La Asociación entre la Probabilidad Pretest de Enfermedad de la Arteria Coronaria y la Realización de la Prueba de Esfuerzo y Sus Resultados en Una Unidad de Dolor Torácico

Objectives Cardiology consensus guidelines recommend use of the Diamond and Forrester (D&F) score to augment the decision to pursue stress testing. However, recent work has reported no association between pretest probability of coronary artery disease ( CAD ) as measured by D&F and physician discretion in stress test utilization for inpatients. The author hypothesized that D&F pretest probability would predict the likelihood of acute coronary syndrome ( ACS ) and a positive stress test and that there would be limited yield to diagnostic testing of patients categorized as low pretest probability by D&F score who are admitted to a chest pain observation unit ( CPU ). Methods This was a prospective observational cohort study of consecutively admitted CPU patients in a large‐volume academic urban emergency department (ED). Cardiologists rounded on all patients and stress test utilization was driven by their recommendations. Inclusion criteria were as follows: age > 18 years, American Heart Association ( AHA ) low/intermediate risk, nondynamic electrocardiograms ( ECG s), and normal initial troponin I. Exclusion criteria were as follows: age older than 75 years with a history of CAD . A D&F score for likelihood of CAD was calculated on each patient independent of patient care. Based on the D&F score, patients were assigned a priori to low‐, intermediate‐, and high‐risk groups (<10, 10 to 90, and >90%, respectively). ACS was defined by ischemia on stress test, coronary artery occlusion of ≥70% in at least one vessel, or elevations in troponin I consistent with consensus guidelines. A true‐positive stress test was defined by evidence of reversible ischemia and subsequent angiographic evidence of critical stenosis or a discharge diagnosis of ACS . An estimated 3,500 patients would be necessary to have 1% precision around a potential 0.3% event rate in low‐pretest‐probability patients. Categorical comparisons were made using Pearson chi‐square testing. Results A total of 3,552 patients with index visits were enrolled over a 29‐month period. The mean (± standard deviation [ SD ]) age was 51.3 (±9.3) years. Forty‐nine percent of patients received stress testing. Pretest probability based on D&F score was associated with stress test utilization (p < 0.01), risk of ACS (p < 0.01), and true‐positive stress tests (p = 0.03). No patients with low pretest probability were subsequently diagnosed with ACS (95% CI  = 0 to 0.66%) or had a true‐positive stress test (95% CI  = 0 to 1.6%). Conclusions Physician discretionary decision‐making regarding stress test use is associated with pretest probability of CAD . However, based on the D&F score, low‐pretest‐probability patients who meet CPU admission criteria are very unlikely to have a true‐positive stress test or eventually receive a diagnosis of ACS , such that observation and stress test utilization may be obviated.