Detection of mechanical complications related to the potential risk of sudden cardiac death in patients with pulmonary arterial hypertension by computed tomography.

Background: We explored the value of cardiac computed tomography (CT) for the detection and prediction of mechanical complications related to the risk of sudden cardiac death (SCD) in pulmonary arterial hypertension (PAH) patients.

Methods: PAH patients (n=60, mean age 47±15, 31.7% male) with pulmonary artery (PA) enlargement (≥40mm) by echocardiography were studied with cardiac CT. Complications explored were the presence of left main coronary artery (LM) compression, airway compression, PA dissection and PA thrombosis in relation to diameters of main PA (MPA) which were measured in (1) axial plane (MPA) and (2) LM oblique view (MPA).

Results: Mechanical complications were found in 21 patients (35.0%): LM compression in 20 patients; airway compression in 3 patients; and PA thrombosis in 4 patients. Patients with complications had more dilated MPA than patients without complication (59.4±13.0mm vs. 42.4±7.0mm, p<0.001). The area under the receiver operating characteristic curve for MPA was 0.889 (95% confidence interval: 0.795 to 0.983, p<0.001) with the highest discriminating sensitivity and specificity being 90.5% and 69.2%, respectively at MPA of 45mm. MPA failed to predict the presence of mechanical complications (p>0.05).

Conclusion: MPA≥45mm was significantly associated with the presence of mechanical complications of PAH. Evaluation with CT should be considered in PAH patients with dilated MPA.