Exercise-Induced ECG Changes Predict Adverse Outcomes in Pulmonary Hypertension

Introduction: Cardiopulmonary exercise testing (CPET) is an important tool in assessing the functional status of patients with pulmonary hypertension (PH). During CPET, ECG is used as marker of exercise induced ischemia. We hypothesize that ECG changes with exercise may be an early indicator of clinical worsening in PH and could predict adverse outcomes. Methods: Clinical, hemodynamic, and CPET data of 101 PH patients who underwent CPET between 2013 and 2019 were included. ECGs were analyzed for ST depressions and T wave inversions during the earliest CPET in this time frame, along with coincident hemodynamic data. These data were correlated to adverse outcomes, including shunt creation (atrial septostomy or POTTs shunt), lung transplantation, and death. Results: Median age was 19 y (7-40 y, IQR 12-26), 68% were female, and median follow up time was 3 y (1-8 y, IQR 1-5). Sixteen patients had an adverse outcome (8 shunt creation, 4 lung transplant, 7 death). Twenty-two patients demonstrated significant ST/T wave changes with exercise, 18 ST depressions and 9 T wave inversions. Multivariate regression, including pulmonary arterial pressure, revealed exercise induced ST/T wave changes to be an independent predictor of procedure-free survival (without lung transplantation or shunt creation) (hazard ratio 11.10, p=.006). Only 21% with ST/T wave changes demonstrated procedure-free survival vs 85% without. Conclusions: ST/T wave changes on exercise ECG are significantly associated with adverse outcomes in PH on a medium term follow up study. These ECG changes with exercise can be used as early indicators of clinical worsening in PH and predictors of adverse outcomes.