Impossible to involve a sufficient number of centers in the study.

The Nordic-Baltic Heart Team Initiative for improved long-term coronary artery revascularization outcome compares quality of life and survival after coronary bypass grafting (CABG) vs. percutaneous coronary intervention (PCI) in patients with 1-vessel disease and proximal stenosis of the anterior descending artery (LAD/in patients with isolated proximal left descending coronary artery (LAD) lesion

It is not clear how operable 1-VD patients with stable or stabilized coronary artery disease involving a pLAD lesion should be treated to optimize long-term survival and quality of life.

According to recent European guidelines, significant pLAD disease may be treated by PCI or by CABG. This recommendation is based on two meta-analyses including 1.210 and 1.952 randomized and non-randomized patients. Generally, the patients were followed for 4-5 years. The analyses reported similar rates of mortality, MI and stroke, but more repeat revascularizations after PCI. Only one study including129 patients provided more than 5-year follow-up. Thus, the there is limited documentation for long-term effect of PCI vs. surgical re-vascularization in pLAD disease.

The American 2014 Guidelines on coronary revascularization recommends CABG for improved survival in patients with solitary proximal LAD stenosis. CABG

The angiographic 90% LIMA patency rate after 1, 2 and 3 decades is well described and suggestive of a survival benefit of surgical revascularization.

Therefore, there is scientific background for an CABG LIMA-to-LAD vs. PCI comparison in 1-VD patients with a pLAD lesion.

Substantiated expectations:

• PCI is superior to bypass operation concerning short-term quality of life.
• Off-pump LIMA-to-LAD is superior to PCI concerning long-term all-cause mortality.
• Long-term (≥10-year) follow-up is essential to evaluate coronary revascularization strategies.
• Outcome may be dependent on lesion complexity, diabetes and gender.

Inclusion Criteria:

Heart Team decision on treatment

1-VD patients with stable coronary artery disease or stabilized unstable angina pectoris/NSTEMI or silent ischemia Proximal LAD (pLAD) stenosis (>90% by visual assessment or FFR <80% The lesion may be treated by both PCI and surgery

Exclusion Criteria:

ST-elevation myocardial infarction within 24 hours. Expected survival <1 year, because of high age or severe cardiac or non-cardiac disease.

Significant LM disease. Earlier CABG. PCI within 3 months. Significant valvular heart disease. Renal failure on dialysis Earlier disabling stroke Relative or absolute contraindication to dual antiplatelet therapy. Allergy relevant to the study treatments. Age < 18 years. Study required information and consent suboptimal or impossible.

After publication of the trial, data will be made available for metaanalyses on request, and after accept by the steering committee.

Study protocol and statistical analysis plan available by now.

At clinicaltrial.gov

The clinical outcomes will be assessed by an independent event committee with no knowledge of treatment allocation.