Aijaz Bilal, Babuin Luciano, Squires Ray W, Kopecky Stephen L, Johnson Bruce D, Thomas Randal J, Allison Thomas G
Department of Internal Medicine, Mayo Clinic, Rochester, MN 55905, USA.
Am Heart J. 2008 Oct;156(4):783-9. doi: 10.1016/j.ahj.2008.05.026. Epub 2008 Jul 11.
Poor exercise capacity, abnormal heart rate responses, and electrocardiographic abnormalities during treadmill exercise testing independently predict mortality. The combined relationship of these 3 variables to determine the incremental increase in mortality was compared in groups with and without known cardiovascular disease (CVD).
Patients referred for treadmill exercise testing during 1986 to 1991 were included. Exercise capacity <74% (of age- and gender-predicted value), heart rate reserve of <68 beat/min, and horizontal or down-sloping ST depression of > or =1 mm were considered abnormal. Cox proportional hazards regression was used to determine all-cause mortality (average follow-up of 16 years) based on the number of exercise test abnormalities (0, 1, 2, or all 3).
Among 10,897 patients, 20.9% (n = 2,277) had CVD. Poor exercise capacity and limited heart rate reserve were associated with increased risk of mortality (P < .0001) in both groups; however, abnormal exercise electrocardiogram was associated with an increased risk of mortality in the no-CVD group only (P < .0001). A graded increase in mortality was observed with increase in number of abnormal exercise test results in both groups. Patients without CVD having 2 or 3 abnormal exercise test results had a similar age-adjusted risk of long-term mortality as those with CVD but normal exercise test results, with a hazard ratio comparing these groups = 1.01 (95% CI 0.79-1.28).
The combinatorial approach validates the prognostic significance of multiple exercise test variables. The presence of > or =2 exercise test abnormalities may constitute a "CVD risk equivalent" in patients without CVD.
在跑步机运动试验期间，运动能力差、心率反应异常和心电图异常可独立预测死亡率。在已知有心血管疾病（CVD）和无心血管疾病的群体中，比较了这三个变量联合起来对死亡率增加的影响。
纳入1986年至1991年间接受跑步机运动试验的患者。运动能力<74%（年龄和性别预测值）、心率储备<68次/分钟以及水平或下斜型ST段压低≥1毫米被视为异常。采用Cox比例风险回归，根据运动试验异常的数量（0、1、2或全部3项）确定全因死亡率（平均随访16年）。
在10897例患者中，20.9%（n = 2277）患有心血管疾病。运动能力差和心率储备受限在两组中均与死亡风险增加相关（P <.0001）；然而，运动心电图异常仅在无心血管疾病组中与死亡风险增加相关（P <.0001）。两组中均观察到随着运动试验异常结果数量的增加，死亡率呈分级上升。无心血管疾病且有2项或3项运动试验异常结果的患者，其年龄调整后的长期死亡风险与有心血管疾病但运动试验结果正常的患者相似，比较这两组的风险比=1.01（95%CI 0.79 - 1.28）。
联合分析方法证实了多个运动试验变量的预后意义。在无心血管疾病的患者中，存在≥2项运动试验异常可能构成“心血管疾病风险等同情况”。
