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EDITORIAL COMMENT Stress Testing After Coronary Revascularization Too Much, Too Soon* George A. Beller, MD Charlottesville, Virginia In response to the observation that the number of stress imaging procedures was rising annually at a very high rate, the American College of Cardiology Foundation proposed a method for evaluating the appropriateness of cardiovascular imaging using technical panels of experts who evaluated possible clinical scenarios where imaging would be used (1). The panels developed appropriate use criteria (AUC) for these varied clinical indications using a modified Delphi exercise. They combined evidence-based medical informa- tion and expert opinion. For example, the revised AUC for radionuclide imaging (2) lists 67 clinical scenarios scored by the panels on a scale of 1 to 9. Indications for radionuclide imaging deemed appropriate were those with scores ranging from 7 to 9; uncertain indications were those that yielded a median score of 4 to 6; and inappropriate indications have median scores from 1 to 3. The inappropriate indications fall into several categories, including testing of asymptom- atic or low-risk patients, routine testing early after coronary revascularization, pre-operative testing of low-risk patients with good functional capacity before noncardiac surgery, and detection of coronary artery disease (CAD) in stable symptomatic patients who have a low pre-test probability of CAD, have an interpretable baseline electrocardiogram, and are able to exercise (2). See page 1328 Several groups have sought to determine how well aca- demic and community physicians fared with respect to adherence to the AUC for stress radionuclide imaging and stress echocardiography (3–6). The rate of inappropriate indications in these studies ranges from 13% to 14%. A recent multicenter study (6) comprising 6 diverse clinical sites and 6,351 prospectively enrolled patients who under- went stress single-photon emission computed tomography myocardial perfusion imaging (MPI) found that 14% of indications were inappropriate, 15% were uncertain, and 71% were appropriate. As observed in the single-center studies, the most frequent inappropriate indications for stress single-photon emission computed tomography MPI was for detecting CAD in asymptomatic patients at low risk, followed by testing asymptomatic patients after revas- cularization 2 years after percutaneous coronary interven- tion (PCI) who had symptoms before PCI. More inappro- priate studies were ordered by noncardiologists than cardiologists and more in women than in men. By multi- variate analysis, asymptomatic status was the best predictor of an inappropriate classification. In the present issue of the Journal, Shah et al. (7) retrospectively examined the use and timing of stress testing more than 90 days after coronary revascularization in patients age 18 to 64 years from a national health insurance claims database. They also looked at subsequent rates of coronary angiography and repeat revascularization after stress testing. They found that among 28,177 patients undergoing revascularization, 59% had at least 1 cardiac stress test within 24 months (61% of PCI and 51% of coronary artery bypass graft [CABG] patients). Nuclear imaging was the predominant testing method. Of interest was the observation that the major spikes for stress testing ordering were at 6 and 12 months after revascularization, presumably coinciding with outpatient follow-up visits. Although more than one-half of the patients underwent stress testing, only 11% had subsequent cardiac catheteriza- tion within 30 days of testing and only 5% of all patients who underwent stress testing had repeat revascularization. There was also marked regional variation in the rate of stress testing after revascularization, with up to a 50% difference in rates of testing between regions. This regional variation is typical for cardiac diagnostic and therapeutic procedures performed in the U.S. (8,9). The study by Shah et al. (7) suggests excessive and inappropriate use of stress testing, mostly with imaging, after coronary revascularization. That is too much imaging too soon after revascularization. From clinical experience and published studies of outcomes after PCI and CABG, it is doubtful that 60% of PCI patients and 50% of CABG patients had significant ischemic symptoms that warranted stress imaging. Shah et al. (7) cite data from the National Heart, Lung, and Blood Institute’s Dynamic registry indicating that 18% of PCI patients report angina symptoms at the 1-year follow-up, a figure considerably lower than the 60% rate of stress testing after PCI reported in their study. With more drug-eluting stents being used for PCI and greater experience of operators in the interventional laboratory, the percentage of patients with recurrent angina at 1 year after PCI has dropped considerably. The data from Shah et al. (7) support prior reports of inappropriate routine imaging tests in asymptomatic pa- tients after uncomplicated PCI or CABG. A major limita- *Editorials published in the Journal of the American College of Cardiology reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology. From the Cardiovascular Division, University of Virginia Health System, Char- lottesville, Virginia. Dr. Beller reports that he has no relationships to disclose. Journal of the American College of Cardiology Vol. 56, No. 16, 2010 © 2010 by the American College of Cardiology Foundation ISSN 0735-1097/$36.00 Published by Elsevier Inc. doi:10.1016/j.jacc.2010.04.055

