Asymptomatic Cardiac Ischemia Pilot (ACIP) study: impact of anti-ischemia therapy on 12-week rest electrocardiogram and exercise test outcomes. The ACIP Investigators.
OBJECTIVE
This report from the Asymptomatic Cardiac Ischemia Pilot (ACIP) study examines differences in the magnitude of reduction of myocardial ischemia as determined by exercise treadmill testing in patients randomized to three different treatment strategies: angina-guided medical therapy, ischemia-guided medical therapy and coronary revascularization.


BACKGROUND
No prospective randomized clinical trials in patients with exercise electrocardiographic (ECG) abnormalities and asymptomatic cardiac ischemia on ambulatory ECG monitoring have compared the impact of different treatment strategies, including coronary revascularization, in terms of reducing myocardial ischemia.


METHODS
The ACIP exercise protocol was used. Exercise variables measured included final exercise stage; presence of exercise-induced angina or ischemia; time to angina; time to 1-mm ST segment depression; number of exercise ECG leads with abnormalities; maximal depth of ST segment depression in any lead; sum of ST segment depression; ST/HR index; and rate-pressure product at time to angina, at time to 1-mm ST segment depression and at peak exertion.


RESULTS
Peak exercise time was increased by 0.5, 0.7 and 1.6 min in patients assigned to the angina-guided, ischemia-guided and coronary revascularization strategies, respectively, from the qualifying visit to the 12-week visit (p < 0.001). At the qualifying visit, the sum of exercise-induced ST segment depression was 9.4 +/- 5.0 (mean +/- SD), 9.6 +/- 4.7 and 9.9 +/- 5.5 mm (p = NS) in the three treatment strategies, respectively. At the 12-week visit, the sum of exercise-induced ST segment depression was 7.4 +/- 5.7, 6.8 +/- 5.3 and 5.6 +/- 5.6 mm (p = 0.02) in the three treatment strategies, respectively. Each treatment strategy resulted in a significant reduction in all exercise-induced variables of myocardial ischemia measured at 12 weeks.


CONCLUSIONS
Coronary revascularization significantly reduced the extent and frequency of exercise-induced myocardial ischemia compared with either medical strategy. The prognostic impact of these observations should be evaluated in a large-scale multicenter clinical trial.
Chaitman
B R
BR
Division of Cardiology, Saint Louis University Health Sciences Center, Missouri 63110-0250, USA.
Stone
P H
PH
Knatterud
G L
GL
Forman
S A
SA
Sopko
G
G
Bourassa
M G
MG
Pratt
C
C
Rogers
W J
WJ
Pepine
C J
CJ
Conti
C R
CR
D000704:Analysis of Variance; D015906:Angioplasty, Balloon, Coronary / Q000706:statistics & numerical data; D002317:Cardiovascular Agents / Q000627:therapeutic use; D003131:Combined Modality Therapy; D001026:Coronary Artery Bypass / Q000706:statistics & numerical data; D004359:Drug Therapy, Combination; D015716:Electrocardiography, Ambulatory / Q000706:statistics & numerical data; D005080:Exercise Test / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000628:therapy*; D010865:Pilot Projects; D011446:Prospective Studies; D012074:Remission Induction; D012146:Rest; D013997:Time Factors; D016896:Treatment Outcome
D002317:Cardiovascular Agents