Peter L M Kerkhof1, Peter M van de Ven2, Byungwon Yoo3, Richard A Peace4, Guy R Heyndrickx5, Neal Handly6. 1. Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands. Electronic address: plm.kerkhof@VUmc.nl. 2. Department Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands. 3. Department Clinical Pharmacology, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea. 4. Nuclear Medicine Dept., Royal Victoria Infirmary, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK. 5. Cardiovascular Center, Onze-Lieve-Vrouw Clinic, Aalst, Belgium. 6. Department Emergency Medicine, Drexel University College of Medicine, Philadelphia, PA, USA.
Abstract
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
Authors: Willeke R Naaktgeboren; Wim G Groen; Judy N Jacobse; Lars C Steggink; Annemiek M E Walenkamp; Wim H van Harten; Martijn M Stuiver; Neil K Aaronson; Berthe M P Aleman; Peter van der Meer; Michael Schaapveld; Gabe S Sonke; Jourik A Gietema; Flora E van Leeuwen; Anne M May Journal: JACC CardioOncol Date: 2022-04-19