Peterson Pamela N, Magid David J, Ross Colleen, Ho P Michael, Rumsfeld John S, Lauer Michael S, Lyons Ella E, Smith Scott S, Masoudi Frederick A
Division of Cardiology, Department of Medicine, Denver Health Medical Center, Denver, Colorado 80204, USA.
Arch Intern Med. 2008 Jan 28;168(2):174-9. doi: 10.1001/archinternmed.2007.68.
Little is known about the association between exercise capacity and nonfatal cardiac events in patients referred for exercise treadmill testing (ETT). Our objective was to determine the prognostic importance of exercise capacity for nonfatal cardiac events in a clinical population.
A cohort study was performed of 9191 patients referred for ETT. Median follow-up was 2.7 years. Exercise capacity was quantified as the proportion of age- and sex-predicted metabolic equivalents achieved and categorized as less than 85%, 85% to 100%, and greater than 100%. Individual primary outcomes were myocardial infarction, unstable angina, and coronary revascularization. All-cause mortality was a secondary outcome.
Patients with lower exercise capacity were more likely to be female (55.38% vs 42.62%); to have comorbidities such as diabetes (23.16% vs 9.61%) and hypertension (59.43% vs 44.05%); and to have abnormal ETT findings such as chest pain on the treadmill (12.09% vs 7.63%), abnormal heart rate recovery (82.74% vs 64.13%), and abnormal chronotropic index (32.89% vs 12.20%). In multivariable analysis, including other ETT variables, lower exercise capacity (<85% of predicted) was associated with increased risk of myocardial infarction (hazard ratio [HR], 2.36; 95% confidence interval [CI], 1.55-3.60), unstable angina (HR, 2.39; 95% CI, 1.78-3.21), coronary revascularization (HR, 1.75; 95% CI, 1.46- 2.08), and all-cause mortality (HR, 2.90; 95% CI, 1.88-4.47) compared with exercise capacity greater than 100% of predicted.
Adjusting for patient characteristics and other ETT variables, reduced exercise capacity was associated with both nonfatal cardiovascular events and mortality in patients referred for ETT.
对于接受运动平板试验（ETT）的患者，运动能力与非致命性心脏事件之间的关联知之甚少。我们的目的是确定在临床人群中运动能力对非致命性心脏事件的预后重要性。
对9191例接受ETT的患者进行了一项队列研究。中位随访时间为2.7年。运动能力被量化为达到年龄和性别预测的代谢当量的比例，并分为低于85%、85%至100%以及高于100%。个体主要结局为心肌梗死、不稳定型心绞痛和冠状动脉血运重建。全因死亡率为次要结局。
运动能力较低的患者更可能为女性（55.38%对42.62%）；更可能患有合并症，如糖尿病（23.16%对9.61%）和高血压（59.43%对44.05%）；并且更可能有ETT异常结果，如运动时胸痛（12.09%对7.63%）、心率恢复异常（82.74%对64.13%）和变时指数异常（32.89%对12.20%）。在多变量分析中，包括其他ETT变量，与运动能力高于预测值100%相比，运动能力较低（<预测值的85%）与心肌梗死风险增加（风险比[HR]，2.36；95%置信区间[CI]，1.55 - 3.60）、不稳定型心绞痛（HR，2.39；95% CI，1.78 - 3.21）、冠状动脉血运重建（HR，1.75；95% CI，1.46 - 2.08）以及全因死亡率（HR，2.90；95% CI，1.88 - 4.47）相关。
在调整患者特征和其他ETT变量后，运动能力降低与接受ETT的患者的非致命性心血管事件和死亡率均相关。
