Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands.
Department Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands.
Int J Cardiol. 2018 Mar 15;255:105-110. doi: 10.1016/j.ijcard.2017.09.019.
Ejection fraction (EF) is commonly applied as a clinically relevant metric to assess ventricular function. The numerical value of EF depends on the interplay between end-systolic volume (ESV) and end-diastolic volume (EDV). Remarkably, the relative impact of the two constitutive components on EF received little attention.
Three patient groups not using beta-blockers were analyzed for a robust investigation into the relative contribution of ESV and EDV when assessing EF: cardiac patients (N=155) with left ventricular (LV) data obtained by biplane ventriculography, near-normals (N=276) by gated SPECT investigation, and an MRI-based post Fallot repair study including right ventricular (RV) data (N=124), besides LV. We compared various routes to evaluate EF via linear and several types of nonlinear regression with ESV as independent variable. Advanced statistics was applied to evaluate sex-specific differences.
In all cases ESV emerges as the dominant component of EF, with less (P<0.0001) impact of EDV. The relationship for EF versus ESV is nonlinear (P<0.0001), and similar for both sexes. A linear approach may be inadequate and generate erroneous statistical outcomes when comparing subgroups of patients.
Values for EF primarily depend on ESV, both for LV and RV. This relationship is essentially nonlinear, and similar for both sexes. A logarithmic approximation is convenient and often acceptable. However, application of linear regression for EF vs ESV may lead to incorrect conclusions, particularly when comparing males and females.
射血分数（EF）通常作为一种临床相关的指标来评估心室功能。EF 的数值取决于收缩末期容积（ESV）和舒张末期容积（EDV）之间的相互作用。值得注意的是，这两个组成部分对 EF 的相对影响很少受到关注。
分析了三组未使用β受体阻滞剂的患者，以深入研究在评估 EF 时 ESV 和 EDV 的相对贡献：通过双平面心室造影获得左心室（LV）数据的心脏患者（N=155）、门控 SPECT 研究的近正常人（N=276）以及包括右心室（RV）数据的基于 MRI 的法洛四联症修复研究（N=124），此外还有 LV。我们比较了通过线性和几种类型的非线性回归以 ESV 为自变量来评估 EF 的各种方法。应用高级统计学来评估性别特异性差异。
在所有情况下，ESV 都是 EF 的主要组成部分，EDV 的影响较小（P<0.0001）。EF 与 ESV 的关系是非线性的（P<0.0001），且在两性中相似。线性方法可能不充分，并且在比较患者亚组时会产生错误的统计结果。
EF 值主要取决于 ESV，无论是 LV 还是 RV。这种关系本质上是非线性的，且在两性中相似。对数近似是方便的，通常是可接受的。然而，EF 与 ESV 的线性回归应用可能会导致错误的结论，特别是在比较男性和女性时。
