DataSheet_1_Predictive performance of aldosterone-to-renin ratio in the diagnosis of primary aldosteronism in patients with resistant hypertension.pdf

BackgroundThe systematic use of confirmatory tests in the diagnosis of primary aldosteronism (PA) increases costs, risks and complexity to the diagnostic work-up. In light of this, some authors proposed aldosterone-to-renin (ARR) cut-offs and/or integrated flow-charts to avoid this step. Patients with resistant hypertension (RH), however, are characterized by a dysregulated renin-angiotensin-aldosterone system, even in the absence of PA. Thus, it is unclear whether these strategies might be applied with the same diagnostic reliability in the setting of RH.
MethodsWe enrolled 129 consecutive patients diagnosed with RH and no other causes of secondary hypertension. All patients underwent full biochemical assessment for PA, encompassing both basal measurements and a saline infusion test.
Results34/129 patients (26.4%) were diagnosed with PA. ARR alone provided a moderate-to-high accuracy in predicting the diagnosis of PA (AUC=0.908). Among normokalemic patients, the ARR value that maximized the diagnostic accuracy, as identified by the Youden index, was equal to 41.8 (ng/dL)/(ng/mL/h), and was characterized by a sensitivity and a specificity of 100% and 67%, respectively (AUC=0.882); an ARR > 179.6 (ng/dL)/(ng/mL/h) provided a 100% specificity for the diagnosis of PA, but was associated with a very low sensitivity of 20%. Among hypokalemic patients, the ARR value that maximized the diagnostic accuracy, as identified by the Youden index, was equal to 49.2 (ng/dL)/(ng/mL/h), and was characterized by a sensitivity and a specificity of 100% and 83%, respectively (AUC=0.941); an ARR > 104.0 (ng/dL)/(ng/mL/h) provided a 100% specificity for the diagnosis of PA, with a sensitivity of 64%.
ConclusionsAmong normokalemic patients, there was a wide overlap in ARR values between those with PA and those with essential RH; the possibility to skip a confirmatory test should thus be considered with caution in this setting. A better discriminating ability could be seen in the presence of hypokalemia; in this case, ARR alone may be sufficient to skip confirmatory tests in a suitable percentage of patients.

背景
在原发性醛固酮增多症（primary aldosteronism, PA）的诊断中系统性使用确诊试验，会增加诊断流程的成本、风险与复杂度。有鉴于此，部分学者提出采用醛固酮肾素比值（aldosterone-to-renin ratio, ARR）截断值或整合诊疗流程图，以省去该确诊步骤。然而，顽固性高血压（resistant hypertension, RH）患者即使未罹患PA，其肾素-血管紧张素-醛固酮系统也存在功能失调情况。因此，目前尚不明确此类策略在RH人群中是否仍能保持同等的诊断可靠性。
方法
本研究连续入组129例确诊为RH且无其他继发性高血压病因的患者。所有患者均接受针对PA的全面生化评估，涵盖基础状态检测与盐水输注试验。
结果
129例患者中34例（26.4%）确诊为PA。仅采用ARR即可对PA诊断实现中至高准确度的预测（曲线下面积AUC=0.908）。在血钾正常的患者中，经约登指数确定的诊断准确度最大化ARR截断值为41.8 (ng/dL)/(ng/mL/h)，其灵敏度与特异度分别为100%和67%（AUC=0.882）；当ARR＞179.6 (ng/dL)/(ng/mL/h)时，PA诊断的特异度可达100%，但灵敏度仅为20%。在低钾血症患者中，经约登指数确定的诊断准确度最大化ARR截断值为49.2 (ng/dL)/(ng/mL/h)，其灵敏度与特异度分别为100%和83%（AUC=0.941）；当ARR＞104.0 (ng/dL)/(ng/mL/h)时，PA诊断的特异度可达100%，灵敏度为64%。
结论
在血钾正常的患者中，PA患者与原发性RH患者的ARR值存在广泛重叠，因此在该人群中应谨慎考虑跳过确诊试验的可能性。而在低钾血症患者中，ARR展现出更优的鉴别效能，此时仅采用ARR即可在合适比例的患者中省去确诊试验步骤。