Quality Challenges and Pitfalls in the Evaluation of Patients with Suspected Heart Disease Joseph A. Ladapo, MD, PhD Assistant Professor of Medicine Department of Population Health NYU School of Medicine Disclosures: K23 HL116787 Award from National Heart, Lung, and Blood Institute; Consultant for CardioDx, Inc Overview • Health and economic burden of coronary artery disease (CAD) • Pitfalls in care of patients suspected of having CAD • Approaches to improve quality of care • Introduction to Corus CAD, a gene expression test for CAD 2 1 Coronary Artery Disease (CAD) is a Major Public Health Challenge Epidemiology • 15.4 million adults in the US live with CAD • 6.4% of adults overall; 7.9% of men and 5.1% of women Mortality Myocardial infarction • Accounts for over 386,000 deaths • Nearly one million new or recurrent annually (1 in 6 of all deaths) heart attacks each year • More than half of sudden cardiac • Early diagnosis is important deaths occur in people with no prior because treatment & preventive history of heart disease practices significantly reduce morbidity and mortality National Health Interview Survey, 2010; Go, Circulation 20133 Healthcare Utilization and Costs Attributable to CAD are Substantial Healthcare utilization and costs • CAD costs $195.2 billion in direct and indirect costs annually (2009) • In 2006, Medicare spent $11.7 billion on inpatient care for CAD • By 2030, medical costs for CAD (real 2010$) projected to increase ≈100% Ambulatory care Hospital care • In 2009, there were over 14 million • 1.3 million hospital admissions with ambulatory care visits with CAD as the CAD listed as the first diagnosis first-listed diagnosis • 954,000 percutaneous coronary interventions (PCIs), 397,000 cardiac bypass surgeries, 1.03 million diagnostic cardiac catheterizations National Health Interview Survey, 2010; Go, Circulation 20134 2 Cardiac Stress Testing Source of picture: American College of Cardiology, CardioSmart website Primary Care Physicians Routinely Manage Patients With Suspected or Diagnosed CAD ~4M Stable, Symptomatic Patients Suggestive of Coronary Disease Annually Diagnostic Tools Clinical Factors Primary Care EKG Treadmill Stress Echo Often Repeat Cardiology Nuclear Imaging Testing CT Angiography Invasive Obstructive CAD is not found in Angiography ~60% patients1 ~$4.5B annual expenditures2 1 Patel et al, N Engl J Med 2010;362:886-95; COMPASS study. 2 IMV Market Reports 6 3 Ambulatory Care: Cardiac Stress Tests In Patients Without CAD, From 1993 To 2010 5,000,000 4,000,000 3,000,000 2,000,000 Any cardiac stress test No. of Tests Stress imaging 1,000,000 Avg. Avg. annual annual cost in cost in - 1993-1995 2008-2010 All cardiac $820M $2.0B stress tests Stress $550M $1.9B imaging 7 Source: Ladapo et al, Annals of Internal Medicine 2014 Opportunities For Quality Improvement Presentation Title Goes Here 8 4 Despite Wide Array of Available Tests for Working Up CAD, Patients Routinely Encounter… 1. Diagnostic uncertainty 2. Unnecessary testing and procedures 3. Unnecessary radiation exposure 9 Challenges to Clinical Care: Diagnostic Uncertainty Presentation Title Goes Here 10 5 Uncertainty About How to Interpret Diagnostic Test Results is Common • Bayes’ theorem defines how pretest disease risk and diagnostic test performance can be used to guide interpretation of test results Missed or Correctly misdiagnosed identified Reverend Thomas Bayes 11 Stress Test Effectiveness in Diagnosing CAD: Results From Meta-analyses Stress MPI Stress ECHO Sens Spec # studies Sens Spec # studies Garber et 88% 77% 10 76% 88% 6 al Fleischma 87% 64% 27 85% 77% 24 nn et al Mowatt et 76% 65% 10 --- al* Mowatt et 92% 74% 4 --- al** *includes or **excludes patients with prior myocardial infarction Garber, Annals 1999; Fleischmann, JAMA 1998; Mowatt, HTA 2004 12 6 Physicians Interpret Test Results in a Bayesian Manner Stress MPI example • Most frequently performed imaging stress test • Sensitivity = 87%, Specificity = 64% Normal test result Abnormal test result • With a pretest probability of 20%, • With a pretest probability of 20%, post-test probability of CAD is 5% post-test probability of CAD is after a normal test result 38% after an abnormal test result • With a pretest probability of 60%, • With a pretest probability of 60%, post-test probability of CAD is 23% post-test probability of CAD is after a normal test result 78% after an abnormal test result 13 Referral Bias also Influences Diagnostic Accuracy and Test Interpretation Referral bias Biases clinical • Sometimes called “verification bias” or “workup bias” decision-making • Occurs because higher-risk patients are preferentially referred to cardiac catheterization • Bayesian methods needed to adjust • Because it biases test diagnostic test performance for