Background: Therapeutic hypothermia has been established to improve survival in patients following cardiac arrest; yet the impact of body mass index (BMI) and gender on survival post hypothermia is lesser known. Given the obesity paradox in heart failure and the gender differences in cardiovascular outcomes, we hypothesized that men and higher BMI patients would have better survival post therapeutic hypothermia than women and lower BMI patients.
Methods: We retrospectively evaluated 183 patients who underwent therapeutic hypothermia following resuscitation at our two large academic centers from 1/2012 to 9/2014. Logistic regression analysis was used to assess for survival based upon BMI, gender, and comorbidities.
Results: The average BMI was 30.5 (standard deviation 9.7 kg/m2). There were 67% men (n=122). Therapeutic hypothermia was performed in 75% patients (n=138) for cardiac arrest, while the rest were cooled for neurologic indications. Mortality post therapeutic hypothermia was 60% (n=110). There was a significantly higher mortality for patients with BMI >30kg/m2 compared to BMI ≤30kg/m2 [Odds Ratio OR 1.94 (95% Confidence Intervals CI 1.04, 3.62), p=0.034]. There was no difference in mortality based upon gender [OR 1.57 (95% CI 0.8, 2.9), p= 0.166] or other comorbidities.
Conclusions: BMI >30kg/m2 was a significant risk factor for mortality post therapeutic hypothermia protocol, while gender was not a factor. Larger studies will be needed to validate these findings.