Association of malnutrition with all-cause and cardiovascular mortality in patients with mild to severe chronic kidney disease undergoing coronary angiography: a large multicenter longitudinal study

Purpose: Evidence on the prognostic impact of malnutrition was focused on patients with advanced kidney disease. The relationships between malnutrition and all-cause and cardiovascular mortality in patients with different severity of chronic kidney disease (CKD) have not been adequately addressed. We aimed to reveal the prevalence of malnutrition and its prognostic value in patients with different severity of CKD undergoing coronary angiography (CAG).

Methods: This was a multicenter, longitudinal, and retrospective cohort study of 12,652 patients with non-dialysis dependent CKD (defined as estimated glomerular filtration rate [eGFR] < 60 mL/min/1.73 m²) undergoing CAG from five tertiary hospitals between January 2007 and December 2020. The controlling nutritional status (CONUT) score was applied to assess nutritional status. Cox regression models and competing risk Fine and Gray models were used to examine the relationships between malnutrition, all-cause and cardiovascular mortality. Further stratified analysis was performed according to baseline CKD severity (mild, moderate and severe, defined by eGFR < 30, 30-44 and 45-59 ml/min/1.73 m²).

Results: During a median follow-up of 5.5 years (interquartile range: 3.2 to 8.6 years), 3801 patients (30.0%) died, and 2150 (17.0%) definitely died of cardiovascular disease. After controlling for confounders, patients had higher all-cause mortality (mild, moderate, and severe vs. absent: HR 1.27, 95 CI % [1.17-1.39]; HR 1.54, 95 CI % [1.39-1.71]; HR 2.22, 95 CI % [1.78-2.77], respectively; P for trend < 0.001) and cardiovascular mortality (mild, moderate and severe vs. absent: HR 1.35, 95 CI % [1.21-1.52]; HR 1.67, 95 CI % [1.45-1.92]; HR 2.10, 95 CI % [1.55-2.85], respectively; P for trend < 0.001) with the severity of malnutrition. In further stratified analysis, a similar prognostic impact of malnutrition was observed in patients with mild to moderate CKD, while mild malnutrition did not seem to have a consistent effect on severe CKD patients.

Conclusion: Malnutrition is common among patients with mild to severe CKD undergoing CAG and is strongly associated with increased risk of all-cause and cardiovascular mortality. Malnutrition seems to have a modestly stronger impact on mortality in patients with mild to moderate CKD. This study was registered at Clinicaltrials.gov as NCT05050877.