Emory Angioplasty Versus Surgery Trial (EAST)
Condition: Cardiovascular Diseases; Coronary Disease; Heart Diseases; Myocardial Ischemia
MeSH terms: Cardiovascular Diseases; Heart Diseases; Coronary Disease; Myocardial Ischemia; Ischemia
Study type: Interventional
Phase: Phase 3

Summary: 
      To compare the efficacy of coronary artery bypass graft (CABG) surgery with percutaneous
      transluminal coronary angioplasty (PTCA) in patients with multiple vessel coronary heart
      disease.
    

Detailed description: 
      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:

      Randomized, single-center. A total of 198 patients were randomized to the PTCA group and 194
      to the CABG group. As initial treatment, one patient in the CABG group underwent angioplasty
      and two patients in the PTCA group underwent surgery, but the groups were followed according
      to an intention-to-treat analysis. Randomization was performed on the basis of four
      angiographic strata. Data were collected at baseline, and the patients were contacted every
      six months for follow-up information. Coronary arteriography and thallium stress scanning
      were performed at one and three years. All patients were followed for the duration of the
      trial. Repeat angiographic studies were performed in 87 percent of the eligible patients at
      one year and in 76 percent at three years. Thallium scans were obtained in 88 percent of the
      patients at one year and in 77 percent at three years. The primary endpoint was a composite
      of death, Q-wave myocardial infarction within the previous three years, and detection of a
      large ischemic defect on thallium scanning at three years. Secondary endpoints involved the
      degree of revascularization at one and three years, ventricular function, exercise
      performance, the need for subsequent revascularization procedures, the quality of life, and
      costs. All patients admitted to Emory University Hospital and Crawford Long Memorial Hospital
      for cardiac catheterization, whether entered into the study or not, were entered into a study
      registry as were patients who were referred for a revascularization procedure but who had
      their initial catheterization performed elsewhere. Recruitment ended in April 1990. The trial
      has been extended through August 1997 to allow a minimum of eight years and a maximum of ten
      years of followup for the registry patients as well as for the main cohort of randomized
      patients. Telephone contact is established annually with study participants in order to
      determine rates of survival, rehospitalization, repeat revascularization procedures, and
      functional status. The justification for the long-term followup is the evidence that CABG
      begins to increase its failure rates between five and ten years.

      The study completion date listed in this record was obtained from the "End Date" entered in
      the Protocol Registration and Results System (PRS) record.
    

Intervention name(s): angioplasty, transluminal, percutaneous coronary; coronary artery bypass
Intervention type(s): Procedure; Procedure
Allocation: Randomized
Intervention model: Parallel Assignment
Primary purpose: Treatment