Abstract 16957: Predictive Value of Cardiopulmonary Exercise Testing in Patients With Aortic Stenosis: Comparison With Traditional Echocardiographic Parameters
Background: Prognosis of patients with aortic stenosis (AS) is currently based on echocardiographic severity parameters and patient-reported symptoms. The value of cardiopulmonary exercise testing (CPX) for predicting outcomes in patients with AS is unknown.
Methods: From November 2007 to March 2010, we identified patients with severe AS (AVA < 1 cm2) or moderate AS (AVA 1 - 1.5 cm2) with or without symptoms who had CPX and echo < 6 months apart. Patients were stratified into 2 groups: 1. low risk = peak VO2 (ml/kg/min) ≥ 15 for men (≥11 for women) and VE/VCO2 nadir < 35; 2. high risk= low peak VO2 and/or high VE/VCO2. Relationship of CPX risk to echo parameters, AVR, and mortality was assessed by a general linear model ANOVA. Cox regression was used to evaluate the relationship of surgical outcomes to CPX risk controlling for symptoms, demographic s, and echo parameters.
Results: Of 170 patients (62% male, age 68±13 years, mean valve area 1.0 ± 0.2 cm2, mean mean-gradient 40 ± 14 mmHg) identified, 82 (48%) had severe AS. After 1137 ± 434 days of follow-up, AVR was performed in 89 (52%) patients, and there were 25 (15%) deaths. Table shows variables according to CPX risk groups. Higher risk was associated with a lower LVEF, higher LV mass index, lower valve gradient, and higher E/e’ with a similar valve area. Mortality with and without AVR was 14% vs. 48% in the high CPX risk group (p = 0.0066) compared to 7% versus 7% (p = 0.8581) in the low CPX risk group. Mortality but not frequency of AVR was inversely related to peak VO2. Low CPX risk (HR = 0.169; 95% CL = 0.067 - 0.424, p = 0.0002) and AVR (HR = 0.285, 95% CL = 0.113 - 0.720, p = 0.0079) were predictive of mortality while symptoms, demographics, and echo parameters were not.
Conclusion: CPX findings of low peak VO2 and high VE/VCO2 are commonly seen in AS and are associated with severity of AS consequences but not severity of valve stenosis per se. CPX can identify high risk AS patients who may benefit from AVR, independently of echo parameters, symptoms, age, and sex.
- © 2013 by American Heart Association, Inc.