Left ventricular wall thickness on systolic-phase pulmonary vein CT as a marker for cardiac amyloidosis.

BACKGROUND: Cardiac amyloidosis (CA) is under-recognized and frequently associated with atrial fibrillation (AF). Pulmonary vein computed tomography (CT) is routinely obtained by electrophysiologists for AF ablation planning, but its potential for identifying incidental features of CA, such as increased left ventricular (LV) wall thickness, remains unexplored. OBJECTIVE: This study aimed to evaluate whether LV wall thickness measured on systolic-phase pulmonary vein CT can identify patients with CA. METHODS: We retrospectively identified 160 patients who underwent systolic-phase pulmonary vein CT for AF ablation planning, including 80 patients with confirmed CA, and 80 age- and sex-matched controls. LV anteroseptal and inferoseptal wall thickness were measured using multiplanar reconstruction. RESULTS: The mean age was 73 years, and 10% were female. Patients with CA had a significantly higher LV wall thickness than controls (mean septal thickness 22.3 ± 3.5 mm vs 14.9 ± 2.5 mm; P < .001). Multivariable logistic regression identified combined LV septal thickness as an independent predictor of CA (odds ratio, 1.78; 95% confidence interval, 1.43-2.21; P < .001). Receiver operating characteristic analysis demonstrated excellent discriminatory performance (area under the curve, 0.964; 95% confidence interval, 0.939-0.988; P < .001), with a combined thickness of 36 mm being the optimal cutoff. Notably, 56% of patients with CA underwent pulmonary vein CT before definitive diagnosis, indicating potential for early recognition. CONCLUSION: Systolic-phase LV wall thickness measured on pulmonary vein CT is significantly increased in patients with CA and may serve as an early imaging prompt for further diagnostic evaluation. Routine assessment of LV thickness on AF ablation CTs could provide an opportunity for earlier detection and intervention for unrecognized CA.