Screening for CVD Risk With Resting or Exercise ECG
What evidence did the authors find on screening asymptomatic adults for cardiovascular disease (CVD) risk using resting electrocardiography (ECG) or stress ECG, to inform the US Preventive Services Task Force (USPSTF)?
The authors’ review included MEDLINE, Cochrane Library, and trial registries through May 2017; and references, experts, and literature surveillance through April 4, 2018. Included were English-language randomized clinical trials (RCTs), as well as prospective cohort studies reporting reclassification, calibration, or discrimination that compared risk assessment using ECG plus traditional risk factors versus traditional risk factors alone. For harms, additional study designs were eligible. Studies of persons with symptoms or a CVD diagnosis were excluded. The main outcomes were mortality, CV events, reclassification, calibration, discrimination, and harms.
Sixteen studies were included (N = 77,140). Two RCTs (n = 1,151) found no significant improvement for screening with exercise ECG (vs. no screening) in adults aged 50-75 years with diabetes for the primary CV composite outcomes (hazard ratios, 1.00; 95% confidence interval [CI], 0.59-1.71, and 0.85; 95% CI, 0.39-1.84 for each study). No RCTs evaluated screening with resting ECG. Evidence from five cohort studies (n = 9,582) showed that adding exercise ECG to traditional risk factors such as age, sex, current smoking, diabetes, total cholesterol level, and high-density lipoprotein cholesterol level produced small improvements in discrimination (absolute improvements in area under the curve [AUC] or C-statistics, 0.02-0.03, reported by three studies); whether calibration or appropriate risk classification improves is uncertain. Evidence from nine cohort studies (n = 66,407) showed that adding resting ECG to traditional risk factors produced small improvements in discrimination (absolute improvement in AUC or C-statistics, 0.001-0.05) and appropriate risk classification for prediction of multiple CV outcomes, although evidence was limited by imprecision, quality, considerable heterogeneity, and inconsistent use of risk thresholds used for clinical decision making. Total net reclassification improvements ranged from 3.6% (2.7% event; 0.6% nonevent) to 30% (17% event; 19% nonevent) for studies using the Framingham Risk Score or Pooled Cohort Equations base models. Evidence on potential harms (e.g., from subsequent angiography or revascularization) in asymptomatic persons was limited.
RCTs of screening with exercise ECG found no improvement in health outcomes, despite focusing on higher-risk populations with diabetes. The addition of resting ECG to traditional risk factors accurately reclassified persons, but evidence for this finding had many limitations. The frequency of harms from screening is uncertain.
The USPSTF has provided many excellent evidence-based studies on the clinical utility of screening. And the conclusion that routine screening with an ECG or stress ECG is consistent with other guidelines regarding little to know cost-effective benefit. There are caveats, however, as presented in the accompanying abstract review that gives the recommendation.
Keywords: Angiography, Cardiovascular Diseases, Cholesterol, HDL, Diabetes Mellitus, Electrocardiography, Exercise Test, Primary Prevention, Myocardial Revascularization, Risk Assessment, Risk Factors, Smoking
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