Relationship Between Anemia and Sudden Cardiac Death in Patients With Severe Aortic Stenosis

Aortic stenosis (AS) is associated with significant morbidity and mortality, including sudden cardiac death (SCD). Anemia is a known risk factor for mortality in patients with AS. We sought to understand the prognostic implications between anemia and SCD in severe AS. The Mayo Clinic AS database includes 8,357 adults with severe AS (mean gradient ≥40 mm Hg, aortic valve area ≤1 cm², or peak aortic jet velocity ≥4 m/s) enrolled between January 1, 1995 and April 30, 2015. Survival and cause of death were ascertained from the National Death Index and SCD from medical records. We excluded patients with multiple valvular abnormalities, leaving 7,292 subjects. The median (interquartile range, [IQR]) age was 76 (68, 82) years with 56% male, and median (IQR) hemoglobin level was 12.9 (11.6, 14.1) g/dl. The frequency of anemia (hemoglobin <13.0g/dl for men, <12.0 g/dL for women) was 40%. During median (IQR) follow up of 4.4 (1.8, 8.1) years, 4,056 died (10-year survival 38%) including 225 with SCD (10-year cumulative incidence 5%). In a multivariate model including age, sex, body-mass index, hypertension, diabetes mellitus, myocardial infarction, estimated glomerular filtration rate, and time dependent aortic valve replacement, anemia was associated with increased all-cause mortality (hazard ratios 1.75, 95%CI 1.64, 1.87; p < 0.001) and increased SCD mortality (hazard ratios 1.42, 95%CI 1.07, 1.86; p = 0.01). In conclusions, anemia is a frequent finding in patients with severe AS and independently associated with increased all-cause mortality and SCD. Anemia may be a useful prognostic marker and a modifiable therapeutic target in managing patients with severe AS.