Overweight is advantageous for heart-transplant candidates to survive the period of critically ill status.

Although extreme obesity and being underweight are both known as risk factors for mortality in patients with ventricular assist devices (VAD) and in those listed for urgent heart transplantation (HTx), the risk in patients between these extremes is controversial. We investigate the risk of mortality after their progression to critically ill status (i.e., urgency listing or VAD implantation) in patients stratified by body mass index (BMI). Risk of mortality on the waiting list was studied in group N (n = 134), normal weight, BMI: 18.5-24.9 kg/m(2); group OWt (n = 112), overweight, BMI: 25.0-29.9 kg/m(2); and group OB-I (n = 39), obesity class I, BMI: 30.0-34.9 kg/m(2). Patients' 1 year survival rate on the waiting list in group N (62.2%) and group OB-I (50.6%) was significantly lower than in group OWt (74.3%, p = 0.036 and p = 0.022, respectively). After adjustment for age, gender, serum creatinine, and primary use of VAD, group OB-I (hazard ratio [HR] 1.971, 95% confidence interval [CI] 1.062-3.659, p = 0.032) and group N (HR 1.792, 95% CI 1.058-3.036, p = 0.030) were at higher risk of mortality compared with group OWt. Overweight HTx candidates have the best prognosis on the waiting list. Obesity class I patients are encouraged to reduce their body weight to at least overweight.