Chest pain after coronary artery stent implantation

A sizeable proportion of patients who undergo successful coronary artery stent implantation experiences chest pain immediately after the procedure and/or in the following months in the absence of in-stent restenosis. We investigated this phenomenon in 57 consecutive patients with stable angina who underwent successful stent implantation. Chest pain characteristics were assessed before stent implantation and during 6-month follow-up. All patients underwent coronary angiography within 6 months of the procedure 48 hours after exercise thallium-201 perfusion scintigraphy. Patients who did not exhibit in-stent restenosis underwent an ergonovine test at the end of routine coronary angiography. During follow-up, 15 patients complained of chest pain. Six of these patients exhibited scintigraphic evidence of myocardial ischemia and in-stent restenosis at angiography. In the remaining 9 patients, chest pain occurred in the absence of in-stent restenosis at angiography. In 8 of these patients intracoronary ergonovine administration reproduced their habitual pain, whereas it did not cause any pain in the 42 patients who were completely asymptomatic at follow-up and without in-stent restenosis. Ergonovine caused more intense vasoconstriction and nitroglycerin caused more intense vasodilation of the reference coronary diameter in patients with than in patients without ergonovine-induced pain (−17 ± 3 vs −9 ± 3%, p <0.001; 9 ± 6 vs 5 ± 4%, p <0.02, respectively). In conclusion, chest pain with features similar to habitual angina occurs in the absence of in-stent restenosis in 1/5 of patients after stent implantation and appears to be associated with more intense coronary vasoreactivity.