Controlling Nutritional Status score as a predictor of ventricular arrhythmias in patients with advanced heart failure

BACKGROUND AND AIMS: Malnutrition is common among heart failure (HF) patients and may affect prognosis. Its effects on arrhythmia outcomes in HF patients remain unclear. We evaluated whether malnutrition, as assessed using the Controlling Nutritional Status (CONUT) score and Geriatric Nutritional Risk Index (GNRI), predicts ventricular arrhythmias and all-cause mortality in advanced HF patients receiving cardiac resynchronization therapy (CRT). METHODS: This retrospective single-centre cohort study enrolled 167 patients (mean age 70.9 ± 9.5 years, 67.1% male) who underwent CRT between March 2004 and February 2023. Nutritional status was assessed using the CONUT score and GNRI before CRT. Malnutrition was defined as a CONUT score ≥5 and a GNRI score <92. The primary endpoint was a composite of ventricular arrhythmias and all-cause mortality. The median follow-up period was 1536 days (IQR: 844-1825 days). RESULTS: Malnutrition was identified in 26 patients (15.6%) based on CONUT scores and in 37 patients (22.2%) based on GNRI scores, showing moderate agreement (κ = 0.44). Kaplan-Meier survival analysis demonstrated significantly higher event rates in patients with CONUT-defined malnutrition for the primary outcome (log-rank P = .0003). Conversely, GNRI-defined malnutrition exhibited only a weak trend (log-rank P = .06). When examined separately, both nutritional indices predicted all-cause mortality (CONUT: P = .0001; GNRI: P = .01), whereas only CONUT-defined malnutrition significantly predicted ventricular arrhythmias (CONUT: P = .01; GNRI: P = .38). The multivariate Cox regression analysis confirmed CONUT-defined malnutrition as an independent predictor of the primary outcome (adjusted HR: 2.33, 95% CI: 1.30-4.20, P < .01). Adding the CONUT score to the base model significantly improved discrimination (concordance index: 0.695 to 0.713, P = .008). Time-dependent receiver operating characteristic analysis showed an AUC of 0.80 (95% CI: 0.67-0.94) at 1825 days for CONUT-defined malnutrition. CONCLUSIONS: CONUT-defined malnutrition was a strong independent predictor of ventricular arrhythmias and all-cause mortality in CRT recipients. Nutritional assessment may enhance risk stratification in patients with advanced HF undergoing CRT.