Comparison of exercise treadmill testing with cardiac computed tomography angiography among patients presenting to the emergency room with chest pain: the Rule Out Myocardial Infarction Using Computer-Assisted Tomography (ROMICAT) study.
ABSTRACT The aims of our study were to (1) examine how data from exercise treadmill testing (ETT) can identify patients who have coronary plaque or stenosis, using CT angiography (CTA) as the reference standard, and (2) identify patient characteristics that may be used in selecting ETT versus CTA.
The Rule Out Myocardial Infarction Using Computer-Assisted Tomography (ROMICAT) trial was an observational cohort study of acute chest pain patients presenting to the emergency department with normal initial troponin and a nonischemic ECG. Univariate and multivariable analyses were performed to assess the relationship of baseline clinical data and ETT parameters with coronary plaque and stenosis on CTA. Of the 220 patients who had ETT (mean age, 51 years; 63% men), 21 (10%) had positive results. A positive ETT had a sensitivity of 30% and specificity of 93% to detect >50% stenosis. The sensitivity increased to 83% after excluding uninterpretable segments and evaluating the ability to detect a >70% stenosis. Predictors of plaque included older age, male sex, diabetes, hypertension, hyperlipidemia, lower functional capacity, and a lower Duke Treadmill Score. Both a positive ETT and a low Duke Treadmill Score were significant univariate and multivariable predictors of stenosis >50% on CTA Whereas the prevalence of stenosis by CTA was greater among patients with more risk factors, coronary stenosis was not present among men <40 years old or women <50 years old or individuals who achieved at least 13 metabolic equivalents on ETT.
Among low- to intermediate-risk patients with acute chest pain, a positive ETT has a limited sensitivity but high specificity for the detection of >50% stenosis by CTA. Although patients with a high number of clinical risk factors are more likely to have obstructive coronary artery disease, those who are young or who would be expected to have a very high exercise capacity are unlikely to have coronary stenosis and therefore may benefit from initial ETT testing instead of CTA.
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ABSTRACT: Recent studies have compared CTA to stress testing and MPI using older Na-I SPECT cameras and traditional rest-stress protocols, but are limited by often using optimized CTA protocols but suboptimal MPI methodology. We compared CTA to stress testing with modern SPECT MPI using high-efficiency CZT cameras and stress-first protocols in an ED population. In a retrospective, non-randomized study, all patients who underwent CTA or stress testing (ETT or Tc-99m sestamibi SPECT MPI) as part of their ED assessment in 2010-2011 driven by ED attending preference and equipment availability were evaluated for their disposition from the ED (admission vs discharge, length of time to disposition), subsequent visits to the ED and diagnostic testing (within 3 months), and radiation exposure. CTA was performed using a 64-slice scanner (GE Lightspeed VCT) and MPI was performed using a CZT SPECT camera (GE Discovery 530c). Data were obtained from prospectively acquired electronic medical records and effective doses were calculated from published conversion factors. A propensity-matched analysis was also used to compare outcomes in the two groups. A total of 1,458 patients underwent testing in the ED with 192 CTAs and 1,266 stress tests (327 ETTs and 939 MPIs). The CTA patients were a lower-risk cohort based on age, risk factors, and known heart disease. A statistically similar proportion of patients was discharged directly from the ED in the stress testing group (82% vs 73%, P = .27), but their time to disposition was longer (11.0 ± 5 vs 20.5 ± 7 hours, P < .0001). There was no significant difference in cardiac return visits to the ED (5.7% CTA vs 4.3% stress testing, P = .50), but more patients had follow-up studies in the CTA cohort compared to stress testing (14% vs 7%, P = .001). The mean effective dose of 12.6 ± 8.6 mSv for the CTA group was higher (P < .0001) than 5.0 ± 4.1 mSv for the stress testing group (ETT and MPI). A propensity score-matched cohort showed similar results to the entire cohort. Stress testing with ETT, high-efficiency SPECT MPI, and stress-only protocols had a significantly lower patient radiation dose and less follow-up diagnostic testing than CTA with similar cardiac return visits. CTA had a shorter time to disposition, but there was a trend toward more revascularization than with stress testing.Journal of Nuclear Cardiology 12/2013; · 2.65 Impact Factor
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ABSTRACT: Introduction: The purpose of this study is to investigate the cost and resource utilization due to recurrent chest pain evaluations after initial evaluation with coronary computed tomography angiography (CCTA) based upon coronary artery disease (CAD) burden. Methods: CCTA results of 1,518 patients from January 2005 until July 2012 at a single high volume, tertiary center performed in the inpatient or outpatient setting for cardiac symptoms. Patients were grouped based on the CCTA results into no CAD, non-obstructive CAD (<50% maximal diameter stenosis), or obstructive CAD (≥50% stenosis). Re-evaluation for chest pain syndrome after initial CCTA, as well as rates of major adverse cardiovascular events (MACE) defined as the incidence of all-cause mortality, non-fatal MI, ischemic stroke, and late revascularization (>90 days following CCTA) were evaluated. Results: Over a review period of six years with a resultant median follow-up period of 22 months (IQR25-7513 - 34 months), the MACE rate was significantly higher with obstructive CAD compared to both non-obstructive CAD and no CAD (8.9% vs. 0.7%, p<0.001; 8.9 vs. 1.6%, p<0.001). In the 1518 patients evaluated, the mean age increased with increasing CCTA disease burden (p<0.001) with equal gender distribution amongst the groups. 174 patients (11.5%) underwent re-evaluation for acute chest pain after index CCTA with rates significantly higher with obstructive CAD compared to both non-obstructive CAD and no CAD (7.5% vs 13.9% vs 17.8%, p<0.001). The incidence of repeat testing was more frequent in patients with obstructive CAD (no CAD 36.5% vs non-obstructive CAD 54.9% vs obstructive CAD 67.7%, p=0.015). Conclusion: Absence of obstructive disease on CCTA is associated with much lower rates of subsequent evaluations for chest pain and repeat testing with associated low MACE event rates over 6-year review period and median follow-up of 22 months.ISRN Software Engineering 04/2014;
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ABSTRACT: Chest pain is a common complaint in the emergency department often necessitating testing to exclude underlying obstructive coronary artery disease. While the traditional evaluation of patients with suspected acute coronary syndrome often consists of serial electrocardiograms and cardiac biomarkers, followed by selective use of stress testing for further risk stratification, this approach is costly and inefficient. Recently, coronary computed tomographic angiography (CTA) has offered an alternative approach with a high sensitivity and negative predictive value to exclude obstructive coronary artery disease that can rapidly identify patients with low rates of downstream major adverse cardiac events. In this review, the authors provide an overview of available data on the use of CTA for evaluating acute chest pain, while emphasizing its advantages and disadvantages compared to existing strategies. In addition, we provide a suggested algorithm to identify how CTA can be incorporated into the evaluation of acute chest pain and discuss tips for successful implementation of CTA in the emergency department.Expert Review of Cardiovascular Therapy 01/2014;