2016•The Thoracic and Cardiovascular SurgeonRequires access
Body Surface Area or Body Mass Index: which is of Greater Prognostic Value for Clinical Outcomes after Transcatheter Aortic Valve Replacement?
Mani Arsalan, Giovanni Filardo, Benjamin D. Pollock, W.-K. Kim, John J. Squiers, Johannes Blumenstein, Christoph Liebetrau, Arnaud Van Linden, H. Moellmann, Thomas Walther
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Abstract
Objectives: Inverse associations between Body Mass Index (BMI) and Body Surface Area (BSA) with mortality in patients after Transcatheter Aortic Valve Replacement (TAVR) have been reported. However, this “obesity paradox”’ is controversial, because not all TAVR series have demonstrated such a relationship. Furthermore, it remains unclear which parameter, BMI or BSA, is of greater prognostic value. The aim of this study was to investigate the association of BMI and BSA on short- and mid-term outcomes after TAVR. Methods: This prospective, observational study consisted of 917 consecutive patients undergoing TAVR at our center from 2011–2014. The association between BMI/BSA and mortality (at 30-days and 1-year) was assessed using restricted cubic spline functions in propensity-adjusted (by Society of Thoracic Surgeons (STS) risk factors) logistic and Cox proportional models, respectively. Results: The mean age of the patients was 82.6 years, with a mean STS Predicted Risk of Mortality (STS-PROM) of 6.6% ± 4.3%. Median BSA was 1.8 m 2 (IQR: 1.7, 2.0) and the median BMI 27.0 kg/m 2 (IQR: 24.2, 31.0). Mean follow-up time was 297 days. Throughout the study period, 150 (16.4%) patients died; 72 (7.9%) patients died within 30 days of TAVR. After risk-adjustment, the association between body constitution and 30-day mortality was not significant for either measure (BMI p = 0.25; BSA p = 0.32). However, BMI ( p = 0.02), but not BSA ( p = 0.19), was significantly associated with 1-year mortality (see Fig. 1). There was no association between stroke, vascular complications, or length of stay with BMI/BSA. Conclusion: No significant association between body constitution and 30-day mortality after TAVR was detected. However, at 1-year, lower BMI was associated with decreased survival. Thus, despite the trend toward implementing BSA, instead of BMI, in risk score calculation, BMI seems to be more suitable for TAVR patients. Fig. 1 1-year probability of mortality.