Gender and age normalization and ventilation efficiency during exercise in heart failure with reduced ejection fraction
Gender and age normalization and ventilation efficiency during exercise in heart failure with reduced ejection fraction
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DOI：
10.1002/ehf2.12582
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发表时间：
2020-01-01
影响因子：
3.8
通讯作者：
Agostoni, Piergiuseppe
中科院分区：
文献类型：
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作者：
Salvioni, Elisabetta;Corra, Ugo;Agostoni, Piergiuseppe
通气量与二氧化碳生成量（VE/VCO 2）是心力衰竭（HF）中最强的心肺运动测试预后参数之一。通常以绝对值表示。目前对正常VE/VCO 2斜率值的定义是不充分的，因为它是从一小群受试者中建立的，其中女性和老年人的数量特别有限。我们的目的是在相当大的人群中定义VE/VCO 2斜率预测公式，并测试如果表示为预测值的百分比或绝对值，HF中VE/VCO 2斜率的预后能力是否不同。方法和结果我们计算了1136名健康受试者（68%男性，年龄44.9 ± 14.5，范围13-83岁）的年龄和VE/VCO 2斜率之间的线性回归。然后，我们应用年龄调整和性别调整的公式来预测包含在代谢运动试验数据中的HF患者的VE/VCO 2斜率，并结合心脏和肾脏指数评分数据库，该数据库计数了6112例患者（82%男性，年龄61.4 ± 12.8，左心室射血分数33.2 ± 10.5%，峰值VO（2）14.8 ± 4.9，mL/min/kg，VE/VCO 2斜率32.7 ± 7.7）。最后，我们评估了使用VE/VCO 2绝对值与百分比预测值是否影响HF预后预测（心血管死亡率+紧急移植或左心室辅助装置的复合终点）。我们在整个心脏和肾脏指数评分人群中以及分别在重度（峰值VO（2）< 14 mL/min/kg，n = 2919，61.1起事件/1000例患者/年）或中度（峰值VO（2）>= 14 mL/min/kg，n = 3183，19.9起事件/1000例患者/年）HF患者中进行了研究。在健康人群中，我们得到了以下方程：女性，VE/VCO_2 = 0.052 ×年龄+23.808（r = 0.192），男性，VE/VCO_2 = 0.095 ×年龄+20.227（r = 0.371）（P = 0.007）。我们应用这些公式计算VE/VCO 2预测值的百分比。VE/VCO 2斜率的2年生存预测能力很强，如果表示为绝对值或预测值的百分比（AUC分别为0.686和0.690），则相似。相比之下，在重度HF患者中，AUC在绝对值（0.637）和预测值百分比（0.650，P = 0.0026）之间存在显著差异。此外，VE/VCO 2斜率表示为预测值的百分比，允许对6.6%的峰值VO（2）< 14 mL/min/kg的患者进行重新分类（净重新分类改善= 0.066，P = 0.0015）。结论VE/VCO 2斜率预测值的百分比可增强VE/VCO 2对重度HF患者的预测能力，在预测HF时应优于绝对值。此外，广泛使用VE/VCO 2斜率表示为预测值的百分比，可以提高我们识别高风险HF患者的能力，这是一个具有最大临床相关性的目标。
Aims Ventilation vs. carbon dioxide production (VE/VCO2) is among the strongest cardiopulmonary exercise testing prognostic parameters in heart failure (HF). It is usually reported as an absolute value. The current definition of normal VE/VCO2 slope values is inadequate, since it was built from small groups of subjects with a particularly limited number of women and elderly. We aimed to define VE/VCO2 slope prediction formulas in a sizable population and to test whether the prognostic power of VE/VCO2 slope in HF was different if expressed as a percentage of the predicted value or as an absolute value. Methods and results We calculated the linear regressions between age and VE/VCO2 slope in 1136 healthy subjects (68% male, age 44.9 +/- 14.5, range 13-83 years). We then applied age-adjusted and sex-adjusted formulas to predict VE/VCO2 slope to HF patients included in the metabolic exercise test data combined with cardiac and kidney indexes score database, which counts 6112 patients (82% male, age 61.4 +/- 12.8, left ventricular ejection fraction 33.2 +/- 10.5%, peakVO(2) 14.8 +/- 4.9, mL/min/kg, VE/VCO2 slope 32.7 +/- 7.7) from 24 HF centres. Finally, we evaluated whether the use of absolute values vs. percentages of predicted VE/VCO2 affected HF prognosis prediction (composite of cardiovascular mortality + urgent transplant or left ventricular assist device). We did so in the entire cardiac and kidney indexes score population and separately in HF patients with severe (peakVO(2) < 14 mL/min/kg, n = 2919, 61.1 events/1000 pts/year) or moderate (peakVO(2) >= 14 mL/min/kg, n = 3183, 19.9 events/1000 pts/year) HF. In the healthy population, we obtained the following equations: female, VE/VCO2 = 0.052 x Age + 23.808 (r = 0.192); male, VE/VCO2 = 0.095 x Age + 20.227 (r = 0.371) (P = 0.007). We applied these formulas to calculate the percentages of predicted VE/VCO2 values. The 2-year survival prognostic power of VE/VCO2 slope was strong, and it was similar if expressed as absolute value or as a percentage of predicted value (AUCs 0.686 and 0.690, respectively). In contrast, in severe HF patients, AUCs significantly differed between absolute values (0.637) and percentages of predicted values (0.650, P = 0.0026). Moreover, VE/VCO2 slope expressed as a percentage of predicted value allowed to reclassify 6.6% of peakVO(2) < 14 mL/min/kg patients (net reclassification improvement = 0.066, P = 0.0015). Conclusions The percentage of predicted VE/VCO2 slope value strengthens the prognostic power of VE/VCO2 in severe HF patients, and it should be preferred over the absolute value for HF prognostication. Furthermore, the widespread use of VE/VCO2 slope expressed as percentage of predicted value can improve our ability to identify HF patients at high risk, which is a goal of utmost clinical relevance.