Disclosure Information

Transcription

1 Coronary CTA Pearls and Pitfalls Ricardo C. Cury, MD, FSCCT, FAHA, FACC Chairman of Radiology Radiology Associates of South Florida Director of Cardiac Imaging Miami Cardiac and Vascular Institute Past-President Society of Cardiovascular CT Disclosure Information Research grant and Consultant GE Healthcare Multi-Detector Cardiac CT slice war YEAR Coverage Spatial Res. 64-Slice mm mm Gantry Rotation Scan Time 350ms 5-15s DSCT mm 0.6mm 330ms 5-10s Dual Energy mm 0.6mm 270ms 2-3s mm 0.5mm 270ms 1s Whole heart HDCT mm 0.3mm 350ms 5-7s Gemstone + Dual Energy 1

2 Multi-Detector Cardiac CT New Technology 2014 YEAR Coverage Spatial Res. Gantry Rotation Scan Time IQon mm 0.6mm 270ms 5-10s Dual layer detector mm 0.5mm 270ms <1s Whole heart DSCT - Force mm 0.6mm 250ms < 1s Speed Revolution CT mm 0.3mm 280ms + SSF 200ms* < 1s Whole Heart + Speed + Gemstone THE GOAL: IMAGE QUALITY One Beat/ 16cm/ 280ms/ High-definition/ motion free 80 kv 500 ma 61 BPM 23 BMI 0.9 msv CAD rule out Revolution Miami Baptist Patient Preparation Quiet and comfortable environment Educating patient / minimizing anxiety Contrast effects Beta-blockers & nitroglycerin Holding breath & motion ECG Placement IV Access 2

3 Patient Preparation Low Heart Rate Beta-blockade e.g. 100 mg metoprolol p.o. up to 4x5 metoprolol i.v. Nitroglicerin SL pill Coronary CTA Protocol Scout Calcium score Test bolus Nitroglycerin Wait 3-5 min CCTA Total ;me from scout to CCTA ~ 10 minutes Coronary Calcium CT Coronary Angiography 3

4 Coronary CTA Stenosis Detection Radiation dose reduction techniques 1. Decrease scan range 2. Lower heart rate with beta blockers 3. Use Prospective trigger technique - HR < Use 100 kv in patients with BMI < Use ECG based tube current modulation 6. Use Iterative reconstruction Typical E values (msv) Chest x-ray Coronary calcium CT 1-3 Coronary CTA Prospective 1-3 Coronary angio (Dx) 5-10 Coronary CTA - Retrospective 5-15 Sestamibi MPI 8-16 Thallium MPI Einstein et al Circulation

5 Standardized Protocols LaBounty, AJC 2010 Effect of a standard protocol in 449 patients at 3 centers Standardized Protocols To balance image quality and radiation dose, consider protocols that: 1. Adjust tube current and tube voltage based on body size 2. Assign gating methods based on HR, HRV, and clinical question LaBounty, AJC 2010 Indications for Coronary CTA Rule out coronary stenoses in patients with chest pain Acute Chest Pain in the emergency department Patient with a prior equivocal stress test Visualize anomalous coronary arteries Establish patency of bypass grafts Pre-operative clearance in low/ intermediate coronary risk patient 5

6 WHERE DO WE STAND? Highly accurate to rule out coronary artery stenoses Accuracy for Stenosis Detection Accuracy for Stenosis Detection There is always a trade-off of sensitivity vs. specificity Multi-Center Trials: Stenosis Detection by CT Angiography n Sensitivity Specifity Prevalence ACCURACY % 83% 24% Meijboom % 64% 68% CORE % 90% 56% Per patient, stenoses > 50% 1 Budoff et al, JACC Meijbom et al, JACC Miller et al, NEJM

7 Accuracy for Stenosis Detection Overestimation possible underestimation rare. Accuracy for Stenosis Detection META-ANALYSES Sens. Spec. NPV PPV Gopalakrishnan Cardiol in Rev 2008 PER SEGMENT 91% 96% 98% 78% PER PATIENT 96% 90% 96% 93% Mowatt Heart 2008 PER SEGMENT 90% 97% 99% 76% 64 Slice CT Meta PER PATIENT Analyses 99% 89% 100% 93% High negative predictive value Positive predictive value not quite as high Accuracy for Stenosis Detection Coronary CT Angiography if performed well allows the detection of coronary artery stenoses with high sensitivity. A negative scan rules out stenoses with a high degree of reliability. A person with a negative CT does not need a cath. 7

