The Efficacy of Non-invasive Diagnostic for CAD in PMK Hospital

Maj. Hutsaya Prasitdumrong, M.D.

Cardiovascular Division, Department of Internal Medicine,Phramongkutklao Hospital

Coronary atherosclerosisCoronary artery disease (CAD)Ischemic heart disease (IHD)

Foam cells Fatty streak Intermediatelesion Atheroma Fibrous

plaque

Complicatedlesion/rupture

From FirstDecade

From ThirdDecade

From FourthDecade

Endothelial Dysfunction

Investigations for CAD

Anatomical Tests

CT angiographyMR angiographyCoronary angiography

Functional Tests

Exercise stress testStress ECHOStress CMRMPI: SPECT PET

Coronary Angiography

• GOLD standard for detection of CAD• Identify coronary arteries stenosis and its severity

Diagnostic Accuracy of Non-invasive Modalities for Detection of CAD

Applied Radiology 2011;40(5):13-22

Coronary Angiography VS Coronary CT Angiography

Coronary Angiography• Invasive• Require day care admission• Iodine contrast• Radiation• Cost• Resume normal activity

after 24 hours• Risk: death, stroke, CA

dissection about 1:1000

Coronary CT Angiography

• Non-invasive• Out patient visit• Iodine contrast• Radiation• Cost• Resume normal activity

right after scanning• Risk: safer

Coronary Angiography VS Coronary CT Angiography

Coronary Angiography Coronary CT Angiography

Non-invasive or Invasive Test

Circulation 2002;106:1883-92

Coronary CT Angiography

• Coronary artery calcified plaque is nearly 100% specific for atheromatous coronary plaque

• Can develop early in the course of subclinical atherosclerosis

• Present in the intima of both obstructive and non-obstructive lesion

Coronary Calcium Score

Developed by David KingPublished by Agatston and coworker

• Coronary calcium by EBCT and atherosclerotic plaque by histopathology

Rumberger, j.a. et al. Circulation 1995;92:2157-62

Coronary Calcium VS Atherosclerosis

Coronary Calcium & Coronary Events

Detrano et al. NEJM 2008;358(13):1336-45

Risk StratificationCAC score Plaque

burdenProbability of

CADCardiac event

riskManagement

0 No Very unlikely<1%

10 yr risk <2%<0.11% annually

ReassureRepeat scan

5 yrs0-80 Small Low 0.2% annually Risk factors

modificationRepeat scan

2-5 yrs

81-400 Moderate Possible 1% annually (2° prevention)± EST

ASA, statin

>400 extensive High likelihood

Up to 4.8% annually

(2° prevention)ASA, statin

640-SLICE CT SCANNER

223

353 373407

547

477

0

100

200

300

400

500

600

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MRI CT

64-Slice VS 640-Slice CT Angiography

64-Slice CTA• 32 mm area detector• Scanning is in helical

mode• Longer exposure time• Higher dose of radiation• Higher dose of contrast

(80-100 cc)• More artifact

640-Slice CTA• 160 mm wide area

detector• Scanning in 1 rotation• Shorter exposure time• Radiation dose reduced

by up to 50%• Less contrast (50 cc)• Less artifact• Available in AF patient

PMK Heart Center Protocol

Take history of previouscontrast allergy and PDE5

drug use

Target HR 60 bpm prior to scanMed: Metoprolol up to 100 mg keep BP > 110/70Alt: Ivabradine 5 mg bid for 3 days

0.4 mg Nitroglycerine oral spray 1 puff

CTA scan: Prospective scan 100-120 kVp Contrast 40-45 cc Effective dose 3.5-4.5 mSv

At observation room

Effective Dose for Cardiovascular Imaging Tests

Catheterization and Cardiovascular Intervention 2011;77:546-56

Appropriate Criteria for Calcium Scan and Coronary CTA

• Calcium scan– Intermediate risk for CAD– Low risk for CAD with family history of premature

coronary heart disease• Coronary CTA– Symptomatic patient with low or intermediate risk– Reduced LVEF with low or intermediate risk– Pre-op evaluation for non-cardiac surgery– Post revascularization

JACC 2010;56(22):1864-1894