Use of Advanced CT Technology to Evaluate Left Atrial Indices in Patients with a High Heart Rate or with Heart Rate Variability: The Converge Registry.

We intended to assess the ability of current-generation 256-slice coronary CT angiography (CCTA) to measure left atrial volume (LAV), comparing patients with a high heart rate (HiHR) of at least 70 bpm and patients with heart rate variability such as atrial fibrillation (AFib). Methods: Using the prospective Converge Registry of patients undergoing 256-detector CCTA on a Revolution scanner, we enrolled 121 HiHR patients (74 men; mean age, 62.7 ± 12.5 y) and 102 AFib patients (72 men; mean age, 60.5 ± 11.0 y) after obtaining informed consent. Quantitative data analysis of LAV was performed using automated methods, and end-systolic phases were chosen for measurements from CCTA. A Student t test, Wilcoxon rank-sum test, or χ2 test assessed baseline parameters. Univariate and multivariate linear regression analysis was used to assess LAV and LAV index (LAVI) while adjusting potentially confounding variables. Results: Mean LAV was significantly higher in AFib subjects (148.6 ± 57.2 mL) than in HiHR subjects (102.1 ± 36.5 mL) (P < 0.0001). Similarly, mean LAVI was significantly higher in AFib subjects (72.4 ± 28.1 mL/m2) than in HiHR subjects (51.5 ± 19.0 mL/m2) (P < 0.0001). After adjusting for age, body mass index, sex, diabetes, hypertension, hyperlipidemia, and smoking, subjects with AFib had, on average, LAV measures higher by 41.2 ± 6.7 mL and LAVI values higher by 23.1 ± 3.4 mL/m2 (P < 0.0001). Conclusion: Misalignment and motion artifacts in CCTA images affect diagnostic CT performance, especially in patients with elevated heart rates or profound arrhythmia. However, the new-generation Revolution CCTA provides detailed information on left-atrium-complex morphology and function, in addition to coronary anatomy, in HiHR and AFib patients without additional radiation, scanning, or contrast requirements.

Relationship between cardio-ankle vascular index and obstructive coronary artery disease.

BACKGROUND: Cardio-ankle vascular index (CAVI) is an inexpensive, noninvasive, office-based method to evaluate arterial stiffness in the aorta and legs, which reflects the degree of coronary atherosclerosis. It has been applied clinically to assess arterial stiffness in patients who were diagnosed with coronary artery disease (CAD), stroke and those at risk. We intend to evaluate relationship between the CAVI and obstructive CAD. METHODS: We enrolled 285 individuals with mean age of 55.8 ± 13.5 years, clinically referred for Coronary Artery Calcium (CAC) scoring and coronary computed tomography angiography (CCTA) at our site. After informed consent, CAVI measurements were done using a vascular screening system, VaSera VS-1500 AU (FUKUDA Denshi) on the same day of CCTA. CAC was measured using the Agatston method. A semiquantitative scale was used by CCTA readers to grade the extent of luminal stenosis as a percentage of the vessel diameter using visual estimations. We evaluated if CAVI was associated with severe stenosis (>50%) or CAC >100, defined as obstructive CAD. RESULTS: The degree of CAC and severe coronary stenosis demonstrated significant correlation with CAVI (r = 0.44, P ≤ 0.0001 and r = 0.43, P ≤ 0.0001). Receiver operating characteristic curve analysis indicated that CAVI measure of 7.8 was an optimal cut-point for sensitivity and specificity in detecting obstructive CAD. Unadjusted logistic regression demonstrated CAVI >7.8, significantly associated with obstructive CAD [odds ratio (OR) = 4.60, 95% confidence interval (CI) (2.0-10.56), P = 0.0003] and CAC score >100 [OR = 6.96, 95% CI (3.68-13.17), P < 0.0001]. CONCLUSION: CAVI reflects coronary atherosclerosis and may be used as a screening tool for early identification of subclinical atherosclerosis in preventive care and optimize management.