Background: Randomized controlled trials indicate that sirolimus-eluting stents (SES) reduce the rates of restenosis and need for subsequent revascularization procedures, but patients enrolled in randomized trials represent a highly selected population. This study examined the performance of SES in a 'real world' setting by comparing the outcomes of trial-eligible versus ineligible patients undergoing percutaneous coronary intervention.
Methods: From the US commercial introduction of SES in April 2003 until December 2003, all patients that received an SES at our institution were followed in a prospective registry (n=838). For the purpose of this analysis, the registry population was divided into two groups based on the inclusion and exclusion criteria of the stenosis in a native coronary artery (SIRIUS) trial. The primary endpoint of the study was the rate of target lesion revascularization (TLR) at follow-up. Secondary endpoints included major adverse cardiac events (MACE) such as cardiac death, myocardial infarction, and target vessel revascularization. Clinical follow-up was complete for 92% of patients with a median duration of 14.2 months.
Results: Overall, 296 patients (35.3%) met entry criteria for the SIRIUS trial and thus comprised the SIRIUS eligible group. Patients in the SIRIUS ineligible group (n=542) were more likely to have chronic kidney disease and earlier bypass surgery and had longer mean stent length. At 1 year, TLR occurred in 3.0% of the SIRIUS eligible population and in 9.2% of the SIRIUS ineligible group (P=0.001). The secondary endpoint of cumulative MACE occurred in 6.6% of the SIRIUS eligible versus in 17.7% of the SIRIUS ineligible population (P<0.001). Two patients (0.4%) in the SIRIUS ineligible group had a late stent thrombosis on days 39 and 99, respectively, versus none in the SIRIUS eligible group.
Conclusion: Among 'real world' patients treated with SES, the incidence of TLR and MACE at 1 year was substantially greater among SIRIUS ineligible patients compared with SIRIUS eligible patients. These findings confirm that pivotal clinical trials of drug-eluting stents tend to enroll low-risk patients and that the estimated rates of TLR and MACE derived from such trials may not reflect subsequent outcomes with unrestricted clinical use.