Abstract 11396: Discordant Grading of Aortic Stenosis Severity: Echocardiographic Predictors of Survival Benefit From Aortic Valve Replacement
Background: Discordant findings between aortic valve area (AVA≤1.0cm2) and mean gradient (MG≥40mmHg) raise uncertainty regarding the actual severity of the aortic stenosis (AS). Some studies suggested that the AVA threshold value to define severe AS should be decreased from 1.0 to 0.8 cm2. Our objective was to assess the survival benefit from aortic valve replacement (AVR) according to echocardiographic markers of AS severity.
Method: 1198 patients with AS were separated into 5 strata of AS severity based on AVA, indexed AVA (AVAi), MG or peak aortic jet velocity (Vpeak) (Figure). We compared the effect of AVR versus conservative therapy on survival in each strata of AS severity. To eliminate covariate differences that may lead to biased estimates of treatment effect, a propensity score adjustment was used.
Results: Among the 1198 patients, 722 (60%) patients were male, mean age was 71±12 years, mean AVA was 0.96±0.32cm2, mean gradient 29±18mmHg, mean ejection fraction 58±15%, and 440 (37%) patients underwent an AVR within 3 months following echocardiographic evaluation. During a mean follow-up of 3.3 ±2.3 years there were 289 deaths.
Patients with an AVA between 0.8 and 1 cm2 had a significant survival benefit from AVR (Hazard ratio of AVR = 0.30[0.14-0.62]; p<0.01; Figure) comparable to that of other strata with AVA <0.8 cm2. Likewise, strata of patients with an AVAi≤0.6cm2/m2 also had a better survival when treated by AVR as compared to medical management. Of note, a survival benefit from AVR was also observed in patients with MG between 25 and 40 mmHg or Vpeak between 3 and 4 m/s (Figure).
Conclusion: These results do not support the suggestion of decreasing AVA threshold value for severe AS to 0.8 cm2 and they confirm that AVR may be beneficial in a substantial number of patients with MG <40mmHg. These findings may thus provide a useful frame of reference to individualize treatment decisions in patients with discordant echocardiographic findings.
- © 2013 by American Heart Association, Inc.