Impact of malnutrition on long-term atrial high-rate episodes, atrial fibrillation, and mortality in octogenarians with dual-chamber pacemakers

BACKGROUND: Malnutrition is common among elderly patients, often leading to severe complications. This study sheds light on the connection between malnutrition and the occurrence of atrial high-rate episodes (AHREs) and atrial fibrillation (AF), as well as all-cause mortality, in individuals aged 80 and older (octogenarians) with dual-chamber permanent pacemakers (DCPM). We employed the Controlling Nutritional Status (CONUT) score and Prognostic Nutritional Index (PNI) to assess malnutrition status effectively. METHODS: In this comprehensive retrospective analysis, we evaluated 324 octogenarians who underwent DCPM implantation and received consistent long-term monitoring at a leading tertiary cardiac clinic. Participants were classified into three nutritional status categories based on their CONUT scores. RESULTS: During long-term follow-up, the incidence of AHREs did not differ significantly across CONUT score categories; however, AF and the combined endpoint of AHREs + AF were significantly higher in the moderate-to-severe malnutrition group (p < 0.001). Long-term mortality rates increased progressively from normal CONUT scores to moderate-to-severe scores. In the adjusted Cox model, mild malnutrition was associated with a 3.6-fold increased risk of mortality (95% CI: 2.2-14.2), while moderate-to-severe malnutrition conferred a 6.0-fold increased risk (95% CI: 3.4-20.4). Mortality risk rose consistently with worsening nutritional status, with multivariable-adjusted hazard ratios of 3.2 (95% CI: 1.6-11.6) and 5.4 (95% CI: 3.0-19.6) for mild and moderate-to-severe malnutrition, respectively. The CONUT score demonstrated superior predictive value compared with the PNI for both AHREs/AF (AUC 0.73 vs. 0.69) and all-cause mortality (AUC 0.67 vs. 0.61). CONCLUSION: Malnutrition, as assessed by the CONUT score, is independently associated with long-term AHREs + AF and all-cause mortality in octogenarians undergoing standard pacemaker follow-up, with the CONUT score demonstrating greater predictive accuracy than the PNI.