A gatekeeper for the gatekeeper: Inappropriate referrals to stress echocardiography

doi:10.1016/j.ahj.2007.04.032

American Heart Journal

Volume 154, Issue 2, August 2007, Pages 285-290

https://doi.org/10.1016/j.ahj.2007.04.032 Get rights and content

Background

Cardiac imaging stress tests have increased nearly 3-fold in the last decade, with >10 million a year performed in the United States alone. Inappropriate selection for testing may have important consequences because small individual costs (and risks) multiplied by millions of examinations represent a significant societal burden. The aim of this study was to assess the appropriateness of selection for stress echocardiography in 2 high-volume laboratories.

Methods

This audit of 350 consecutive stress echocardiograms for evaluation of known or suspected coronary artery disease was performed from May to June 2006 at centers in Australia and Italy. Appropriateness was independently scored by a senior clinical cardiologist as follows: I = definitely appropriate, IIa = probably appropriate, IIb = probably inappropriate, or III = definitely inappropriate, based on current guidelines for cardiac stress testing. All referrals were accepted at one center, and referrals were prescreened by cardiology fellows working at the other.

Results

Examinations were definitely appropriate in 217 (62%), probably appropriate in 35 (10%), probably inappropriate in 76 (22%), and definitely inappropriate in 22 (6%) patients. The main reasons of inappropriateness were (1) performance as first-line test (37% of inappropriate tests) and (2) test repeated too often in the absence of change in clinical status (30%). The inappropriate testing rate was higher when no screening of external referral was implemented (43% vs 13%, P < .0001).

Conclusions

Inappropriate indications for stress echocardiography are common but avoidable if referrals are screened. Targeting inappropriateness opens a unique opportunity to cut health care expenditure with no reduction, and possibly improvement, in health care standards.

Section snippets

Study design

We audited 350 stress echocardiography examinations performed at the Institute of Clinical Physiology, Pisa, Italy, and the University of Queensland Cardiovascular Imaging group, Princess Alexandra Hospital, Brisbane, Australia—each center contributing 175 consecutive examinations. All indications were clinically driven and referred from a clinician through the outpatient clinic or inpatient wards. However, the general policy of test booking was different in the 2 contributing centers: center 1

Patient characteristics

Starting from 1 May 2006, 350 consecutive patients (age = 62 ± 7 years, 231 men) underwent stress echocardiography for the evaluation of known or suspected ischemic heart disease. The stress used was exercise (n = 187) or pharmacological (with dipyridamole or dobutamine in 38 and 125, respectively, patients unable to exercise). The clinical presentation of the 350 patients and the classes of indications broken down according to clinical status are listed in Table I.

Appropriateness of testing

Indications were partially or

Discussion

The results of this audit of highly experienced stress echocardiography laboratories show that the number of costly examinations with inappropriate indication and/or inadequate clinical utilization of test results is high. There is variability of test indication and patient selection between sites; and this seems to be based on local practice for test approval, with more inappropriate testing in the setting of open access to testing.

