Left main stenting is associated with similar rates of death, Q wave myocardial infarction and stroke compared with CABG at 3-year follow-up

March 31, 2008 By Katherine Ogando [mailto:kogando@perfuse.org]

SCAI-ACCi2 08-Chicago, IL: A non-randomized study from Korea demonstrates no significant difference in mortality or the composite risk of death, Q-wave myocardial infarction or stroke among patients undergoing stenting or surgery for unprotected left main stem disease.

The results of this study were presented by Dr. Seung-Jung Park at the SCAI-ACC i2 summit late breaking clinical trials section in Chicago today. His presentation was followed by a commentary by Dr. David R. Holmes Jr.

Seung and colleagues utilized MAIN-COMPARE (Revascularization for Unprotected Left Main Coronary Artery Stenosis: Comparison of Percutaneous Coronary Angioplasty versus Surgical Revascularization), a registry which maintains data from 12 major cardiac centers in Korea on patients with stenosis greater than 50% in unprotected left main coronary arteries (LMCA) who underwent percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery. The data was gathered between January 2000 and June 2006.

Prior research based on LMCA disease maintains that CABG is the gold standard for the treatment of unprotected LMCA disease in comparison to PCI. Since the introduction of drug eluting stents (DES), however, the treatment of LM disease through PCI with DES has yielded decreased short-term adverse cardiac events, with rates approximating those of CABG surgery.

The MAIN-COMPARE study is an observational study comparing the long-term outcomes of patients who were treated with stents versus those who underwent CABG surgery with unprotected left main disease. In addition, the study compared the outcomes of bare metal stent (BMS) against CABG separately from DES versus CABG. In total, 1138 CABG patients and 1102 PCI patients participated in the study. In the PCI group, patients that were treated from January 2000 through May 2003 received bare metal stents (BMS), while from May 2003 through June 2006 patients were treated with DES. The exclusion criteria consisted of CABG surgery prior to the inclusion of the study, valvular and aortic surgery, ST-elevation myocardial infarction, or cardiogenic shock.

Clinical follow-up for PCI and CABG was recommended at 1 month, 6 months, and 1 year after treatment. The median follow-up for the PCI and CABG group were 1017 days (IQ range 688 to1451) and 1152 days (IQ range 681 to 1590), respectively. The adverse endpoints of the study were death from any cause, the composite of death and Q-wave myocardial infarction or stroke, and target vessel revascularization (TVR).

Compared to CABG, there was no significant difference in the endpoint component of death for the stent group (HR 1.18; 95% CI, 0.77 to 1.80, p=0.45), or composite outcome (HR 1.10; 95% CI, 0.75 to 1.62, p=0.61).

There was a significant reduction in the rate of TVR in the CABG group as compared to the PCI group (HR 4.76; 95% CI, 2.80 to 8.11 p<0.001). This reduction was significant in the BMS group (HR 10.70; 95% CI, 3.80 to 29.90, p<0.001) and the DES group (HR 5.96; 95% CI, 2.51-14.10, p<0.001) compared with the CABG group.

The MAIN-COMPARE study is limited mainly by the fact that it is a non-randomized observational study. Because of this, the results may have been influenced by confounders. In addition, according to the authors, a larger sample size is needed to appropriately power the study to detect significant differences in mortality. Results of the larger randomized studies are awaited.

This study was supported by the Korean Society of Interventional Cardiology and by Cardiovascular Research Foundation, Seoul.