CABG versus PCI for three-vessel disease

This study compared the effects of percutaneous coronary intervention (PCI) with coronary artery bypass grafting (CABG) on long term mortality and morbidity in patients with three-vessel coronary artery disease.

Coronary artery disease, characterized by narrowing of the arteries and disrupted blood supply to the heart muscle, is a leading cause of death worldwide. Therefore, many therapies aim to restore optimal blood supply in order to reduce the risk of future fatal heart attacks. Tri-vessel coronary artery disease involves three or more major coronary arteries, supplying blood to three different territories of the heart, and often requires aggressive surgical intervention in order to restore proper blood flow to the heart muscle.

Coronary artery bypass grafting (CABG) is a surgical procedure in which the blocked coronary arteries are bypassed using blood vessels harvested from another area of the patient’s body (usually from the leg or chest).

Percutaneous coronary intervention (PCI) is a minimally invasive therapy, restoring normal blood flow by inserting a small catheter through an artery in the hand or thigh and into the narrowed artery of the heart. A small balloon at the end of the catheter is then inflated, opening the narrowed artery. Often, a stent (a small mesh tube) is placed in the narrowed vessel to help keep the artery open. Recent advances such as replacement of ordinary stents with drug secreting stents have led to improved prognosis in patients with coronary artery disease undergoing PCI.

For years CABG has been considered the first choice of treatment for tri-vessel coronary artery disease. However, due to the rapid progress in PCI technology, several randomized clinical trials have been conducted over the last decade comparing the outcomes of PCI and CABG among different patients, such as the large SYNTAX trial.

This study performed a comprehensive analysis on the 5-year outcomes of tri-vessel coronary artery disease patients receiving PCI or CABG in the previously published SYNTAX trial. 

Overall, in the original SYNTAX trial, 1,800 patients were randomized to receive either CABG or PCI. 1,095 of the 1,800 patients suffered from tri-vessel coronary artery disease. Of the tri-vessel patients, 549 were randomly assigned to undergo CABG surgery and 546 were randomized to undergo PCI (employing drug-eluting stents). Analysis of patient outcomes was preformed after achieving an average follow-up of 5 years.

Analysis showed that the occurrence of major adverse events (such as heart attacks) at 5-years was significantly greater in patients who underwent PCI compared to those who underwent CABG surgery. 37.5% of PCI patients experienced a major adverse event during the 5-year follow-up, compared to 24.2% of CABG patients.
Mortality risk was also increased with PCI among tri-vessel patients, with a 14.6% 5-year mortality rate for PCI compared to a 9.2% 5-year mortality rate for CABG.

This study concluded that CABG results in significantly reduced mortality and morbidity compared with PCI among tri-vessel coronary artery disease patients.