Ribeiro Antonio Luiz P, Teixeira Mauro M, Reis Adelina M, Talvani Andre, Perez Amanda A, Barros Márcio Vinicius L, Rocha Manoel Otávio C
Postgraduate Course of Tropical Medicine, Internal Medicine Department, School of Medicine, Federal University of Minas Gerais, Av. Alfredo Balena, 190-Campus Saúde, 30130-100, Belo Horizonte, Brazil.
Int J Cardiol. 2006 Apr 28;109(1):34-40. doi: 10.1016/j.ijcard.2005.05.048. Epub 2005 Jul 14.
Left ventricular dysfunction (LVd) is the main predictor of mortality in Chagas disease (ChD).
To compare the diagnostic performance of the conventional approach (ECG and chest X-ray) in the recognition of LVd in ChD, with a new strategy, in which BNP is measured in patients with an abnormal ECG.
Consecutive ChD patients recruited at an Outpatient Reference Center in Belo Horizonte, Brazil, without other systemic diseases, in 1998-99 (sample 1, n = 165) and in 2001-02 (sample 2, n = 62) underwent ECG, chest X-ray, BNP measurement and echocardiography.
The prevalence of LVd (ejection fraction <or=0.40) was 9.1% in the sample 1. The conventional strategy recognized all patients with LVd (sensitivity: 100%, 95% CI: 79.6-100% and negative predictive value -PV 100%, 92.1-100%), but with low specificity (30%, 95% CI: 23.2-37.8) and +PV (12.5%, 95% IC: I7.7-19.6). The BNP/ECG strategy showed significantly better specificity (96.0%, 95% CI: 91.5-98.2, p < 0.001) and +PV (66.7%, 95% CI: 43.7-83.7, p < 0.001), and non-significantly lower sensitivity (80.0%, 95% CI: 54.8-93.0, p = 0.25) and -PV (98.0%,95% CI: 94.2-99.3, p = 0.08). Overall accuracy was improved with the new strategy. (94.5%,95% CI: 90.0-97.1 x 36.4%, 95% CI: 29.4-43.9, p < 0.001). Similar results were obtained for the sample 2.
The BNP-based strategy was more accurate than the conventional approach in the detection of LVd in ChD patients and should be considered as a valid option.
左心室功能障碍（LVd）是恰加斯病（ChD）死亡率的主要预测指标。
比较传统方法（心电图和胸部X线）与一种新策略在识别ChD患者LVd方面的诊断性能，新策略是对心电图异常的患者测量脑钠肽（BNP）。
1998 - 1999年（样本1，n = 165）和2001 - 2002年（样本2，n = 62）在巴西贝洛奥里藏特的一家门诊参考中心招募的连续ChD患者，无其他系统性疾病，接受了心电图、胸部X线、BNP测量和超声心动图检查。
样本1中LVd（射血分数≤0.40）的患病率为9.1%。传统策略识别出了所有LVd患者（敏感性：100%，95%可信区间：79.6 - 100%；阴性预测值 -PV 100%，92.1 - 100%），但特异性较低（30%，95%可信区间：23.2 - 37.8）和阳性预测值（+PV）较低（12.5%，95%可信区间：7.7 - 19.6）。BNP/心电图策略显示出显著更高的特异性（96.0%，95%可信区间：91.5 - 98.2，p < 0.001）和 +PV（66.7%，95%可信区间：43.7 - 83.7，p < 0.001），而敏感性（80.0%，95%可信区间：54.8 - 93.0，p = 0.25）和 -PV（98.0%，95%可信区间：94.2 - 99.3，p = 0.08）无显著降低。新策略提高了总体准确性（94.5%，95%可信区间：90.0 - 97.1对36.4%，95%可信区间：29.4 - 43.9，p < 0.001）。样本2也得到了类似结果。
基于BNP的策略在检测ChD患者的LVd方面比传统方法更准确，应被视为一种有效的选择。