Stress Testing After Coronary Revascularization: Too Much, Too Soon

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Page 1: Stress Testing After Coronary Revascularization: Too Much, Too Soon

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Journal of the American College of Cardiology Vol. 56, No. 16, 2010© 2010 by the American College of Cardiology Foundation ISSN 0735-1097/$36.00Published by Elsevier Inc. doi:10.1016/j.jacc.2010.04.055

EDITORIAL COMMENT

tress Testing Afteroronary Revascularizationoo Much, Too Soon*

eorge A. Beller, MD

harlottesville, Virginia

n response to the observation that the number of stressmaging procedures was rising annually at a very high rate,he American College of Cardiology Foundation proposed aethod for evaluating the appropriateness of cardiovascular

maging using technical panels of experts who evaluatedossible clinical scenarios where imaging would be used (1).he panels developed appropriate use criteria (AUC) for

hese varied clinical indications using a modified Delphixercise. They combined evidence-based medical informa-ion and expert opinion. For example, the revised AUC foradionuclide imaging (2) lists 67 clinical scenarios scored byhe panels on a scale of 1 to 9. Indications for radionuclidemaging deemed appropriate were those with scores rangingrom 7 to 9; uncertain indications were those that yielded aedian score of 4 to 6; and inappropriate indications haveedian scores from 1 to 3. The inappropriate indications

all into several categories, including testing of asymptom-tic or low-risk patients, routine testing early after coronaryevascularization, pre-operative testing of low-risk patientsith good functional capacity before noncardiac surgery,

nd detection of coronary artery disease (CAD) in stableymptomatic patients who have a low pre-test probability ofAD, have an interpretable baseline electrocardiogram, and

re able to exercise (2).

See page 1328

Several groups have sought to determine how well aca-emic and community physicians fared with respect todherence to the AUC for stress radionuclide imaging andtress echocardiography (3–6). The rate of inappropriatendications in these studies ranges from 13% to 14%. Aecent multicenter study (6) comprising 6 diverse clinicalites and 6,351 prospectively enrolled patients who under-ent stress single-photon emission computed tomography

Editorials published in the Journal of the American College of Cardiology reflect theiews of the authors and do not necessarily represent the views of JACC or themerican College of Cardiology.

tFrom the Cardiovascular Division, University of Virginia Health System, Char-

ottesville, Virginia. Dr. Beller reports that he has no relationships to disclose.

yocardial perfusion imaging (MPI) found that 14% ofndications were inappropriate, 15% were uncertain, and1% were appropriate. As observed in the single-centertudies, the most frequent inappropriate indications fortress single-photon emission computed tomography MPIas for detecting CAD in asymptomatic patients at low

isk, followed by testing asymptomatic patients after revas-ularization �2 years after percutaneous coronary interven-ion (PCI) who had symptoms before PCI. More inappro-riate studies were ordered by noncardiologists thanardiologists and more in women than in men. By multi-ariate analysis, asymptomatic status was the best predictorf an inappropriate classification.In the present issue of the Journal, Shah et al. (7)

etrospectively examined the use and timing of stress testingore than 90 days after coronary revascularization in

atients age 18 to 64 years from a national health insurancelaims database. They also looked at subsequent rates oforonary angiography and repeat revascularization aftertress testing. They found that among 28,177 patientsndergoing revascularization, 59% had at least 1 cardiactress test within 24 months (61% of PCI and 51% oforonary artery bypass graft [CABG] patients). Nuclearmaging was the predominant testing method. Of interestas the observation that the major spikes for stress testingrdering were at 6 and 12 months after revascularization,resumably coinciding with outpatient follow-up visits.lthough more than one-half of the patients underwent

tress testing, only 11% had subsequent cardiac catheteriza-ion within 30 days of testing and only 5% of all patientsho underwent stress testing had repeat revascularization.here was also marked regional variation in the rate of stress

esting after revascularization, with up to a 50% difference inates of testing between regions. This regional variation isypical for cardiac diagnostic and therapeutic procedureserformed in the U.S. (8,9). The study by Shah et al. (7)uggests excessive and inappropriate use of stress testing,ostly with imaging, after coronary revascularization. That

