Appropriate test selection for single-photon emission computed tomography imaging: association with clinical risk, posttest management, and outcomes

Appropriate use criteria in myocardial perfusion imaging in a tertiary care hospital in South India: An audit

Myocardial perfusion imaging (MPI) is an important investigative tool in the diagnosis and management of coronary artery disease. This investigation has seen a manifold increase in number in past decades as compared to other investigations such as cardiac magnetic resonance imaging/positron emission tomography or computed tomography. In 2005, “Appropriate use criteria (AUC) in cardiac radionuclide imaging” was formulated by the American College of Cardiology Foundation and the American Society of Nuclear Cardiology for effective use of this investigation, later revised in 2009. We assessed the appropriateness of indications for MPI in patients presenting to the nuclear medicine department of a tertiary care hospital according to the latest AUC for cardiac radionuclide imaging. This is a retrospective analysis of all cardiac perfusion scans performed from June 2019 to January 2020 in a tertiary care teaching hospital in South India. All patients' indications for MPI were assessed for appropriateness using AUC 2009 as appropriate, inappropriate, and uncertain indications by two experienced nuclear medicine physicians blinded for results of the test and hospital stay of the patients. A total of 1015 cardiac scans were performed in the given period, which were analyzed. This included 613 males and 402 females, with most of the patients aged above 60 years (n = 640; males = 385, females = 255). Most of the patients had diabetes mellitus or hypertension or both except in 161 patients (15.8%) which did not have either of the comorbidities. Chest pain and/or shortness of breath were the most common presenting complaints. The appropriate indication for imaging was found in 784 patients (77.2%), inappropriate in 121 patients (12%), and uncertain in 110 patients (10.8%). Our results showed appropriate indication to be 77.2% and inappropriate indications as 12% for MPI referrals in a tertiary care teaching hospital, similar to Western literature but can be improved further by continued teaching and awareness campaigns.

Appropriate Use of Cardiac Stress Testing with Imaging: A Systematic Review and Meta-Analysis

BACKGROUND

Appropriate use criteria (AUC) for cardiac stress tests address concerns about utilization growth and patient safety. We systematically reviewed studies of appropriateness, including within physician specialties; evaluated trends over time and in response to AUC updates; and characterized leading indications for inappropriate/rarely appropriate testing.

METHODS

We searched PubMed (2005-2015) for English-language articles reporting stress echocardiography or myocardial perfusion imaging (MPI) appropriateness. Data were pooled using random-effects meta-analysis and meta-regression.

RESULTS

Thirty-four publications of 41,578 patients were included, primarily from academic centers. Stress echocardiography appropriate testing rates were 53.0% (95% CI, 45.3%-60.7%) and 50.9% (42.6%-59.2%) and inappropriate/rarely appropriate rates were 19.1% (11.4%-26.8%) and 28.4% (23.9%-32.8%) using 2008 and 2011 AUC, respectively. Stress MPI appropriate testing rates were 71.1% (64.5%-77.7%) and 72.0% (67.6%-76.3%) and inappropriate/rarely appropriate rates were 10.7% (7.2%-14.2%) and 15.7% (12.4%-19.1%) using 2005 and 2009 AUC, respectively. There was no significant temporal trend toward rising rates of appropriateness for stress echocardiography or MPI. Unclassified stress echocardiograms fell by 79% (p = 0.04) with updated AUC. There were no differences between cardiac specialists and internists.

CONCLUSIONS

Rates of appropriate use tend to be lower for stress echocardiography compared to MPI, and updated AUC reduced unclassified stress echocardiograms. There is no conclusive evidence that AUC improved appropriate use over time. Further research is needed to determine if integration of appropriateness guidelines in academic and community settings is an effective approach to optimizing inappropriate/rarely appropriate use of stress testing and its associated costs and patient harms.

Outcomes after inappropriate nuclear myocardial perfusion imaging: A meta-analysis

BACKGROUND

The relationship between inappropriate MPI and cardiovascular outcomes is poorly understood. We sought to systematically review the literature on appropriate use criteria (AUC) for MPI, including temporal trend of inappropriate testing and resulting cardiovascular outcomes.

METHODS

We searched the MEDLINE database for studies related to AUC and MPI. The co-primary outcomes were abnormal test results and the presence of cardiac ischemia. Random effects odds ratios (OR) were constructed using DerSimonian-Laird method.

RESULTS

A total of 22 studies with 23,443 patients were included. The prevalence of inappropriate testing was 14.8% [95% confidence interval (CI) 11.6%-18.7%]. Inappropriate MPI studies were less likely to be abnormal (OR 0.41 95% CI 0.35-0.49, P < .0001) and to demonstrate ischemia (OR 0.40, 95% CI 0.24-0.67, P < .0001) compared to appropriate testing. No difference in the rate of inappropriate tests was detected based on the midpoint of the enrollment year (P = .54). The pattern of ordering inappropriate studies was not different between cardiology and non-cardiology providers (OR 0.74, 95% CI 0.51-1.06, P = .10).

CONCLUSION

Inappropriate MPI studies are less likely to yield abnormal results or demonstrate myocardial ischemia. The rate of inappropriate MPI has not decreased over time.

