Malnutrition Among Heart Failure Outpatients
What are the prevalence, clinical associations, and prognostic consequences of malnutrition in ambulatory patients with heart failure (HF)?
The study authors applied the geriatric nutritional risk index (GNRI; a score of >98 was considered normal; scores of 92-98, 82-91, and <82 reflect mild, moderate, and severe malnutrition, respectively), controlling nutritional status score (CONUT; a score of 0-1 is considered normal; scores of 2-4, 5-8, and 9-12 reflect mild, moderate, and severe malnutrition, respectively), and prognostic nutritional index (PNI; a score >38 is considered normal; scores of 35-38 and <35 reflect moderate and severe malnutrition, respectively, and there is no “mild” category) to consecutive patients referred with suspected HF to a clinic serving a local population (n = 550,000). They phenotyped HF patients as reduced ejection fraction (HFrEF: left ventricular EF [LVEF] <40%, or at least moderate LV systolic dysfunction by visual inspection on echocardiography if LVEF was not available) or normal EF (HFnEF: LVEF ≥40%, or better than, or equal to, mild to moderate LV systolic dysfunction by visual inspection on echocardiography if LVEF was not available, and N-terminal pro–B-type natriuretic peptide [NT-proBNP] >125 ng/L). Patients with LVEF ≥40% and NT-proBNP ≤125 ng/L were considered not to have HF. Patients with HF were stratified by plasma NT-proBNP concentration: ≤400, 401-1,000, 1,001-2,000, 2,001-4,000, and >4,000 ng/L. Patients were classified into five body mass index (BMI) (kg/m2) categories: underweight (BMI <18.5), normal (BMI 18.5-24.9), overweight (BMI 25.0-29.9), obese (BMI 30.0-39.9), and morbidly obese (BMI ≥40). The primary endpoint was all-cause mortality.
The final study cohort was comprised of 3,386 HF patients (61% men; median age, 75 years; interquartile range [IQR], 67-81 years, median NT-proBNP 1,103 ng/l [IQR, 415-2,631 ng/L]). In about 35% of the patients, LVEF was <40%. Using scores for GNRI ≤91, CONUT >4, and PNI ≤38, the investigators found that 6.7%, 10.0%, and 7.5% of patients were moderately or severely malnourished, respectively, and 57% were at least mildly malnourished by at least 1 score. Worse scores were most strongly related to older age, lower BMI, worse symptoms and renal function, atrial fibrillation, anemia, and reduced mobility. The prevalence of moderate to severe malnutrition measured by any of the three indices was much higher in patients with plasma NT-proBNP >4,000 ng/L. Not surprisingly, the highest prevalence of malnutrition was found in patients who were underweight (BMI <18.5 kg/m2; 1.4% of patients with HF). A substantial proportion of patients with BMI ≥30 kg/m2 (36% of patients with HF) were malnourished defined by CONUT (50%) or PNI (5%) scores, but none by GNRI. During a median follow-up of 1,573 days (IQR, 702-2,799 days), 51% of the patients (n = 1,723) patients died: 351 (10%), 600 (18%), and 818 (24%) after 1, 2, and 3 years, respectively. For patients moderately or severely malnourished, 1-year mortality was 28% for CONUT, 41% for GNRI, and 36% for PNI, compared with 9% for those with mild malnutrition or normal nutritional status. A model including only age, urea, and logNT-proBNP, predicted 1-year survival (C-statistic, 0.719) and was slightly improved by adding nutritional indices (up to 0.724; p < 0.001), but not BMI.
The study authors concluded that malnutrition is common among outpatients with HF and is strongly related to increased mortality.
The findings of this single-center study are important because they suggest that screening for malnutrition is an important tool in the assessment of HF, and potentially improving the nutritional status should improve the prognosis. Larger studies are needed to validate these important findings, particularly to determine whether GNRI, CONUT, and PNI add incremental value to serum albumin and/or the frailty index in predicting poor outcomes. Important characteristics of the malnutrition phenotype include elderly, male gender, anemia, atrial fibrillation, decreased renal function, decreased mobility, decreased BMI, increased New York Heart Association class, increased NT-proBNP, and on loop diuretics.
Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Geriatric Cardiology, Heart Failure and Cardiomyopathies, Noninvasive Imaging, Prevention, Anticoagulation Management and Atrial Fibrillation, Atrial Fibrillation/Supraventricular Arrhythmias, Acute Heart Failure, Chronic Heart Failure, Heart Failure and Cardiac Biomarkers, Echocardiography/Ultrasound
Keywords: Anemia, Atrial Fibrillation, Atrial Function, Body Mass Index, Echocardiography, Frail Elderly, Geriatrics, Heart Failure, Heart Failure, Systolic, Malnutrition, Natriuretic Peptide, Brain, Nutrition Assessment, Nutritional Status, Obesity, Morbid, Outpatients, Peptide Fragments, Renal Insufficiency, Secondary Prevention, Serum Albumin, Sodium Potassium Chloride Symporter Inhibitors, Stroke Volume, Thinness
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