referral performance, it may also bias clinical decision-making • Studies of stress test performance do not adjust Most studies do for this phenomenon so not account for estimates of sensitivity and referral specificity biased Begg, Biometrics 1983 14 7 Presentation Title Goes HereLadapo et al, JAHA 2013 15 Cardiac Catheterization Referral Rates After Normal Exercise ECHO or MPI Results Referral rates are low after a normal study • Range of ~1% to 5% generally Homogenous • Geographic location and patient characteristics vary but little variation in referral rates Ladapo et al, JAHA 2013 16 8 Cardiac Catheterization Referral Rates After Abnormal Exercise ECHO or MPI Results Referral rates higher after an abnormal test • Range of ~20% to 50% generally Heterogeneity • Significant variation in referral rates Ladapo et al, JAHA 2013 17 Observed vs. True Diagnostic Performance of Exercise ECHO 99% 100% 91% 81% 80% 60% 40% 40% 20% 0% Sensitivity Specificity Observed performance True performance True performance = observed performance after adjustment for referral18 9 Observed vs. True Diagnostic Performance of Exercise MPI 97% 100% 91% 80% 67% 60% 44% 40% 20% 0% Sensitivity Specificity Observed performance True performance True performance = observed performance after adjustment for referral19 Challenges to Clinical Care: Unnecessary Testing and Procedures Presentation Title Goes Here 20 10 Unnecessary Testing is Common Our Threshold for Testing Patients is Falling • 39,515 patients undergoing stress MPI between 1991- 2009 at Cedars Sinai • Incidence of abnormal scans fell from 41%→9% • Incidence of ischemic scans fell from 30%→5% • Only 3% of patients who did not have typical angina and could exercise had an abnormal scan Rozanski, JACC 2013 21 Unnecessary Procedures are Common Cardiac Catheterization Frequently Performed Needlessly • 398,978 patients in American College of Cardiology (ACC) National Cardiovascular Data Registry (NCDR) • Noninvasive cardiac testing performed in 84% of patients prior to catheterization • Only 1 in 3 patients were found to have obstructive coronary disease • No coronary artery disease was reported in 39% of patients Patel, NEJM 2010 22 11 Inappropriate Imaging is Common What is appropriate imaging? • Imaging that provides (1) accurate information, (2) influences behavior, and (3) yields benefits that outweigh risks • In general, imaging in intermediate to high-risk patients is appropriate (diabetics, AAA, PVD, angina/ischemic equiv., ECG uninterpretable) • Number of inappropriate cardiac imaging stress tests in patients evaluated for CAD has risen • Primary care doctors fare worse than cardiologists Presented at American College of Cardiology 63rd Annual Scientific Session, March 23 2014 in Washington, DC Challenges to Clinical Care: Unnecessary Radiation Presentation Title Goes Here 24 12 25 Unnecessary Radiation Exposure is a Growing Problem Potential harms related to radiation exposure are poorly understood • Stress MPI accounts for 22% of cumulative effective radiation from medical sources • One MPI ≈ 1,000 chest x-rays ≈ 10-15 mSv • Persons at risk for repeated radiation exposure, such as healthcare workers and the nuclear industry, typically restricted to max 100 mSv every 5 years Columbia University Medical Center Medicare population • 1,097 consecutive patients, 8-10 years of • Between 1993-2001, 34% of enrollees follow-up underwent repeat testing • Multiple MPIs performed in 424 patients (39%) • Median cumulative effective dose from MPI US nonelderly population was 29 mSv • Median cumulative effective dose from • 952,420 adults in 5 US markets (2005-2007) medical sources was 64 mSv • Among patients undergoing cardiac imaging, mean cumulative dose 16.4 mSv (1.5-190 mSv) • MPI accounted for 74% of cumulative dose Fazel, NEJM 2009; Einstein, JAMA 2010; Gerber, Circulation 2009; Lucas, Circulation 2006; Chen, JACC 201026 13 Improving Quality Of Care Presentation Title Goes Here 27 Improving Quality of Care: Reducing Unnecessary Testing Appropriate use criteria • Growing physician awareness of appropriate use criteria for diagnostic testing in patients suspected of having CAD • ACC and United Healthcare registry reported that 34% of stress MPIs were inappropriate or of uncertain appropriateness Insurer policies and regulation Patient/Professional education • Prior authorization by radiology benefits managers • Informed decision-making • Reductions in reimbursement • Medicare released national coverage • Shared decision-making decision requesting more evidence for coronary CT angiography (CTCA) • Professional society scrutiny …Impact on health is unknown and needs to be studied Shaw, JACC: CV Imaging 2010; Gibbons, JACC 2008 28 14 Improving Quality of Care: Comparative Effectiveness Research