October 1, 1996
View Full PaperAsymptomatic Cardiac Ischemia Pilot (ACIP) Study
Key Result
Ambulatory ECG monitoring and exercise treadmill testing showed significant but limited correlation in estimating ischemia severity, indicating the two tests are not redundant.
Study Design
Type
Cross-Sectional (n=802)
Structured PICO
Can clinical characteristics or exercise treadmill test performance predict the presence and frequency of asymptomatic ischemic episodes on ambulatory ECG in patients with stable coronary disease?
P
Population
802 patients with stable coronary disease who had 48-hour ambulatory ECG (AECG) monitoring and an exercise treadmill test (ETT) with ≥ 1-mm ST-segment depression (143 without AECG ischemic episodes and 659 with AECG ischemic episodes)
I
Intervention
Ambulatory ECG (AECG) monitoring and Exercise treadmill test (ETT)
O
Outcome
Presence and frequency of asymptomatic ischemic episodes on AECG, and correlation of ischemia severity between AECG and ETTsurrogate
Ambulatory ECG and exercise treadmill testing provide non-redundant information in characterizing ischemia in patients with stable coronary disease.
Limitations
- Lack of follow-up for clinical events to determine the prognostic significance of the ischemia identified by each modality
Abstract
BACKGROUND: We investigated whether the presence and frequency of asymptomatic ischemic episodes recorded during ambulatory ECG (AECG) monitoring could be predicted on the basis of clinical characteristics or exercise treadmill test (ETT) performance in patients with stable coronary disease and whether the estimate of ischemia severity was similar between the AECG and ETT. METHODS AND RESULTS: Patients screened for the Asymptomatic Cardiac Ischemia Pilot (ACIP) study were selected for the current analysis if data were available from 48-hour AECG monitoring as well as from an ETT during which the patient developed > or = 1-mm ST-segment depression. Exercise ECG data were available for 143 of the 910 patients without ischemic episodes and for 659 of the 910 patients with ischemic episodes during AECG monitoring. Angina was more frequent among patients with ambulatory ischemic episodes than among patients without such ischemia (P < .001). Patients with AECG ischemia had a consistently more marked ischemic response on the ETT than patients without AECG ischemia; patients likely to have AECG ischemia could be predicted on the basis of ETT performance characteristics. However, the correlation coefficients between the severity of ischemia estimated by ETT and by AECG were small. CONCLUSIONS: There are significant relations between ischemia detected by AECG monitoring and by ETT, but the relations are limited, indicating that the two tests are not redundant to characterize coronary patients. A larger study investigating the prognostic significance of the ischemia identified by each modality, with follow-up for clinical events, will be necessary to determine the most appropriate methods to evaluate patients with stable coronary disease.