Significance of aortic valve calcification in patients with low-gradient low-flow aortic stenosis

Background Assessment of patients with aortic stenosis (AS) and impaired left ventricular function remains challenging. Aortic valve calcium (AVC) scoring with computed tomography (CT) and fluoroscopy has been proposed as means of diagnosing and predicting outcomes in patients with severe AS. Hypothesis Severity of aortic valve calcification correlates with the diagnosis of true severe AS and outcomes in patients with low-gradient low-flow AS. Methods Echocardiography and CT database records from January 1, 2000 to September 26, 2009 were reviewed. Patients with aortic valve area (AVA) < 1.0 cm ² who had ejection fraction (EF) ≤ 25% and mean valvular gradient ≤ 25 mmHg with concurrent noncontrast CT scans were included. AVC was evaluated using CT and fluoroscopy. Mortality and aortic valve replacement (AVR) were established using the Social Security Death Index and medical records. The role of surgery in outcomes was evaluated. Results Fifty-one patients who met the above criteria were included. Mean age was 75.1 ± 9.6 years, and 15 patients were female. Mean EF was 21% ± 4.6% with AVA of 0.7 ± 0.1 cm². The peak and mean gradients were 35.5 ± 10.6 and 19.0 ± 5.1 mmHg, respectively. Median aortic valve calcium score was 2027 Agatston units. Mean follow-up was 908 days. Patients with calcium scores above the median value were found to have increased mortality (P = 0.02). The benefit of surgery on survival was more pronounced in patients with higher valvular scores (P = 0.001). Fluoroscopy scoring led to similar findings, where increased AVC predicted worse outcomes (P = 0.04). Conclusions In patients with low-gradient low-flow AS, higher valvular calcium score predicts worse long-term mortality. AVR is associated with improved survival in patients with higher valve scores.