Abstract
OBJECTIVE: The rate of rise of total plasma creatine kinase (CK) activity in the first 12 hours from presentation can be used to diagnose acute myocardial infarction. The aim of this study was to evaluate the performance of an abbreviated form of this test in the diagnosis of acute myocardial infarction in patients in whom the initial electrocardiogram was inconclusive. METHODS: Using a protocol that requires only two CK measurements (separated by four hours) to estimate the rate of rise, the performance of the test was investigated using data accrued from 345 consecutive admissions with suspected acute myocardial infarction. RESULTS: A CK increment (delta CK) of > 20% in the first four hours from presentation had a diagnostic sensitivity of 84.4% (95% confidence interval 75.5 to 93.3), specificity of 85.8% (80.1 to 91.5), positive predictive accuracy of 73.0% (62.9 to 83.1), and negative predictive accuracy of 92.4% (87.9 to 96.9). Using more stringent diagnostic criteria (delta CK > 20% and 4 h CK value > 160 U/litre) resulted in an increase in specificity and positive predictive accuracy to 96.5% and 91.1% respectively, and a small reduction in sensitivity and negative predictive accuracy to 79.7% and 91.3%, respectively, 94% of all infarcts were correctly identified using the ECG as the initial investigation and paired CK measurement as an additional test when this was inconclusive. In the 44 patients who received thrombolysis on the basis of an early biochemical diagnosis of acute myocardial infarction, the median time delay (75th centile) to thrombolysis was 10.75 (SD 15.0) hours. CONCLUSIONS: When the presenting ECG is non-diagnostic, sequential sampling of cardiac enzymes is a feasible alternative in the early diagnosis of patients with suspected myocardial infarction, even in the emergency setting. Further studies are required to define the optimal biochemical assay and timed sampling protocol.
Full text
PDF




Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Altman D. G., Bland J. M. Diagnostic tests 2: Predictive values. BMJ. 1994 Jul 9;309(6947):102–102. doi: 10.1136/bmj.309.6947.102. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Altman D. G., Bland J. M. Diagnostic tests 3: receiver operating characteristic plots. BMJ. 1994 Jul 16;309(6948):188–188. doi: 10.1136/bmj.309.6948.188. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bakker A. J., Koelemay M. J., Gorgels J. P., van Vlies B., Smits R., Tijssen J. G., Haagen F. D. Failure of new biochemical markers to exclude acute myocardial infarction at admission. Lancet. 1993 Nov 13;342(8881):1220–1222. doi: 10.1016/0140-6736(93)92192-v. [DOI] [PubMed] [Google Scholar]
- Blanke H., Cohen M., Schlueter G. U., Karsch K. R., Rentrop K. P. Electrocardiographic and coronary arteriographic correlations during acute myocardial infarction. Am J Cardiol. 1984 Aug 1;54(3):249–255. doi: 10.1016/0002-9149(84)90176-0. [DOI] [PubMed] [Google Scholar]
- Collinson P. O., Moseley D., Stubbs P. J., Carter G. D. Troponin T for the differential diagnosis of ischaemic myocardial damage. Ann Clin Biochem. 1993 Jan;30(Pt 1):11–16. doi: 10.1177/000456329303000102. [DOI] [PubMed] [Google Scholar]
- Collinson P. O., Ramhamadany E. M., Rosalki S. B., Joffe J., Evans D. H., Fink R. S., Greenwood T. W., Baird I. M. Diagnosis of acute myocardial infarction from sequential enzyme measurements obtained within 12 hours of admission to hospital. J Clin Pathol. 1989 Nov;42(11):1126–1131. doi: 10.1136/jcp.42.11.1126. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Collinson P. O., Rosalki S. B., Flather M., Wolman R., Evans T. Early diagnosis of myocardial infarction by timed sequential enzyme measurements. Ann Clin Biochem. 1988 Jul;25(Pt 4):376–382. doi: 10.1177/000456328802500409. [DOI] [PubMed] [Google Scholar]
- Downie A. C., Frost P. G., Fielden P., Joshi D., Dancy C. M. Bedside measurement of creatine kinase to guide thrombolysis on the coronary care unit. Lancet. 1993 Feb 20;341(8843):452–454. doi: 10.1016/0140-6736(93)90205-u. [DOI] [PubMed] [Google Scholar]
