Left Main Coronary Artery Stenting in Pulmonary Arterial Hypertension-Related External Compression

Pulmonary arterial hypertension (PAH) can cause significant dilatation of the pulmonary arteries, which may externally compress the left main coronary artery (LMCA). We present 2 such cases successfully treated with percutaneous coronary intervention using drug-eluting stents. Case A was a 29-year-old woman with idiopathic group 1 PAH with severe LMCA stenosis due to main pulmonary artery compression, diagnosed during routine cardiac catheterization. Case B was a 23-year-old woman with PAH secondary to secundum atrial septal defect who presented with non-ST-segment elevation myocardial infarction by LMCA compression from a dilated right pulmonary artery. Both patients underwent successful intravascular ultrasound-guided percutaneous coronary implantation with drug-eluting stent. Follow-up computed tomography coronary angiography at 6 months showed patent stents. Case A is awaiting heart-lung transplantation, and case B is planned for surgical atrial septal defect closure, yet unsuitable given high pulmonary vascular resistance. As this condition is serious but rare, we provide our cases and treatment strategy as recommendations to consider. Coronary treatment aside, addressing the underlying PAH is crucial for sustained outcomes.