Aortic valve calcification in 499 consecutive patients referred for computed tomography

Estimation of Aortic Valve Calcium Score Based on Angiographic Phase Versus Reduction of Ionizing Radiation Dose in Computed Tomography

The aim of the study was to evaluate the estimation efficacy of aortic valve calcium score (AVCS) based on the multislice computed tomography (MSCT) angiographic phase. The evaluation of the reduced amount of ionizing radiation dose was performed because of this estimation. The study included 51 consecutive patients who qualified for transcatheter aortic valve implantation (TAVI) (78.59 ± 5.72 years). All subjects underwent MSCT: in the native phase dedicated to AVCS as well as angiographic phases aimed to morphologically assess the aortic ostium and arterial accesses for TAVI. Based on the native phase, an AVCS assessment was performed for axial reconstructions at 3.0 mm and 2.0 mm slice thickness (AVCS_native3.0 and AVCS_native2.0). Based on the angiographic phase AVCS was estimated for axial reconstruction at 0.6 mm slice thickness with increased values of lesion density in aortic valve cusps/aortic valve annulus, which is considered a calcification, from a typical value of 130 HU to 500 HU and 600 HU (AVCS_{CTA0.6 500 HU} and AVCS_{CTA0.6 600 HU}). Mathematical formulations were developed, allowing for AVCS native calculation based on AVCS values estimated based on the angiographic phase: AVCS_native3.0 = 813.920 + 1.510 AVCS_{CTA0.6 500 HU}; AVCS_native3.0 = 1235.863 + 1.817 AVCS_{CTA0.6 600 HU}; AVCS_native2.0 = 797.471 + 1.393 AVCS_{CTA0.6 500 HU}; AVCS_native2.0 = 1228.310 + 1.650 AVCS_{CTA0.6 600 HU}. The amount of a potential reduction in dose length product (DLP) in the case of AVCS estimation was 4.45 ± 1.54%. In summary, relying solely on the angiographic phase of MSCT examination before TAVI, it is possible to conclusively estimate AVCS. This estimation results in a marked reduction in radiation dose in MSCT.

Is the coronary artery calcium score the first-line tool for investigating patients with severe hypercholesterolemia?

Background

Coronary artery calcium (CAC) is known as a reliable tool for estimating risk of myocardial infarction, coronary death, all-cause mortality and is even used to evaluate suitable asymptomatic patients. We therefore aimed to evaluate whether CAC scoring can be applied in the algorithm for clinical examination of patients with severe hypercholesterolemia (SH).

Methods

During the period of 2016–2017 a total of 213 asymptomatic adults, underwent computed tomography angiography to evaluate their CAC scoring. The sample consisted of 110 patients with SH and 103 age and sex matched controls without dyslipidemia and established cardiovascular disease.

Results

In total there were 79 (37.2%) subjects with elevated (≥25th) CAC percentiles. Out of them 47 (59.5%) had SH and 32 (40.5%) did not. CAC score did not differ between groups (SH (+) 140.30 ± 185.72 vs SH (−) 87.84 ± 140.65, p = 0.146), however there was a comparable difference in how the participants of these groups distributed among different percentile groups (p = 0.044). Gender, blood pressure, tabaco use, physical activity, family history of coronary artery disease and diabetes mellitus were not associated with CAC score (p > 0.05). There were no significant correlations between biochemical parameters and CAC percentiles except for increase in lipoprotein(a) (p = 0.038). Achilles tendon pathology, visceral obesity, body mass index and increased waist-hip ratio were not associated with CAC percentiles either (p > 0.05).

Conclusions

CAC score is not associated with presence of SH. CAC score is not an appropriate diagnostic tool in the algorithm for clinical examination of patients with SH. Further larger studies are needed to support our findings.