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  • There were no significant differences in patient baseline characteristics between the conventional and MDCT strategies (
  • Mdct2

    1. 1. Usefulness of 64-slice MDCT as an initial diagnostic approach in patients with acute chest pain Sung-A Chang, Sang Il Choi, Eue-Keun Choi, et al. Am Heart J 2008;156:375-83 Journal Club 7 th August 2008 Dr. Rashidi Ahmad Dr. Emily Tan Dato’ Dr. Azhari Rosman
    2. 2. Introduction <ul><li>Appropriate triage of patients with acute CP is the most important issues for EPs </li></ul><ul><li>– high morbidity and mortality of missed </li></ul><ul><li>cases of ACS </li></ul><ul><li>To date, the triage of patients with CP depends on the individual's symptom history, serial ECG, and cardiac biomarkers. </li></ul>Pope JH, et al. Missed diagnoses of acute cardiac ischemia in the emergency department. N Engl J Med 2000;342:1163-70.
    3. 3. Rationale of the study <ul><li>Patients with ACS may have non-diagnostic findings on their initial evaluation. </li></ul><ul><li>Current diagnostic tools have limited capability to define the etiology of acute chest pain. </li></ul><ul><li>As a result: overcrowded state of ED,  unnecessary admission & misappropriation of resources. </li></ul><ul><li>Solution… </li></ul>Antman EM, et al. The TIMI risk score for USA/NSTEMI: a method for prognostication and therapeutic decision making. JAMA 2000;284:835-42.
    4. 4. MDCT <ul><li>With rapid technical improvements, cardiac MDCT permits noninvasive imaging of coronary anatomy with high accuracy & may also provide insight into non-coronary causes of chest pain. </li></ul>Raff GL, et al. Diagnostic accuracy of noninvasive coronary angiography using 64-slice spiral computed tomography. J Am Coll Cardiol 2005;46:552-7. Johnson TR, et al. ECG-gated 64- MDCT angiography in the differential diagnosis of acute chest pain. Am J Roentgenol 2007;188:76-82.
    5. 5. MDCT <ul><li>64-slice MDCT in acute chest pain is safe, feasible and facilitates early triage of acute CP in low-risk patients, primarily relying on their negative MDCT result </li></ul><ul><li>The appropriate use and timing of MDCT in the ED are still unclear and its role in patients with different risk profiles has not been studied yet. </li></ul>White CS, et al. Chest pain evaluation in the ED: can MDCT provide a comprehensive evaluation? Am J Roentgenol 2005;185:533-40. Rubinshtein R, et al. Usefulness of 64-slice MDCT for diagnosing ACS & predicting clinical outcome in ED patients with chest pain of uncertain origin. Circulation 2007;115:1762-8.
    6. 6. Objectives <ul><li>To investigate whether 64-slice MDCT as part of the initial diagnostic strategy </li></ul><ul><li>-  ED and hospital length of stay (LOS) </li></ul><ul><li>-  admissions </li></ul><ul><li>-  30-day MACE </li></ul><ul><li>in patients presenting with chest pain stratified based on the pretest probability for ACS. </li></ul>
    7. 7. Measured outcome <ul><li>ED length of stay </li></ul><ul><li>Hospital length of stay (LOS), </li></ul><ul><li>Admissions </li></ul><ul><li>30-day major adverse cardiac events (MACE) </li></ul>
    8. 9. Methods <ul><li>Approved by IRB of Seoul National University Bundang Hospital, and written informed consent was obtained from all patients </li></ul><ul><li>Prospective, randomization study from May 2006 to February 2007 </li></ul><ul><li>No sample size calculation </li></ul><ul><li>Patients presenting to the ED were cared for by attending physicians trained in EM/internal Med </li></ul>
    9. 10. <ul><li>Inclusion criteria: Patients older than 18 years presenting to the ED with acute chest pain syndrome </li></ul><ul><li>Exclusion criteria: </li></ul><ul><li>Patients deemed very low and very high risk. </li></ul><ul><li>Constant arrhythmia </li></ul><ul><li>Hemodynamic or clinical instability </li></ul><ul><li>History of allergy to radio-contrast dye </li></ul><ul><li>Documented renal insufficiency, </li></ul><ul><li>Pregnancy or women of childbearing age who are not using contraception </li></ul><ul><li>CI to β blockade, </li></ul><ul><li>Recent (b1 month) diagnostic work-up for coronary disease </li></ul>
    10. 11. MDCT protocol <ul><li>MDCT: Brilliance 64; Philips Medical Systems, Best, The Netherlands </li></ul><ul><li>Contrast: a bolus of 80 mL iomeprol (Iomeron 400; Bracco, Milan, Italy) </li></ul><ul><li>All MDCT data sets were analyzed with the clinical information by a single, experienced radiologist immediately after acquisition. </li></ul>
    11. 12. A month after the index ED visit, clinical status and cardiac events were assessed by individual interviews and using the hospital computer database. 2 cardiologist