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The technique has been proved to be effective in risk stratification after surgical revascularization in several studies showing that the evidence of ischemia adds significant prognostic information to that provided by clinical data and resting echo [2–6]. Appropriate and inappropriate stress echocardiography after CABG account for 5 to 10% of all indications in large volume laboratories [7–9]. However, the assessment of the value of the technique is made difficult by the lack of reliable data with state-of-the-art protocols.
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In a prospective, multicenter, observational study, 349 patients (270 men; 69 ± 9 years; 262 symptomatic) with history of CABG underwent high-dose dipyridamole (0.84 mg/kg over 6 min) stress echocardiography with CFVR evaluation of LAD by Doppler. The composite endpoint of death and myocardial infarction was considered in the survival analysis. Positivity rate with either criteria was 13% in the 262 symptomatic patients with appropriate and 6% in the 87 asymptomatic patients with maybe/rarely appropriate indications on the basis of 2014 American College of Cardiology Foundation guidelines. During a median follow-up of 22 months (1st quartile 8, 3rd quartile 44), there were 56 (16%) events: 21 deaths, and 35 nonfatal myocardial infarctions. At Cox analysis, ischemia at stress echo (HR 4.80, 95% CI 2.69–8.55; p < 0.0001), and CFVR of LAD ≤2 (HR 2.28, 95% CI 1.32–3.95; p = 0.003) were multivariable prognostic predictors. Considering the group with no ischemia, patients with CFVR ≤2 showed 2.5 fold higher yearly hard events as compared to those with CFVR >2 (7.5 vs 2.9%; p = 0.002).
Dual imaging stress echocardiography provides useful prognostic information following CABG. Inducible ischemia and abnormal CFVR are strong and independent prognostic indicators in patients with appropriate and rarely/maybe appropriate indications.
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The aim of this study was to assess the validity and prognostic value of exercise stress echocardiography, as a newly introduced method at our workplace, over the medium-term time horizon.
Between February 2014 and May 2017, 204 patients (63% males, 60 ± 11 years) underwent exercise stress echocardiography (ESE) due to stable symptoms including chest pain or exertional dyspnea, with a known or suspected ischemic heart disease (IHD). A pre-test probability of IHD was 45 ± 17%. The contrast agent was used in 25 (12%) patients. Positive test: new appearance of wall motion abnormalities in at least two adjacent left ventricular segments. The test complication rate was 0%.
ESE was positive in 13 (6%) patients, 10 of them (77%) had a significant coronary artery stenosis. ESE was nondiagnostic (patients failed to achieve 85% of maximum predicted heart rate) in 27 (13%) patients.
During the follow-up (median 17, IQR 8–29 months) 195 patients (96%) were successfully contacted. 2 (1%) patients died of malignancy, 68 (33%) were referred to coronary angiography, 2 (1%) had unstable angina pectoris (UAP), 2 (1%) had myocardial infarction (MI), 12 (6%) underwent percutaneous coronary intervention (PCI) or surgical revascularization. Patients with positive test result: n = 13 (6%): 9 (69%) underwent revascularization due to significant coronary artery stenosis, 2 (15%) had MI. Patients with non-diagnostic test n = 27 (14%): 2 (7%) died of malignancy, 1 patient underwent PCI. Patients with negative diagnostic test n = 164 (80%), 2 cases of new-onset angina pectoris within 12 months following the testing (PCI was performed).
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Exercise stress echocardiography in hands of an experienced operator is a safe and valuable method. Negative result of a diagnostic exercise stress echocardiography has, based on our experience, an excellent negative predictive value concerning cardiovascular morbidity and mortality within the 17 month-time median.
The declining frequency of inducible myocardial ischemia during stress echocardiography over 27 consecutive years (1983–2009)
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Yet, in recent years cardiovascular imaging has become the focus of intensive efforts on the part of public and private payers, since it has contributed substantially to the escalating health care costs in the last 20 years [5]. According to recent estimates, 20 to 50% of all SE examinations are partially or completely inappropriate [6–11], i.e., risks and costs may outweigh benefits [12]. Although SE is less expensive and risky than other alternative techniques and is radiation-free, nevertheless SE also contributes to imaging wastes and unwanted collateral damage, including the risks of the procedure itself with physical or pharmacological stressors [13–16] and the downstream impact of poor performance such as delay in diagnosis (false-negative results) or inappropriate diagnosis (false-positive results).
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Development of an Educational Strategy and Decision Support Tool to Enhance Appropriate Use of Stress Echocardiography at a Large Academic Medical Center: A Prospective, Pre- and Postintervention Analysis
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Diagnostic imaging has increased dramatically over the past few years, driven largely by an increase in cardiovascular services. In this study, we demonstrated that the baseline proportion of rarely appropriate stress echocardiographic studies is approximately one third of all studies, which represents a similar number to those seen in the United States, Europe, and Australia.9-13 Through the implementation of educational strategies and the development of a DS tool, we were able to show almost a 39% reduction in rarely appropriately ordered SE and a corresponding 17% increase in appropriately ordered SE.
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Clinical InvestigationImaging and Diagnostic TestingA gatekeeper for the gatekeeper: Inappropriate referrals to stress echocardiography

Background

Methods

Results

Conclusions

Section snippets

Study design

Patient characteristics

Appropriateness of testing

Discussion

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Clinical Investigation
Imaging and Diagnostic Testing
A gatekeeper for the gatekeeper: Inappropriate referrals to stress echocardiography