A case report of cardiac allograft vasculopathy complicated with coronary vasospasm: insights from near-infrared spectroscopy, intravascular ultrasound, and optical coherence tomography.

Background: Cardiac allograft vasculopathy (CAV) remains a major complication after heart transplantation. Although coronary vasospasm after heart transplantation has occasionally been reported, the association between CAV and coronary vasospasm remains unclear.

Case Summary: A 68-year-old male with a history of heart transplantation 21 years ago presented with atypical angina. Coronary angiography demonstrated intermediate stenoses in the proximal and mid left anterior descending artery (LAD) and right posterolateral artery. Intracoronary acetylcholine provocation testing resulted in subtotal occlusion of the coronary arteries bilaterally, which was resolved by nitroglycerine administration, but the intermediate stenoses remained. The stenosis in the proximal LAD was physiologically significant based on fractional flow reserve. The patient was diagnosed with a developed CAV and concomitant coronary vasospasm and treated with percutaneous coronary intervention and nifedipine. Near-infrared spectroscopy and intravascular ultrasound showed a large isoechoic plaque with a low lipidic burden, suggesting a non-atherosclerotic plaque. Optical coherence tomography revealed a layered homogenous plaque, an intravascular imaging finding common in both CAV and coronary vasospasm. A drug-eluting stent dilated the stenosis, and follow-up angiography at 4 months showed no CAV progression.

Discussion: This case highlights the potential association between CAV and coronary vasospasm. Intravascular imaging detected similarities in plaque morphology between CAV and coronary vasospasm, suggesting that coronary vasospasm might contribute to the development of CAV. Although coronary vasospasm may be underdiagnosed in heart transplant recipients due to the lack of symptoms involving the denervated heart, this case showed that appropriate provocation testing may be beneficial for evaluating the cause of CAV.