Rate of Obstructive Coronary Disease in Elective Diagnostic

Rate of Obstructive Coronary Disease in Elective Diagnostic Cath Manesh R. Patel, MD Assistant Professor of Medicine Director Cath Lab Research – Duke University Medical Center

Disclosures n Interventional cardiologist l Clinical Cardiovascular MRI and Vascular Ultrasound n Division of Cardiology l Majority of Revenue from cardiovascular imaging n Genzyme l Advisory Board n Chair of Writing Group for ACC/AHA Coronary Revascularization Appropriateness Criteria

The Challenge in Cardiology Practice

Patient Case - Mrs. M n 58 years old with DM n Lives independently l n 7/08 seen by PCP l l n Shops, Cleans, works in bank Occasional Chest “ache” with walking at grocery store Cramping in calves Referred to Duke Cardiology / Vascular Clinic for evaluation

What would you do? n How do you determine risk and identify disease? n What data do you need to determine if invasive angiography and subsequent coronary revascularization will improve here symptoms and/or longevity

Step 1 - How do you decide pre-test probability

Clinical Decision Making - Question 1 n Which is the best model to calculate pretest probability of CAD in this patient? n A. Framingham Risk Score n B. Diamond Forrester Score n C. TIMI UA/NSTEMI Score n D. GRACE Score

Decision Question 2 n Based on the Diamond-Forrester classification, the pretest probability of this patient having CAD is: A. Very Low B. Low C. Intermediate D. High

Stratifying patients with Chest pain Intermediate Probability = 10 -90% ACC/AHA Chronic Stable Angina Guidelines

Question # 1 n In patients with intermediate pre-test probability of coronary artery disease - what cardiovascular test should be done to diagnose and risk stratify for coronary artery disease?

Imaging Use n Non-invasive cardiac imaging has improved assessment of cardiac function, anatomy, and pathology.

Imaging Use Dollars (billions) n Medicare spending on imaging services more than doubled from 2000 through 2006 413% annual growth Source: GAO Analysis of Medicare Data, Report GAO-08 -452.

How good are we at identifying obstructive CAD? Rate of Obstructive CAD* 60. 3% All ACC-NCDR patients who had cardiac catheterization 1, 989, 779 patients at 663 sites Exclude: Prior MI, PCI, CABG, Cardiac Transplant, Valve surgery 51. 7% 1, 148, 405 patients at 663 sites Exclude: Emergent admission symptoms (AMI and ACS) and cardiogenic shock 36. 2% 629, 325 patients at 663 sites Exclude: other diagnostic cath indications 37. 5% 397, 954 patients at 663 sites January 2004 -April 2008

Rate of Obstructive CAD n Obstructive CAD l ≥ 50% LM or ≥ 70% Epicardial Vessel l 38% l ≥ 50% Any vessel l 41% n Minimal CAD l < 20% stenosis in any vessel l 39%�entire cohort

Obstructive CAD Disease At Cath (NCDR data) n n 397, 954 patients 2004 -2008 without known CAD/MI or prior PCI/CABG undergoing diagnostic cath to R/O CAD 59% of patients with positive non-invasive tests have no obstructive CAD on invasive angiography (False positive)

Obstructive CAD over time

ACC-NCDR Study n Current risk stratification including non-invasive testing used to inform decisions to perform angiography to identify obstructive CAD need significant improvement