Objective: To study the correlation between clinical parameters and the occurrence of in-stent restenosis in a cohort of patients from the Tel Aviv Medical Center who underwent repeat angiograms for clinical indications following stenting.
Background: After stenting, recurrences of symptoms or ischemia on functional tests are considered to be clinical signs of restenosis.
Methods: The authors' study group consisted of 149 out of 1469 patients (10%) who underwent stent implantation between 1996 and 1998 and were under clinical follow-up. This group had a repeat angiogram for clinical indications: chest pain or a positive functional test (thallium study or ergometry).
Results: Sixty-eight patients (45%) had in-stent restenosis (ISR), 32 (21%) had a patent stent site with a significant coronary atherosclerosis elsewhere requiring revascularization (NTLR), and 51 (34%) had a patent stent site and did not require additional revascularization (PS). Baseline characteristics were similar in all the groups. There was a 63% rate of objective evidence of ischemia in the PS group, similar to the ISR (63%) and NTLR (74%) groups. In the ISR versus the NTLR and PS groups the stents were longer (22 +/- 10 versus 17 +/- 7 and 16 +/- 6 mm, p < 0.001) with a smaller diameter (3 +/- 0.4 versus 3.3 +/- 0.5 and 3.2 +/- 0.4 mm, p < 0.05) and a higher rate of multiple stents in the target lesion (34% versus 19% and 14%, p < 0.05)
Conclusions: In the cohort of patients who underwent angiography following stenting for chest pain or a positive functional test, 55% were found to have a patent stent site. The 5% total in-stent restenosis is significantly lower than the rate in angiography-based reports. On the other hand, the group with a patent stent had a higher than expected rate of objective evidence of ischemia. Therefore clinical parameters and functional tests are not predictive for in-stent restenosis.