July 26, 2012Circulation211 citationsOpen Access
View Full PaperDeterminants and Prognostic Significance of Exercise Pulmonary Hypertension in Asymptomatic Severe Aortic Stenosis
Structured PICO
Does exercise pulmonary hypertension predict cardiac events in asymptomatic patients with severe aortic stenosis?
P
Population
105 asymptomatic patients with severe aortic stenosis (aortic valve area <0.6 cm2/m2) and preserved left ventricular systolic function (ejection fraction ≥55%), mean age 71±9 years, 59% male.
I
Intervention
Exercise stress echocardiography to assess exercise pulmonary hypertension (Ex-PHT, defined as systolic pulmonary arterial pressure >60 mm Hg)
C
Comparator
Patients without exercise pulmonary hypertension
O
Outcome
Cardiac event-free survivalcomposite
Exercise pulmonary hypertension is a strong independent predictor of cardiac events in asymptomatic patients with severe aortic stenosis, supporting the prognostic value of exercise stress echocardiography in this population.
Abstract
BACKGROUND: Recent studies emphasized the usefulness of exercise stress echocardiography in asymptomatic patients with aortic stenosis. Nevertheless, the additive value of exercise pulmonary hypertension (Ex-PHT) in such patients remains unexplored. We therefore aimed to identify the determinants and to test the impact on outcome of Ex-PHT in asymptomatic patients with severe aortic stenosis. METHOD AND RESULTS: Asymptomatic patients with severe aortic stenosis (n=105; aortic valve area 50 and >60 mm Hg, respectively. Ex-PHT was more frequent than resting PHT (55% versus 6%; P<0.0001). On multivariable logistic regression, the independent predictors of Ex-PHT were male sex (odds ratio, 4.3; P=0.002), resting systolic pulmonary arterial pressure (odds ratio, 1.16; P=0.002), exercise indexed left ventricular end-diastolic volume (odds ratio, 1.04; P=0.026), exercise e'-wave velocity (odds ratio, 1.35; P=0.047), and exercise-induced changes in indexed left atrial area (odds ratio, 1.36; P=0.006). Ex-PHT was associated with reduced cardiac event-free survival (at 3 years, 22±7% versus 55±9%; P=0.014). In a multivariable Cox proportional hazards model, Ex-PHT was identified as an independent predictor of cardiac events (hazard ratio, 1.8; 95% confidence interval, 1.0-3.3; P=0.047). When exercise-induced changes in mean aortic pressure gradient were added to the multivariable model, Ex-PHT remained independently associated with reduced cardiac event-free survival (hazard ratio, 2.0; 95% confidence interval, 1.1-3.6; P=0.025). CONCLUSIONS: In asymptomatic patients with severe aortic stenosis, the main determinants of Ex-PHT are male sex, resting systolic pulmonary arterial pressure, and exercise parameters of diastolic burden. Moreover, Ex-PHT is associated with a 2-fold increased risk of cardiac events. These results strongly support the use of exercise stress echocardiography in asymptomatic aortic stenosis.