Abstract 476: Exercise Induced Pulmonary Hypertension in Patient Presenting With Acute Cardiac Symptoms

Abstract

Introduction: Patients presenting with symptoms of angina, dyspnea, and fatigue with negative cardiac and pulmonary test findings are often investigated with exercise right heart catheterization. Patients displaying pulmonary hypertension or exercise-induced pulmonary hypertension (EIPH) were isolated and studied further to elaborate upon similarities and differences with patients with normal pressures. Hypothesis: EIPH may be an under-recognized cause of cardiac complaints. Methods: Clinical data was obtained from 172 randomly and retrospectively selected patients including data on hemodynamics, cardiopulmonary exercise testing (CPET), and echocardiogram findings. Patients with EIPH had a resting mean pulmonary arterial pressure below 25 mmHg and on exercise above 25 mmHg. Patients with resting pulmonary hypertension were stratified into WHO group 1 (pulmonary arterial) and WHO group 2 (due to left heart). Prior response to treatment with long-acting nitrates was also reviewed. Results: 27 patients had EIPH, 24 had WHO group 1 pulmonary hypertension, 37 had WHO group 2 pulmonary hypertension, 54 did not have pulmonary hypertension, and 30 did not have any exercise data. No significant differences were found across any groups in resting or exercise CPET performance. The mean age of those with pulmonary hypertension was 71.67 years and 58.89 for those without (p<0.01). Both had a mean left ventricular ejection fraction between 53-57%. The mean VO2 max for those with resting pulmonary hypertension or EIPH was below 20 ml/kg/min. For every 1-year increase in age the odds of developing EIPH increased by 1.08. The use of long-acting nitrate was associated with improvement of symptoms in symptomatic patients. Most of the EIPH patients were noted to have exercise-induced diastolic dysfunction and many also had concomitant chronotropic incompetance. Conclusions: EIPH represents those who have negative left-heart stress cardiac findings yet have underlying abnormalities significant enough to require symptomatic treatment during exercise. This includes diastolic dysfunction and chronotropic incompetency. Cardiovascular performance was found to be equally poor in patients with EIPH as compared to those with resting pulmonary hypertension.