Determinants and Prognostic Significance of Exercise Pulmonary Hypertension in Asymptomatic Severe Aortic Stenosis
Background—Recent studies emphasized the usefulness of exercise stress echocardiography (ESE) in asymptomatic patients with aortic stenosis (AS). 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 AS.
Method and Results—Asymptomatic patients with severe AS (n=105, aortic valve area<0.6cm2/m2, 71±9 years, 59% of male) and preserved left ventricular (LV) systolic function (ejection fraction≥55%) were prospectively submitted to ESE. Resting and ExPHT were defined as a systolic pulmonary arterial pressure (SPAP) >50mmHg and >60mmHg, respectively. Ex PHT was more frequent than resting PHT (55% vs. 6%, p<0.0001). On multivariable logistic regression, the independent predictors of ExPHT were male gender (odds-ratio [OR]=4.3, p=0.002), resting SPAP (OR=1.16, p=0.002), exercise indexed LV end-diastolic volume (OR=1.04, p=0.026), exercise e'-wave velocity (OR=1.35, p=0.047) and exercise-induced changes in indexed LA area (OR=1.36, p=0.006). Ex-PHT was associated with reduced cardiac event-free survival (3-year: 22±7 vs. 55±9%, p=0.014). In multivariable Cox proportional hazard model, Ex-PHT was identified as an independent predictor of cardiac events (hazard ratio [HR]=1.8, 95% confidence interval [CI]: 1.0-3.3, p=0.047). When adding exercise-induced changes in mean aortic pressure gradient to the multivariable model, Ex-PHT remained independently associated with reduced cardiac event-free survival (HR=2.0, 95%CI: 1.1-3.6, p=0.025).
Conclusions—In asymptomatic patients with severe AS, the main determinants of Ex-PHT are male gender, resting SPAP and exercise parameters of diastolic burden. Moreover, Ex-PHT is associated with 2-fold increased risk of cardiac events. These results strongly support the use of ESE in asymptomatic AS.
- Received December 20, 2011.
- Accepted June 14, 2012.
- Copyright © 2012, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited