Interventional Cardiac and Vascular Service, The Medical Group, Beverly, MA, USA.
Am J Cardiol. 2011 Mar 1;107(5):778-82. doi: 10.1016/j.amjcard.2010.10.060. Epub 2011 Jan 19.
Peripheral arterial disease predicts future cardiovascular events and all-cause mortality. Conventional methods of assessment might underestimate its true prevalence. We sought to determine whether a postexercise ankle-brachial index (ABI), not only improved peripheral arterial disease detection, but also independently predicted death. This was an observational study of consecutive patients referred for ABI measurement before and after the fixed-grade treadmill or symptom-limited exercise component to a noninvasive vascular laboratory from January 1990 to December 2000. The subjects were classified into 2 groups. Group 1 included patients with an ABI of ≥0.85 before and after exercise, and group 2 included patients with a normal ABI at rest but <0.85 after exercise. A total of 6,292 patients underwent ABI measurements with exercise during the study period. Propensity score matching of the groups was performed to minimize observational bias. Overall mortality, as determined using the United States Social Security death index, was the end point. The 10-year mortality rate of groups 1 and 2 was 32.7% and 41.2%, respectively. An abnormal postexercise ABI result independently predicted mortality (hazard ratio 1.3, 95% confidence interval 1.07 to 1.58, p = 0.008). Additional independent predictors of mortality were age, male gender, diabetes, and hypertension. After the exclusion of patients with a history of cardiovascular events, the predictive value of an abnormal postexercise ABI remained statistically significant (hazard ratio 1.67, 95% confidence interval 1.29 to 2.17, p <0.0001). In conclusion, our results have shown that the postexercise ABI is a powerful independent predictor of all-cause mortality and provides additional risk stratification beyond the ABI at rest.
外周动脉疾病可预测未来心血管事件和全因死亡率。传统的评估方法可能低估了其真实患病率。我们旨在确定运动后踝臂指数（ABI）是否不仅能提高外周动脉疾病的检出率，而且能独立预测死亡。这是一项观察性研究，纳入了 1990 年 1 月至 2000 年 12 月期间连续因ABI 测量而被转诊至非侵入性血管实验室的患者，这些患者在进行固定坡度跑步机或症状限制运动前和运动后均进行了 ABI 测量。根据运动前后 ABI 是否均≥0.85，将患者分为两组。组 1 包括运动前后 ABI 均≥0.85的患者，组 2 包括静息时 ABI 正常但运动后<0.85的患者。在研究期间，共有 6292 例患者接受了ABI 测量和运动。采用倾向评分匹配对两组进行匹配，以尽量减少观察性偏倚。使用美国社会保障死亡索引确定总体死亡率作为终点。组 1 和组 2 的 10 年死亡率分别为 32.7%和 41.2%。异常的运动后 ABI 结果独立预测死亡率（风险比 1.3，95%置信区间 1.07 至 1.58，p=0.008）。死亡率的其他独立预测因素为年龄、男性、糖尿病和高血压。排除有心血管事件病史的患者后，异常运动后 ABI 的预测价值仍具有统计学意义（风险比 1.67，95%置信区间 1.29 至 2.17，p<0.0001）。总之，我们的研究结果表明，运动后 ABI 是全因死亡率的有力独立预测指标，可提供比静息 ABI 更具预测价值的风险分层。
