Neointimal Hyperplasia Inhibition Effect of Angiotensin II Type 1 Receptor Blockers in Patients after Coronary Stent Implantation

Background and Objective

It remains unclear whether angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) can inhibit neointimal hyperplasia after stent implantation in patients with coronary artery disease. The aim of this meta-analysis was therefore to evaluate the benefits of ARBs in patients after coronary stent implantation based on the currently available randomized controlled trials.

Methods

We conducted a pooled analysis of randomized controlled trials to compare outcomes after stent implantation in patients administered ARBs with those not administered ARBs. We searched Ovid/MEDLINE, EMBASE, and the ISI web of knowledge using the terms ‘angiotensin receptor blocker,’ ‘renin angiotensin system inhibitor,’ ‘angiotensin receptor antagonist,’ ‘stent,’ ‘angiograph,’ ‘percutaneous coronary intervention (PCI),’ and ‘coronary artery disease.’ Published meta-analyses, review articles, and editorials were reviewed for potential studies of interest. The inclusion criteria were randomized controlled trials published in English, with a follow-up period of 6 months, comparing the outcomes after coronary stent implantation with and without the administration of any kind of ARB, reporting at least one outcome of interest (restenosis rate and late lumen loss). Data abstraction included study design, patient characteristics, follow-up period, type of ARB, type of stent, restenosis rate, and late lumen loss. Fixed-effects models were used to calculate the pooled relative risk for the restenosis rate and the standardized mean difference for late lumen loss.

Results

Five studies were included, with a total number of 624 patients. Seventy-five of 314 patients in the ARB group were diagnosed with in-stent restenosis at the 6-month follow-up, compared with 87 of 310 patients in the control group (relative risk 0.85; 95% CI 0.65, 1.11; p = 0.23). Consistent with this, there was no significant difference in late lumen loss between the two groups (0.04 mm; 95% CI ?0.15, 0.23; p = 0.66).

Conclusion

There is no evident benefit with the use of an ARB in terms of inhibition of neointimal hyperplasia in patients after coronary stent implantation.