Best Treatment for Single-Vessel Coronary Artery Disease

CLINICAL QUESTION: What is the best treatment for left anterior descending artery stenosis in patients with stable angina?

BACKGROUND: Long-term studies comparing surgical bypass, angioplasty (PTCA), and medical therapy in the treatment of patients with stable angina and left anterior descending (LAD) artery stenosis are not available. LAD lesions are thought to have a worse prognosis than other singe-vessel lesions; therefore, more aggressive strategies have been promoted.

POPULATION STUDIED: Consecutive patients at a single institution in Brazil were selected from 1988 to 1991. Patients had stable angina, a proximal LAD stenosis, no previous myocardial infarction, and normal left ventricular function. Of 313 patients, approximately 15% did not meet the medical or angiographic criteria, and 15% refused to participate. Baseline characteristics were similar in the 3 groups, except mean total cholesterol levels, which were 240 in the medical group, 213 in the PTCA group, and 230 in the bypass group (no test of significance was performed).

STUDY DESIGN AND VALIDITY: This was a randomized control trial in which participants were randomly assigned to one of the 3 treatment groups (with approximately 70 patients in each group). Crossover from one group to another, according to symptoms, was allowed at any time. Medical therapy could include b-blockers, nitrates, calcium antagonists, and antiplatelet agents. Angiograms were repeated with the occurrence of a new ischemic event and after 5 years of follow-up. Analysis was by intention to treat. Advantages of the study design include careful clinical and angiographic case definitions, care at a single institution, and long-term and complete follow-up. Limitations included generalizability of the study (as most of the patients were Brazilian men) and lack of blinding of the physicians caring for the patients. Researchers may not have been prevented from knowing to which group the patient would be assigned before entering him in the trial (concealed allocation), which could introduce selective randomization of patients.

OUTCOMES MEASURED: The primary end point was the occurrence of cardiac-related death, acute myocardial infarction, or refractory angina requiring revascularization.

RESULTS: Patients treated either with bypass or medical therapy were significantly more likely than patients treated with PTCA to be event-free at the end of 5 years: 91% in the bypass group, 76% in the medical group, and 60% in the PTCA group (P = .001 for PTCA vs the other 2 treatments). Cardiac-related deaths were similar in the 3 groups. Of 72 medically treated patients, 8 required surgery, and 4 were treated with PTCA. Of 72 PTCA patients, 30% received repeat PTCA, and 8 underwent surgery. After 5 years, significantly fewer patients treated medically were free of angina: 26% of the medical group compared with 65% of the PTCA group and 73% of the surgery group (P <.001). No study patients had refractory angina. During follow-up, 50% of all patients developed new stenoses >50%) with no differences among groups. Rates of return to regular employment were similar among the groups.

CLINICAL QUESTION: What is the best treatment for left anterior descending artery stenosis in patients with stable angina?

BACKGROUND: Long-term studies comparing surgical bypass, angioplasty (PTCA), and medical therapy in the treatment of patients with stable angina and left anterior descending (LAD) artery stenosis are not available. LAD lesions are thought to have a worse prognosis than other singe-vessel lesions; therefore, more aggressive strategies have been promoted.

POPULATION STUDIED: Consecutive patients at a single institution in Brazil were selected from 1988 to 1991. Patients had stable angina, a proximal LAD stenosis, no previous myocardial infarction, and normal left ventricular function. Of 313 patients, approximately 15% did not meet the medical or angiographic criteria, and 15% refused to participate. Baseline characteristics were similar in the 3 groups, except mean total cholesterol levels, which were 240 in the medical group, 213 in the PTCA group, and 230 in the bypass group (no test of significance was performed).

