Incremental prognostic value of the exercise electrocardiogram in the initial assessment of patients with suspected angina: cohort study.
OBJECTIVE
To determine whether resting and exercise electrocardiograms (ECGs) provide prognostic value that is incremental to that obtained from the clinical history in ambulatory patients with suspected angina attending chest pain clinics.


METHODS
Multicentre cohort study.


METHODS
Rapid access chest pain clinics of six hospitals in England.


METHODS
8176 consecutive patients with suspected angina and no previous diagnosis of coronary artery disease, all of whom had a resting ECG recorded. 4848 patients with a summary exercise ECG result recorded (positive, negative, equivocal for ischaemia) comprised the summary ECG subset of whom 1422 with more detailed exercise ECG data recorded comprised the detailed ECG subset.


METHODS
Composite of death due to coronary heart disease or non-fatal acute coronary syndrome during median follow-up of 2.46 years.


RESULTS
Receiver operating characteristics curves for the basic clinical assessment model alone and with the results of resting ECGs were superimposed with little difference in the C statistic. With the exercise ECGs the C statistic in the summary ECG subset increased from 0.70 (95% confidence interval 0.68 to 0.73) to 0.74 (0.71 to 0.76) and in the detailed ECG subset from 0.74 (0.70 to 0.79) to 0.78 (0.74 to 0.82). However, risk stratified cumulative probabilities of the primary end point at one year and six years for all three prognostic indices (clinical assessment only; clinical assessment plus resting ECG; clinical assessment plus resting ECG plus exercise ECG) showed only small differences at all time points and at all levels of risk.


CONCLUSIONS
In ambulatory patients with suspected angina, basic clinical assessment encompasses nearly all the prognostic value of resting ECGs and most of the prognostic value of exercise ECGs. The limited incremental value of these widely applied tests emphasises the need for more effective methods of risk stratification in this group of patients.
Sekhri
Neha
N
Newham University Hospital, London.
Feder
Gene S
GS
Junghans
Cornelia
C
Eldridge
Sandra
S
Umaipalan
Athavan
A
Madhu
Rashmi
R
Hemingway
Harry
H
Timmis
Adam D
AD
D054058:Acute Coronary Syndrome / Q000175:diagnosis; D000787:Angina Pectoris / Q000209:etiology*; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000175:diagnosis; D004562:Electrocardiography / Q000379:methods*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D012680:Sensitivity and Specificity