Perspective:

Approximately 20-40% of patients have recurrent or persistent angina after percutaneous coronary intervention (PCI). Potential mechanisms include recurrent ischemic lesion due to stent thrombosis, in-stent restenosis, residual diffuse disease, or myocardial bridging. With newer-generation stents, rates of stent thrombosis are <1% and rates of recurrent stenosis are about 5% at 1 year, but can vary based on clinical risk. Persistent angina due to coronary vasomotor disorders should also be considered. Significant constriction of epicardial coronary arteries post-PCI may be related to increased activation of rho-kinase pathways, which can increase vascular smooth muscle constriction. In addition, coronary microvascular dysfunction due to microvascular spasm and impaired microvascular dilation may also mediate recurrent angina post-PCI.

Noninvasive testing such as exercise stress testing with imaging should be the first step to further diagnose and/or risk stratify. Invasive testing strategies include physiologic and anatomic assessment using pressure wire or intravascular ultrasound or optical coherence tomography when there is concern for obstructive epicardial disease. In the absence of obstructive lesions, functional assessment using acetylcholine or ergonovine to diagnose epicardial or microvascular spasm can be considered.

For patients who are on optimal tolerated medical therapy and with persistent post-PCI angina, further diagnostic testing should be considered. Presence of angina and/or ischemia on a noninvasive functional test should prompt coronary angiography. Additional invasive testing of moderate epicardial stenosis or coronary vasomotor disorders may be needed. There still remain significant knowledge gaps when symptoms are due to coronary vasomotor dysfunction.