Clinical Trial Diversity, Equity, and Inclusion: Roadmap of the Cardiothoracic Surgical Trials Network.

BACKGROUND: There is a recognized lack of diversity among patients enrolled in cardiovascular interventional and surgical trials. Diverse patient representation in clinical trials is necessary to enhance generalizability of findings, which may lead to better outcomes across broader populations. The Cardiothoracic Surgical Trials Network (CTSN) recently developed a plan of action to increase diversity among participating investigators and trial participants and is the focus of this review. METHODS: A review of literature and enrollment data from CTSN trials was conducted. RESULTS: CTSN completed more than a dozen major clinical trials (2008-2022), enrolling >4000 patients, of whom 30% were women, 11% were non-White, and 5.6% were Hispanic. CTSN also completed trials of hospitalized patients with coronavirus disease 2019, wherein enrollment was more diverse, with 42% women, and 58% were Asian, Black, Hispanic, or from another underrepresented racial group. The discrepancy in diversity of enrollment between cardiac surgery trials and coronavirus disease trials highlights the need for a more comprehensive understanding of (1) the prevalence of underlying disease requiring cardiac interventions across broad populations, (2) differences in access to care and referral for cardiac surgery, and (3) barriers to enrollment in cardiac surgery trials. CONCLUSIONS: Committed to diversity, CTSN's multifaceted action plan includes developing site-specific enrollment targets, collecting social determinants of health data, understanding reasons for nonparticipation, recruiting sites that serve diverse populations, emphasizing greater diversity among clinical trial teams, and implicit bias training. The CTSN will prospectively assess how these interventions influence enrollment as we work to ensure trial participants are more representative of the communities we serve.

Endocarditis, invasive dental procedures, and antibiotic prophylaxis efficacy in US Medicaid patients.

OBJECTIVE: Antibiotic prophylaxis is recommended before invasive dental procedures to prevent endocarditis in those at high risk, but supporting data are sparse. We therefore investigated any association between invasive dental procedures and endocarditis, and any antibiotic prophylaxis effect on endocarditis incidence. SUBJECTS AND METHODS: Cohort and case-crossover studies were performed on 1,678,190 Medicaid patients with linked medical, dental, and prescription data. RESULTS: The cohort study identified increased endocarditis incidence within 30 days of invasive dental procedures in those at high risk, particularly after extractions (OR 14.17, 95% CI 5.40-52.11, p < 0.0001) or oral surgery (OR 29.98, 95% CI 9.62-119.34, p < 0.0001). Furthermore, antibiotic prophylaxis significantly reduced endocarditis incidence following invasive dental procedures (OR 0.20, 95% CI 0.06-0.53, p < 0.0001). Case-crossover analysis confirmed the association between invasive dental procedures and endocarditis in those at high risk, particularly following extractions (OR 3.74, 95% CI 2.65-5.27, p < 0.005) and oral surgery (OR 10.66, 95% CI 5.18-21.92, p < 0.0001). The number of invasive procedures, extractions, or surgical procedures needing antibiotic prophylaxis to prevent one endocarditis case was 244, 143 and 71, respectively. CONCLUSIONS: Invasive dental procedures (particularly extractions and oral surgery) were significantly associated with endocarditis in high-risk individuals, but AP significantly reduced endocarditis incidence following these procedures, thereby supporting current guideline recommendations.

Association Between Peripheral Versus Central Access for Alternative Access Transcatheter Aortic Valve Replacement and Mortality and Stroke: A Report From the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry.

