Gula Lorne J, Klein George J, Hellkamp Anne S, Massel David, Krahn Andrew D, Skanes Allan C, Yee Raymond, Anderson Jill, Johnson George W, Poole Jeanne E, Mark Daniel B, Lee Kerry L, Bardy Gust H
University of Western Ontario, London, Ontario, Canada.
Am Heart J. 2008 Dec;156(6):1196-200. doi: 10.1016/j.ahj.2008.08.007. Epub 2008 Nov 6.
Ejection fraction (EF) is an important method of mortality prediction among cardiac patients, and has been used to identify the highest risk patients for enrollment in the defibrillator primary prevention trials. Evidence suggests that measures of EF by different imaging modalities may not be equivalent. In the SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial), the type of imaging modality for EF assessment was not mandated.
Baseline assessment of EF was performed using either echocardiography, radionuclide angiography (RNA), or contrast angiography. Multivariable analysis using a Cox proportional hazards model was used to examine whether the modality of assessing EF affected the likelihood of survival.
Among the 2,521 patients enrolled in SCD-HeFT, EF was measured by RNA in 616 (24%), echocardiography in 1,469 (58%), and contrast angiography in 436 (17%). Mean EF as measured by RNA was 25.1% +/- 6.9%; by echocardiography, 23.8 +/- 6.9%; and by angiography, 21.9 +/- 6.9%. These measures were significantly different (P < .001), and each pairwise comparison differed significantly (P < .001 for each). Multivariable analysis showed no significant difference in survival between patients enrolled based on RNA versus echocardiography (HR 1.06, 95% CI 0.88-1.28), RNA versus angiography (HR 1.25, 95% CI 0.97-1.62), or echocardiography versus angiography (HR 1.18, 95% CI 0.94-1.48).
Among patients enrolled in SCD-HeFT, the distribution of ejection fractions measured by radionuclide angiography differed from those measured by echocardiography or contrast angiograms. Survival did not differ according to modality of EF assessment.
射血分数（EF）是预测心脏病患者死亡率的重要方法，已被用于确定参与除颤器一级预防试验的高危患者。有证据表明，不同成像方式测量的EF值可能并不等效。在心力衰竭试验中的心脏性猝死（SCD-HeFT）研究中，并未规定评估EF的成像方式类型。
使用超声心动图、放射性核素血管造影（RNA）或造影血管造影对EF进行基线评估。采用Cox比例风险模型进行多变量分析，以检验评估EF的方式是否会影响生存可能性。
在SCD-HeFT研究纳入的2521例患者中，616例（24%）通过RNA测量EF，1469例（58%）通过超声心动图测量，436例（17%）通过造影血管造影测量。RNA测量的平均EF为25.1%±6.9%；超声心动图测量的为23.8±6.9%；造影血管造影测量的为21.9±6.9%。这些测量值存在显著差异（P<.001），且每对比较均有显著差异（每对P<.001）。多变量分析显示，基于RNA与超声心动图纳入的患者之间（风险比1.06，95%置信区间0.88-1.28）、RNA与造影血管造影之间（风险比1.25，95%置信区间0.97-1.62）或超声心动图与造影血管造影之间（风险比1.18，95%置信区间0.94-1.48）的生存率无显著差异。
在SCD-HeFT研究纳入的患者中，放射性核素血管造影测量的射血分数分布与超声心动图或造影血管造影测量的不同。根据EF评估方式的不同，生存率无差异。