8 Stents? Stents >= 3.5 mm usually ok Stents = 3.0 mm often ok Stents < 3.0 mm often not ok Stents? BSP TP STENTS 8

9 Stents? BSP FP Bypass Graft Patency a b Bypass Graft Patency One-beat, high definition, motion-free: even for challenging patients 100 kv 400 ma 79 BPM 24 BMI 3.2 msv Patient with bypass grafts, valve prosthesis and high heart rate Revolution Miami Baptist 9

10 INDICATIONS Anomalous Coronary Arteries ANOMALOUS RCA ORIGIN FROM THE LEFT SINUS OF VALSALVA Dodd JD, et al. AJR. Feb year old with Kawasaki s Disease Prospec;ve triggering and 100Kv 1.6 msv Detection of Coronary Plaque Calcific Visualization of non-stenotic plaque by CT Accuracy? Quantification, Characterization? Clinical Significance? Mixed Non-calcific 10

11 CARDIAC CT RECONSTRUCTIONS Axial VR Curved Full FOV Function 4-CH Valves Perfusion Cury RC et al. J Nucl Cardiol 2007 Apr;14(2): Triple Rule Out Protocol CAD, PE, AD Coronary CTA Increased scan volume to cover the aortic arch Triple Rule Out Protocol Coronary CT Protocol TRO Protocol 11

12 The Triple Rule Out 120 cc 5 ml/ sec Triple-phase 1 st 90 cc Mix 30cc/20cc Saline CAD PE - AD MIAMI BAPTIST ACUTE CHEST PAIN PROTOCOL 5 Hospitals 5000 patients per year Miami Baptist 100-Bed Emergency Department Revolution CT + Seven 64-slice MDCT and Two HDCT Operation 7 days/week DO - PATIENT SELECTION Cury RC et al. JNC 2011:18;

13 MIAMI BAPTIST ACUTE CHEST PAIN PROTOCOL STEMI NSTEMI UAP Cardiac Cath Lab MIAMI BAPTIST ACUTE CHEST PAIN PROTOCOL Non-diagnostic ECG Normal cardiac enzymes TIMI > 2 TIMI 2 SPECT-MPI Coronary CTA MIAMI BAPTIST ACUTE CHEST PAIN PROTOCOL LEVEL 5 Non-cardiac Chest Pain Lung CA PE Ao Aneur. Pneumonia Pericarditis Chest Wall GI - CXR - PE-CT if positive D-dimer - Aortic Dissection CT protocol - V/Q scan - Very low risk discharge CAD Fruergaard et al. European Heart Journal 1996 Department of Medicine B, Hillerod Sygehus, Denmark 13

14 Cury RC et al. JNC 2011:18; Raff et al. JCCT 2014:

15 CASE 1 61 y/o Male/ CP for 2 weeks / negative enzymes and EKG Echo: Mild LVH Preserved global and regional LV function/ EF = 65 to 70% LAD = 90-95% LAD = 95% CASE 2 Woman, 57 y/o with ACP and lightheadness in the ER, normal ECG and normal cardiac enzymes CASE 2 Woman, 57 y/o with ACP and lightheadness in the ER, normal ECG and normal cardiac enzymes 15

16 CASE 2 Woman, 57 y/o with ACP and lightheadness in the ER, normal ECG and normal cardiac enzymes Coronary CTA Reporting and Management Level 4 Degree of coronary stenosis 0% 40-50% 70% 100% Discharge from ED Mild Moderate Severe Discharge from ED and OP consult with Cardiologist Stress Myocardial Perfusion (NM) + FFR Cardiac Cath Lab Cury RC et al. JNC 2011:18; Raff et al. JCCT 2014:

17 CAD RADS - ACUTE CHEST PAIN Cury RC et al. JCCT/ JACC Imaging/ JACR In Press Contra-indications " Atrial Fibrilation" Irregular heart rate or multiple PVCs" Inability to perform a breath-hold for 10 seconds" High heart rate and contra-indications for beta-blocker" Unlikely to benefit from CTA " Patients with HIGH Likelihood of CAD" Elderly patients >70 y/o" Multiple stents or stents in distal vessels" Obese patients (BMI > 40 or > 350 pounds)" " " Main role to rule out coronary stenoses 17

18 Coronary CT Angiography Age, Gender Risk factors Stress Test Clinical likelihood for coronary artery disease 0% 100% Asymptomatic Symptomatic Low Intermediate High Low Intermediate High?? Calcium scoring Coronary CTA Cath or Stress Perfusion Imaging Conclusions Cardiac CT is an invaluable test with high diagnostic accuracy and conveying significant prognostic information Adequate patient preparation and appropriate protocol design is necessary to optimize image quality Adherence to recently published appropriateness guidelines is important to ensure that the benefit of cardiac CT is realized THANK YOU! 18