Associations of the Prognostic Nutritional Index with the Cardiac Function and Survival after Cardiac Resynchronization Therapy

Objective The relationship between changes in the nutritional status after cardiac resynchronization therapy (CRT) and the prognosis has not been fully elucidated. We aimed to evaluate the changes in the nutritional status as assessed by the prognostic nutritional index (PNI) and their associations with the improvement in the cardiac function and subsequent clinical outcomes. Methods The study population consisted of 119 patients with a CRT-device. They were divided into 2 groups, based on whether their PNI had increased at 6 months after CRT-device implantation (positive ΔPNI group, n=73) or not (negative ΔPNI group, n=46). The left ventricular (LV) end-diastolic volume (LVEDV), LV end-systolic volume (LVESV), and LV ejection fraction (LVEF) were measured before and six months after CRT-device implantation. We compared the changes in the cardiac function and prevalence of adverse events (re-hospitalization due to worsening heart failure or all cause death) between the two groups. Results In the positive ΔPNI group, the LVEDV (186±93 mL vs. 149±71 mL, p<0.05) and LVESV (134±75 mL vs. 98±62 mL, p<0.05) were significantly decreased 6 months after CRT-device implantation. In addition, the LVEF (31±11% vs. 37±12%, p<0.05) was significantly increased after CRT-device implantation. In the negative ΔPNI group, no significant changes were observed in any echocardiographic parameters. During a median follow-up period of 914 days, there were 67 (56.3%) adverse events. In the Kaplan-Meier analysis, the positive ΔPNI group was associated with a lower risk of adverse events than the negative ΔPNI group (50.6% vs. 65.2%, log-rank p=0.042). Conclusion Our results suggest that improvement in the cardiac function after CRT-device implantation is associated with increases in the PNI, resulting in favorable outcomes.