Dale Reid, Bahatyrevich Nataliya, Leipzig Matthew, Currie Maria Elizabeth
Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California.
Department of Surgery, University of California, Davis, Sacramento, California.
JHLT Open. 2024 Oct 28;7:100172. doi: 10.1016/j.jhlto.2024.100172. eCollection 2025 Feb.
Guidelines regarding recipient's body mass index (BMI) for heart transplant are evolving with variable cutoffs depending on the country and institution. It is imperative to provide updated nonlinear estimates of postoperative risk attributable to a recipient's BMI to evaluate the relevance of existing cutoffs.
A total of 30,787 patients were analyzed from the United Network for Organ Sharing (UNOS) database. Patients receiving an isolated heart transplant ages 18 and older since 2010 were included. Overall survival was the primary outcome. A multivariate Cox proportional hazards model was applied and included a penalized smoothing spline term for recipient BMI and risk factors such as diabetes. We assessed the overall significance of the nonlinear penalized spline terms using an asymptotic Wald test.
The cohort consisted of 662 (2.2%) BMI <18.5, 9,359 (30%) BMI 18.5 to 24.9, 10,997 (36%) BMI 25 to 29.9, 9,550 (31%) BMI 30 to 39.9, and 206 (0.7%) BMI ≥40 patients. The nonlinear spline terms for recipient BMI were statistically significant ( < 0.01). The hazard ratio (HR) appeared to grow linearly in BMI at an inflection point of BMI = 26. No inflection point was observed at either of the International Society for Heart and Lung Transplantation recommended cutoffs of BMI = 30 (HR 1.11, confidence interval [CI] 1.07-1.15) or BMI = 35 (HR 1.29, CI 1.24-1.37).
After multivariable adjustment, there is no sharp cutoff in survival risk at either BMI = 30 or BMI = 35. Unlike previously reported, postoperative survival risk grows approximately linearly in the BMI range from 26 to 40.
关于心脏移植受者体重指数（BMI）的指南不断演变，不同国家和机构的临界值各不相同。必须提供因受者BMI导致的术后风险的最新非线性估计值，以评估现有临界值的相关性。
对器官共享联合网络（UNOS）数据库中的30787例患者进行分析。纳入2010年以来接受孤立心脏移植的18岁及以上患者。总生存是主要结局。应用多变量Cox比例风险模型，纳入受者BMI的惩罚平滑样条项以及糖尿病等风险因素。我们使用渐近Wald检验评估非线性惩罚样条项的总体显著性。
该队列包括662例（2.2%）BMI<18.5、9359例（30%）BMI 18.5至24.9、10997例（36%）BMI 25至29.9、9550例（31%）BMI 30至39.9以及206例（0.7%）BMI≥40的患者。受者BMI的非线性样条项具有统计学显著性（<0.01）。风险比（HR）在BMI = 26的拐点处似乎随BMI呈线性增长。在国际心肺移植学会推荐的BMI = 30（HR 1.11，置信区间[CI] 1.07 - 1.15）或BMI = 35（HR 1.29，CI 1.24 - 1.37）临界值处均未观察到拐点。
多变量调整后，BMI = 30或BMI = 35时生存风险均无明显临界值。与先前报道不同，术后生存风险在BMI 26至40范围内大致呈线性增长。
