Is it possible to create a risk tool to identify intermediate-risk patients with stable chest pain unlikely to benefit from noninvasive testing?
In this secondary analysis of a randomized clinical trial, 1243 of 4631 patients (26.8%) with stable chest pain had normal coronary arteries (without atherosclerosis) and no long-term clinical events. These minimal-risk patients can be identified with good discrimination using pretest clinical characteristics alone.
A clinical tool using readily available pretest variables discriminates such minimal-risk patients, for whom deferred testing may be considered.
Guidelines recommend noninvasive testing for patients with stable chest pain, although many subsequently have normal test results and no adverse clinical events.
To describe a risk tool developed to use only pretest clinical data to identify patients with chest pain with normal coronary arteries and no clinical events during follow-up (minimal-risk cohort).
Design, Setting, and Participants
This secondary analysis of a randomized, pragmatic comparative effectiveness trial (Prospective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]) includes stable, symptomatic outpatients without known coronary artery disease referred for noninvasive testing at 193 sites in North America.
Patients were randomized to receive coronary computed tomography angiography (CCTA) vs functional testing.
Main Outcomes and Measures
A low-risk tool was developed and internally validated from July 27, 2010, to September 19, 2013, in 4631 patients receiving CCTA as their initial test, with a median follow-up of 25 months. Logistic regression analysis was used to evaluate pretest variables to determine factors associated with minimal risk using a two-thirds random sample for model derivation (n = 3087) and a one-third sample for testing and validation (n = 1544). The model was then applied to the CCTA and functional testing arms, and test results and event rates were ascertained.
A total of 1243 of 4631 patients (26.8%) were in the minimal-risk cohort. The final minimal-risk model included 10 clinical variables that together were correlated with normal CCTA results and no clinical events (C statistic = 0.725 for the derivation and validation subsets; 95% CI, 0.705-0.746): 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 level. Across the entire PROMISE cohort, this model was associated with the lowest rates of severely abnormal test results (1.3% for CCTA; 5.6% for functional) and cardiovascular death or myocardial infarction (0.5% for a median of 25 months) among patients at the highest probability (10th decile) of minimal risk.
Conclusions and Relevance
In contemporary practice, more than 25% of patients with stable chest pain referred for noninvasive testing will have normal coronary arteries and no long-term clinical events. A clinical tool using readily available pretest variables discriminates such minimal-risk patients, for whom deferred testing may be considered.
clinicaltrials.gov Identifier: NCT01174550
Fordyce CB, Douglas PS, Roberts RS, Hoffmann U, Al-Khalidi HR, Patel MR, Granger CB, Kostis J, Mark DB, Lee KL, Udelson JE, for the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) Investigators. Identification of Patients With Stable Chest Pain Deriving Minimal Value From Noninvasive TestingThe PROMISE Minimal-Risk Tool, A Secondary Analysis of a Randomized Clinical Trial. JAMA Cardiol. Published online February 15, 2017. doi:10.1001/jamacardio.2016.5501