Poor cardiovascular outcomes of underweight abdominal obesity in the entire population of newly diagnosed heart failure

Aims Body mass index (BMI) has been widely used as a simple tool for predicting cardiovascular risk. Here we aimed to analyse the distribution and cardiovascular outcomes according to BMI and waist circumference (WC) of the newly diagnosed heart failure (HF) patients in the entire population of the Republic of Korea for 10 years. Methods A total of 999 127 patients newly diagnosed with HF between 2012 and 2021 among the entire population were included. The epidemiologic data of each subgroup according to BMI and WC were analysed, and cardiovascular outcomes were evaluated. Results Over the decade from 2012 to 2021, the obese group accounted for 47.1% of the newly diagnosed HF population. Kaplan–Meier curve and hazard ratio of cardiovascular events in each subgroup revealed significantly increased rates of hospitalization, death from all causes, cardiovascular death, acute myocardial infarction, atrial fibrillation and composite cardiac events in the underweight group compared with other groups ( P value < 0.05). The subgroups of abdominal obesity in normal, overweight and obese patients revealed significantly high hazard ratio in almost all cardiovascular events ( P value < 0.05). Conversely, the overweight and obese groups without abdominal obesity showed the best cardiovascular outcomes. Increased cardiovascular risk was shown in groups with abdominal obesity even at the same BMI. Conclusion The cardiovascular prognosis was significantly worse in the underweight group than in the obese group, especially in the underweight abdominal obesity group. Even in the same BMI group, the prognosis is worse in the group with abdominal obesity. For a more accurate cardiovascular prognosis analysis, it is necessary to use WC along with BMI.