Abstract 11598: Impact of Valvuloarterial Impedance on Cardiovascular Outcome in Patients with Asymptomatic Aortic Stenosis (The SEAS Study)
Introduction: Valvuloarterial impedance (Zva) is a measure of the combined valvular and arterial load opposing left ventricular (LV) ejection in aortic stenosis (AS). We assessed the hypothesis that Zva had prognostic significance in patients with asymptomatic AS. This had not yet been studied prospectively.
Methods: 1473 patients with mild-moderate, asymptomatic AS in the Simvastatin Ezetimibe in Aortic Stenosis (SEAS) study were followed-up during 4.3 years of randomized, placebo-controlled treatment with combined simvastatin 40 mg and ezetimibe 10 mg daily. The impact of baseline Zva on rate of major cardiovascular events (CV, primary endpoint), as well as aortic valve events and ischemic CV events (both secondary endpoints), was assessed in Cox proportional hazards models. Zva was calculated using Doppler-derived stroke volume and indexed for height2.04, and LV ejection fraction by Simpson's biplane method.
Results: Baseline peak aortic velocity was 3.08±0.54m/s and Zva 6.17±1.93 mm Hg/ml · m2.04. During follow-up, a total of 509 major CV events occurred. In Cox regression analyses, 1 standard deviation (1.93 mm Hg/ml · m2.04) higher Zva predicted a 23% higher rate of major CV events, and 24% and 15% higher rates of aortic valve and ischemic CV events, respectively (all p<0.05), independent of study treatment, severity of AS, degree of aortic valve calcification, hypertension and LV ejection fraction (Table).
Conclusion: Assessment of valvuloarterial impedance adds valuable prognostic information in asymptomatic AS to that provided by established prognosticators like peak aortic jet velocity, degree of aortic valve calcification and LV ejection fraction.
- © 2011 by American Heart Association, Inc.