Testing the obesity paradox in patients on long-term milrinone infusion for end-stage heart failure

Obese patients with chronic HF have a lower mortality than do non-obese patients with heart failure (HF) i.e. "obesity paradox". We sought to determine the relationship between obesity (defined by body-mass index; BMI) and survival in inotrope-dependent patients with Stage D HF.

We screened the medical records of adults with ACC/AHA stage D HF who were admitted to our institution between January, 2010 and July, 2018 who were both initiated and discharged on continuous intravenous milrinone. Patients were divided into three groups: non-obese patients (Nob-BMI < 30 kg/m²), Class 1 obese patients (Ob1-BMI 30 to 34.9 kg/m²), and class 2/3 obese patients (Ob2/3-BMI ≥ 35 kg/m²). The primary endpoint was all-cause mortality. Of the 233 patients included in the study, 154 were NOb, 39 were Ob1, and 40 were OB2/3. Age and baseline comorbidities did not differ significantly among the groups. Mean follow up was 21.8 months (Median: 12.4, IQ range: 3.6-31.3). Compared to the NOb, relative mortality (HR) was 0.68 for Ob1 patients and 1.21 for Ob2/3 patients (P = 0.30). Adjusting for age, sex, race, and medical comorbidities, relative mortality was 0.85 in the Ob1 and 1.77 in the Ob2/3 (P = 0.08).

In this retrospective study of stage D inotrope-dependent HF patients, there was trend of an "obesity paradox" with higher survival in the Ob1 group patients compared to NOb and Ob2/3 patients. Ob2/3 patients had the worst survival.