Association of growth and differentiation factor-15 with coronary artery calcium score and ankle-brachial index in a middle-aged and elderly Caucasian population sample free of manifest cardiovascular disease

Growth and differentiation factor-15 (GDF-15) is a stress-associated cytokine of the transforming growth factor-β superfamily. The inflammatory and angiogenic effects of GDF-15 in atherosclerosis are controversial, and its correlation with the long asymptomatic phase of the disease is not well understood. Coronary artery calcium score (CACS) and ankle-brachial index (ABI) are sensitive markers of subclinical atherosclerosis. To date, only a few studies have examined the impact of GDF-15 on coronary artery calcification, and the association between GDF-15 and ABI has not been evaluated. Therefore, we aimed to investigate the possible relationship between serum GDF-15 concentrations and CACS and ABI in a Caucasian population sample of middle-aged (35-65 years) and elderly (> 65 years) people. In addition to recording demographic and anthropometric characteristics, atherosclerotic risk factors, and laboratory tests including serum HDL-cholesterol, LDL-cholesterol, hemoglobin A1c (HbA1c), high-sensitivity C-reactive protein, and N-terminal pro-B-type natriuretic peptide (NT-proBNP); GDF-15 level, cardiac computed tomography, and ABI measurements were also performed. A total of 269 asymptomatic individuals (men, n = 125; median age, 61.5 [IQR, 12.7] years) formed the basis of this study. Participants were divided into two groups according to their age (middle-aged, n = 175 and elderly, n = 94). Hypertension and diabetes mellitus were significantly more prevalent and CACS values and HbA1c, NT-proBNP, and GDF-15 levels were significantly higher (all p < 0.001) in the elderly group compared to the middle-aged group. Multivariate ridge regression analysis revealed a significant positive association between GDF-15 and CACS (middle-aged group: β = 0.072, p = 0.333; elderly group: β = 0.148, p = 0.003), and between GDF-15 and ABI (middle-aged group: β = 0.062, p = 0.393; elderly group: β = 0.088, p = 0.041) only in the elderly group. Our results show that GDF-15 is not only a useful biomarker of inflammation but can also predict early signs of asymptomatic atherosclerosis, especially in elderly people with chronic systemic inflammation associated with aging (inflammaging).

Heart Rate-Dependent Degree of Motion Artifacts in Coronary CT Angiography Acquired by a Novel Purpose-Built Cardiac CT Scanner

Although reaching target heart rate (HR) before coronary CT angiography (CCTA) is still of importance, adequate HR control remains a challenge for many patients. Purpose-built cardiac scanners may provide optimal image quality at higher HRs by further improving temporal resolution. We aimed to compare the amount of motion artifacts on CCTA acquired using a dedicated cardiac CT (DCCT) compared to a conventional multidetector CT (MDCT) scanner. We compared 80 DCCT images to 80 MDCT scans matched by sex, age, HR, and coronary dominance. Image quality was graded on a per-patient, per-vessel and per-segment basis. Motion artifacts were assessed using Likert scores (1: non-diagnostic, 2: severe artifacts, 3: mild artifacts, 4: no artifacts). Patients were stratified into four groups according to HR (<60/min, 60−65/min, 66−70/min and >70/min). Overall, 2328 coronary segments were evaluated. DCCT demonstrated superior overall image quality compared to MDCT (3.7 ± 0.4 vs. 3.3 ± 0.7, p < 0.001). DCCT images yielded higher Likert scores in all HR ranges, which was statistically significant in the 60−65/min, 66−70/min and >70/min ranges (3.9 ± 0.2 vs. 3.7 ± 0.2, p = 0.008; 3.5 ± 0.5 vs. 3.1 ± 0.6, p = 0.048 and 3.5 ± 0.4 vs. 2.7 ± 0.7, p < 0.001, respectively). Using a dedicated cardiac scanner results in fewer motion artifacts, which may allow optimal image quality even in cases of high HRs.

Model-based adaptive filter for a dedicated cardiovascular CT scanner: Assessment of image noise, sharpness and quality

BACKGROUND

Filtered back projection (FBP) and adaptive statistical iterative reconstruction (ASIR) are ubiquitously applied in the reconstruction of coronary CT angiography (CCTA) datasets. However, currently no data is available on the impact of a model-based adaptive filter (MBAF2), recently developed for a dedicated cardiac scanner.

PURPOSE

Our aim was to determine the effect of MBAF2 on subjective and objective image quality parameters of coronary arteries on CCTA.

METHODS

Images of 102 consecutive patients referred for CCTA were evaluated. Four reconstructions of coronary images (FBP, ASIR, MBAF2, ASIR + MBAF2) were co-registered and cross-section were assessed for qualitative (graininess, sharpness, overall image quality) and quantitative [image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR)] image quality parameters. Image noise and signal were measured in the aortic root and the left main coronary artery, respectively. Graininess, sharpness, and overall image quality was assessed on a 4-point Likert scale.

RESULTS

As compared to FBP, ASIR, and MBAF2, ASIR + MBAF2 resulted in reduced image noise [53.1 ± 12.3, 30.6 ± 8.5, 36.3 ± 4.2, 26.3 ± 4.0 Hounsfield units (HU), respectively; p < 0.001], improved SNR (8.4 ± 2.6, 14.1 ± 3.6, 11.8 ± 2.3, 16.3 ± 3.3 HU, respectively; p < 0.001) and CNR (9.4 ± 2.7, 15.9 ± 4.0, 13.3 ± 2.5, 18.3 ± 3.5 HU, respectively; p < 0.001). No difference in sharpness was observed amongst the reconstructions (p = 0.08). Although ASIR + MBAF2 was non-superior to ASIR regarding overall image quality (p = 0.99), it performed better than FBP (p < 0.001) and MBAF2 (p < 0.001) alone.

CONCLUSION

The combination of ASIR and MBAF2 resulted in reduced image noise and improved SNR and CNR. The implementation of MBAF2 in clinical practice may result in improved noise reduction performance and could potentiate radiation dose reduction.