BACKGROUND: In some patients, the alternative access route for transcatheter aortic valve replacement (TAVR) is utilized because the conventional transfemoral approach is not felt to be either feasible or optimal. However, accurate prognostication of patient risks is not well established. This study examines the associations between peripheral (transsubclavian/transaxillary, and transcarotid) versus central access (transapical and transaortic) in alternative access TAVR and 30-day and 1-year end points of mortality and stroke for all valve platforms. METHODS: Using data from The Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry with linkage to Medicare claims, patients who underwent alternative access TAVR from June 1, 2015 to June 30, 2018 were identified. Adjusted and unadjusted Cox proportional hazards modeling were performed to determine the association between alternate access TAVR site and 30-day and 1-year end points of mortality and stroke. RESULTS: Of 7187 alternative access TAVR patients, 3725 (52%) had peripheral access and 3462 (48%) had central access. All-cause mortality was significantly lower in peripheral access versus central access group at in-hospital and 1 year (2.9% versus 6.3% and 20.3% versus 26.6%, respectively), but stroke rates were higher (5.0% versus 2.8% and 7.3% versus 5.5%, respectively; all P<0.001). These results persisted after 1-year adjustment (death adjusted hazard ratio, 0.72 [95% CI, 0.62-0.85] and stroke adjusted hazard ratio, 2.92 [95% CI, 2.21-3.85]). When broken down by individual subtypes, compared with transaxillary/subclavian access patients, transapical, and transaortic access patients had higher all-cause mortality but less stroke (P<0.05). CONCLUSIONS: In this real-world, contemporary, nationally representative benchmarking study of alternate access TAVR sites, peripheral access was associated with favorable mortality and morbidity outcomes compared with central access, at the expense of higher stroke. These findings may allow for accurate prognostication of risk for patient counseling and decision-making for the heart team with regard to alternative access TAVR.

Antibiotic Prophylaxis Against Infective Endocarditis Before Invasive Dental Procedures.

BACKGROUND: Antibiotic prophylaxis (AP) before invasive dental procedures (IDPs) is recommended to prevent infective endocarditis (IE) in those at high IE risk, but there are sparse data supporting a link between IDPs and IE or AP efficacy in IE prevention. OBJECTIVES: The purpose of this study was to investigate any association between IDPs and IE, and the effectiveness of AP in reducing this. METHODS: We performed a case-crossover analysis and cohort study of the association between IDPs and IE, and AP efficacy, in 7,951,972 U.S. subjects with employer-provided Commercial/Medicare-Supplemental coverage. RESULTS: Time course studies showed that IE was most likely to occur within 4 weeks of an IDP. For those at high IE risk, case-crossover analysis demonstrated a significant temporal association between IE and IDPs in the preceding 4 weeks (OR: 2.00; 95% CI: 1.59-2.52; P = 0.002). This relationship was strongest for dental extractions (OR: 11.08; 95% CI: 7.34-16.74; P < 0.0001) and oral-surgical procedures (OR: 50.77; 95% CI: 20.79-123.98; P < 0.0001). AP was associated with a significant reduction in IE incidence following IDP (OR: 0.49; 95% CI: 0.29-0.85; P = 0.01). The cohort study confirmed the associations between IE and extractions or oral surgical procedures in those at high IE risk and the effect of AP in reducing these associations (extractions: OR: 0.13; 95% CI: 0.03-0.34; P < 0.0001; oral surgical procedures: OR: 0.09; 95% CI: 0.01-0.35; P = 0.002). CONCLUSIONS: We demonstrated a significant temporal association between IDPs (particularly extractions and oral-surgical procedures) and subsequent IE in high-IE-risk individuals, and a significant association between AP use and reduced IE incidence following these procedures. These data support the American Heart Association, and other, recommendations that those at high IE risk should receive AP before IDP.

Nationally Representative Repeat Transcatheter Aortic Valve Replacement Outcomes: Report From the Centers for Medicare and Medicaid Services.

