Impact of body mass index on 90-day survival in patients in cardiogenic shock treated with V-A ECMO: A propensity weighted analysis

Abstract

Objective

The impact of body mass index (BMI) on outcomes in refractory cardiogenic shock requiring extracorporeal membrane oxygenation (ECMO) is not well understood. We aimed to assess: (i) whether BMI is independently associated with outcomes, and (ii) whether patients with obesity (BMI > 30 kg/m²) have worse outcomes than lean counterparts.

Methods

We conducted a retrospective analysis of a prospectively maintained database from two French ECMO centers (2006–2022). The impact of BMI was evaluated using inverse propensity-score weighted (IPSW), propensity-score (PS) matching, and multivariable (MV) models, adjusting for predefined confounders. The primary outcome was 90-day mortality. The relationship between BMI and outcomes was examined using generalized additive models. Outcomes were compared across three BMI categories (<25 kg/m², 25-30 kg/m², and > 30 kg/m²). Patients treated with extracorporeal cardiopulmonary resuscitation (E-CPR) were analyzed separately.

Results

Among 921 patients, BMI was not significantly associated with 90-day mortality (HR 0.99, 95 % CI 0.97–1.01, p = 0.2), despite more ECMO-related complications. This was consistent across PS-matched, IPSW, and MV models. No significant non-linear relationship between BMI and 90-day mortality was found. Among the 204 patients with ECMO during cardiopulmonary resuscitation, those with BMI < or ≥ 30 kg/m² had 90-day mortality rates of 76 % and 71 %, respectively (p = 0.5).

Conclusion

Patients with obesity treated with ECMO for refractory cardiogenic shock have similar 90-day outcomes to their lean counterparts, despite higher respiratory, renal, and device-related complications.