Short-term and long-term outcome in low body mass index patients undergoing cardiac surgery

We sought to assess the effect of low body mass index (BMI) on short- and long-term outcomes following cardiac surgery.

This is a retrospective review of a prospectively collected departmental database over a 6-year period. Patients were eligible for the study if the BMI was <25 kg/m(2). All morbidities, length of hospital stay, and short- and long-term mortality were reviewed.

There were 704 patients divided into low (n = 71) and normal (n = 633) BMI. Postoperative pulmonary complications were higher in the low BMI group compared to the normal BMI group (24% vs. 11%, P < 0.001) with a higher incidence of in-hospital mortality (10% vs. 5%). Using multiple logistic regression, low BMI was an independent risk factor for in-hospital mortality. The 1-, 3-, and 5-year survivals for the low group were 90%, 78%, and 70% compared to 94%, 86%, and 81% in the normal BMI group.

Low BMI is associated with increased morbidity and mortality following cardiac surgery. Risk scoring systems should utilize the BMI in the preoperative risk assessment with special attention to low BMI.