OBJECTIVES: The aim of this study was to examine real-world experience with repeat transcatheter aortic valve replacement (TAVR) in a population-based national database. BACKGROUND: Repeat TAVR is a growing option in patients requiring reintervention for TAVR. However, large-scale studies with longitudinal follow-up are limited. METHODS: All Medicare beneficiaries who underwent TAVR from 2012 to 2017 were included. Outcomes included 30-day and longitudinal mortality and major adverse cardiovascular events, defined as death, stroke, pacemaker insertion, major bleeding, acute kidney injury, or cardiac arrest. Outcomes of repeat TAVR were compared with surgical explantation after TAVR (TAVR explantation) in a matched analysis. RESULTS: Of 133,250 patients who underwent TAVR, 617 (0.46%) underwent subsequent repeat TAVR at a median interval of 154 days (interquartile range: 58-537 days). Mortality at 30 days and 1 year was 6.0% and 22.0%, respectively. Rates of 30-day stroke and pacemaker insertion were 1.8% and 4.2%. Mortality at 30 days was lower in those who underwent their first TAVR during the later era (2015-2017) compared with earlier years (2012-2014) (4.6% vs 8.7%; P = 0.049). Repeat TAVR was associated with lower 30-day mortality compared with a matched group undergoing TAVR explantation (6.2% vs 12.3%; P = 0.05), although 1-year mortality was similar (21.0% vs 20.8%; P = 1.000). The incidence of 30-day major adverse cardiovascular events was higher with TAVR explantation compared with repeat TAVR (risk ratio: 2.92; 95% CI: 1.88-4.99; P ≤ 0.001). CONCLUSIONS: Repeat TAVR was performed with acceptable 30-day mortality in this high-risk population. Short-term outcomes were superior to surgical explantation, but 1-year outcomes were similar. Repeat TAVR will likely be an important option for aortic valve reintervention after TAVR.

Incidence, Characteristics, Predictors, and Outcomes of Surgical Explantation After Transcatheter Aortic Valve Replacement.

BACKGROUND: Currently, there is a paucity of information on surgical explantation after transcatheter aortic valve replacement (TAVR). OBJECTIVES: The purpose of this study was to examine the incidence, patient characteristics, predictors, and outcomes of surgical explantation after TAVR using a population-based, nationally representative database. METHODS: We analyzed the Medicare Provider profile to include all U.S. patients undergoing TAVR from 2012 to 2017. Time to surgical explant was calculated from the index TAVR discharge to surgical explantation. Post-operative survival was assessed using time-dependent Cox proportional hazard regression analysis and landmark analysis. RESULTS: The incidence of surgical explantation was 0.2% (227 of 132,633 patients), and was 0.28% and 0.14% in the early and newer TAVR era, respectively. The median time to surgical explant was 212 days, whereas 8.8% and 70.9% underwent surgical explantation within 30 days and 1 year, respectively. The primary indication for reintervention was bioprosthetic failure (79.3%). Compared with the no-explant cohort, the explant cohort was significantly younger (mean age 73.7 years vs. 81.7 years), with a lower prevalence of heart failure (55.9% vs. 65.8%) but more likely a lower-risk profile cohort (15% vs. 2.4%; all p < 0.05). The 30-day and 1-year mortality rates were 13.2% and 22.9%, respectively, and did not vary by either time to surgical explant or TAVR era, or between patients with versus without endocarditis (all p > 0.05). The time-dependent Cox regression analysis demonstrated a higher mortality in those with surgical explantation (hazard ratio: 4.03 vs. no-explant group; 95% confidence interval: 1.81 to 8.98). Indication, time-to-surgical-explant, and year of surgical explantation were not associated with worse post-explantation survival (all p > 0.05). CONCLUSIONS: The present study provides updated evidence on the incidence, timing, and outcomes of surgical explantation of a TAVR prosthesis. Although the overall incidence was low, short-term mortality was high. These findings stress the importance of future mechanistic studies on TAVR explantation and may have implications on lifetime management of aortic stenosis, particularly in younger patients.

Quantifying the Impact of Care Fragmentation on Outcomes After Transcatheter Aortic Valve Implantation.

