Combined ECG parameters (S Ⅰ mv, S Ⅴ 6mv, and P Ⅴ 1ms) with transthoracic echocardiography for constructing a screening model for pulmonary arterial hypertension: a case-control study

Pulmonary arterial hypertension (PAH) is a cardiovascular disorder characterized by progressive elevation of pulmonary vascular resistance and increased right ventricular afterload. Right heart catheterization (RHC) currently serving as the diagnostic gold standard for PAH, is an invasive procedure with inherent risks, whereas transthoracic echocardiography (TTE) is susceptible to multiple interfering factors when estimating pulmonary artery pressure (PAP). This study aims to construct a noninvasive screening model for PAH by integrating electrocardiography (ECG) and TTE parameters, thereby improving the early detection rate of PAH.

A retrospective case-control study was conducted on the patients hospitalized and undergoing RHC in Department of Cardiovascular Medicine of our hospital from August 1, 2014 to May 31, 2021. According to RHC results, the participants were divided into a PAH group (mean PAP ≥20 mmHg) and a control group (mean PAP <20 mmHg). Baseline demographic data, comorbidities, serum biochemical indicators, ECG parameters, TTE assessment of PAH and RHC findings were collected. ECG indicators with favorable diagnostic performance were screened by ROC curve analysis. A combined model was constructed by integrating ECG parameters and echocardiographic findings, and corresponding statistical analyses were performed to evaluate its diagnostic efficacy.

Regarding baseline characteristics, the PAH group exhibited significantly advanced age (P=0.004), higher proportion of hypertension (P=0.021), increased CHA₂DS₂-VASc score (P<0.001) and HAS-BLED score (P<0.001) for atrial fibrillation, and elevated b-type natriuretic peptide (BNP) level (P<0.001) than the control group. For ECG parameters, obviously higher values of PⅡms (P<0.001), PⅡmv (P<0.001), PⅤ1ms (P<0.001), PⅤ1mv (P<0.001), RⅤ1mv (P<0.001), RⅤ2mv (P=0.011), SⅠmv (P<0.001), SⅤ6mv (P<0.001), Ⅴ1R/S (P<0.001), Ⅴ2R/S (P=0.002), Ⅴ6R/S (P=0.044), STⅡmv (P=0.028), STⅢmv (P=0.007), STavFmv (P=0.001), STⅤ1mv (P=0.019) and STⅤ2mv (P=0.015) were observed in the PAH group than the control group. ROC curve analysis on the statistically significant ECG parameters and TTE for PAH prediction revealed that SⅠmv, SⅤ6mv and PⅤ1ms exhibited favorable diagnostic efficacy, with AUC values of 0.854 (95%CI: 0.803 to 0.904), 0.865 (95%CI: 0.817 to 0.914) and 0.739 (95%CI: 0.658 to 0.812), respectively, while TTE yielded an AUC value of 0.614 (95%CI: 0.534 to 0.694) for predicting PAH. The combined model constructed by integrating TTE results with S Ⅰ mv, S Ⅴ 6mv, and P Ⅴ 1ms yielded an AUC value of 0.874 (95%CI: 0.827 to 0.921). Under the premise of the specificity approaching 100% (maximized within the actual data distribution), the sensitivity was maximized at a cutoff value of 0.894, with a sensitivity of 0.656, a positive predictive value of 1.000, and a negative predictive value of 0.470, demonstrating superior predictive efficacy over any single ECG or TTE parameter.

The non-invasive model constructed based on ECG parameters (SⅠmv, SⅤ6mv, and PⅤ1ms) integrated with TTE estimation for PAH presents good screening performance for PAH, and has certain value for clinical promotion.