STUDY DESIGN AND VALIDITY: This was a randomized control trial in which participants were randomly assigned to one of the 3 treatment groups (with approximately 70 patients in each group). Crossover from one group to another, according to symptoms, was allowed at any time. Medical therapy could include b-blockers, nitrates, calcium antagonists, and antiplatelet agents. Angiograms were repeated with the occurrence of a new ischemic event and after 5 years of follow-up. Analysis was by intention to treat. Advantages of the study design include careful clinical and angiographic case definitions, care at a single institution, and long-term and complete follow-up. Limitations included generalizability of the study (as most of the patients were Brazilian men) and lack of blinding of the physicians caring for the patients. Researchers may not have been prevented from knowing to which group the patient would be assigned before entering him in the trial (concealed allocation), which could introduce selective randomization of patients.

OUTCOMES MEASURED: The primary end point was the occurrence of cardiac-related death, acute myocardial infarction, or refractory angina requiring revascularization.

RESULTS: Patients treated either with bypass or medical therapy were significantly more likely than patients treated with PTCA to be event-free at the end of 5 years: 91% in the bypass group, 76% in the medical group, and 60% in the PTCA group (P = .001 for PTCA vs the other 2 treatments). Cardiac-related deaths were similar in the 3 groups. Of 72 medically treated patients, 8 required surgery, and 4 were treated with PTCA. Of 72 PTCA patients, 30% received repeat PTCA, and 8 underwent surgery. After 5 years, significantly fewer patients treated medically were free of angina: 26% of the medical group compared with 65% of the PTCA group and 73% of the surgery group (P <.001). No study patients had refractory angina. During follow-up, 50% of all patients developed new stenoses >50%) with no differences among groups. Rates of return to regular employment were similar among the groups.

CLINICAL QUESTION: What is the best treatment for left anterior descending artery stenosis in patients with stable angina?

BACKGROUND: Long-term studies comparing surgical bypass, angioplasty (PTCA), and medical therapy in the treatment of patients with stable angina and left anterior descending (LAD) artery stenosis are not available. LAD lesions are thought to have a worse prognosis than other singe-vessel lesions; therefore, more aggressive strategies have been promoted.

POPULATION STUDIED: Consecutive patients at a single institution in Brazil were selected from 1988 to 1991. Patients had stable angina, a proximal LAD stenosis, no previous myocardial infarction, and normal left ventricular function. Of 313 patients, approximately 15% did not meet the medical or angiographic criteria, and 15% refused to participate. Baseline characteristics were similar in the 3 groups, except mean total cholesterol levels, which were 240 in the medical group, 213 in the PTCA group, and 230 in the bypass group (no test of significance was performed).

STUDY DESIGN AND VALIDITY: This was a randomized control trial in which participants were randomly assigned to one of the 3 treatment groups (with approximately 70 patients in each group). Crossover from one group to another, according to symptoms, was allowed at any time. Medical therapy could include b-blockers, nitrates, calcium antagonists, and antiplatelet agents. Angiograms were repeated with the occurrence of a new ischemic event and after 5 years of follow-up. Analysis was by intention to treat. Advantages of the study design include careful clinical and angiographic case definitions, care at a single institution, and long-term and complete follow-up. Limitations included generalizability of the study (as most of the patients were Brazilian men) and lack of blinding of the physicians caring for the patients. Researchers may not have been prevented from knowing to which group the patient would be assigned before entering him in the trial (concealed allocation), which could introduce selective randomization of patients.

OUTCOMES MEASURED: The primary end point was the occurrence of cardiac-related death, acute myocardial infarction, or refractory angina requiring revascularization.

RESULTS: Patients treated either with bypass or medical therapy were significantly more likely than patients treated with PTCA to be event-free at the end of 5 years: 91% in the bypass group, 76% in the medical group, and 60% in the PTCA group (P = .001 for PTCA vs the other 2 treatments). Cardiac-related deaths were similar in the 3 groups. Of 72 medically treated patients, 8 required surgery, and 4 were treated with PTCA. Of 72 PTCA patients, 30% received repeat PTCA, and 8 underwent surgery. After 5 years, significantly fewer patients treated medically were free of angina: 26% of the medical group compared with 65% of the PTCA group and 73% of the surgery group (P <.001). No study patients had refractory angina. During follow-up, 50% of all patients developed new stenoses >50%) with no differences among groups. Rates of return to regular employment were similar among the groups.