A 59-year-old woman met previous diagnostic criteria for exercise-induced pulmonary hypertension but had a negative mPAP/CO slope, highlighting potential limitations in current diagnostic methods.
Case Report (n=1)
This case highlights a potential limitation in current diagnostic criteria for exercise-induced pulmonary hypertension when a negative mPAP/CO slope occurs due to decreased cardiac output during exercise.
Abstract Introduction Exercise-induced pulmonary hypertension (EiPH) is currently described by a mean pulmonary artery pressure/cardiac output (mPAP/CO) slope of 3 mmHg/L/min between rest and exercise. Prior recommendations used mPAP above 30 mmHg during invasive exercise hemodynamics OR tricuspid regurgitation velocity (TRV) exceeding 3.4 m/s during exercise echocardiography as the primary diagnostic thresholds. Case description A 59-year-old woman with a past medical history significant for systemic lupus erythematosus established care with the pulmonology office for dyspnea on exertion that started insidiously two years ago. Her exercise capacity gradually declined from running marathons to being able only to go up one flight of stairs. Further workup showed unremarkable pulmonary function test with FEV1/FVC ratio of 84%, FEV1 70% and FVC 65%, DLCO of 77% of predicted. Echocardiogram showed ejection fraction of 60%, right ventricular systolic pressure (RVSP) 20-25 mmHg, mild mitral regurgitation (MR) with mild myxomatous degeneration, and E/E’ medial and lateral ratios of 10.5 and 9.0, respectively. Computed tomography of the thorax without intravenous contrast was unremarkable. On Cardiopulmonary exercise test (CPET), the patient reached 49% of the peak oxygen uptake (V̇O2 max), early anerobic threshold at 30% of the predicted peak V̇O2, and appropriate ventilatory reserve with no evidence of hypoxemia at maximal exercise — suggesting circulatory impairment. The CT angiogram showed no coronary artery obstruction. Bicycle stress echocardiogram (achieved 81% predicted heart rate compared to 85%) showed no evidence of ischemia but findings suggestive of hemodynamically significant dynamic mitral valve regurgitation with exercise. At rest, there was mild MR with estimated pulmonary artery systolic pressure (PASP) 30-35 mmHg with peak TRV of 2 m/s. On peak exercise, her MR worsened to at least moderate with an estimated PASP of 60-65 mmHg based on a TRV of 3.5 m/s. Cardiac magnetic resonance imaging showed no evidence of myocardial ischemia, fibrosis, or infiltration. The patient thereby underwent supine bicycle exercise right heart catheterization (RHC) (Table), which showed a negative mean pulmonary artery pressure/cardiac output (mPAP/CO) slope. Discussion The patient qualifies for the diagnosis of EiPH based on the previous criteria, but the current criteria do not clarify how to interpret a negative mPAP/CO slope. In a patient with true pulmonary vascular disease, CO may go down during exercise, which may lead to a negative slope. This raises a question about the reconsideration of the current diagnostic methods. This abstract is funded by: None
Singh et al. (2026) conducted a case report in Exercise-induced Pulmonary Hypertension (n=1). Current vs previous diagnostic criteria for EiPH was evaluated on Diagnosis of Exercise-induced Pulmonary Hypertension. A 59-year-old woman met previous diagnostic criteria for exercise-induced pulmonary hypertension but had a negative mPAP/CO slope, highlighting potential limitations in current diagnostic methods.