Left main coronary artery compression in patients of atrial septal defect with dilated pulmonary artery

Abstract Background External compression of Left main coronary artery (LMCA) by dilated pulmonary artery is a rare and less known phenomenon. Objective To find incidence and associated angiographic findings of LMCA compression by a dilated pulmonary artery in adult patients with an Atrial septal defect (ASD). Methods It was a retrospective observational study done in 55 patients with ASD and age more than 35 years. All patients underwent coronary angiogram along with cardiac catheterization to look for hemodynamic parameters and status of the epicardial coronary artery. Patients with significant LMCA compression underwent computed tomography and intravascular imaging to confirm significant compression and rule out atherosclerotic stenosis. Patients with and without LMCA compression were compared to find any causation, and patients with LMCA compression were followed up after the final consensus of management. Results As compared to patients without LMCA compression, significant LMCA compression was found in 4 (7.27%) of patients and associated with reduced ejection fraction (46.3 ± 10.3% vs 60 ± 2.0%; p-value 0.001), increased pulmonary artery diameter (55 ± 14.5 mm vs 24.9 ± 4.7 mm; p-value Conclusions LMCA compression is rarely seen in patients with an atrial septal defect and associated with a reduced ejection fraction, increased pulmonary artery diameter, increased pulmonary artery/aortic diameter ratio and raised mPAP. Treatment modalities like medical management, percutaneous intervention by stenting, and surgical correction play an important role in management.