Emory Angioplasty Versus Surgery Trial (EAST)

BACKGROUND:

PTCA is widely practiced as the procedure of choice for revascularization of the myocardium in patients with single-vessel disease who are deemed to need intervention and is probably more widely applied than surgery would be in the same group of patients. No study has shown improved survival by intervention in such patients. The early natural history study by Oberman showed survival experience of patients with single-vessel disease, including the anterior descending, to resemble more closely patients with no coronary artery disease than those with multivessel disease. Quality of life studies including the CASS randomized study, which included 27 percent single-vessel disease patients, showed improved exercise tolerance and less need for medication in patients who received PTCA For single-vessel disease. Balloon angioplasty in single-vessel disease thus appears justified for the treatment of angina pectoris.

In multivessel disease the CASS randomized trial has shown an improved survival at seven years in the subset of patients with three-vessel disease and impaired ventricular function. However, seven years may prove to be the point of widest separation between the medical and surgical survival curves, based on the experience of the VA study which has presented results to 11 years showing convergence of survival experience. Data from the Montreal Heart Institute also indicate accelerated deterioration of venous grafts five to seven years after surgery. The late failure of grafts is a potent argument for delaying CABG as long as possible in the patients with multivessel disease. Should PTCA prove to be only a delaying action in multivessel disease patients, a delay of several years until the first CABG operation would confer an obvious advantage, even if repeat PTCA's were required. Repeat CABG may carry an increased risk and presumably the possibility of inadequate revascularization as autologous graft material is used up.

As long as treatment for coronary artery disease is only palliative, management for the individual patient requires a long-term (a lifetime) strategy, beginning with medical management. PTCA could occupy an intermediate position in the time line of management of multivessel disease patients if its relative efficiency in providing relief of ischemia and ability to avoid or delay CABG were known. Most centers performing PTCA now have expanded the indications for the procedure to patients with multivessel disease. However, its efficacy in those patients has not been proven. Although data from the NHLBI PTCA Registry do include patients with multivessel disease, most of those patients underwent only single PTCA procedures even though they may have had stenoses in other vessels. Hence, a number of questions must be raised concerning the usefulness of PTCA in patients with multivessel disease.

DESIGN NARRATIVE: