 1.14-2.30, P = 0.008), AF (HR 1.67, 95% CI 1.19-2.3, P = 0.01), age ≥70 years (HR 1.44, (95% CI 1.04-2.00, P = 0.02), and LVEF <22% (HR 1.83, 95% CI 1.33-2.52, P ≤ 0.001). The EAARN score (EF, Age, AF, Renal dysfunction, NYHA class IV) summarizes the predictors. Each additional predictor increased the mortality: one predictor, HR 3.28 (95% CI 1.37-7.8, P = 0.008); two, HR 5.23 (95% CI 2.24-12.10, P < 0.001); three, HR 9.63 (95% CI 4.1-22.60, P < 0.001); and four or more, HR 14.38 (95% CI 5.8-35.65, P < 0.001).

Conclusion: The predictors of mortality have a significant add-on predictive effect on mortality. The EAARN score could be useful to stratify the prognosis of CRT patients.

Keywords: Age; Atrial fibrillation; Cardiac resynchronization therapy; Ejection fraction; Glomerular filtration rate; Mortality; NYHA functional class.