Fisher Bruce W, Ramsay Gillian, Majumdar Sumit R, Hrazdil Chantelle T, Finegan Barry A, Padwal Rajdeep S, McAlister Finlay A
Division of General Internal Medicine, University of Alberta, Edmonton, Canada.
Anesth Analg. 2008 Jul;107(1):149-54. doi: 10.1213/ane.0b013e31817c6186.
Peripheral arterial disease, as detected by a reduced ankle-to-arm blood pressure index (AAI), has been shown to predict future cardiac events. However, the utility of measuring the AAI to predict postoperative cardiac complications in patients undergoing noncardiac surgery is unknown.
We prospectively studied 242 consecutive patients aged 50 yr or older presenting to a university hospital preadmission clinic before elective noncardiac surgery. We performed a standardized clinical evaluation that included calculation of the revised cardiac risk index (rCRI) and measurement of the AAI using both palpation and Doppler techniques. Independent observers, blinded to preoperative assessment and AAI results, ascertained cardiac complications in the first 7 days after surgery. We assessed the ability of an abnormal AAI (<or=0.9 or absence of all four pedal pulses) to predict postoperative cardiac complications using likelihood ratios (LR), area under the ROC curves (AUC), and multivariable logistic regression in which we adjusted for the rCRI result.
The cohort had a median age of 67 yr, 60% were male, 19% had diabetes, 14% had ischemic heart disease, and 35% underwent intraperitoneal or intrathoracic surgery. Postoperatively, 14 of 242 (6%) patients suffered cardiac complications, but no patients died. An abnormal AAI was present in 44 patients, 10 (23%) of whom had postoperative cardiac complications: positive LR 4.79 (95% CI: 3.04-7.54), negative LR 0.34 (95% CI: 0.15-0.77), AUC = 0.80. The AAI compared favorably with the rCRI, which had positive LR 4.22 (95% CI: 2.24-7.95), negative LR 0.57 (95% CI: 0.34-0.96), and AUC = 0.74. In multivariate analysis, the adjusted odds ratio for having a cardiac complication was 10.16 (95% CI: 2.90-36.02) for those patients with an abnormal AAI, even after adjusting for rCRI results.
An abnormally low AAI, indicative of underlying peripheral arterial disease, is an independent risk factor for postoperative cardiac complications. The accuracy of the AAI is similar to the rCRI, and it provides additional independent predictive value for preoperative cardiac risk stratification.
通过踝臂血压指数（AAI）降低检测出的外周动脉疾病已被证明可预测未来心脏事件。然而，测量AAI以预测非心脏手术患者术后心脏并发症的效用尚不清楚。
我们前瞻性研究了242例年龄在50岁及以上、连续入住大学医院入院前门诊接受择期非心脏手术的患者。我们进行了标准化临床评估，包括计算修订后的心脏风险指数（rCRI）以及使用触诊和多普勒技术测量AAI。对术前评估和AAI结果不知情的独立观察者确定术后前7天的心脏并发症。我们使用似然比（LR）、ROC曲线下面积（AUC）以及对rCRI结果进行校正的多变量逻辑回归评估异常AAI（≤0.9或四个足背动脉搏动均未触及）预测术后心脏并发症的能力。
该队列的中位年龄为67岁，60%为男性，19%患有糖尿病，14%患有缺血性心脏病，35%接受了腹腔或胸腔内手术。术后，242例患者中有14例（6%）发生心脏并发症，但无患者死亡。44例患者存在异常AAI，其中10例（23%）发生术后心脏并发症：阳性似然比4.79（95%CI：3.04 - 7.54），阴性似然比0.34（95%CI：0.15 - 0.77），AUC = 0.80。AAI与rCRI相比表现良好，rCRI的阳性似然比为4.22（95%CI：2.24 - 7.95），阴性似然比为0.57（95%CI：0.34 - 0.96），AUC = 0.74。在多变量分析中，即使对rCRI结果进行校正后，AAI异常的患者发生心脏并发症的校正比值比为10.16（95%CI：2.90 - 36.02）。
AAI异常降低，提示潜在的外周动脉疾病，是术后心脏并发症的独立危险因素。AAI的准确性与rCRI相似，并且为术前心脏风险分层提供了额外的独立预测价值。
