The European bifurcation club Left Main Coronary Stent study: a randomized comparison of stepwise provisional vs. systematic dual stenting strategies (EBC MAIN)

Patients with non-left-main (LM) coronary bifurcation lesions are usually treated with a provisional stepwise single stent strategy. However, the DKCRUSH-V study found that an upfront, systematic dual stent strategy gave better outcomes.

The aim of this study was to evaluate clinical outcomes in patients with distal bifurcation LM stem lesions undergoing percutaneous intervention (PCI) with either a provisional single-stent strategy or a systematic dual stenting strategy.

No difference was seen in clinical outcomes between the provisional single stenting and the upfront use of two-stent techniques.

The 2018 European Society of Cardiology (ESC) Guidelines recommended an upfront two-stent approach in true LM bifurcations, but this study provides evidence to contradict this recommendation, particularly since upfront two-stent techniques have been associated with a higher long-term mortality risk than a single-stent strategy.

The European Bifurcation Club Left Main Coronary Stent Study (EBC MAIN) study (NCT02497014) was an investigator-led prospective randomised multicentre trial. A total of 467 patients were randomly allocated to PCI using the stepwise provisional strategy (n=230) or the upfront, systematic dual stenting approach (n=237), with the technique left to the discretion of the operator. The OnyxTM zotarolimus eluting coronary stent (Medtronic) was used in the study. The 6-month follow-up assessed patient symptoms and wellbeing, while the 1-year follow-up assessed symptoms, angina index, adverse events, and study endpoints.

Composite of all-cause death, myocardial infarction, and target lesion revascularisation at 12 months.

• Individual components of the primary endpoint
• Angina status
• Angina medication
• Adjudicated stent thrombosis

• ‘True’ unprotected bifurcation LM stem coronary artery disease in which both vessel reference diameters were ≥ 2.75mm.
• Either ischaemic symptoms, positive non-invasive imaging for ischaemia, a positive fractional flow reserve or a left main stem intravascular ultrasound (IVUS)-derived minimum luminal area of <6 mm2.
• Patients with ≤ 2 additional coronary lesions could be included in the study   
• Age ≥18 years

• STEMI <72 hours prior to intervention
• Cardiogenic shock
• Chronic total occlusion of either vessel
• >2 other coronary lesions planned for treatment
• SYNTAX score for planned lesions to be treated >32

• The mean age was 71 ± 10 years, 77 % were male and 28 % were diabetic
• The primary endpoint occurred in 14.7% and 17.7% of the stepwise provisional and systematic dual groups, respectively (hazard ratio, 0.8; 95% confidence interval, 0.5-1.3; p=0.34)
• There was no significant difference in secondary endpoints between the two groups: death (3 % vs. 4.2 %), MI (10 % vs. 10.1 %), TLR (6.1 % vs. 9.3 %) or stent thrombosis (1.7 % vs. 1.3 %)

There was no significant difference in outcomes between the stepwise provisional and systematic dual stent strategies, and the majority (78%) of patients in the provisional single stent group did not require a second stent. A systematic dual stent strategy involves a more complex procedure than a provisional single-stent approach. A pooled analysis of the BBC ONE and NORDIC trials, found that upfront two-stent techniques had a higher long-term mortality risk compared with an initial single-stent strategy. The investigators concluded that the stepwise provisional strategy should remain the treatment of choice for distal LM true bifurcation procedures.

• Only 1-year follow up reported at present but the study will proceed to 3-year follow-up
• The open-label design could have led to theoretical bias in interpreting outcomes
• Event rates were lower than anticipated and therefore the study was underpowered to detect clinical differences between the two groups