Corrà Ugo, Mezzani Alessandro, Bosimini Enzo, Giannuzzi Pantaleo
Division of Cardiology, Salvatore Maugeri Foundation, IRCCS, Veruno, Italy.
Eur J Cardiovasc Prev Rehabil. 2006 Apr;13(2):186-92. doi: 10.1097/01.hjr.0000189807.22224.54.
Although peak oxygen consumption (VO2) is an objective measurement of functional capacity linked to survival, most clinicians use clinical history to monitor changes over time of functional disability. The aim was to verify the prognostic value of time-related changes (Delta) of symptom-limited cardiopulmonary exercise testing (CPX) indices in stable chronic heart failure (CHF).
We studied 231 stable CHF patients (200 men) with left ventricular ejection fraction (LVEF) of 24 +/- 8% and peak VO2 of 14.3 +/- 8 ml/kg per min, who performed two symptom-limited CPX over time.
The two incremental CPX were separated by a mean interval of 258 +/- 42 days; 59 (26%) suffered cardiovascular death or underwent urgent heart transplantation during the follow-up (1167 +/- 562 days). Peak VO2, LVEF (measured at second evaluation), Deltapeak VO2 and DeltaNYHA (New York Heart Association classification) were selected as independent predictors in the total population, and LVEF, Deltapeak VO2, and NYHA in patients with peak VO2 of 14 ml/kg per min or less (106 patients); no Delta parameter was selected in patients with preserved exercise tolerance. Survival analysis was performed taking into consideration the inter-test variability of peak VO2 (6%): true fall: more than 6% decrease, decline within the measurement variability; less than 6% decrease, improvement within the measurement variability; less than 6% increase and true rise; more than 6% increase: total mortality rate was 51, 23, 19 and 14% (P < 0.0001), respectively.
Deltapeak VO2 is a useful outcome index; a combination of static (single) and time-related functional variables can enhance the prognostication process in stable CHF patients.
尽管峰值耗氧量（VO2）是与生存相关的功能能力的客观测量指标，但大多数临床医生使用临床病史来监测功能残疾随时间的变化。目的是验证稳定型慢性心力衰竭（CHF）中症状限制性心肺运动试验（CPX）指标的时间相关变化（Delta）的预后价值。
我们研究了231例稳定型CHF患者（200例男性），左心室射血分数（LVEF）为24±8%，峰值VO2为14.3±8 ml/kg每分钟，这些患者随时间进行了两次症状限制性CPX。
两次递增CPX的平均间隔为258±42天；59例（26%）在随访期间（1167±562天）发生心血管死亡或接受紧急心脏移植。峰值VO2、LVEF（在第二次评估时测量）、Delta峰值VO2和Delta纽约心脏协会（NYHA）分级被选为总体人群的独立预测因素，峰值VO2为14 ml/kg每分钟或更低的患者（106例）中，LVEF、Delta峰值VO2和NYHA分级被选为独立预测因素；运动耐量保留的患者未选择任何Delta参数。考虑到峰值VO2的测试间变异性（6%）进行生存分析：真正下降：下降超过6%，在测量变异性范围内下降；下降小于6%，在测量变异性范围内改善；增加小于6%和真正上升；增加超过6%：总死亡率分别为51%、23%、19%和14%（P<0.0001）。
Delta峰值VO2是一个有用的预后指标；静态（单一）和时间相关功能变量的组合可以增强稳定型CHF患者的预后评估过程。