s too much imaging too soon after revascularization. Fromlinical experience and published studies of outcomesfter PCI and CABG, it is doubtful that 60% of PCIatients and 50% of CABG patients had significantschemic symptoms that warranted stress imaging. Shaht al. (7) cite data from the National Heart, Lung, andlood Institute’s Dynamic registry indicating that 18% ofCI patients report angina symptoms at the 1-year

ollow-up, a figure considerably lower than the 60% ratef stress testing after PCI reported in their study. Withore drug-eluting stents being used for PCI and greater

xperience of operators in the interventional laboratory,he percentage of patients with recurrent angina at 1 yearfter PCI has dropped considerably.

The data from Shah et al. (7) support prior reports ofnappropriate routine imaging tests in asymptomatic pa-

ients after uncomplicated PCI or CABG. A major limita-
Page 2: Stress Testing After Coronary Revascularization: Too Much, Too Soon

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1336 Beller JACC Vol. 56, No. 16, 2010Stress Testing After Coronary Revascularization October 12, 2010:1335–7

ion of the study, noted by the authors, is the lack ofnformation on the percentage of patients who had symp-oms after revascularization for which a stress test would beppropriate. They report only the International Classifica-ion of Diseases-Ninth Edition codes for the commoniagnoses at the time of testing, and although some of theseodes provide potential symptom states, the most commoni.e., 414) reflects only known disease (CAD). Billing dataor clinical syndromes may be inaccurate. Nevertheless, theact that approximately only 10% of the patients whonderwent testing had downstream cardiac catheterizationmplies that most of the stress tests studies were low risk andikely were not indicated in the first place. Because thenvestigators eliminated any tests performed before 90 daysfter revascularization, those stress tests performed forardiac rehabilitation were probably not included in theirata after 90 days.The claims data reviewed by Shah et al. (7) spanned the

eriod from July 2004 through June 2007. The AUC for usef stress imaging procedures were perhaps not yet fullyppreciated in that time. Physicians today are more cogni-ant of AUC, as are health insurance companies pre-uthorizing stress tests. The latest AUC for stress radionu-lide imaging (2) indicate that it is appropriate to perform atress MPI to evaluate symptomatic patients after revascu-arization with an ischemic equivalent of 5 years or morefter CABG. It clearly states that it is inappropriate toerform stress imaging for risk assessment after revascular-zation �2 years after PCI in asymptomatic patients.nterestingly, the indication for stress MPI �2 years afterCI in an asymptomatic patient received an uncertain

ndication. This would not apply to the study by Shah et al.7), because they report stress test use rates only within 24onths after PCI, a period when the AUC clearly state such

esting is inappropriate in asymptomatic patients.There is one caveat regarding the value of post-revas-

ularization stress imaging that deserves mention. In theOURAGE (Clinical Outcomes Utilizing Revasculariza-

ion and Aggressive Drug Evaluation) trial nuclear sub-tudy, Shaw et al. (10) found that patients in either theptimal medical therapy arm or the optimal medical therapylus PCI arm who did not have at least a �5% reduction inschemia 6 to 18 months after assigned treatment had aorse cumulative event-free survival at follow-up comparedith those who had a significant reduction in myocardial

schemia. Similarly, regardless of treatment assignment, theagnitude of residual ischemia at follow-up was propor-

ional to the risk of death or nonfatal infarction. Therevalence and extent of residual ischemia were determinedy serial imaging before and 6 to 18 months after PCI orfter randomization to medical therapy without a PCI. Only1% of the PCI patients who underwent serial imaging hadngina at the time of the follow-up stress test. The numberf patients in this substudy was too small to make definitiveonclusions and was considered to be hypothesis generating.

f, in the future, a larger randomized study comparing a

erial imaging strategy versus no post-procedure imaging insymptomatic patients who have undergone PCI shows aenefit of detecting silent residual ischemia that is associ-ted with better long-term outcomes, the appropriateness oftress testing after PCI will have to be re-evaluated. Thisssumes that eliminating or reducing residual ischemiadentified in such patients can be accomplished and that itill be associated with improved infarct-free survival. Out-

omes will have to be substantially better than with justffective control of risk factors such as reducing low-densityipoprotein cholesterol levels, maintaining blood pressure inhe normotensive range, weight reduction, exercise therapy,nd smoking cessation, but without routine post-treatmenterial single-photon emission computed tomography MPI.

