True coronary bifurcation lesions: meta-analysis and review of literature.

AIM: Percutaneous intervention of true coronary bifurcation lesions is challenging. Based on the results of randomized trials and registry data, the approach of stenting of main vessel only with balloon dilatation of the side branch has become the default approach for false bifurcation lesions except when a complication occurs or in cases of suboptimal result. However, the optimal stenting strategy for true coronary bifurcation lesions - to stent or not to stent the side branch - is still a matter of debate. The purpose of this study was, therefore, to compare the clinical and angiographic outcomes of the double stent technique (stenting of the main branch and side branch) over the single stent technique (stenting of main vessel only with balloon dilatation of the side branch) for treatment of true coronary bifurcation lesions, with drug-eluting stents (DES).

METHODS: Comparative studies published between January 2000 and February 2009 of the double stent technique vs. single stent technique with DES for true coronary bifurcations were identified using an electronic search and reviewed using a random effects model. The primary endpoints of our study were side-branch and main-branch restenoses, all-cause mortality, myocardial infarction (MI) and target lesion revascularization (TLR) at longest available follow-up. The secondary endpoints of our analysis were postprocedural minimal luminal diameter (MLD) of the side branch and main branch, follow-up MLD of side branch and main branch and stent thrombosis. Heterogeneity was assessed and sensitivity analysis was performed to test the robustness of the overall summary odds ratios (ORs).

RESULTS: Five studies comprising 1145 patients (616 single stent and 529 double stent) were included in the analysis. Three studies were randomized comparisons between the two techniques for true coronary bifurcation lesions. Incomplete reporting of data in the primary studies was common. The lengths of clinical and angiographic follow-up ranged between 6 and 12 months and 6 and 7 months, respectively. Postprocedural MLD of the side branch was significantly smaller in the single stent group [standardized mean difference (SMD) -0.71, 95% CI -0.88 to -0.54, P < 0.000, I2 = 0%]. The odds of side-branch restenosis (OR 1.11, 95% CI 0.47-2.67, P = 0.81, I2 = 76%), main-branch restenois (OR 0.88, 95% CI 0.56-1.39, P = 0.58, I = 0%), all-cause mortality (OR 0.52, 95% CI 0.11-2.45, P = 0.41, I2 = 0%), MI (OR 0.92, 95% CI 0.34-2.54, P = 0.87, I = 49%) and TLR (OR 0.87, 95% CI 0.46-1.65, P = 0.68, I2 = 0%) were similar between the two groups. Postprocedural MLD of the main branch [standardized mean difference (SMD) -0.08, 95% CI -0.42 to -0.26, P < 0.65, I2 = 67%], follow-up MLD of side branch (SMD -0.19, 95% CI -0.40 to 0.01, P < 0.31, I2 = 15%) and main branch MLD (SMD 0.17, 95% CI -0.18 to 0.542, P < 0.35, I2 = 65%) were also similar between the two groups.

CONCLUSION: In patients undergoing percutaneous coronary intervention (PCI) for true coronary bifurcations, there is no added advantage of stenting both branches as compared with a conventional one-stent strategy. The results, however, need to be interpreted considering the poor study methods and/or poor quality of reporting in publications. We propose to move forward and consider the conduct of more systematic, well-designed and scientific trials to investigate the treatment of true coronary bifurcation lesions.