Abstract 13751: Clinical Characteristics With High Extracellular Volume Fraction in Patients Who Performed Cardiac Computed Tomography Angiography for the Purpose of Evaluating Coronary Arteries

Abstract

Background: Cardiac computed tomography angiography (CCTA) is useful for the evaluation of anatomical coronary artery lesions. Recently, extracellular volume fraction by computed tomography (ECV CT ) have become possible by imaging the delay phase after coronary CT angiography. ECV CT has been reported to be useful for detailed examination and prognosis prediction after therapeutic intervention of cardiomyopathy. Cardiac amyloidosis is known as a cardiomyopathy with noticeable increased ECV, and cardiac amyloidosis should be suspected in patients with high ECV. The aim of this study was to evaluate clinical characteristics of high ECV CT and incidental detection of cardiac amyloidosis in patients who underwent CCTA for the purpose of evaluation of coronary arteries. Methods and Results: We examined consecutive 875 patients (mean age; 74.3 ± 7.1 years, men; 64%) who underwent CCCA in men aged ≥ 60 years and women aged ≥ 70 years. ECV CT quantification was performed with pre-contrast and post-contrast delayed phase CT images with the subtraction-derived method. Mean ECV CT was 29.7 ± 5.2%, and a total of 109 patients (12.3%) had ECV CT ≥ 35%. The patients with ECV CT ≥ 35% were significantly older (75.8±8.1 years vs. 74.1±6.9 years; P=0.038) and male dominant 75.4% vs 63.1%; P=0.007). Increased of high-sensitivity cardiac troponin T and B-type natriuretic peptide levels, left ventricular diastolic diameter, left ventricular thickness, impaired left ventricular ejection fraction, and E/e’ were significantly associated with ECV CT ≥ 35%. The prevalence of cardiac amyloidosis was estimated to be at least 1.7% (15/875) in entire study patients and 14.2% (15/106) in patients with ECV CT ≥ 35%. In these cases, increased ECV CT was a clue of the diagnosis of cardiac amyloidosis. Conclusion: CCTA was useful not only for evaluation of coronary arteries but also for evaluation of myocardial properties by ECV CT . Elevated ECV CT was associated with elevated cardiac biomarkers and structural changes of myocardium. There is an incidental diagnosis of cardiac amyloidosis in approximately 1.7% of cases underwent CCTA for the purpose of coronary artery evaluation detected by increased ECV CT .