In summary, nearly 25% of all inappropriate stress imag-ng studies are performed in asymptomatic patients whoave undergone revascularization �2 years after PCI (6).he study by Shah et al. (7), despite its limitations as a

etrospective analysis of insurance claims, highlights theigh and probably excessive use of stress testing in the firstear after revascularization, with marked regional variationn test use. This study serves as another wake-up call toardiovascular specialists to be more diligent in adhering tovidence-based practice guidelines and AUC. The value oftress imaging is greatest in the evaluation of risk for futureardiac events in symptomatic patients to identify those whoould benefit the most from revascularization strategies.ur goal as cardiovascular specialists is to educate patients

nd referral physicians regarding the appropriate indicationsor expensive stress imaging procedures and where diagnos-ic and prognostic value is greatest. If we fail in this duty, weill be coerced into constantly securing pre-authorization

rom payers for diagnostic imaging tests to be performed forur patients. The problems with pre-authorization forormal approval of use of testing have been well described11). They include no evidence for improved quality of care,he favoring of indiscriminate volume reduction, the lack ofransparency, the fact that such measures are not based onUC, inconsistent processes often characterized by confu-

ion and inefficiency, reduced timeliness, an unstated goal ofteerage to the test of least resistance, labor intensiveness,nd scant data available for feedback or education (11).hus, it behooves cardiovascular specialists to advocate for

nd adhere to accepted AUC developed by our own scien-ific societies.

eprint requests and correspondence: Dr. George A. Beller,niversity of Virginia, Private Clinics Building, Room 5593, P.O.ox 800158, Charlottesville, Virginia 22908-0158. E-mail: [email protected].

EFERENCES

1. Patel MR, Spertus JA, Brindis RG, et al. ACCF proposed method for

evaluating the appropriateness of cardiovascular imaging. J Am CollCardiol 2005;46:1606–13.
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2. Hendel RC, Berman DS, DiCarli MF, et al. ACCF/ASNC/ACR/AHA/ASE/SCCT/SCMR/SNM 2009 appropriate use criteria forcardiac radionuclide imaging. J Am Coll Cardiol 2009;53:2201–29.

3. Gibbons RJ, Miller TD, Hodge D, et al. Application of appropriate-ness criteria to stress single-photon emission computed tomographysestamibi studies and stress echocardiograms in an academic medicalcenter. J Am Coll Cardiol 2008;51:1283–90.

4. McCully RB, Pellikka PA, Hodge DO, Araoz PA, Miller TD,Gibbons RJ. Applicability of appropriateness criteria for stress imag-ing: similarities and differences between stress echocardiography andsingle-photon emission computed tomography myocardial perfusionimaging criteria. Circ Cardiovasc Imaging 2009;2:213–18.

5. Mehta R, Ward RP, Chandra S, Agarwal R, Williams KA. Evaluationof the American College of Cardiology Foundation/American Societyof Nuclear Cardiology appropriateness criteria for SPECT myocardialperfusion imaging. J Nucl Cardiol 2008;15:337–44.

6. Hendel RC, Cerqueira M, Douglas PS, et al. A multicenter assess-ment of the use of single-photon emission computed tomographymyocardial perfusion imaging with appropriateness criteria. J Am Coll

Cardiol 2010;55:156–62. p

7. Shah BR, Cowper PA, O’Brien SM, et al. Patterns of cardiac stresstesting after revascularization in community practice. J Am CollCardiol 2010;56:1328–34.

8. The Dartmouth Atlas Working Group. The Dartmouth Atlas ofHealthcare. Available at: http://www.dartmouthatlas.org/atlases/atlasseries.shtm. Accessed April 3, 2010.

9. Gwande A. The cost conundrum: what a Texas town can teach usabout health care. The New Yorker. June 1, 2009, 36–45.

0. Shaw LJ, Berman DS, Maron DJ, et al. Optimal medical therapy withor without percutaneous coronary intervention to reduce ischemicburden: results from the Clinical Outcomes Utilizing Revasculariza-tion and Aggressive Drug Evaluation (COURAGE) trial nuclearsubstudy. Circulation 2008;117:1283–91.

1. Hendel RC. Utilization management of cardiovascular imaging. J AmColl Cardiol Img 2008;1:242–48.

ey Words: appropriate use criteria y exercise stress testing y

ercutaneous coronary intervention.