title: Incremental prognostic value of cardiac computed tomography angiography in asymptomatic aortic stenosis: significance of aortic valve calcium score.
abstract: BACKGROUND
  Cardiac computed tomography angiography (CCTA) provides the simultaneous evaluation of the aortic valve, myocardium, and coronary arteries. In particular, aortic valve calcium score (AVCS) can be accurately measured on the same scanning sequence used to measure coronary artery calcification, with no additional cost or radiation exposure. We sought to evaluate the prognostic value of CCTA measures, including AVCS, in asymptomatic aortic stenosis (AS).
  
  
  RESULTS
  Sixty-four initially asymptomatic patients with AS with a normal ejection fraction were prospectively enrolled and followed for median 29 (IQR=18-50) months. During follow-up, 27 (42%) patients experienced cardiac events, including five cardiac deaths, eleven aortic valve replacements. Multivariate Cox proportional hazards analysis identified three CCTA measures as significant predictors of cardiac events: aortic valve area (per 0.1cm(2) decrease; hazard ratio [HR]: 1.19, 95% confidence interval [CI]: 1.05-1.34); multi-vessel obstructive coronary artery disease (HR: 2.84, 95% CI: 1.10-7.32); and AVCS (per 100; HR: 1.09, 95% CI: 1.04-1.15). Kaplan-Meier analysis showed that patients with AVCS greater than or equal to the median value of 723 had significantly worse outcomes than those with AVCS less than 723 (p<0.0001). The C-statistic value for cardiac events substantially increased when these CCTA measures were added to clinical characteristics plus echocardiographic peak transaortic velocity (0.913 vs. 0.702, p<0.001).
  
  
  CONCLUSIONS
  In patients with asymptomatic AS, CCTA measures of valve area, coronary stenosis, and calcification severity provide independent and incremental prognostic value after accounting for the echocardiographic severity of stenosis.
authors: Department of Cardiovascular Medicine, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan.
authors: Hiroto
authors: H
authors: Utsunomiya
authors: Hideya
authors: H
authors: Yamamoto
authors: Toshiro
authors: T
authors: Kitagawa
authors: Eiji
authors: E
authors: Kunita
authors: Yoji
authors: Y
authors: Urabe
authors: Hiroshi
authors: H
authors: Tsushima
authors: Takayuki
authors: T
authors: Hidaka
authors: Kazuo
authors: K
authors: Awai
authors: Yasuki
authors: Y
authors: Kihara
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000473:pathology*; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000401:mortality; D058070:Asymptomatic Diseases / Q000401:mortality; D002114:Calcinosis / Q000000981:diagnostic imaging* / Q000401:mortality; D057791:Cardiac Imaging Techniques / Q000379:methods*; D017023:Coronary Angiography / Q000379:methods*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Aortic stenosis; Aortic valve calcification; Cardiac computed tomography angiography; Doppler echocardiography; Prognosis