Computed Tomographic Coronary Artery Calcium Assessment for Evaluating Chest Pain in the Emergency Department: Long-term Outcome of a Prospective Blind Study

Abstract

For editorial comment, see page 309 C hest pain is the presenting concern for more than 8 million emergency department (ED) visits annually. The ED evaluation of chest pain is resource-intense and has inherent limitations. Medical history and physical examination frequently yield little insight into the source of the chest pain. More than one-third of patients with docu- OBJECTIVE: To determine the long-term outcome of computed tomographic (CT) quantification of coronary artery calcium (CAC) used as a triage tool for patients presenting with chest pain to an emergency department (ED). PATIENTS AND METHODS:Patients (men aged 30-62 years and women aged 30-65 years) with chest pain and low-to-moderate probability of coronary artery disease underwent both conventional ED chest pain evaluation and CT CAC assessment prospectively. Patients' physicians were blinded to the CAC results. The results of the conventional evaluation were compared with CAC findings on CT, and the long-term outcome in patients undergoing CT CAC assessment was established. Primary end points (acute coronary syndrome, death, fatal or nonfatal non-ST-segment elevation myocardial infarction, fatal or nonfatal ST-segment elevation myocardial infarction) and secondary outcomes (coronary artery bypass grafting, percutaneous transluminal coronary angioplasty, coronary stenting, or a combination thereof) were obtained when the patient was dismissed from the ED or hospital and then at 30 days, 1 year, and 5 years. RESULTS:Of the 263 study patients, 133 (51%) had a CAC score of zero. This absence of CAC correlated strongly with the likelihood of noncardiac chest pain. Among 133 patients with a CAC score of zero, only 1 (<1%) had cardiac chest pain. Conversely, of the 31 patients shown to have cardiac chest pain, 30 (97%) had evidence of CAC on CT. When a CAC cutoff score of 36 was used, as suggested by receiver operating characteristic analysis, sensitivity was 90%; specificity, 85%; positive predictive value, 44%; and negative predictive value, 99%. During long-term follow-up, patients without CAC experienced no cardiac events at 30 days, 1 year, and 5 years.CONCLUSION: Findings suggest that CT CAC assessment is a powerful adjunct in chest pain evaluation for the population at low-tointermediate risk. Absent or minimal CAC in this population makes cardiac chest pain extremely unlikely. The absence of CAC suggests an excellent long-term (5-year) prognosis, with no primary or secondary cardiac outcomes ocurring in study patients at 5-year follow-up. Proc. 2010;85(4):314-322 ACS = acute coronary syndrome; CAC = coronary artery calcium; CAD = coronary artery disease; CI = confidence interval; CT = computed tomography; CTA = CT angiography; ECG = electrocardiography; ED = emergency department; IQR = interquartile range; MDCT = multidetector CT; MI = myocardial infarction; ROC = receiver operating characteristic mented acute myocardial infarctions (MIs) lack chest pain on presentation. Mayo Clin2 Resting 12-lead electrocardiography (ECG) has limited value in ...

Calcium Imaging in the Emergency Department

“…The ability of calcium imaging to rule out ACS in low-risk patients has been demonstrated repeatedly, and a negative calcium score is associated with an excellent prognosis. [13][14][15][16][17] The combined data in this study similarly demonstrate the high negative predictive value of a negative calcium scan. There was a single myocardial infarction in ≈800 patients with a negative calcium scan, whereas another 3 patients were classified as unstable angina.…”

Systematic review, meta-analysis and economic modelling of diagnostic strategies for suspected acute coronary syndrome

“…[138][139][140][141][142][143][144][145][146][147][148][149][150] We also identified a prognostic study of CT CAC scoring without angiography. 151 Two of the prognostic studies of CTCA reported different follow-up for the same cohort, 132,133 and two of the prognostic studies of exercise ECG reported some patients in common. 138,140 The lack of any diagnostic studies comparing exercise ECG with ICA is not surprising, as exercise ECG only started to be used in patients presenting to hospital with acute pain many years after its diagnostic accuracy for CAD had been evaluated in patients with stable chest pain.…”

“…The study of CT CAC scoring 151 reported that 9 out of 91 patients with a CAC score of > 0 had MACEs (two MI and nine PCI), compared with 0 out of 82 with a CAC score = 0.…”

Optimizing Evaluation of Patients with Low-to-Intermediate-Risk Acute Chest Pain: A Randomized Study Comparing Stress Myocardial Perfusion Tomography Incorporating Stress-Only Imaging Versus Cardiac CT

“…CACS may also challenge SPECT, which requires additional patient preparation, must be performed in conjunction with a stressor modality through coordination of medical and technical staff, is dependent on radiotracer availability, has higher radiation exposure, and may require considerable expertise for accurate interpretation. Most low-to-intermediaterisk patients (;55%) with ACP have a CACS of 0 (7,17,(23)(24)(25)(26)(27)(28) in whom there is a low likelihood of abnormal SPECT (0.8%) (7) or significant CAD as shown in the current study. Pooled data from 8 studies and ours suggest high sensitivity (96%; 95% confidence interval, 92%-98%) and negative predictive accuracy (99.4%; 95% confidence interval, 99%-100%) (7,17,(23)(24)(25)(26)(27)(28) for excluding ACS with CACS, which is comparable to CTA or SPECT (3)(4)(5)(6)(7)9).…”