Effect of body mass index on the clinical outcomes of adult patients treated with venoarterial ECMO for cardiogenic shock
Abstract
Objective
Current guidelines consider obesity to be a relative contraindication to veno-arterial extracorporeal membrane oxygenation (VA-ECMO) for refractory cardiogenic shock. The authors investigated the effect of body mass index (BMI) on clinical outcomes in patients treated with VA-ECMO for cardiogenic shock.
Design
This was a retrospective and observational study.
Setting
University hospital.
Participants
The study comprised 150 adult patients who underwent VA-ECMO for cardiogenic shock.
Measurements and Main Results
The primary outcome was intensive care unit (ICU) mortality. Of the 150 included patients, 10 were underweight (BMI < 18.5 kg/m²), 62 were normal weight (BMI = 18.5-24.9 kg/m²), 34 were overweight (BMI = 25.0-29.9 kg/m²), 34 were obese class I (BMI = 30.0-34.9 kg/m²), and 10 were obese class II (BMI = 35.0-39.9 kg/m²). All-cause ICU mortality was 62% (underweight, 70%; normal weight, 53%; overweight, 65%; class I obese, 71%; class II obese, 70%). After multivariable logistic regression, BMI was not associated with ICU mortality (adjusted odds ratio (aOR) 0.99 [0.92 – 1.07], p = 0.8). Analysis by BMI category showed unfavorable mortality trends in underweight patients (aOR 3.58 [0.82-19.6], p = 0.11) and class I obese patients (aOR 2.39 [0.95 – 6.38, p = 0.07). No statistically significant differences were found between BMI categories in the incidences of complications.
Conclusion
Our results suggest that BMI alone should not be considered an exclusion criterion for VA-ECMO. The unfavorable trend observed in underweight patients could be the result of malnutrition.