Relation of Serum Albumin Levels to Myocardial Extracellular Volume in Patients With Severe Aortic Stenosis

Severe aortic stenosis (AS) is often characterized by myocardial interstitial fibrosis. Myocardial interstitial fibrosis, classically measured by magnetic resonance imaging, was also shown to be accurately measured by computed tomography (CT)-derived extracellular volume fraction (ECVF). Serum albumin (SA) level (g/dl) has been shown to correlate with ECVF among patients with heart failure and preserved ejection fraction. Our objective was to evaluate the association between SA and ECVF among patients with severe symptomatic AS. Patients with symptomatic severe AS who were evaluated as candidates for intervention between 2016 and 2018 were enrolled prospectively. All patients underwent precontrast and postcontrast CT for estimating myocardial ECVF. Valid ambulatory SA within 6 weeks of the cardiac CT were obtained and classified as (tertiles) <3.8, 3.8 to 4.19, and ≥4.2 g/dl. Patients with acute systemic illness at the time of the albumin test were excluded. The study included 68 patients, mean age 81 ± 6 years, 53% women. Patients with lower SA were more likely to have chronic renal failure, previous percutaneous coronary interventions, and a reduced functional class. The mean ECVF (%) in the study cohort was 41 ± 12%, significantly higher among the patients in the lower SA level groups (50 ± 12% vs 38 ± 7% vs 33 ± 9% in the <3.8 g/dl, 3.8 to 4.19 g/dl and ≥4.2 g/dl groups respectively, p for trend <0.001). A statistically significant inverse correlation was found between SA levels and ECVF (r −0.7, p <0.001). Multivariable analysis showed significant independent association between low SA and ECVF. In conclusion, the SA level is inversely associated with CT-derived ECVF in patients with severe AS.