- Effects of tissue plasminogen activator and a comparison of early invasive and conservative strategies in unstable angina and non-Q-wave myocardial infarction. Results of the TIMI IIIB Trial. Thrombolysis in Myocardial Ischemia. Circulation. 1994 Apr;89(4):1545–1556. doi: 10.1161/01.cir.89.4.1545. [DOI] [PubMed] [Google Scholar]
- Hedges J. R., Young G. P., Henkel G. F., Gibler W. B., Green T. R., Swanson J. R. Early CK-MB elevations predict ischemic events in stable chest pain patients. Acad Emerg Med. 1994 Jan-Feb;1(1):9–16. doi: 10.1111/j.1553-2712.1994.tb02794.x. [DOI] [PubMed] [Google Scholar]
- Hoekstra J. W., Hedges J. R., Gibler W. B., Rubison R. M., Christensen R. A. Emergency department CK-MB: a predictor of ischemic complications. National cooperative CK-MB project group. Acad Emerg Med. 1994 Jan-Feb;1(1):17–27. doi: 10.1111/j.1553-2712.1994.tb02795.x. [DOI] [PubMed] [Google Scholar]
- Johnston J. D., Collinson P. O., Rosalki S. B. MIDAS: myocardial infarct diagnosis by assessment of slope. Ann Clin Biochem. 1993 Jul;30(Pt 4):407–409. doi: 10.1177/000456329303000411. [DOI] [PubMed] [Google Scholar]
- Lee H. S., Cross S. J., Garthwaite P., Dickie A., Ross I., Walton S., Jennings K. Comparison of the value of novel rapid measurement of myoglobin, creatine kinase, and creatine kinase-MB with the electrocardiogram for the diagnosis of acute myocardial infarction. Br Heart J. 1994 Apr;71(4):311–315. doi: 10.1136/hrt.71.4.311. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lee H. S., Cross S. J., Rawles J. M., Jennings K. P. Patients with suspected myocardial infarction who present with ST depression. Lancet. 1993 Nov 13;342(8881):1204–1207. doi: 10.1016/0140-6736(93)92186-w. [DOI] [PubMed] [Google Scholar]
- Lee T. H., Weisberg M. C., Brand D. A., Rouan G. W., Goldman L. Candidates for thrombolysis among emergency room patients with acute chest pain. Potential true- and false-positive rates. Ann Intern Med. 1989 Jun 15;110(12):957–962. doi: 10.7326/0003-4819-110-12-957. [DOI] [PubMed] [Google Scholar]
- Mair J., Artner-Dworzak E., Lechleitner P., Morass B., Smidt J., Wagner I., Dienstl F., Puschendorf B. Early diagnosis of acute myocardial infarction by a newly developed rapid immunoturbidimetric assay for myoglobin. Br Heart J. 1992 Nov;68(5):462–468. doi: 10.1136/hrt.68.11.462. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ohman E. M., Casey C., Bengtson J. R., Pryor D., Tormey W., Horgan J. H. Early detection of acute myocardial infarction: additional diagnostic information from serum concentrations of myoglobin in patients without ST elevation. Br Heart J. 1990 Jun;63(6):335–338. doi: 10.1136/hrt.63.6.335. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rude R. E., Poole W. K., Muller J. E., Turi Z., Rutherford J., Parker C., Roberts R., Raabe D. S., Jr, Gold H. K., Stone P. H. Electrocardiographic and clinical criteria for recognition of acute myocardial infarction based on analysis of 3,697 patients. Am J Cardiol. 1983 Nov 1;52(8):936–942. doi: 10.1016/0002-9149(83)90508-8. [DOI] [PubMed] [Google Scholar]
- Rutty G., Patel S., O'Gorman P. Application of the regression coefficient to timed serial serum creatine kinase measurements in the early diagnosis of myocardial infarction. Ann Clin Biochem. 1989 Nov;26(Pt 6):558–559. doi: 10.1177/000456328902600619. [DOI] [PubMed] [Google Scholar]
- Timmis A. D. Will serum enzymes and other proteins find a clinical application in the early diagnosis of myocardial infarction? Br Heart J. 1994 Apr;71(4):309–310. doi: 10.1136/hrt.71.4.309. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Weston C. F., Penny W. J., Julian D. G. Guidelines for the early management of patients with myocardial infarction. British Heart Foundation Working Group. BMJ. 1994 Mar 19;308(6931):767–771. doi: 10.1136/bmj.308.6931.767. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yusuf S., Pearson M., Sterry H., Parish S., Ramsdale D., Rossi P., Sleight P. The entry ECG in the early diagnosis and prognostic stratification of patients with suspected acute myocardial infarction. Eur Heart J. 1984 Sep;5(9):690–696. doi: 10.1093/oxfordjournals.eurheartj.a061728. [DOI] [PubMed] [Google Scholar]
