Effect of Aortic Valve Calcium Quantity on Outcome After Balloon Aortic Valvuloplasty for Severe Aortic Stenosis

Balloon aortic valvuloplasty has a role in a select group of patients with severe aortic stenosis. Identifying those appropriate patients who will benefit most is key. Given previous evidence demonstrating that histologically the intervention involves a physical disrupting of the cusp's calcium we hypothesized that the quantity of calcium seen at CT will influence outcome. We examined our cohort of patients who had undergone balloon aortic valvuloplasty and CT-quantified aortic valve calcium (AVC) between July 2011 and April 2014. All patients underwent echocardiography pre- and post-procedure and for those patients managed medically, again at 6 months. A potential predictive AVC value for mortality was calculated using Youden's index. A total of 240 aortic valvuloplasties were performed in 206 patients (male = 124). Valvuloplasty caused a significant (pre 0.63 ± 0.21 vs post 0.77 ± 0.27 cm², p <0.01, n = 240), but temporary (post 0.80 ± 0.27 vs 6 months: 0.64 ± 0.18 cm², p <0.01, n = 88) increase in valve area. Those patients with a non-severe AVC (<1853.5 AU) had a larger increase in valve area after valvuloplasty compared with those with more calcium (0.10 [95% confidence interval {CI} 0.05 to 0.10] vs 0.15 [95%CI 0.10 to 0.22] cm², p = 0.049). Multivariate analysis revealed severe AVC (Hazard ratio 2.79, 95% CI 1.18 to 6.63, p = 0.02) along with pulmonary artery pressure post-valvuloplasty (Hazard ratio 1.02, 95% CI 1.00 to 1.03, p = 0.03) to be predictive of survival. In conclusion, in patients with severe aortic stenosis the degree of AVC impacts on the success of valvuloplasty.