Temporal changes in appropriateness of cardiac imaging

BACKGROUND

Appropriate use criteria (AUC) for cardiac imaging have been available for almost 10 years. The extent to which there has been a reported improvement in appropriate use is undefined.

OBJECTIVES

This study systematically reviewed published evidence to identify whether the promulgation of AUC has led to an improvement in the proportion of appropriate cardiac imaging requests.

METHODS

Electronic databases were systematically searched for English-language papers related to AUC and cardiovascular imaging. We found 59 reports involving 103,567 tests that were published from 2000 to 2012. The rate of appropriate testing over time was analyzed in a meta-regression.

RESULTS

New AUC were associated with apparent improvements in appropriateness for transthoracic echocardiography (TTE) (80% [95% confidence interval (CI): 0.75 to 0.84] vs. 85% [95% CI: 0.81 to 0.89]), transesophageal echocardiography (TEE) (89% [95% CI: 0.81 to 0.94] vs. 95% [95% CI: 0.93 to 0.96]) and computed tomography angiography (CTA) (37% [95% CI: 0.21 to 0.55] vs. 55% [95% CI: 0.44 to 0.65]) but not stress echocardiography (53% [95% CI: 0.45 to 0.61] vs. 52% [95% CI: 0.42 to 0.61]) or single-photon emission computed tomography (72% [95% CI: 0.66 to 0.77] vs. 68% [95% CI: 0.60 to 0.74]). Although there were no correlations between the proportion of appropriate TTEs and published year (p = 0.36) for 2007 AUC, there was a positive correlation between proportion of appropriateness and the year of publication (p = 0.01) for 2011 AUC. There was a significant decrease in the proportion of appropriateness over time using the 2007 TEE AUC (p = 0.03) and 2006 CT AUC (p = 0.02). There were no meaningful associations between appropriateness and publication year for stress echocardiography, CTA, or single-photon emission computed tomography.

CONCLUSIONS

Rates of reported appropriate use in imaging show improvements for TTE and CTA but not for stress imaging and TEE. The observed reductions in imaging studies are not matched by reported rates of appropriate use.

Clinical utility of inappropriate positron emission tomography myocardial perfusion imaging: test results and cardiovascular events

BACKGROUND

Appropriate use criteria for myocardial perfusion imaging (MPI) were developed to categorize scenarios where MPI might be beneficial (appropriate) or not (inappropriate). Few investigations have evaluated the clinical utility of this categorization strategy, particularly with positron emission tomography (PET) MPI.

METHODS AND RESULTS

We conducted this retrospective cohort investigation in a Veterans Affairs (VA) medical center, on predominantly male subjects who underwent PET-MPI. We correlated appropriateness to test result and cardiovascular events. Of 521 subjects, 414 (79.5%) were appropriate, 54 (10.4%) were uncertain, and 53 (10.2%) were inappropriate. PET-MPI was abnormal more often when appropriate or uncertain (28% and 34.6%, respectively, vs 7.7% for inappropriate, P = .003). Among abnormal inappropriate tests, none detected occult ischemia. By Cox regression, summed difference score ≥5 (HR 5.06, 95% CI 2.72-9.44) and an abnormal test result (HR 4.48, 95% CI 2.19-9.14) were associated with higher likelihood of catheterization. Log-rank analysis demonstrated similar likelihood of catheterization when comparing abnormal vs normal test result (P < .0001) and between appropriate, uncertain, and inappropriate tests (P = .024).

CONCLUSIONS

Inappropriate PET-MPI was rarely abnormal, associated with low catheterization rates, and failed to detect occult ischemia for any subjects. The clinical utility of inappropriate PET-MPI is negligible.

Applicability of the Appropriate use Criteria for Myocardial Perfusion Scintigraphy

Background

Appropriateness Criteria for nuclear imaging exams were created by American College of Cardiology (ACC) e American Society of Nuclear Cardiology (ASNC) to allow the rational use of tests. Little is known whether these criteria have been followed in clinical practice.

Objective

To evaluate whether the medical applications of myocardial perfusion scintigraphy (MPS) in a private nuclear medicine service of a tertiary cardiology hospital were suitable to the criteria of indications proposed by the American medical societies in 2005 and 2009 and compare the level of indication of both.

Methods

We included records of 383 patients that underwent MPS, November 2008 up to February 2009. Demographic characteristics, patient's origin, coronary risk factors, time of medical graduation and appropriateness criteria of medical applications were studied. The criteria were evaluated by two independent physicians and, in doubtful cases, defined by a medical expert in MPS.

Results

Mean age was 65 ± 12 years. Of the 367 records reviewed, 236 (64.3%) studies were performed in men and 75 (20.4%) were internee. To ACC 2005, 255 (69.5%) were considered appropriate indication and 13 (3.5%) inappropriate. With ACC 2009, 249 (67.8%) were considered appropriate indications and 13 (5.2%) inappropriate.

Conclusions

We observed a high rate of adequacy of medical indications for MPS. Compared to the 2005 version, 2009 did not change the results.