A Rare Case of Nitroglycerin Resistant Coronary Arterial Vasospasm During Coronary Artery Bypass Surgery.

BACKGROUND

Coronary artery vasospasm following coronary artery bypass grafting (CABG) is a rare but potentially life-threatening complication that can lead to myocardial ischemia, arrhythmias, and cardiogenic shock. Nitroglycerin-resistant vasospasm, particularly involving the left main coronary artery (LMCA), poses significant diagnostic and therapeutic challenges.

CASE PRESENTATION

We report the case of a 47-year-old female with a history of hypertension, hyperlipidemia, and ADHD on dextroamphetamine-amphetamine, who presented with chest pain and was found to have a suspected severe LMCA lesion. Coronary angiography revealed a 95% LMCA stenosis that was unresponsive to intracoronary nitroglycerin, raising concern for catheter-induced vasospasm versus true stenosis. The patient underwent urgent CABG. Intraoperatively and postoperatively, she experienced recurrent, diffuse coronary vasospasm refractory to nitroglycerin, necessitating multiple interventions including mechanical circulatory support with intra-aortic balloon pump and percutaneous ventricular assist device. Coronary angiography confirmed severe diffuse coronary and peripheral vasospasm. The patient was managed with intravenous vasodilators, vasopressors, and supportive care, and eventually recovered with restoration of cardiac function and discharge to cardiac rehabilitation.

DISCUSSION

This case underscores the difficulty in differentiating vasospasm from true atherosclerotic disease in the LMCA, the potential for nitroglycerin resistance, and the risk of severe complications during CABG. The use of adjunctive imaging modalities, vasodilators beyond nitroglycerin, and early mechanical circulatory support may be critical in managing such complex cases.

CONCLUSION

Nitroglycerin-resistant coronary vasospasm, especially in the LMCA, can mimic fixed stenosis and lead to inappropriate surgical intervention and life-threatening complications. A multidisciplinary, imaging-guided approach is essential for accurate diagnosis and optimal management.