Data from a secondary analysis showed that an online tool can accurately predict which patients with chest pain are likely to have normal non-invasive test results and remain free of cardiac adverse events. Full findings are published in JAMA Cardiology.
Currently, guidelines recommend noninvasive testing for patients with stable chest pain though many of these patients may have normal test results and no adverse events. Researchers assessed a risk tool that was developed to use only pretest data to identify the ‘minimal-risk cohort’—patients with chest pain with normal coronary arteries and no clinical events at follow-up. To do this, Christopher B. Fordyce, MD, MHS, MSc, and colleagues conducted a secondary analysis of the PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) trial, a randomized, pragmatic comparative efficacy trial among stable, symptomatic outpatients without known coronary artery disease referred for noninvasive testing.
Study patients were randomized to either coronary computed tomography angiography (CCTA) or functional testing. The low-risk tool was created and validated from July 27, 2010 to September 19, 2013 in patients initially receiving CCTA (n=4,631) with a median follow-up of 25 months. Pretest variables were evaluated to determine which factors were associated with minimal risk using a random sample for model derivation (n=3,087) and a sample for testing and validation (n=1,544). This was then applied to the CCTA and functional testing groups to calculate test results and event rates.
A total of 1,243 of the total patients (26.8%) were found to be in the minimal-risk cohort. The final minimal-risk tool evaluated 10 clinical variables that were associated with normal CCTA results and no clinical events: younger age; female sex; racial or ethnic minority, no history of hypertension, diabetes, or dyslipidemia; family history of premature coronary artery disease; never smoking, symptoms unrelated to physical or mental stress; and higher high-density lipoprotein cholesterol levels. This model was linked to the lowest rates of severely abnormal test results for the whole PROMISE cohort (1.3% for CCTA and 5.6% for functional testing, as well as for cardiovascular death or myocardial infarction (0.5% for a median of 25 median months) among patients at the highest probability of minimal risk.
Based on this data, it was determined that more than 25% of patients with stable chest pain who have noninvasive testing will have completely normal tests results and no long-term adverse events. “A clinical tool using readily available pretest variables discriminates such minimal-risk patients, for whom testing may be considered,” Dr. Fordyce added.
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