Journal of cardiovascular computed tomography最新文献

Background: Complete coronary revascularization has significant clinical outcome implications; however, there is no objective, quantitative, or universal definition.

Aim: To provide a quantitative personalized assessment of myocardium at risk before and after coronary artery bypass grafting (CABG) surgery.

Methods: Percent left ventricular myocardial blood flow distribution (LV%MYO) was derived from coronary CT angiography (CCTA) and used to quantify the myocardium at risk of ischemia in the 16 SYNTAX coronary segments of the 114 patients in the multicenter, prospective FASTTRACK CABG trial. Given each point of the fixed SYNTAX myocardial weighting factor represents 16.7 ​% (1/6) of myocardial blood flow, the myocardial weighting factor of each coronary segment was calculated as 6 ​× ​LV%MYO. The patency of bypass grafts was assessed on 30-day follow-up CCTA, and the residual LV%MYO was obtained by subtracting the LV%MYO in segments anastomosed with non-stenotic grafts from the pre-CABG global LV%MYO.

Results: LV%MYO were analyzable in 106 patients (mean age 65.6 (8.9) years, 87 ​% male); 53 had ≥1 total occlusion. The fixed myocardial weighting factor for most SYNTAX coronary segments differs significantly from the weighting factor derived from LV%MYO. The pre-CABG global LV%MYO, and the residual LV%MYO in 96 patients with post-CABG CCTA were 70.1 (18.8)% and 14.0 (15.3)%, respectively. Complete revascularization (residual LV%MYO ≤10 ​%) was achieved in 42 patients (43.8 ​%). The operator's discretion not to graft was the main reason that 106 coronary segments were not revascularized, with graft occlusion accounting for 22.6 ​%.

Conclusion: CCTA-derived LV%MYO allows an objective and individualized quantification of the myocardium at risk, facilitating prospective prediction and retrospective assessment of the completeness of revascularization in CABG patients.

Background: Medical examiners' offices are increasingly utilizing postmortem computed tomography (CT). While dual energy CT (DECT) has been applied in both clinical and postmortem settings, research on the application to postmortem coronary computed tomographic angiography (PMcCTA) is extremely limited. This study aims to evaluate whether DECT performed following PMcCTA using two contrast agents with differing chemical and physical properties allows for agent discrimination and simultaneous characterization of coronary artery patency and myocardial perfusion.

Methods: Phantoms were created using iodine (lipophilic Angiofil, aqueous Omnipaque) and gadolinium (aqueous Dotarem) contrast agents with water dilutions of the aqueous agents, and imaged using single-source DECT. Ex vivo PMcCTA of six porcine hearts was conducted, with imaging before and serially after injection of aqueous gadolinium followed by viscous iodinated Angiofil. The hearts were then imaged using single-source DECT and SyngoVia software was used to post-process the image data.

Results: SyngoVia post-processing of DECT image data allowed for calculation of a material separation ratio of 1.7, and application of this ratio allowed discrimination between the iodinated and gadolinium agents. In the hearts, injection of Angiofil allowed for isolation of the epicardial vessels from tissue perfusion as assessed by the gadolinium which perfused the microcirculation and diffused into the extracellular space of the myocardial tissue.

Conclusion: This study demonstrates the capacity of DECT to isolate lipophilic iodinated contrast from aqueous gadolinium contrast in the setting of ex vivo PMcCTA, allowing for simultaneous characterization of vascular patency and changes in myocardial perfusion associated with vessel obstruction or infarction.

Background: Higher serum phosphate levels are associated with cardiovascular diseases, including coronary artery calcification (CAC). However, there exists limited evidence supporting a causal relationship between phosphate levels and CAC progression.

Methods: Using the KOrea Initiatives on Coronary Artery Calcification (KOICA) registry, we assessed CAC using the CAC score assessed by cardiac computed tomography (CT) in participants with normal serum phosphate (2.5-4.5 ​mg/dL) and calcium levels and without renal dysfunction (estimated glomerular filtration rate ≥60 ​mL/min/1.73 ​m²). The effect of serum phosphate and calcium levels on the prevalence and severity of CAC at baseline and the longitudinal progression of CAC were analyzed using multivariable regression models.

Results: A total of 12,251 individuals and 31,251 CT scans were selected for analysis, with a median follow-up duration of 3.5 (interquartile range 2.1-5.1) years. In the baseline cross-sectional analysis, serum phosphate levels were associated with higher CAC prevalence (OR per 1 ​mg/dL increase, 1.09, 95 ​% CI 1.06-1.11, p ​< ​0.001) and CAC severity (β-coefficient per 1 ​mg/dL increase, 0.35, 95 ​% CI 0.25, 0.45, p ​< ​0.001). In longitudinal analysis, serum phosphate levels also showed a significant association with higher probability of CAC progression (HR per 1 ​mg/dL increase, 1.19, 95 ​% CI, 1.06, 1.32; p ​< ​0.001) and faster CAC score progression (β coefficient per 1 ​mg/dL, 2.54 ​× ​10^-2; 95 ​% CI, 1.43 ​× ​10^-2-3.67 ​× ​10^-2; p ​< ​0.001).

Conclusion: Higher serum phosphate levels, even within the normal range, are associated with faster CAC progression. Further studies are needed to demonstrate the possibility of slowing CAC development through the regulation of calcium-phosphate metabolism.