چکیده (انگلیسی):

Background:Evaluation of angina symptoms in primary care often includes clinical exercise testing. We sought to
identify clinical characteristics that predicted the outcome of exercise testing and to describe the occurrence of
cardiovascular events during follow-up.
Methods:This study followed patients referred to exercise testing for suspected coronary disease by general
practitioners in the County of Jämtland, Sweden (enrolment, 25 months from February 2010). Patient characteristics
were registered by pre-test questionnaire. Exercise tests were performedwith a bicycle ergometer, a 12-lead
electrocardiogram, and validated scales for scoring angina symptoms. Exercise tests were classified as positive
(ST-segment depression >1 mm and chest pain indicative of angina), non-conclusive (ST depression or chest pain), or
negative. Odds ratios (ORs) for exercise-test outcome were calculated with a bivariate logistic model adjusted for age, sex,
systolic blood pressure, and previous cardiovascular events. Cardiovascular events (unstable angina, myocardial infarctions,
decisions on revascularization, cardiovascular death, and recurrent angina inprimary care) were recorded within six
months. A probability cut-off of 10% was used to detect cardiovasculareventsinrelationtothepredictedtestoutcome.
Results:We enrolled 865 patients (mean age 63.5 years, 50.6% men); 6.4% of patients had a positive test, 75.5%
were negative, 16.4% were non-conclusive, and 1.7% werenot assessable. Positive or non-conclusive test results
were predicted by exertional chest pain (OR 2.46, 95% confidence interval (CI) 1.69-3.59), a pathologic ST-T
segment on resting electrocardiogram (OR 2.29, 95% CI 1.44-3.63), angina according to the patient (OR 1.70,
95% CI 1.13-2.55), and medication for dyslipidaemia (OR 1.51, 95% CI 1.02-2.23). During follow-up, cardiovascular
events occurred in 8% of all patients and 4% were referred to revascularization. Cardiovascular events occurred
in 52.7%, 18.3%, and 2% of patients with positive, non-conclusive, or negative tests, respectively. The model
predicted 67/69 patients with a cardiovascular event.
Conclusions:Clinical characteristics can be used to predict exercise test outcome. Primary care patients with a
negative exercise test have a very low risk of cardiovascular events, within six months. A predictive model based
on clinical characteristics can be used to refine the identification of low-risk patients.