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Heart, Lung and Circulation S292009;18S:S1–S286 Abstracts

score >9. No correlation was observed between the pres-ence of major stenosis with TnI rise and ACE. Stenosisscores were higher in patients with more plaque.

Conclusion: Postoperative TnI elevation in stablepatients following hip/knee replacement correlates withthe distribution and extent of plaque more than with thepresence of underlying severe stenosis. This has impli-cations for treatment and gives some insight into thepathophysiology of postoperative MI.

doi:10.1016/j.hlc.2009.05.061

60DIAGNOSTIC ACCURACY OF 320-SLICE CT CORO-NARY ANGIOGRAPHY: A COMPARISON WITH INVA-SIVE CORONARY ANGIOGRAPHY

A. Nasis 1, M.C. Leung 1, P.R. Antonis 1, J.D. Cameron 1,I.T. Meredith 1, W.S. Moir 1, S.A. Hope 1, J.M. Troupis 2,M.P. Crossett 2, S.K. Seneviratne 1

1 Monash Cardiovascular Research Centre, MonashHEARTand Monash University Department of Medicine (MMC), Mel-bourne, Australia2 Department of Diagnostic Imaging, Southern Health, Mel-bourne, Australia

Background: CT coronary angiography (CTCA) isincreasingly used to diagnose coronary atherosclerosis.We sought to evaluate the diagnostic accuracy of 320-sliceCTCA, for which no data currently exists, using invasivecoronary angiography (ICA) as the gold standard.

Methods: Forty-one sequential patients (63% male, age64 ± 14 years) with suspected coronary artery diseasewithout prior PCI or CABG who underwent both CTCA(320 mm × 0.5 mm slice collimation, 0.35 s gantry rotationtime, 0.35–0.70 s scan time) and ICA within 45 days wereanalysed. A single observer unaware of CTCA resultsassessed ICA images. CTCA studies were assessed by con-sensus between two observers blinded to ICA findings. Allavailable coronary segments were analysed, regardless ofsize. Lesions with >50% diameter stenoses by visual esti-mate were considered significant. Per-segment, per-vesseland per-patient analysis was performed.

Results: Twenty-five patients (61%), 42/169 vessels (25%)and 61/596 segments (10%) had at least one significantstenosis on ICA. Mean heart rate was 64 ± 6 bpm duringimage acquisition, with 6 patients (15%) in atrial fibrilla-tion. No patients were excluded due to impaired imagequality. The diagnostic accuracy (95%CI) for detecting sig-nificant coronary stenoses was:

Sensitivity Specificity Positive predictivevalue

Negative predictivevalue

Patient 96% (78–100) 94% (67–100) 96% (77–100) 94% (67–100)Vessel 76% (60–87) 97% (91–99) 89% (73–96) 93% (86–96)Segment 74% (61–84) 98% (96–99) 80% (66–88) 97% (95–98)

Conclusion: 320-slice CTCA provides high diagnosticaccuracy in the diagnosis of coronary artery disease, par-ticularly in the exclusion of significant stenoses across allcoronary segments, regardless of size.

doi:10.1016/j.hlc.2009.05.062

61DIAGNOSTIC ACCURACY OF CARDIAC MAGNETICRESONANCE IMAGING IN THE DIAGNOSIS OFMYOCARDITIS—A REAL WORLD AUSTRALIANEXPERIENCE

S.C. McKenzie, M. Butler, H. Pfluger, A.J. Taylor

The Alfred Hospital, Melbourne, Australia

Cardiovascular magnetic resonance imaging (CMR)can differentiate acute myocarditis from healthy controls,but its efficacy in differentiating acute myocarditis fromchronic cardiomyopathy is less certain. We present theexperience of the Alfred Hospital with CMR in the diag-nosis of myocarditis in patients presenting with reducedleft ventricular (LV) function of unknown aetiology.

Between January 2005 and December 2008 we per-formed 95 CMR studies for suspected myocarditis. 52/107patients met CMR criteria for myocarditis on the basisof elevated myocardial oedema, early and late postGadolinium-DTPA enhancement. Endomyocardial biopsy(EMB) was performed in 10/52 patients with a CMRdiagnosis of myocarditis and 4/43 patients without CMRcriteria for myocarditis. Ten patients with a CMR diagnosisof myocarditis underwent serial CMR studies.

The mean left ventricular ejection fraction (LVEF) was49 ± 7%. In patients who underwent CMR and EMB, therewas agreement between CMR and EMB in 9/10 cases witha CMR diagnosis of myocarditis and all 4 patients in whomCMR did not suggest myocarditis, yielding a sensitivityand specificity of 100% and 80%, respectively. Seven of 10patients who underwent serial CMR demonstrated reso-lution of CMR changes which was associated with a strongtrend towards improved LVEF from a mean of 28 ± 7% atdiagnosis to 40 ± 9% (P = 0.08) with resolution. Of the otherthree patients, two demonstrated a fluctuating course ofCMR changes and the remaining patient manifested per-sisting CMR abnormalities.

In patients presenting with reduced LV function or highclinical suspicion of myocarditis CMR is a sensitive tool inthe diagnosis of myocarditis.

doi:10.1016/j.hlc.2009.05.063