Abstract 662: Outcome of Asymptomatic Patients With Low Gradient “Severe” Aortic Valve Stenosis and Preserved Ejection Fraction - Results From the Prospective SEAS Study
Background: Low gradient “severe” aortic valve stenosis (LGSAS) is observed in up to 30% of patients with normal left ventricular ejection fraction (EF) with a constellation of severe stenosis based on aortic valve area (AVA) <1.0 cm2 and non-severe stenosis based on mean pressure gradient (MPG) ≤ 40mmHg. The natural history is not known. We evaluated the outcome of patients with LGSAS in the prospective SEAS (Simvastatin and Ezetimibe in Aortic Stenosis) study.
Methods: 1525 asymptomatic patients (mean age 67.3±9.6 years, 39 % women) with mild to moderate aortic stenosis (AS), (peak velocity ≥ 2.5 and ≤ 4.0 m/s, prospectively followed for a mean of 51.8 months) and normal EF were analysed. Outcome was determined by the occurrence of major cardiac events (MACE), which include death from cardiovascular causes, aortic valve replacement, nonfatal myocardial infarction, hospitalisation for unstable angina pectoris, heart failure, coronary artery bypass grafting, percutaneous coronary intervention and nonhemorrhagic stroke. Furthermore aortic valve related events (AVE) including aortic valve replacement, heart failure due to progression of AS, and cardiovascular death were compared between patients with LGSAS, moderate AS (AVA 1–1.5cm2 and MPG 25– 40mmHg) and patients with consistently graded severe AS (AVA <1.0cm2 and MPG > 40mmHg).
Results: At baseline 435 of the 1525 patients (29%) had LGSAS, 184 (12%) had moderate AS and 35 (2%) had consistently graded severe AS. The remaining patients had mild AS. During follow up MACE occurred in 50.9% (CI 40 –57%) of patients with LGSAS and 48.4% (CI 42–59%) of patients with moderate AS (p=0.58). Similarly, there was no significant difference in AVE or cardiovascular death between the two groups (48.5% (CI 36 –53%) vs. 44.6% (CI 40 –57%), p=0.37 and 7.8% (CI 1–9%) vs. 4.9% (CI 4 –12%), p=0.19, respectively). In contrast, patients with consistently graded severe AS suffered a MACE in 74.3 % (p<0.01).
Conclusion: Asymptomatic patients with low gradient “severe” AS and normal left ventricular ejection fraction appear to have a relatively good outcome similar to patients with moderate AS and significantly better than those with consistently graded severe AS.