Undernutrition Severity Is Associated With Worse Outcomes in Patients With Acute Myocardial Infarction

Malnutrition has been associated with inferior outcomes in patients admitted with acute myocardial infarction (AMI). However, there is a lack of data to assess if the degree of malnutrition correlates with outcome severity. We used the Nationwide Readmission Database for 2016 to 2019 in our cross-sectional study. First, we extracted all cases older than 18 years that include a primary diagnosis of AMI. Appropriate survey and domain analyses were applied to obtain the national estimates using Statistical Analysis Software 9.4. We identified 2,280,393 discharges for AMI. Malnutrition was present in 4% of the study cohort (or 89,490 cases). Half of the patients with malnutrition (or 44,919) had moderate-to-severe malnutrition. The other 44,371 (or 50%) had a milder degree of malnutrition. Patients with malnutrition were younger than those without malnutrition (mean age 72 vs 75 years, p <0.001) and were more often women (48% vs 37%, p <0.001). Patients with malnutrition had a higher prevalence of underlying heart failure, dementia, coagulopathy, and chronic (liver, renal, and lung) diseases (p <0.001). Patients with malnutrition also had a significantly higher inpatient mortality (12.5% vs 4.6%, p <0.001), length of stay (mean of 13 vs 7 days, p <0.001), and 30-day all-cause readmission rates (19% vs 13%, p <0.001). Inpatient mortality on readmission was also higher in those with malnutrition (2% vs 0.6%, p <0.001). The univariate analysis showed that the severity of malnutrition also correlated with a higher inpatient mortality (odds ratio [OR] 2.34 [2.24 to 2.46] for mild malnutrition and 3.65 [3.49 to 3.82] for advanced malnutrition). After adjusting for age, gender, heart failure, dementia, coagulopathy, chronic (liver, renal, and lung) diseases, and history of cardiovascular revascularization, the presence of malnutrition and the severity of malnutrition continued to be associated with a higher inpatient mortality than those without malnutrition (OR 1.20 [1.14 to 1.26] for mild malnutrition and OR 1.69 [1.61 to 1.78] for more severe malnutrition). In conclusion, underlying malnutrition is associated with worse outcomes in patients hospitalized with AMI. The severity of malnutrition also correlates with worse outcomes.