We have read with great interest the study by Cantey et al1 in which they sought to assess the role of obesity in predicting post–transcatheter aortic valve replacement (TAVR) outcomes. To do so, the investigators retrospectively analyzed the data of 1,412 predominantly Asian TAVR recipients who were divided into underweight, normal, overweight, and obese using standard World Health Organization body mass index (BMI)-based classifications. Notably, when BMI groups were adjusted for baseline characteristics, there was no significant difference in the risk of 1-year morbi-mortality following the procedure, which does not support the obesity paradox in TAVR.2 Cantey et al1 attributed their finding to the competing distinct comorbidities across study cohorts that could have mutually neutralized their burden.
However, they acknowledged the potential inaccuracy of BMI in discriminating obesity groups particularly in Asian populations. Undoubtedly, the definition of obesity based exclusively on BMI is an oversimplification that can lead to incorrect stratifications and interpretations. Obesity is a complex condition with heterogeneous phenotypes differing in many anatomic, physiologic, and metabolic aspects that variations in BMI—at least alone—may not adequately reflect. In a previous study on patients with severe aortic stenosis, the 2-year post-TAVR outcomes did not differ between morbidly obese vs nonobese groups, whether unmatched or propensity matched, categorized according to BMI. Nevertheless, when obesity was defined differently (an abdominal visceral adipose tissue-to-subcutaneous adipose tissue ratio ≥1) using baseline computed tomography scan findings, it was strongly associated with increased risk of all-cause and cardiovascular mortality.3 By underestimating visceral adiposity,4 BMI may categorize TAVR recipients as being underweight or of normal weight, whereas in reality, they carry morbid fat accumulation. At the same time, BMI fails to distinguish between fat mass and lean muscle/bone mass, thus favoring overestimation of obesity status. The disadvantages of BMI become clearer in the non-Western populations because the standard thresholds for obesity should be lower,5 though such disparity is often not respected.
Consequently, the obesity paradox in TAVR could be partially due to patient misclassification where apparent obesity is identified instead of morbid clinically relevant obesity. In any case, considering BMI alone as a single obesity criterion adds another paradox that does not serve a proper understanding of the impact of this important patient-related factor on TAVR outcomes. Therefore, to avoid the BMI paradox when studying the obesity paradox, it is mandatory to incorporate various and/or more sophisticated pre-TAVR population-adapted anthropometric measures that accurately quantify pathological adiposity.
Footnotes
The authors have reported that they have no relationship relevant to the contents of this paper to disclose.
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the Author Center.
References
- 1.Cantey E.P., Samhan A., Baldridge A.S., et al. Body mass index and outcomes after transcatheter aortic valve replacement: insights from the Transpacific-TAVR registry. JACC Asia. 2025;5(9):1124–1133. doi: 10.1016/j.jacasi.2025.06.012. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Tezuka T., Higuchi R., Hagiya K., et al. Midterm outcomes of underweight patients undergoing transcatheter aortic valve implantation: insight from the LAPLACE-TAVR registry. JACC Asia. 2023;3(1):78–89. doi: 10.1016/j.jacasi.2022.08.014. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.McInerney A., Tirado-Conte G., Rodes-Cabau J., et al. Impact of morbid obesity and obesity phenotype on outcomes after transcatheter aortic valve replacement. J Am Heart Assoc. 2021;10(12) doi: 10.1161/JAHA.120.019051. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Lear S.A., Humphries K.H., Kohli S., Chockalingam A., Frohlich J.J., Birmingham C.L. Visceral adipose tissue accumulation differs according to ethnic background: results of the Multicultural Community Health Assessment Trial (M-CHAT) Am J Clin Nutr. 2007;86(2):353–359. doi: 10.1093/ajcn/86.2.353. [DOI] [PubMed] [Google Scholar]
- 5.WHO Expert Consultation Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies. Lancet. 2004;363(9403):157–163. doi: 10.1016/S0140-6736(03)15268-3. [DOI] [PubMed] [Google Scholar]