Bypass Surgery Beats Angioplasty for Treatment of Severe Coronary Artery Disease

Reviewed by Elizabeth Klodas, MD, FACC

(CardioSmart) September 1, 2008--Given the recent advances in the fields of both coronary artery bypass grafting (CABG) as well as angioplasty (more correctly referred to as “percutaneous coronary intervention” or “PCI”), the comparison of the two techniques for the treatment of severe coronary artery disease was long overdue.  Two studies just presented at the annual European Society of Cardiology Congress meeting in Munich, Germany help shed light on which approach is best.

The SYNTAX trial was designed to compare CABG and PCI (using drug coated stents) in patients with coronary blockages affecting either the left main coronary artery (an artery which supplies the vast majority of heart muscle) and/or blockages in multiple other coronary arteries.  1800 patients were enrolled in the trial and were split equally into two groups receiving the different treatment approaches.  All patients were deemed to be candidates for either CABG or PCI, almost 30% were diabetic, and one third had a history of prior heart attack.

Of the patients undergoing PCI, the mean number of stents implanted was 4.6.  Of the patients in the CABG group, the mean number of grafts used was 2.8 and almost all patients received at least one artery graft (artery grafts are considered better than vein grafts because they tend to last longer). 

During an average 12 month follow-up, the patients undergoing CABG required far fewer repeat coronary artery procedures, but the PCI patients experienced fewer strokes (which were uncommon in both groups).  There was no difference in rates of death or heart attack between the two groups, and no differences in graft or stent failure.   When all of these outcomes were combined, the patients undergoing CABG overall fared better.

Looking at specific subgroups, patients with diabetes and patients with blockages in multiple coronary arteries were the most likely to benefit from coronary artery bypass surgery.

A second smaller study, the CARDia trial, enrolled 510 patients with similar types of blockages, similar rates of diabetes, and similar use of artery grafts in the CABG group.  The patients in the PCI group received an average of 3.5 stents, but not all were drug coated.  The average number of bypass grafts used was 2.8.  Overall results of this trial mimicked the findings of the larger SYNTAX study, with similar populations benefiting from CABG, and the same finding of a slightly higher stroke risk in bypass surgery patients.

The results of both studies suggest that patients with severe coronary artery disease, especially those who are diabetic and those with blockages in multiple coronary arteries may be best off with bypass surgery.  However, because all patients are unique and because the risk of stroke is slightly higher with CABG, treatment options should still be discussed in detail with your cardiologist.

References: The Synergy Between Percutaneous Coronary Intervention With TAXUS and Cardiac Surgery: The SYNTAX Study. Presented by Dr. Patrick Serruys at the European Society of Cardiology Congress, Munich, Germany, August/September 2008.

 Coronary Artery Revascularization in Diabetics: The CARDia Trial. Presented by Dr. Akhil Kapur at the European Society of Cardiology, Munich, Germany, August/September 2008.