Angioplasty Compared to Medicine - ACME

Description:

PTCA vs. medical management for symptoms of stable single-vessel disease.

Hypothesis:

PTCA would be more effective than medical therapy in reducing angina and increasing exercise tolerance in patients with stable single-vessel coronary artery disease.

Study Design

Study Design:

Patients Screened: 9,573
Patients Enrolled: 212
Mean Follow Up: 6 months
Mean Patient Age: 62.5
Female: 0
Mean Ejection Fraction: - Medical therapy group: 65.5±1.3
- PTCA group: 64.9±1.1

Patient Populations:

Stable angina pectoris
A strikingly positive exercise-tolerance test (ETT)
A myocardial infarction (MI) within the past three months

Angiographic requirement:
Stenosis of 70 to 99% of the diameter in the proximal 2/3 of one major epicardial coronary artery, or similar serial stenoses limited to the proximal 2/3 of the same artery or its branches (qualifying lesions were referred to as index lesions).

Exercise test requirement (one of the following):
Horizontal or down-sloping ST-segment depression > 1.0 mm in one or more leads measured 80 msec after the J point that occurred during or after treadmill exercise testing.

Angina during the exercise test. with evidence on thallium scanning of a defect in the area corresponding to the index lesion that "filled in" during the period after the exercise test

Exclusions:

Multivessel coronary-artery disease
Total occlusion
Previous coronary-artery surgery or PTCA
Ongoing unstable angina
Female sex
Participation in another trial
Unable to return monthly
Negative ETT
Valvular disease
Ejection fraction < 30%

Primary Endpoints:

Change in exercise tolerance between the baseline and follow-up exercise tests
Frequency of angina attacks
The use of nitroglycerin between the baseline and final month of the study

Secondary Endpoints:

Change in the degree of stenosis in the originally identified index lesions
Change in the score on a standard self-administered questionnaire designed to measure psychological well-being
Employment status

Drug/Procedures Used:

Medical therapy group received a stepped-care approach designed to eliminate angina, including one or more of the following:
Oral isosorbide dinitrate with sublingual prophylactic and therapeutic nitroglycerin
β-blocking agents
Calcium-c.

Concomitant Medications:

325 mg aspirin qd (all patients)

Principal Findings:

Two of the 105 patients in the PTCA group required emergency coronary-artery bypass surgery.

By six months after the initial PTCA procedure, 16 patients had had repeat PTCA.

MI occurred in 5/105 patients assigned to PTCA and 3/107 assigned to medical therapy.

At 6 months, 64% of the patients in the PTCA group were free of angina, compared with 46% of medically-treated patients ( p < 0.01).

PTCA patients were able to increase their total exercise duration more than medical patients: 2.1 minutes for the PTCA group, 0.5 minutes for the drug therapy group (p <0.001), and were able to exercise longer without angina on treadmill testing (p < 0.01). An extension of this study by these investigators randomized 328 male patients with stable angina pectoris and ischemia on treadmill testing. A total of 101 patients had two-vessel disease, and 227 had single-vessel disease. PTCA-treated and medically treated patients with two-vessel disease experienced comparable improvement in exercise duration (+1.2 vs. +1.3 min, respectively, p = 0.89), freedom from angina (53% and 36%, respectively, p = 0.09) and improvement of overall quality of life score (+1.3 vs. +4.4, respectively, p = 0.32) at 6 months compared with baseline. Patients undergoing double-vessel dilation had less complete initial revascularization (45% vs. 83%) and greater average stenosis of worst lesions at 6 months (74% vs. 56%). Likewise, patients with double-vessel disease showed less improved myocardial perfusion imaging (59% vs. 75%).

Interpretation:

For patients with single-vessel coronary artery disease, PTCA offered earlier and more complete relief of angina than medical therapy and was associated with better performance on exercise tests. However, PTCA initially cost more and was associated with a higher frequency of complications. PTCA was beneficial for male patients with two-vessel disease; however, the advantage over medical therapy was not as well defined as for single-vessel disease patients. Less complete revascularization and greater restenosis for patients having multiple dilations would account for these findings. Technical advances since completion of this trial might improve these outcomes.

References:

1. N Engl J Med 1992;326:10-16. Final results (single-vessel disease)
2. J Am Coll Cardiol 1997;29:1505-11. Two-vessel disease

Keywords: Exercise Tolerance, Isosorbide Dinitrate, Myocardial Perfusion Imaging, Coronary Artery Disease, Myocardial Infarction, Angina, Stable, Quality of Life, Constriction, Pathologic, Coronary Artery Bypass, Nitroglycerin, Exercise Test


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