The Center for Medicare & Medicaid Services has identified readmission as an important quality metric in assessing hospital performance and value of care. The aim of this study was to quantify the impact of "care fragmentation" on transcatheter aortic valve implantation (TAVI) outcomes. Readmission to nonindex hospitals was defined as any hospital other than the hospital where the TAVI was performed. In this multicenter, population-based, nationally representative study, a nationally weighted cohort of US adult patients who underwent TAVI in the National Readmission Database between 01/01/2010 and 9/31/2015 were analyzed. Patient characteristics, trends, and outcomes after 90-day nonindex readmission were evaluated. Thirty-day metric was used as a reference group for comparison. A weighted total of 51,092 patients met inclusion criteria. Overall, the 90-day readmission rate after TAVI was 27.6% (30-day reference group: 17.4%), and 42% of these readmissions were to nonindex hospitals. Noncardiac causes accounted for most nonindex readmissions, but major cardiac procedures were more likely performed at index hospitals during readmission within 90 days. Despite the high co-morbidity burden of patients readmitted to nonindex hospitals, unadjusted and risk-adjusted all-cause mortality, readmission length of stay and total hospital costs following nonindex readmission were lower compared with index readmission at 90 days. In conclusion, in this real world, nationally representative cohort of TAVI patients in the United States, care fragmentation remains prevalent and represent an enduring, residual target for future health policies. Although the impactful readmissions may be directed toward index hospitals, concerted efforts are needed to address mechanisms that increase care fragmentation.

Relationship Between Hospital Surgical Aortic Valve Replacement Volume and Transcatheter Aortic Valve Replacement Outcomes.

OBJECTIVES: The aim of this study was to examine whether hospital surgical aortic valve replacement (SAVR) volume was associated with corresponding transcatheter aortic valve replacement (TAVR) outcomes. BACKGROUND: Recent studies have demonstrated a volume-outcome relationship for TAVR. METHODS: In total, 208,400 fee-for-service Medicare beneficiaries were analyzed for all aortic valve replacement procedures from 2012 to 2015. Claims for patients <65 years of age, concomitant coronary artery bypass grafting surgery, other heart valve procedures, or other major open heart procedures were excluded, as were secondary admissions for aortic valve replacement. Hospital SAVR volumes were stratified on the basis of mean annual SAVR procedures during the study period. The primary outcomes were 30-day and 1-year post-operative TAVR survival. Adjusted survival following TAVR was assessed using multivariate Cox regression. RESULTS: A total of 65,757 SAVR and 42,967 TAVR admissions were evaluated. Among TAVR procedures, 21.7% (n = 9,324) were performed at hospitals with <100 (group 1), 35.6% (n = 15,298) at centers with 100 to 199 (group 2), 22.9% (n = 9,828) at centers with 200 to 299 (group 3), and 19.8% (n = 8,517) at hospitals with ≥300 SAVR cases/year (group 4). Compared with group 4, 30-day TAVR mortality risk-adjusted odds ratios were 1.32 (95% confidence interval: 1.18 to 1.47) for group 1, 1.25 (95% confidence interval: 1.12 to 1.39) for group 2, and 1.08 (95% confidence interval: 0.82 to 1.25) for group 3. These adjusted survival differences in TAVR outcomes persisted at 1 year post-procedure. CONCLUSIONS: Total hospital SAVR volume appears to be correlated with TAVR outcomes, with higher 30-day and 1-year mortality observed at low-volume centers. These data support the importance of a viable surgical program within the heart team, and the use of minimum SAVR hospital thresholds may be considered as an additional metric for TAVR performance.

Cost-effectiveness of coronary artery bypass grafting plus mitral valve repair versus coronary artery bypass grafting alone for moderate ischemic mitral regurgitation.

