Clinical parameters and functional tests are not predictive for in-stent restenosis

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.

After stenting, recurrences of symptoms or ischemia on functional tests are considered to be clinical signs of restenosis.

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).

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)

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.