Correlation of degree of aortic valve stenosis by Doppler echocardiogram to quantity of calcium in the valve by electron beam tomography

To validate aortic valve calcium (AVC) load measurements by multidetector row computed tomography (MDCT), to evaluate the impact of tube potential and slice thickness on AVC scores, to examine the accuracy of AVC load in distinguishing severe from nonsevere aortic stenosis (AS) and to investigate its effectiveness as an alternative diagnosis method when echocardiography remains inconclusive.

We prospectively studied 266 consecutive patients with moderate to severe AS who underwent MDCT to measure AVC load and a comprehensive echocardiographic examination to assess AS severity. AVC load was validated against valve weight in 57 patients undergoing aortic valve replacement. The dependence of AVC scores on tube potential and slice thickness was also tested, as well as the relationship between AVC load and echocardiographic criteria of AS severity.

MDCT Agatston score correlated well with valve weight (r = 0.82, p < 0.001) and hemodynamic indices of AS severity (all p < 0.001). Ex-vivo Agatston scores decreased significantly with increasing tube potential and slice thickness (repeated measures ANOVA p < 0.001). Multivariate analysis identified mean gradient, the indexed effective orifice area, male gender and left ventricular outflow tract cross-sectional area as independent correlates of the in-vivo AVC load.

MDCT-derived AVC load correlated well with valve weight and hemodynamic indices of AS severity. It also depends on tube potential and slice thickness, thus suggesting that these parameters should be standardized to optimize reproducibility and accuracy.

The aim of this study was to evaluate the role of incidental aortic valve calcification on routine computed tomographic scans as a marker for stenosis, as assessed by echocardiography, in patients with bicuspid aortic valve (BAV) and tricuspid aortic valve.

Computed tomographic and echocardiographic studies were retrospectively reviewed for 182 consecutive, unselected patients and 426 patients identified by a record search for “aortic valve calcification.” Location and severity of valve calcification were correlated with aortic valve morphology and stenosis. Differences between subgroups were assessed using χ² or Fisher’s exact tests.

In unselected patients, calcification was present in 25.8% with tricuspid aortic valves (46 of 178) and 75% (three of four) with BAV. In patients selected for valve calcification, the average age of those with tricuspid aortic valves (n = 395) was 14.3 years older than those with BAV (n = 31). Patients with BAV were more likely to have severe calcification (87% vs 50%, P < .001), and if severe calcification was present, it was more likely to involve only the valve leaflets (41% vs 9%, P < .001) and result in aortic stenosis (85% vs 58%, P = .006). Patients aged < 60 years with severe calcification were more likely to have BAV (56% vs 7%; odds ratio, 7.9; 95% confidence interval, 3.4–18.7).

Aortic valve calcification was found 14 years earlier in patients with BAV and was more severe and strongly linked to aortic stenosis. Valve calcification on computed tomographic scans should be considered a marker for BAV if found before the seventh decade.

Patients with chronic renal failure have increased cardiac calcium loads. Previous studies have investigated the prevalence and quantitative extent of aortic valve calcium (AVC) and coronary artery calcium (CAC) in patients with various stages of chronic kidney disease (CKD). However, the impact of preexisting atherosclerosis on the calcification burden has not been clarified. Therefore, this study was conducted to examine the effect of CKD stage as well as the primary cause of renal failure (atherosclerotic vs nonatherosclerotic) on AVC and CAC. Twenty-two, 13, and 28 patients with stage 3, 4, and 5 CKD, respectively, were included, of whom 24 had atherosclerotic CKD. Patients underwent electron-beam computed tomography to assess AVC and CAC. AVC was present in 27% of patients with stage 3 CKD, in 38% of patients with stage 4 CKD, and in 43% of patients with stage 5 CKD. CAC was present in 77% of patients with stage 3 CKD, in 54% of patients with stage 4 CKD, and in 64% of patients with stage 5 CKD. There was no correlation between CKD stage and the quantitative extent of AVC and CAC. AVC was more frequent (58% vs 23%, p <0.01) and more extensive (median score 43 [range 0 to 494] vs 0 [range 0 to 8], p <0.01) in patients with CKD caused by atherosclerotic renal disease than in patients with nonatherosclerotic causes of CKD. CAC was more frequent (83% vs 56%, p <0.05) and more extensive (median score 437 [range 61 to 1,565] vs 31 [range 0 to 155], p <0.001) in patients with atherosclerotic causes of CKD than in patients with CKD caused by nonatherosclerotic renal disease. In conclusion, the prevalence as well as the severity of AVC and CAC did not vary between patients with stage 3, 4, and 5 CKD. Cardiac calcification, both AVC and CAC, were more frequent and more severe in patients with atherosclerotic causes of renal failure. These results suggest that cardiac calcium is related to atherosclerotic burden rather than to the severity of CKD.

The aim was to correlate the degree of valvular calcification in patients with aortic stenosis determined by retrospectively electrocardiogram (ECG)-gated multislice spiral computed tomography with stenosis severity assessed by cardiac catheterization.

Prospective study on 41 patients (18 men, mean age 71±8 years) with aortic stenosis, who underwent four detector row multislice spiral computed tomography and cardiac catheterization. Severity of aortic stenosis was classified by cardiac catheterization. Aortic valve area, peak to peak and mean transvalvular gradients were correlated with the degree of calcification determined by multislice spiral computed tomography. Aortic valve calcification was assessed using aortic Agatston score, aortic mass score and aortic volume score.

All measured aortic valve calcification scores were significantly higher in patients with severe aortic stenosis (n=29) than in patients with moderate (n=7) or mild aortic stenosis (n=5, p<0.001). Aortic valve calcification scores correlated significantly with aortic valve area (r=−0.49, p=0.001 for aortic mass score) and with peak to peak (r=0.68, p<0.001) and mean (r=0.60, p<0.001) transvalvular gradients.

Severity of aortic valve calcification assessed by cardiac multislice spiral computed tomography is inversely related to aortic valve area and positively correlated with transvalvular gradients. Based on this preliminary data larger studies should be performed with echocardiography as a reference standard in order to validate this new information and its utility in the clinical management of the patient.