Routine Chest CTA Reliably Quantifies Left Ventricular Myocardial Mass

Background: Routine chest computed tomography angiography (CTA) is the primary imaging modality for thoracic aortic disease, yet cardiac information within these examinations remains underutilized. We evaluated whether left ventricular myocardial mass (LVMM) can be reliably quantified from routine non-electrocardiographically (ECG)-gated chest CTA and its application in thoracic aortic pathology. Methods: CTA scans were obtained from 257 patients without aortic disease and 181 patients with thoracic aortic aneurysm or dissection. LVMM was quantified using automated three-dimensional segmentation. In a separate 10-patient validation cohort, LVMM was compared across end-systolic, end-diastolic, and non-ECG-gated source reconstructions. CTA-derived LVMM was compared with published echocardiographic and cardiovascular magnetic resonance (CMR) reference values using Cohen's d. Results: LVMM remained stable across cardiac phases and non-ECG-gated images (mean coefficient of variation, 2.4%), whereas left ventricular volume varied substantially (36.9%). CTA-derived LVMM demonstrated small effect sizes with the Penn method (d = 0.22) and moderate effect sizes with ASE linear (d = 0.67), area-length (d = 0.68), and CMR (d = 0.63). LVMM increased through young adulthood, with minimal association with age beyond 30 years. LVMM was comparable between patients with thoracic aneurysms and normal adults (140 ± 43 g vs. 141 ± 40 g; adjusted p = 1.0) but significantly greater in acute (199 ± 61 g) and chronic (191 ± 57 g) aortic dissection (both adjusted p < 0.001). Conclusions: Routine non-ECG-gated chest CTA enables reliable automated LVMM quantification without additional imaging or radiation and may facilitate large-scale investigations of ventricular remodeling in thoracic aortic disease.