Estimation of myocardial extracellular volume fraction with cardiac CT in subjects without clinical coronary artery disease: A feasibility study

Aim Collagens are major cardiac extracellular matrix components, known to be actively remodelled and accumulated during diffuse myocardial fibrosis. We evaluated whether accelerated collagen turnover described by neo-epitope biomarkers reflecting collagen formation and degradation separates patients with diffuse myocardial fibrosis from asymptomatic controls. Methods and results Seventy-one women with angina pectoris without significant coronary artery disease assessed by invasive coronary angiogram were included. Competitive enzyme-linked immunosorbent assays (ELISAs) measuring circulating protein fragments in serum assessed the formation and degradation of collagen type III (Pro-C3, C3M and C3C), IV (P4NP7S and C4M), V (Pro-C5 and C5M) and VI (Pro-C6 and C6M), and degradation of collagen type I (C1M). Serum samples from 32 age-matched asymptomatic women were included as controls. Symptomatic women presented significantly elevated levels of Pro-C6, C3C, C3M, C4M and C8-C ( p < 0.0001–0.0058) and significantly decreased levels of Pro-C3, C5M and C6M ( p < 0.0001–0.041), reflecting accelerated collagen turnover and an imbalanced collagen formation and degradation compared to controls. Cardiac magnetic resonance T1 mapping was performed to determine extracellular volume fraction and thus diffuse myocardial fibrosis. A significant association was identified between C5M and extracellular volume fraction by cardiac magnetic resonance ( p = 0.01). Conclusion Women with angina pectoris, but without significant obstructive coronary artery disease, showed an imbalanced collagen turnover compared to asymptomatic controls. The examined biomarkers are tools to monitor active collagen remodelling in patients with angina pectoris, in risk of developing myocardial fibrosis.

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Diagnostic and prognostic value of coronary artery calcium score of zero: is it time for guidelines to change?

European Heart Journal ◽

10.1093/ehjci/ehaa946.1383 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

E Arbas Redondo ◽

D Tebar Marquez ◽

I.D Poveda Pinedo ◽

R Dalmau Gonzalez-Gallarza ◽

S.C Valbuena Lopez ◽

...

Keyword(s):

Coronary Artery Disease ◽

Coronary Artery ◽

Coronary Angiography ◽

Coronary Artery Calcium ◽

Cardiac Ct ◽

Invasive Coronary Angiography ◽

Agatston Score ◽

Non Invasive ◽

Artery Disease

Abstract Introduction Cardiac computed tomography (CT) use has progressively increased as the preferred initial test to rule out coronary artery disease (CAD) when clinical likelihood is low. Coronary artery calcium (CAC) detected by CT is a well-established marker for cardiovascular risk. However, it is not recommended for diagnosis of obstructive CAD. Absence of CAC, defined as an Agatston score of zero, has been associated to good prognosis despite underestimation of non-calcified plaques. Purpose To evaluate whether zero CAC score could help ruling out obstructive CAD in a safely manner. Methods Observational study based on a prospective database of patients (pts) referred to cardiac CT between 2017 and 2019. Pts with an Agatston score of zero were selected. Results We included 176 pts with zero CAC score and non-invasive coronary angiography performed. The median duration of follow-up was 23.9 months. Baseline characteristics of the population are shown in Table 1. In 117 pts (66.5%), cardiac CT was indicated as part of their chest pain evaluation. Mean age was 57.2 years old, 68.2% were women and only and 9.4% were active smokers. Normal coronary arteries were found in 173 pts (98.3%). Obstructive CAD, defined as ≥50% luminal diameter stenosis of a major vessel, was present in 1/176 (0.6%); while non-obstructive atherosclerotic plaques were found in 2 pts (1.1%). During follow-up, one patient died of out-of-hospital cardiac arrest. None either suffered from myocardial infarction or needed coronary revascularization. Conclusions In our cohort, a zero CAC score detected by cardiac CT rules out obstructive coronary artery disease in 98.3%, with only 1.7% of non-calcified atherosclerosis plaques and 0.6% of major adverse events. Although further research on this topic is needed, these results support the fact that non-invasive coronary angiography could be avoided in patients with low clinical likelihood of CAD and zero CAC score, facilitating the management of the increasing demand for coronary CT and reduction of radiation dose. Funding Acknowledgement Type of funding source: None

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