Introduction:Cardiac magnetic resonance (CMR) derived biventricular global function index (BVGFI) is a new CMR parameter that integrates biventricular volumes, mass, and function using clinically available CMR parameters. The associations of BVGFI with clinical outcomes in repaired tetralogy of Fallot are unknown.Methods:Patients with repaired tetralogy of Fallot who had a CMR before the occurrence of a composite outcome of death, resuscitated sudden death, or sustained ventricular tachycardia were studied. BVGFI was calculated as the average of right and left GFI. GFI was defined as (ventricular stroke volume×100)/(ventricular mean cavity volume + total ventricular myocardial volume). Ventricular mean cavity volume was defined as ([end-diastolic + end-systolic volume]/2). Cox multivariable regression analysis and classification and regression tree methodology were used.Results:Of the 736 eligible subjects (mean age at CMR 25.4±14.5 years), with a median follow-up of 28 months, 55 subjects (7.4%) reached the composite outcome (46 deaths and 9 sustained ventricular tachycardia). Independent associations with the composite outcome were as follows: BVGFI <37 (hazard ratio, 2.52; P=0.004), right ventricular end-systolic volume index >85 mL/m² (hazard ratio, 3.25; P<0.001), atrial tachycardia (hazard ratio, 2.03; P=0.021), and age at repair >2.5 years (hazard ratio, 3.37; P<0.001). Classification and regression tree analysis identified BVGFI as the most discriminatory CMR parameter associated with a high risk for adverse outcomes.Conclusions:BVGFI, a novel CMR-derived imaging biomarker combining biventricular volumes, mass, and function, may improve risk stratification for adverse clinical outcomes in patients with repaired tetralogy of Fallot.

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双心室总体功能指数与修复法洛四联症的不良结果相关

简介：心脏磁共振 (CMR) 衍生的双心室全局功能指数 (BVGFI) 是一种新的 CMR 参数，它使用临床可用的 CMR 参数整合了双心室体积、质量和功能。BVGFI 与修复法洛四联症临床结果的关联尚不清楚。方法：研究了在发生死亡、复苏性猝死或持续性室性心动过速复合结局之前进行过 CMR 的修复法洛四联症患者。BVGFI 计算为左右 GFI 的平均值。GFI定义为（心室每搏输出量×100）/（心室平均腔容积+心室心肌总容积）。心室平均腔容积定义为（[舒张末期 + 收缩末期容积]/2）。使用 Cox 多变量回归分析和分类和回归树方法。 结果：在 736 名合格受试者中（CMR 平均年龄 25.4±14.5 岁），中位随访 28 个月，55 名受试者（7.4%）达到复合结果（46 例死亡和 9 例持续性室性心动过速）。与复合结果的独立关联如下：BVGFI <37（风险比，2.52；P = 0.004），右心室收缩末期容积指数 >85 mL/m ²（风险比，3.25；P <0.001），房性心动过速（风险比，2.03；P = 0.021），修复年龄 >2.5 岁（风险比，3.37；P <0.001）。分类和回归树分析将 BVGFI 确定为与不良结局高风险相关的最具辨别力的 CMR 参数。修复法洛四联症患者。