Corrà Ugo, Mezzani Alessandro, Bosimini Enzo, Scapellato Francesco, Imparato Alessandro, Giannuzzi Pantaleo
Division of Cardiology, Salvatore Maugeri Foundation, Istituto di Ricerca e Cura a Carettere Scientifico, Veruno, NO, Italy.
Am Heart J. 2002 Mar;143(3):418-26. doi: 10.1067/mhj.2002.120772.
Peak oxygen consumption (VO2) has an important prognostic role in chronic heart failure (CHF), but its discriminatory power is limited in patients with intermediate exercise capacity (peak VO2 between 10-18 mL/kg/min). Thus, supplementary exertional indexes are greatly needed.
Six hundred patients with CHF with left ventricular ejection fraction (LVEF) < or = 40% who performed a symptom-limited cardiopulmonary exercise testing were screened and followed up for 780 +/- 450 days.
Eighty-seven patients had major cardiac events (77 cardiac deaths and 10 urgent heart transplantations). Multivariate analysis revealed the rate of increase of minute ventilation per unit of increase of carbon dioxide production (VE/VCO2 slope) (chi2, 79.3, P <.0001), LVEF (chi2, 24.6, P <.0001), and peak VO2 (chi2, 9.4, P <.0001) as independent and additional predictors of major cardiac events. VE/VCO2 slope was the strongest independent predictor of outcome (chi2, 20.9, P =.0001) in patients with intermediate peak VO2 (n = 403), and the best cutoff value was 35 (chi2, 25.8; relative risk = 3.2, 95% CI 2.0-5.1, P <.0001). Total mortality rate was 30% in patients with VE/VCO2 slope > or = 35 (n = 103, 26%) and 10% in those with VE/VCO2 slope <35 (n = 300, 74%) (P <.0001). Patients with VE/VCO2 slope > or = 35 had a similar total mortality rate to those with peak VO2 < or = 10 mL/kg/min (30% vs 37%, P not significant).
A rational and pragmatic risk stratification process with symptom-limited cardiopulmonary exercise testing in CHF should include both peak VO2 and VE/VCO2 slope, the latter index effectively predicting outcome in almost one fourth of patients with intermediate exercise capacity.
峰值耗氧量（VO₂）在慢性心力衰竭（CHF）中具有重要的预后作用，但其在运动能力中等（峰值VO₂在10 - 18 mL/kg/min之间）的患者中的鉴别能力有限。因此，非常需要补充运动指标。
对600例左心室射血分数（LVEF）≤40%且进行了症状限制性心肺运动试验的CHF患者进行筛选，并随访780±450天。
87例患者发生了主要心脏事件（77例心源性死亡和10例紧急心脏移植）。多因素分析显示，每单位二氧化碳产生量增加时分钟通气量的增加率（VE/VCO₂斜率）（χ² = 79.3，P <.0001）、LVEF（χ² = 24.6，P <.0001）和峰值VO₂（χ² = 9.4，P <.0001）是主要心脏事件的独立且额外的预测因素。在峰值VO₂中等（n = 403）的患者中，VE/VCO₂斜率是结局的最强独立预测因素（χ² = 20.9，P =.0001），最佳截断值为35（χ² = 25.8；相对风险 = 3.2，95% CI 2.0 - 5.1，P <.0001）。VE/VCO₂斜率≥35的患者总死亡率为30%（n = 103，26%），而VE/VCO₂斜率<35的患者总死亡率为10%（n = 300，74%）（P <.0001）。VE/VCO₂斜率≥35的患者总死亡率与峰值VO₂≤10 mL/kg/min的患者相似（30%对37%，P无显著性差异）。
在CHF中，通过症状限制性心肺运动试验进行合理且实用的风险分层过程应同时包括峰值VO₂和VE/VCO₂斜率，后一指标能有效预测近四分之一运动能力中等患者的结局。