OBJECTIVE: The Cardiothoracic Surgical Trials Network reported that left ventricular reverse remodeling at 2 years did not differ between patients with moderate ischemic mitral regurgitation randomized to coronary artery bypass grafting plus mitral valve repair (n = 150) or coronary artery bypass grafting alone (n = 151). To address health resource use implications, we compared costs and quality-adjusted survival. METHODS: We used individual patient data from the Cardiothoracic Surgical Trials Network trial on survival, hospitalizations, quality of life, and US hospitalization costs to estimate cumulative costs and quality-adjusted life years. A microsimulation model was developed to extrapolate to 10 years. Bootstrap and deterministic sensitivity analyses were performed to address uncertainty. RESULTS: In-hospital costs were $59,745 for coronary artery bypass grafting plus mitral valve repair versus $51,326 for coronary artery bypass grafting alone (difference $8419; 95% uncertainty interval, 2259-18,757). Two-year costs were $81,263 versus $67,341 (difference 13,922 [2370 to 28,888]), and quality-adjusted life years were 1.35 versus 1.30 (difference 0.05; -0.04 to 0.14), resulting in an incremental cost-effectiveness ratio of $308,343/quality-adjusted life year for coronary artery bypass grafting plus mitral valve repair. At 10 years, its costs remained higher ($107,733 vs $88,583, difference 19,150 [-3866 to 56,826]) and quality-adjusted life years showed no difference (-0.92 to 0.87), with 5.08 versus 5.08. The likelihood that coronary artery bypass grafting plus mitral valve repair would be considered cost-effective at 10 years based on a cost-effectiveness threshold of $100K/quality-adjusted life year did not exceed 37%. Only when this procedure reduces the death rate by a relative 5% will the incremental cost-effectiveness ratio fall below $100K/quality-adjusted life year. CONCLUSIONS: The addition of mitral valve repair to coronary artery bypass grafting for patients with moderate ischemic mitral regurgitation is unlikely to be cost-effective. Only if late mortality benefits can be demonstrated will it meet commonly used cost-effectiveness criteria.

Antibiotic Prophylaxis and Incidence of Endocarditis Before and After the 2007 AHA Recommendations.

BACKGROUND: The American Heart Association updated its recommendations for antibiotic prophylaxis (AP) to prevent infective endocarditis (IE) in 2007, advising that AP cease for those at moderate risk of IE, but continue for those at high risk. OBJECTIVES: The authors sought to quantify any change in AP prescribing and IE incidence. METHODS: High-risk, moderate-risk, and unknown/low-risk individuals with linked prescription and Medicare or commercial health care data were identified in the Truven Health MarketScan databases from May 2003 through August 2015 (198,522,665 enrollee-years of data). AP prescribing and IE incidence were evaluated by Poisson model analysis. RESULTS: By August 2015, the 2007 recommendation change was associated with a significant 64% (95% confidence interval [CI]: 59% to 68%) estimated fall in AP prescribing for moderate-risk individuals and a 20% (95% CI: 4% to 32%) estimated fall for those at high risk. Over the same period, there was a barely significant 75% (95% CI: 3% to 200%) estimated increase in IE incidence among moderate-risk individuals and a significant 177% estimated increase (95% CI: 66% to 361%) among those at high risk. In unknown/low-risk individuals, there was a significant 52% (95% CI: 46% to 58%) estimated fall in AP prescribing, but no significant increase in IE incidence. CONCLUSIONS: AP prescribing fell among all IE risk groups, particularly those at moderate risk. Concurrently, there was a significant increase in IE incidence among high-risk individuals, a borderline significant increase in moderate-risk individuals, and no change for those at low/unknown risk. Although these data do not establish a cause-effect relationship between AP reduction and IE increase, the fall in AP prescribing in those at high risk is of concern and, coupled with the borderline increase in IE incidence among those at moderate risk, warrants further investigation.

