Coronary vasomotor abnormalities in patients with stable angina after successful stent implantation but without in-stent restenosis

Background Coronary angiography is often performed in patients with recurrent or ongoing angina after successful percutaneous coronary intervention (PCI) in search of an in-stent restenosis (ISR). However, in many of these patients, no significant ISR can be detected. We speculate that enhanced coronary vasoconstriction represents an alternative explanation for angina in these patients. Methods From 1,285 patients with angiographically unobstructed coronaries (no stenosis >= 50 %) who underwent intracoronary acetylcholine provocation testing (ACH-test) between 2008 and 2011, we consecutively recruited 104 patients (42 female (40 %), mean age 64 +/- 11 years) who fulfilled the following inclusion criteria: previous stent implantation due to obstructive coronary artery disease (CAD), ongoing/recurrent exertional angina, no significant (<50 %) ISR. Results In fifty-one patients with previous PCI (49 %), the ACH-test elicited enhanced epicardial vasoconstriction (>= 75 % diameter reduction with reproduction of the patient's symptoms) and microvascular vasoconstriction (reproduction of symptoms, ischemic ECG-changes and no epicardial vasoconstriction) was seen in 18 additional patients (17 %). The ACH-test was uneventful in the remaining 35 patients (34 %). Epicardial vasoconstriction in patients with previous PCI was most often distal and diffuse (31/51, 61 %, p < 0.01). Conclusion Enhanced epicardial and microvascular coronary vasoconstrictions are frequently found in patients with stable angina after successful PCI but without significant ISR. Intracoronary acetylcholine provocation testing may be useful in these patients to determine the cause of angina and initiate appropriate medical treatment.