    12. 13. Statistical analysis <ul><li>All values are expressed as means ± SD or percentages </li></ul><ul><li>Student t test: to compare the continuous variables with normal distribution. </li></ul><ul><li>ED and hospital LOS (negatively skewed) - medians (interquartile ranges) </li></ul><ul><li>Pairwise group comparisons: Mann-Whitney U test. </li></ul><ul><li>Pearson's χ2 test or Fisher exact test - categorical variables. </li></ul><ul><li>One-way analysis of variance with Sheffe's post hoc test for parametric variables or linear-by-linear association for categorical variables was used to determine differences between 3 groups. </li></ul><ul><li>Probability values of <.05 were considered statistically significant. </li></ul>
    13. 14. (high, intermediate, low probability) 21% 42% 37%
    14. 15. Low probability patients: younger and had less history of hypertension, diabetes, dyslipidemia & CAD than high-probability patients
    15. 16. MDCT image acquisition <ul><li>The mean time from ED arrival to MDCT imaging: 1.67 ± 1.62 hours. </li></ul><ul><li>Time for patient preparation & scanning:15.2 ± 4.5 min & for image reconstruction and interpretation: 24.2 ± 3.7 min </li></ul><ul><li>Coronary artery image quality: good in 92%, adequate in 6%, and poor in 2% on a segmental basis. </li></ul><ul><li>Reasons for poor image quality: motion artifact (56%), blooming artifact (28%), or low contrast-to-noise ratio (16%). </li></ul>
    16. 17. P:0.07 144 (54%) patients were discharged from the ED and 122 (46%) patients were hospitalized
    17. 19. Study outcome <ul><li>In the conventional strategy, 57 (85.1%) of 67 admitted patients underwent invasive coronary angiography and 39 (58%) were ultimately diagnosed with an ACS. </li></ul><ul><li>In the MDCT-based strategy, 39 (71%) of 55 admitted patients were ultimately diagnosed with an ACS. </li></ul>
    18. 20. <ul><li>Reductions in unnecessary admissions were more prominent in patients with intermediate probability (20% for control vs 4% for the MDCT-based strategy, P = .015). </li></ul><ul><li>There were no differences in unnecessary admissions in low probability groups possibly because of the small number of patients admitted in both strategies </li></ul>
    19. 21. Emergency department LOS <ul><li>Emergency department LOS was not different between the conventional and MDCT strategies (4.8 [3.1-7.6] vs 4.6 [3.2-7.1] hours, P = .98). </li></ul><ul><li>In patients with intermediate probability for ACS, there was a non-significant trend toward decreased ED LOS in the MDCT-based strategy (6.0 [4.1-8.9] vs 4.5 [3.2-7.7] hours, P = .055) </li></ul><ul><li>There were no differences in ED LOS between strategies in low- and high-risk patients. </li></ul>
    20. 22. Hospital LOS <ul><li>Hospital LOS was decreased in the MDCT-based strategy compared with the conventional strategy for all patients studied (7.1 [4.1-97.5] vs 26.6 [4.8-131.1] hours, P = .049). </li></ul><ul><li>Subgroup analysis, hospital LOS was significantly decreased only in patients with a high probability for ACS (94.7 [56.9-159.9] vs 155.2 [95.5-266.1] hours, P = .036) </li></ul>
    21. 23. A, Length of ED stay showed no difference between the conventional and MDCT-based strategies, which was similar in subgroup analysis according to the risk for ACS. B, Length of hospital stay tended to be lower in the MDCT-based strategy. In subgroup analysis, hospital LOS was significantly reduced in high-risk patients (*P < .05).
    22. 24. F/up <ul><li>One-month follow-up was completed in all patients </li></ul><ul><li>One patient in the conventional strategy – non-fatal MI </li></ul><ul><li>None of the patients discharged from the ED in the MDCT-based strategy experienced MACE at follow-up. </li></ul><ul><li>No patients experienced clinical or laboratory evidence of contrast-induced nephropathy during follow-up. </li></ul>
    23. 25. Study limitations/opportunity <ul><li>Small numbers of patients, especially low-risk individuals who had significant MDCT findings. </li></ul><ul><li>The follow-up period was too short to assess future cardiac events in patients presenting with acute chest pain </li></ul>
    24. 26. Conclusions <ul><li>Application of MDCT as part of the initial diagnostic approach for patients presenting with acute CP to the ED is safe, efficient, and reduces avoidable admissions in patients with an intermediate risk for ACS. </li></ul><ul><li>The use of MDCT to assist in triage of CP in the ED needs to be applied in the context of the patient risk profile and available conventional diagnostic tests. </li></ul>