Cost-Effectiveness of Mitral Valve Repair Versus Replacement for Severe Ischemic Mitral Regurgitation: A Randomized Clinical Trial From the Cardiothoracic Surgical Trials Network

BACKGROUND: The CTSN (Cardiothoracic Surgical Trials Network) recently reported no difference in left ventricular end-systolic volume index or in survival at 2 years between patients with severe ischemic mitral regurgitation (MR) randomized to mitral valve repair or replacement. However, replacement provided more durable correction of MR and fewer cardiovascular readmissions. Yet, costeffectiveness outcomes have not been addressed. METHODS AND RESULTS: We conducted a cost-effectiveness analysis of the surgical treatment of ischemic MR based on the CTSN trial (n=126 for repair; n=125 for replacement). Patient-level data on readmissions, survival, qualityof- life, and US hospital costs were used to estimate costs and quality-adjusted life years per patient over the trial duration and a 10-year time horizon. We performed microsimulation for extrapolation of outcomes beyond the 2 years of trial data. Bootstrap and deterministic sensitivity analyses were done to address parameter uncertainty. In-hospital cost estimates were $78 216 for replacement versus $72 761 for repair (difference: $5455; 95% uncertainty interval [UI]: −7784­21 193) while 2-year costs were $97 427 versus $96 261 (difference: $1166; 95% UI: −16 253­17 172), respectively. Quality-adjusted life years at 2 years were 1.18 for replacement versus 1.23 for repair (difference: −0.05; 95% UI: −0.17 to 0.07). Over 5 and 10 years, the benefits of reduction in cardiovascular readmission rates with replacement increased, and survival minimally improved compared with repair. At 5 years, cumulative costs and quality-adjusted life years showed no difference on average, but by 10 years, there was a small, uncertain benefit for replacement: $118 023 versus $119 837 (difference: −$1814; 95% UI: −27 144 to 22 602) and qualityadjusted life years: 4.06 versus 3.97 (difference: 0.09; 95% UI: −0.87 to 1.08). After 10 years, the incremental cost-effectiveness of replacement continued to improve. CONCLUSIONS: Our cost-effectiveness analysis predicts potential savings in cost and gains in quality-adjusted survival at 10 years when mitral valve replacement is compared with repair for severe ischemic MR. These projected benefits, however, were small and subject to variability. Efforts to further delineate predictors of long-term outcomes in patients with severe ischemic MR are needed to optimize surgical decisions for individual patients, which should yield more cost-effective care. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00807040.

Diabetes and the Association of Postoperative Hyperglycemia With Clinical and Economic Outcomes in Cardiac Surgery.

OBJECTIVE: The management of postoperative hyperglycemia is controversial and generally does not take into account pre-existing diabetes. We analyzed clinical and economic outcomes associated with postoperative hyperglycemia in cardiac surgery patients, stratifying by diabetes status. RESEARCH DESIGN AND METHODS: Multicenter cohort study in 4,316 cardiac surgery patients operated on in 2010. Glucose was measured at 6-h intervals for 48 h postoperatively. Outcomes included cost, hospital length of stay (LOS), cardiac and respiratory complications, major infections, and death. Associations between maximum glucose levels and outcomes were assessed with multivariable regression and recycled prediction analyses. RESULTS: In patients without diabetes, increasing glucose levels were associated with a gradual worsening of outcomes. In these patients, hyperglycemia (≥180 mg/dL) was associated with an additional cost of $3,192 (95% CI 1,972 to 4,456), an additional hospital LOS of 0.8 days (0.4 to 1.3), an increase in infections of 1.6% (0.5 to 2.8), and an increase in respiratory complications of 2.6% (0.0 to 5.3). However, among patients with insulin-treated diabetes, optimal outcomes were associated with glucose levels considered to be hyperglycemic (180 to 240 mg/dL). This level of hyperglycemia was associated with cost reductions of $6,225 (-12,886 to -222), hospital LOS reductions of 1.6 days (-3.7 to 0.4), infection reductions of 4.1% (-9.1 to 0.0), and reductions in respiratory complication of 12.5% (-22.4 to -3.0). In patients with non-insulin-treated diabetes, outcomes did not differ significantly when hyperglycemia was present. CONCLUSIONS: Glucose levels <180 mg/dL are associated with better outcomes in most patients, but worse outcomes in patients with diabetes with a history of prior insulin use. These findings support further investigation of a stratified approach to the management of patients with stress-induced postoperative hyperglycemia based on prior diabetes status.

