PURPOSE: The prevalence of pulmonary hypertension (PH) in patients referred for treadmill stress echocardiography is not well defined.
METHODS: A total of 2,306 patients (exclusions: <18 years, significant valvular disease, a history of coronary artery disease, left ventricular (LV) ejection fraction <50%, and atrial fibrillation/flutter) were evaluated by Bruce protocol treadmill stress echocardiography and Doppler-derived assessment of right ventricular systolic pressure (RVSP). Pulmonary hypertension (PH) was defined as RVSP>35 mm Hg at rest.
RESULTS: PH was present in 275 pts (11.9%). Pts with PH were older (67±13 vs 59±13, p<0.0001); weighed more (BMI 28.7±5 vs 27.7±5, p<0.005), had increased vascular stiffness (pulse pressure 58±18 vs. 50± 15 mmHg, P<0.001) and a greater degree of left atrial enlargement suggesting diastolic dysfunction (67% vs 43%, p<0.0001). E/e’ (a Doppler estimate of left ventricular filling pressure) was also higher (11±4 vs 9±4, p<0.0001). PH was a major predictor of exercise capacity. Exercise duration was significantly reduced in patients with PH (7.1±3 mins) vs those without PH (8.7±3 mins, p<0.0001). This effect persisted after adjusting for age and gender, p<0.0001.
CONCLUSION: PH is present in a significant proportion of patients (11.9%) referred for treadmill stress echocardiography and correlates with impaired exercise capacity. Although likely related to a range of factors, the association of PH with increasing age, diastolic dysfunction and vascular stiffness suggests a predominance of LV diastolic dysfunction-related PH (Group II of the WHO Classification).
CLINICAL IMPLICATIONS: Whether treatment strategies directed at this cohort will affect exercise capacity remains to be seen.
DISCLOSURE: Garvan Kane, None.