Multidetector CT Angiography for the Detection of Left Main - PowerPoint PPT Presentation

Multidetector CT Angiography for the Detection of Left Main Coronary Artery Disease Rani K. Hasan, M.D. Intro to Clinical Research July 22 nd , 2011

Outline  Background  Hypot hesis  S t udy Populat ion  Met hodology  S ignificance

Background  Mult idet ect or CT angiography (MDCTA) has est ablished accuracy in t he diagnosis of coronary art ery disease.  Two recent prospective multicenter trials have shown that MDCTA compares favorably to invasive angiography (reference standard).  MDCTA compares favorably t o invasive angiography (ICA)wit h regards t o cost and safet y.  Cost: ~$500 for MCDTA vs ~$3000 for ICA  Radiation: 3-15 mS V for MDCTA vs 2-20 mS V for ICA  The use of MDCTA is increasing for non-invasive evaluat ion of suspect ed coronary art ery. AJR Am J Roent genol 2010;194:1257-62. Circulat ion 2007;116:1290-1350.

MDCTA versus Invasive Coronary Angiography (ICA) MDCTA ICA  S  S patial resolution patial resolution  ~0.5 mm  ~0.2 mm  Temporal resolution  Temporal resolution  ~50-200 ms  ~5-10 ms  Vessel wall and lumen  Lumenography  Reference diameters Limited image planes  Plaque morphology  Dependent on views taken, increase contrast and  3-D reconstruction allows radiation with more views visualization in numerous  Vessel overlap, foreshortening planes artifacts  No vessel overlap or  Real-time imaging foreshortening artifacts

Diagnostic Accuracy of Cardiac MDCTA in S ymptomatic Patients Mean Mean Area Under the Positive Negative Sensitivity Specificity Curve Likelihood Likelihood Ratio Ratio All Studies (89) 97.2 (96.2-98.0) 87.4 (84.5-89.8) 0.98 (0.96-0.99) 7.7 (6.2-9.5) 0.03 (0.02-0.04) Scanner Rows >16 98.1 (97.0-99.0) 89.4 (86.0-92.0) 12-16 95.6 (94.0-97.0) 84.7 (80.0-89.0) Heart Rate < 60 bpm 99.0 (98.1-99.5) 85.8 (79.4-90.5) > 60 bpm 96.2 (94.7-97.3) 87.7 (84.1-90.5) chuet z GM et al. Ann Int ern Med. 2010;152(3):167-77 . S

Background  Left main coronary artery disease has been recognized as the highest risk form of CAD, with an observed three-year mortality of up to 37% without revascularization.  Coronary artery bypass surgery is the current standard treatment for left main coronary artery disease, but use of percutaneous coronary intervention is increasing.  Accurate detection and morphologic characterization of left main coronary disease is paramount in selection of the appropriate revascularization strategy.  ICA is t he current st andard  MDCTA may provide a non-invasive alternative to ICA and obviate need for cardiac catheterization in patients in whom surgery is more appropriate

Hypothesis MDCTA can accurately detect left main coronary artery disease and characterize important morphologic characterist ics of left main lesions compared to ICA.

S tudy Population  S TUDY DES IGN: S econdary dat a analysis of t wo complet ed prospect ive mult icent er t rials t hat assessed t he diagnost ic accuracy of MDCTA compared t o ICA for t he diagnosis of obst ruct ive coronary disease.  INCLUS ION CRITERIA:  Adults ≥ 40 years of age  Chest pain and suspected coronary artery disease referred for ICA.  Left main coronary artery disease defined as ≥ 50% luminal stenosis by quantitative coronary angiography.

Methods  EXCLUS ION CRITERIA:  Contraindication to iodinated contrast dye  Atrial fibrillation or other arrhythmia  Evidence of severe symptomatic HF  Moderate or severe aortic stenosis  Previous cardiac surgery  Percutaneous coronary intervention within 6 months  Intolerance or contraindication to beta-blockers  Morbid obesity  Inadequate CT images

Methods 850 patients with suspected CAD MDCTA 20 patients with inadequate CT images ICA (within 30 days) 680 patients without left main disease 150 patients in analysis

Methods ICA MDCTA Core Lab Core Lab S tatistical analysis  Blinded image analysis by 2 independent reviewers for each imaging modalit y  S t andardized imaging and analysis prot ocols  Adj udicat ion process t o ensure cross-modalit y correspondence

Methods Outcome Analysis Primary Obstructive left main disease Sensitivity, specificity Left main calcification S ensitivity, specificity Secondary Left main bifurcation S ensitivity, specificity Left main bifurcation type S ensitivity, specificity Radiation dose Mann-Whitney U test Contrast dose Mann-Whitney U test Adverse event rate Fisher’s exact test

S ignificance  MDCTA is growing as a non-invasive means of diagnosing coronary artery disease.  Left main coronary artery disease portends a poor prognosis without revascularization, and ICA is the current standard for diagnosis and selection of a revascularization strategy.  Non-invasive detection and characterization of left main lesions may enable selection of a revascularization strategy without the need for diagnostic cardiac catheterization.  Avoid an addit ional and cost ly invasive st udy for pat ient s who will require surgery wit hout compromising safet y  Compared to earlier studies, this analysis will have the advantage of building on pre-existing robust study design including standardized imaging protocols and blinded evaluation of imaging findings by centralized laboratories.

Acknowledgements  Ment or: Julie Miller  S mall Group Members: Jeanne Clark Nisa Maruthur Martha Zeiger S haron Ahluwalia Dara Neuman-S unshine Angela Wabulya Amy Rushing