Are cardiologists truly better at appropriately selecting patients for stress myocardial perfusion imaging?

Prevalence of abnormal SPECT myocardial perfusion imaging during the COVID-19 pandemic

Purpose

The aim of this study is to evaluate the rate of abnormal myocardial perfusion imaging (MPI) studies at a single medical center during the COVID-19 pandemic compared to prior to the pandemic.

Methods

We retrospectively studied stress single-photon emission computed tomography (SPECT)-MPI studies performed during the peak of COVID-19 restrictions at the University of Alabama Medical Center in comparison to the same time period in 2019.

Results

SPECT-MPI volume was reduced from 553 per month in 2019 to 105 per month in 2020. The proportion of abnormal SPECT-MPI for the 2020 cohort (61 ± 13 years, 48% men, 41% black) was not different from the 2019 cohort (62 ± 12 years, 48% men, 42% black) (31% vs. 27%, p = 0.4). Similar proportion of patients in the 2 cohorts had abnormal myocardial perfusion, moderate-large perfusion defects, myocardial ischemia, myocardial scar, and abnormal left ventricular ejection fraction. The proportion of abnormal SPECT-MPIs was not different based on whether patients were evaluated face-to-face or by telemedicine (28% vs. 27%, p > 0.9) but was higher for cardiology providers (40% vs. 20%, p < 0.001).

Conclusions

There was a significant reduction in the number of SPECT-MPI studies performed during the peak restrictions from the pandemic. Despite this restriction, the rate of abnormal studies remained stable. Our study suggests that it remains difficult to predict which patients will have abnormal SPECT-MPI even when providers and stress laboratories are forced to prioritize the performance of studies to high-yield patients.

Comparison of the Appropriateness of Myocardial Perfusion Imaging in Men Versus Women

After a decade of appropriate use criteria publication, the degree and predictors of inappropriate use in women compared with men are not known. We conducted a retrospective cohort investigation comparing appropriateness categories (appropriate, maybe appropriate, and rarely appropriate) and cardiovascular outcomes in patients undergoing nuclear myocardial perfusion imaging (MPI) between June 2011 and September 2014 in predominantly inpatient setting. Of 1,475 cases reviewed, 747 (50.6%) were women, and they were more likely to have rarely appropriate use 118 (15.8%) than men 62 (8.5%), p <0.01, but they were less likely to have an abnormal MPI 102 (13.6%) than men 183 (25.6%), p <0.01. Subsequent angiography and revascularization rates were similar in women 38 (37.2%) and 5 (4.9%) and men 52 (28.4%) and 16 (8.7%), p = 0.12, p = 0.23, respectively. After median follow-up of 6 months, myocardial infarction rates were similar in women 3 (2.9%) and men 7 (3.8%), p = 0.67. Death rates were similar in women 8 (7.8%) and men 18 (9.8%), p = 0.57. The most common clinical scenario designated as rarely appropriate was in those with low pretest probability of coronary artery disease, who have interpretable electrocardiogram and are able to exercise in women 58 (49.1%) and men 21 (33.8%). In conclusion, based on the most contemporary appropriate use criteria publication, rarely appropriate use of MPI remains higher in women than that in men. This phenomenon was mostly observed in low-risk patients who can exercise.

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.

Appropriate use criteria for SPECT myocardial perfusion imaging: Are they appropriate for women?

BACKGROUND

Several studies have reported that women are more likely to receive inappropriate SPECT myocardial perfusion imaging (MPI), suggesting gender disparity in AUC determination. We investigated the impact of gender on the diagnostic and prognostic utility of AUC.

METHODS AND RESULTS

We analyzed a multi-site prospective cohort of 1511 consecutive patients (43.5% women) who underwent outpatient, community-based SPECT-MPI. Subjects were stratified into gender groups and appropriateness subgroups, and followed for 27 ± 10 months for cardiac death, myocardial infarction, and coronary revascularization. Women were more likely to receive inappropriate MPI (60.7% vs 33.8%, P < .001). Irrespective of appropriateness, women were less likely to have an abnormal MPI (6.1% vs 14.9%, P < .001), even after adjusting for clinical covariates [odds ratio = 0.40 (95% confidence interval = 0.26-0.60), P < .001]. Irrespective of appropriateness, women were at lower risk for MACE (composite of cardiac death, myocardial infarction, or coronary revascularization) after adjusting for clinical and imaging covariates [hazard ratio = 0.49 (95% confidence interval = 0.28-0.86), P = .01]. There was no interaction between gender and appropriateness group as a determinant of abnormal MPI or MACE (interaction P values ≥ .26), indicating that female gender was associated with similar relative risk of an abnormal MPI and MACE irrespective of appropriateness group. Abnormal MPI was similarly predictive of increased hazard of MACE in both genders, regardless of appropriateness (interaction P values ≥ .46).

CONCLUSION

In this multi-site cohort, there was no demonstrable gender-based differential impact of AUC on the diagnostic or prognostic utility of SPECT-MPI. The study validates the methods used in determining risk in the AUC algorithm and endorses the widespread application of AUC in men and women.

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.

Effective risk stratification of patients on the basis of myocardial perfusion SPECT is dependent on appropriate patient selection

Myocardial perfusion imaging (MPI) with single-photon emission computed tomography (SPECT) is commonly used in risk assessment, as an abnormal scan predicts a multifold increase in cardiac risk. Recent studies have showed that application of the appropriate use criteria (AUC) sharpens the prognostic value of SPECT-MPI, while inappropriate use is clinically ineffective and may lead to unnecessary downstream invasive testing and revascularization procedures. In this review, we will discuss recent literature examining the impact of appropriate use on the prognostic value of SPECT-MPI and downstream decision-making. We will also discuss the implications of appropriate use on cost-effectiveness of MPI.

Impact of insurance carrier, prior authorization, and socioeconomic status on appropriate use of SPECT myocardial perfusion imaging in private community-based office practice

BACKGROUND

The impact of health insurance carrier and socioeconomic status (SES) on the adherence to appropriate use criteria (AUC) for radionuclide myocardial perfusion imaging (MPI) is unknown.

HYPOTHESIS

Health insurance carrier's prior authorization and patient's SES impact adherence to AUC for MPI in a fee-for-service setting.

METHODS

We conducted a prospective cohort study of 1511 consecutive patients who underwent outpatient MPI in a multi-site, office-based, fee-for-service setting. The patients were stratified according to the 2009 AUC into appropriate/uncertain appropriateness and inappropriate use groups. Insurance status was categorized as Medicare (does not require prior authorization) vs commercial (requires prior authorization). Socioeconomic status was determined by the median household income in the ZIP code of residence.

RESULTS

The proportion of patients with Medicare was 33% vs 67% with commercial insurance. The rate of inappropriate use was higher among patients with commercial insurance vs Medicare (55% vs 24%; P < 0.001); this difference was not significant after adjusting for confounders known to impact AUC determination (odds ratio: 1.06, 95% confidence interval: 0.62-1.82, P = 0.82). The mean annual household income in the residential areas of patients with inappropriate use as compared to those with appropriate/uncertain use was $72 000 ± 21 000 vs $68 000 ± 20 000, respectively (P < 0.001). After adjusting for covariates known to impact AUC determination, SES (top vs bottom quartile income area) was not independently predictive of inappropriate MPI use (odds ratio: 0.9, 95% confidence interval: 0.53-1.52, P = 0.69).

CONCLUSIONS

Insurance carriers prior authorization and SES do not seem to play a significant role in determining physicians adherence to AUC for MPI.