Effects of Candesartan Cilexetil on Cardiovascular Events in Japanese Patients With Hypertension After Sirolimus- or Paclitaxel-Eluting Stents Implantation

It was reported that low-dose angiotensin II receptor blocker, candesartan, was effective to prevent cardiovascular events in patients with coronary artery disease treated with coronary angioplasty (Am Heart J 146:E20, 2003). In this study, patients without significant coronary stenosis on follow-up angiography 6 months after intervention were randomly assigned into a candesartan group (baseline treatment plus candesartan 4 mg/d) or a control group (baseline treatment alone). It is well known that patients treated with drug-eluting stents (DES) have lower restenosis rate as compared with those with bare metal stents. Therefore, we hypothesized that candesartan started immediately after DES implantation was effective to prevent cardiovascular events.

The primary endpoint is a composite of any cause death and cardiovascular events (nonfatal myocardial infarction, recurrent symptomatic myocardial ischemia, congestive heart failure, and stroke). The secondary endpoints are target lesion revascularization, binary restenosis, newly onset diabetes and newly onset of atrial fibrillation.

Patient population which needs to prove the hypothesis is estimates to be 1,130 cases in total (565 cases in each group). We set the parameters which are needed to calculate the number of study patients as follows; a drop out rate 10%, an event rate of the primary end point for 3 years 20%, a risk reduction rate brought by candesartan 25%, a statistical power 90% and a two-sided significance level 0.05. We assumed the event rate from the study which was conducted to prove the effects of statins after PCI in Japan named MUSASHI-PCI. Also the risk reduction rate from two major RCTs of candesartan conducted in Japan named the Ogaki and HIJ-CREATE studies. In the Ogaki study, the risk reduction rate by candesartan was 52%. However, stents used in the study were only BMS after surviving restenosis. The risk reduction of the present study will be lower because of the higher onset rate of stent thrombosis in regard to DES. Furthermore, the risk reduction rate of candesartan for Japanese was 11% reported in HIJ-CREATE. The ACE-I usage rate was almost 70% in the control subjects of HIJ-CREATE. In the present study, ACE-I will be administered less frequently as low as 30%. Therefore, assumed risk reduction rate by candesartan in the present study could be higher. Considering all the various factors together, a reasonable risk reduction rate could be 25%.