INTRODUCTION• Recent registry and sub-study results have shown that percutaneous coronary intervention (PCI) is safe and effective in patients with unprotected left main coronary artery (ULMCA) stenosis.• However, due to the lack of randomized clinical trials, the comparability of PCI with coronary artery bypass graft (CABG) remains uncertain.
PRECOMBAT Trial Premier of Randomized Comparison of BypassSurgery versus Angioplasty Using Sirolimus-Eluting Stent inPatients with Left Main Coronary Artery Disease • DESIGN: a prospective, randomized clinical trial • OBJECTIVE: To compare PCI with sirolimus-eluting stents and CABG surgery for optimal revascularization of patients with ULMCA stenosis. • PRINCIPAL INVESTIGATOR Seung-Jung Park, MD, PhD, Asan Medical Center, Seoul, Korea
MAJOR INCLUSION CRITERIA• 18 years of age.• Significant de novo ULMCA stenosis (>50%)• Left main lesion and lesions outside ULMCA (if present) potentially comparably treatable with PCI and CABG.• Objective evidence of ischemia or ischemic symptom with angina or NSTEMI
MAJOR EXCLUSION CRITERIA • Any contraindication to dual antiplatelet therapy • Any previous PCI within 1 year • Previous CABG • Chronic total occlusion > 1 • AMI within 1 week • Shock or LV EF < 30% • Planned surgery • Disabling stroke • Other comorbidity, such as CRF, liver disease, etc
STUDY PROCEDURES• Sirolimus-eluting Cypher stent for all lesions• Strong recommendation of IVUS-guidance• Other adjunctive devices at the operator’s discretion• Use of LIMA to LAD anastomosis• Off- or on-pump surgery at the operator’s discretion• Dual antiplatelet therapy at least for 6 months after PCI• Standard medical treatment after PCI and CABG
FOLLOW-UP• Clinical follow-up at 30 days and 6, 9, and 12 months via clinic visit or telephone interview.• Routine angiographic follow-up at 8-10 months after PCI.• Ischemia-guided angiographic follow-up after CABG.• Retrospective SYNTAX score measurement in the Core Lab, CVRF, Seoul, Korea
PRIMARY END POINT• A composite of major adverse cardiac or cerebrovascular events (MACCE) for the 12-month period after randomization including – Death from any cause – Myocardial infarction (MI) – Stroke – Ischemia-driven target vessel revascularization (TVR)
POWER CALCULATION• A non-inferiority margin : 7%• A one-sided type I error rate : 0.05• Power : 80%• Assumption : a total of 572 patients (286 per group)• A final sample size : 600 patients (300 per group) assuming 5% of loss
The baseline clinical characteristics of the PCI and CABG groups were similar. Mean age of participants- 62 years 76.5% were men. The baseline angiographic characteristics of thetwo groups were also similar.
PROCEDURAL CHARACTERISTICS OF THE STUDY GROUPS. Complete revascularization 68.3% in the PCI group 70.3% in the CABG group (P = 0.60). Duration of the hospital stay after the procedure 8.4±14.5 days in the CABG group 3.1±5.8 days in the PCI group (P<0.001). At the time of discharge, patients in the PCI group more consistently received medications. Follow-up angiography at 8 to 10 months performed more frequently in the PCI group
TRIAL END POINT median follow-up period was 24.0 months in both the PCI and CABG groups. The primary end point of major adverse cardiac or cerebrovascular events at 12 months occurred in 26 patients assigned to PCI 20 patients assigned to CABG
INFERENCE No significant between-group differences in the cumulative incidence rates of the individual components of the primary end point . 2-year rate of ischemia-driven target-vessel revascularization was significantly lower in the CABG group than in the PCI group. There was no significant differences between the PCI and CABG groups in the registry cohort with respect to the rates of most of the major trial end points at 1 or 2 years. The exception was the end point of ischemia-driven target-vessel revascularization, which occurred significantly more frequently in PCI group.
DISCUSSION: COMPARISON WITH SYNTAX TRIAL PRECOMBAT SYNTAX Lower CV or cerebrovascular Higher event rate event rate. Event rate similar in Lower in stent thrombosis PCI/CABG Pt. had less complex coronary Mean SYNTAX score=30 lesions & clinical settings. Mean EUROSCORE=3.8 Mean SYNTAX score=25 US & European population Mean EUROSCORE=2.7 Better device & technique Asian population
LIMITATIONS OF THE STUDY Underpowered study due to low event rate Wide inferiority margin of 7% point, so findings can not be considered clinically directive. Relatively high rate of cross over between PCI & CABG group. 2 yr follow up period may not be enough for comparison. Restricted sample size. Difficult to extrapolate.
CONCLUSION At 1 yr, rate of CV or cerebrovascular events are similar in PCI & CABG groups . Meets the pre-specified criteria on non-inferiority of PCI to CABG. However due to low power and wide inferiority margin of trial, findings can not be considered as clinically directive.