Organizational Change, Leadership, and the Transformation of Continuing Professional Development: Lessons Learned From the American College of Cardiology.

There is a need for a transformational change in clinical education. In postgraduate medical education we have traditionally had a faculty-centric model. That is, faculty knew what needed to be taught and who were the best teachers to teach it. They built the agenda, and worked with staff to follow Accreditation Council for Continuing Medical Education (ACCME) accreditation criteria and manage logistics. Changes in the health care marketplace now demand a learner-centric model-one that embraces needs assessments, identification of practice gaps relative to competency, development of learning objectives, contemporary adult learning theory, novel delivery systems, and measurable outcomes. This article provides a case study of one medical specialty society's efforts to respond to this demand.

ACCF/AHA/ASE/ASNC/HFSA/HRS/SCAI/SCCT/SCMR/STS 2013 multimodality appropriate use criteria for the detection and risk assessment of stable ischemic heart disease: a report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, American Heart Association, American Society of Echocardiography, American Society of Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, Society for Cardiovascular Angiography and Interventions, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance, and Society of Thoracic Surgeons.

The American College of Cardiology Foundation along with key specialty and subspecialty societies, conducted an appropriate use review of common clinical presentations for stable ischemic heart disease (SIHD) to consider use of stress testing and anatomic diagnostic procedures. This document reflects an updating of the prior Appropriate Use Criteria (AUC) published for radionuclide imaging (RNI), stress echocardiography (Echo), calcium scoring, coronary computed tomography angiography (CCTA), stress cardiac magnetic resonance (CMR), and invasive coronary angiography for SIHD. This is in keeping with the commitment to revise and refine the AUC on a frequent basis. A major innovation in this document is the rating of tests side by side for the same indication. The side-by-side rating removes any concerns about differences in indication or interpretation stemming from prior use of separate documents for each test. However, the ratings were explicitly not competitive rankings due to the limited availability of comparative evidence, patient variability, and range of capabilities available in any given local setting. The indications for this review are limited to the detection and risk assessment of SIHD and were drawn from common applications or anticipated uses, as well as from current clinical practice guidelines. Eighty clinical scenarios were developed by a writing committee and scored by a separate rating panel on a scale of 1-9, to designate Appropriate, May Be Appropriate, or Rarely Appropriate use following a modified Delphi process following the recently updated AUC development methodology. The use of some modalities of testing in the initial evaluation of patients with symptoms representing ischemic equivalents, newly diagnosed heart failure, arrhythmias, and syncope was generally found to be Appropriate or May Be Appropriate, except in cases where low pre-test probability or low risk limited the benefit of most testing except exercise electrocardiogram (ECG). Testing for the evaluation of new or worsening symptoms following a prior test or procedure was found to be Appropriate. In addition, testing was found to be Appropriate or May Be Appropriate for patients within 90 days of an abnormal or uncertain prior result. Pre-operative testing was rated Appropriate or May Be Appropriate only for patients who had poor functional capacity and were undergoing vascular or intermediate risk surgery with 1 or more clinical risk factors or an organ transplant. The exercise ECG was suggested as an Appropriate test for cardiac rehabilitation clearance or for exercise prescription purposes. Testing in asymptomatic patients was generally found to be Rarely Appropriate, except for calcium scoring and exercise testing in intermediate and high-risk individuals and either stress or anatomic imaging in higher-risk individuals, which were all rated as May Be Appropriate. All modalities of follow-up testing after a prior test or percutaneous coronary intervention (PCI) within 2 years and within 5 years after coronary artery bypass graft (CABG) in the absence of new symptoms were rated Rarely Appropriate. Pre-operative testing for patients with good functional capacity, prior normal testing within 1 year, or prior to low-risk surgery also were found to be Rarely Appropriate. Imaging for an exercise prescription or prior to the initiation of cardiac rehabilitation was Rarely Appropriate except for cardiac rehabilitation clearance for heart failure patients.