Prognostic value of changes in electrocardiographic abnormalities in patients with pulmonary arterial hypertension

Introduction In pulmonary arterial hypertension (PAH), electrocardiogram abnormalities are associated with more advanced disease and worse prognosis. Although they are potentially modifiable variables, the data about the prognostic value of longitudinal electrocardiographic analysis is scarce. Objective To describe the changes in the follow-up of electrocardiographic alterations present in PAH and to analyze their impact on mortality. Methods A single-center retrospective study included 213 patients diagnosed with PAH from January 2010 to March 2022 with at least two electrocardiograms at follow-up. The parameters included were: axis deviation>90º, right ventricular strain pattern, p wave DII>2.5 mm, R/S>1, right bundle branch block, prolonged QTc, S1Q3T3 pattern. We analyzed the electrocardiographic changes suggestive of PAH present at the time of the first and last available electrocardiogram and studied their association with mortality at follow-up. Results The median age was 47.0 years (IQR: 37.8-61.0), and 75% were women. Idiopathic pulmonary hypertension was the leading PAH cause (46%), followed by connective tissue disease-associated PAH (23.9%). Right axis deviation and strain pattern were the most frequent abnormalities. In the first evaluation, no alterations in the electrocardiogram were associated with increased mortality. At follow-up, at least 20% of the patients presented changes in all the electrocardiographic abnormalities analyzed (Figure 1). The presence of axis deviation>90º and QTc interval prolongation were associated with an increased risk of mortality (HR: 2.05 [1.63- 2.56] p<0.001), (5.14 [2.49-10.63] p<0.001) respectively. Patients with Axis deviation>90º and QTc prolongation at follow-up had lower survival compared to those with isolated axis>90º and QTc prolongation ( log rank<0.001). (figure 2) Conclusions In PAH, the electrocardiogram alterations are potentially modifiable parameters. The right axis deviation and QTc prolongation at follow-up are associated with a higher mortality risk at follow-up.Changes between the first and last ECG Kaplan Meier survival curve