The Utility of a Resting Electrocardiogram (ECG-PH Index) in Evaluating the Efficacy of Pulmonary Endarterectomy in Chronic Thromboembolic Pulmonary Hypertension

Background: The ECG-PH index (PH-ECG score) has been proposed as a valuable ECG-derived method of evaluating the effectiveness of balloon pulmonary angioplasty (BPA) in chronic thromboembolic pulmonary hypertension (CTEPH). Pulmonary endarterectomy (PEA) is the main form of therapy for CTEPH with a proximal clot location. The objective of this study was to assess the clinical utility of a resting electrocardiogram (ECG-PH index) in assessing the effectiveness of PEA in CTEPH patients. Methods: The retrospective analysis included 73 patients who underwent PEA. Their ECG-PH index values were calculated using four ECG parameters: R-wave amplitude V-1 + S-wave amplitude V-5/V-6 > 10.5 mm, QRS-wave axis > 110 degrees, R-wave amplitude V-1 > S-wave amplitude V-1, and SIQIII pattern. PH-ECG scores were assessed after a median time of 13 months (IQR: 8-31 months) had passed since the PEA procedures. Results: The current analysis documented that ECG-PH index = 0 is a good reflection of mPAP < 25mmHg (sensitivity 76.1%; specificity 66.7%; positive predictive value 79.5%; negative predictive value 62.1%) or mPAP <= 20 mmHg (sensitivity 69.6%; specificity 70.6%; positive predictive value 88.6%; negative predictive value 41.4%) after PEA. The values of the area under the ROC curve for ECG-PH index were 0.772 (95% CI: 0.676-0.867) and 0.743 (95% CI: 0.637-0.849) for the mPAP < 25 mmHg and mPAP <= 20 mmHg patient groups, respectively. Conclusion: The ECG-PH index may be useful for monitoring the haemodynamic effect of PEA in CTEPH patients.