CT FFR: Are you ready to totally change the way you diagnose Coronary Artery Disease? Madan Mohan MD MRCP FACC CQO, Division of Cardiovascular Medicine University Hospitals Case Medical Center Assistant Professor Case Western Reserve University School of Medicine
Disclosure Statement of Financial Interest No financial disclosures I will be discussing unapproved indications 2
Case 55 year old male with atypical chest pain Hypertension and hyperlipidemia but non smoker and no diabetes Normal exam and LVH with strain on EKG What would you order next? 1. Reassure 2. Treadmill EKG 3. Stress nuclear 4. Direct to angiography 5. Something else 3
Accuracy of stress tests 390000 pts Probability of obstructive CAD 41% if positive stress test 35% if negative stress test 4
CAD: Two fundamental questions FUNCTION: Is coronary ischemia causing my patient s symptoms? + ANATOMY: Are there stenoses in the coronary arteries? Stress testing Myocardial Perfusion Imaging (e.g. SPECT) Stress Echocardiography Coronary CT Angiography Invasive coronary angiography FFR CT 5
Concept of Fractional Flow Reserve A test to determine the functional significance of a stenosis Ratio of maximum blood flow in stenotic artery to theoretical maximum blood flow if no stenosis. (pressure is used as surrogate) Measured in cath lab after IV NTG, and adenosine Pressure after and before stenosis: P d / P a Thus normal artery has FFR of 1. <0.80 is considered abnormal 6
FFR in cath lab Pijls et al. JACC. 59:12. 1045-57 7
FFR in 3 vessel disease Pijls et al. JACC. 59:12. 1045-57 8
FFR: A Game Changing Technology 4.6% vs 8.0%, p=0.04 888 patients with stable CAD FAME 2 (2 yrs) De Bruyne et al, NEJM 2014 9
What is CT FFR? CT FFR is a non-invasive method employing computational fluid dynamics (CFD) for evaluation of the hemodynamic (HD) significance of coronary artery lesions. One Stop Shop Uses standard images Post processing 10
CT FFR values are available at every point on the coronary tree 11
FFR CT : The NXT Trial Diagnostic performance of non-invasive fractional flow reserve derived from coronary CT angiography in suspected coronary artery disease: The NXT trial. Bjarne L. Nørgaard, MD, PhD et al Conclusions: FFRCT provides high diagnostic accuracy, and discrimination for the diagnosis of hemodynamically significant CAD with invasive FFR as the reference standard. When compared to anatomic testing by coronary CTA, FFRCT leads to a marked increase in specificity. 12
Case Example Figure 1. Co-registration of angiography and 3-dimentional CT model. Red lines indicate pressure-wire location for FFR measurements across the serial lesions (A = distal, B = proximal). Figure 2. FFR gradient across the serial lesions. Red arrows show stepped-up FFR after crossing the stenoses. (A = distal measured point, B = proximal measured point, C = equalization point). Kantaro Tanaka and Hiram Bezerra 13
HeartFlow Clinical Trial Case Examples 14
Is CT FFR a game changer? 15
Use of FFR CT to select patients for ICA and PCI may result in 30% lower costs and 12% fewer events at one year compared to the most common strategy of ICA and visual guidance for PCI Hlatky et al, Clin Cardiol 2013; DOI:10.1002/clc.22205 16
Cath and angio guided PCI FFRCT prior to cath FFR in every vessel of every case CTA prior to cath $11,500 $10,500 $9,500 $8,500 $7,500 $6,500 $5,500 $4,500 1.8% 1.9% 2.0% 2.1% 2.2% 2.3% Event Rate Cost / Patient
Estimated Patient Radiation Exposure Based on CAD Diagnostic Pathway Leipsic et al, in preparation 1) ICA visual 18
Summary: CT FFR at UH could result in For non ACS patients presenting for evaluation of chest pain Current Practice Pathway Using FFR CT Change 1. Angio without + ve FFR/FFR CT Disease Angio with + ve FFR/FFR CT Disease PCI 1,081 874 913 0 1,323 827 1,081 +449 86 2. Clinical Events (1 yr death / MI) 2.9% 2.2% 26 Patients (Δ25%) 3. Total Costs to Health System (index costs only) $14.8M $9.6M $5.2M (Δ35%) 19
Implications for a Health System Patient Fewer invasive procedures which turn out to be negative Recognize subclinical disease Greater pre procedure understanding of planned PCI Less Death / MI / Urgent revascularization (DEFER, FAME and FAME 2) Physician Decision making pre cath lab Heart Team as needed Hospital Cath lab operational efficiencies Longer term effects on fixed costs (CT scanners, SPECT cameras, cath labs) Payer Triple Aim: outcomes, patient experience, costs 20
Triple Aim of Healthcare 1. Improve the Experience of Care 2. Improve the Health of Populations FFR CT can reduce dx tests, as well as unnecessary interventions while simultaneously identifying patients that do need invasive care. FFR CT can reduce morbidity and mortality by more accurately diagnosing patients with coronary artery disease. 3. Reduce per capita Costs of Care FFR CT can reduce the costs of managing CAD Source: The Triple Aim: Care, Health, and Cost; Donald Berwick, Health Affairs 2008 21
Is FFR CT the game changer for diagnosis of CAD? 22
Thank you Questions?