Abstract 17994: Impact of Aortic Valve Replacement on Outcome of Low Gradient ‰Severe” Aortic Stenosis despite Preserved Left Ventricular Ejection Fraction
Background: Low gradient severe AS (LGAS) with preserved LVEF may be associated with poor outcome. The optimal management of this subgroup remains controversial. We sought to compare the outcome of LGAS after AVR vs medical therapy.
Methods: In a prospective group of 1588 pts with symptomatic “severe” AS (AVA ≤0.6 cm²/m²), 260 had low transvalvular gradient (MG<40mmHg) despite preserved LVEF (LVEF>50%). Comprehensive echocardiographic measurements including hemodynamic calculations were completed. Mortality was gathered either from telephone visits or the Social Security Death Index. A propensity score was developed to compensate for referral to AVR, and the score and other variables were entered into a Cox model to explore the independent effect of AVR on outcome.
Results: Of 260 pts, 123 (47%) underwent AVR. Over 28±24m follow-up, 105 pts (40%) died - 32 (30%) in AVR and 73 (70%) on medical therapy. In comparison to AVR group, medical pts had a higher prevalence of diabetes, lower stroke volume index (36.4 ± 8.4 ml/m2 vs 34.4 ± 8.7 ml/m2, p=0.02), higher pulmonary artery pressure (38.2 ± 11 mmHg vs 47.8 ± 21 mmHg, p=0.001), higher creatinine level (1.1 ± 0.4 mg/dl vs 1.22 ± 0.5 mg/dl, p=0.02); these and other variables were entered the propensity model (C statistic 0.75). AVR (HR: 0.39, 95%CI 0.22-0.70, p<0.001) was independently associated with outcom. (Table) and remained a strong predictor of survival after adjusting for propensity score.
Conclusion: AVR is associated with better survival in pts with symptomatic low gradient severe AS and preserved LVEF.
- © 2012 by American Heart Association, Inc.