Low Yield of Stress Imaging in a Population-Based Study of Asymptomatic Patients After Percutaneous Coronary Intervention

Patient Symptoms and Stress Testing After Elective Percutaneous Coronary Intervention in the Veterans Affairs Health Care System

IMPORTANCE

Up to 60% of patients in the US receive a stress test within 2 years of percutaneous coronary intervention (PCI), prompting concerns about the possible overuse of stress testing.

OBJECTIVE

To examine the proportion of patients who underwent stress testing within 2 years of elective PCI, proportion of patients who had symptoms that were consistent with coronary artery disease (CAD), timing of stress testing, and site-level variation in stress testing among symptomatic and asymptomatic patients.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used administrative claims data and clinical records from the US Department of Veterans Affairs (VA) Clinical Assessment, Reporting, and Tracking program. Patients who underwent stress testing within 2 years of elective PCI for stable CAD between November 1, 2013, and October 31, 2015, at 64 VA facilities were included in the analysis. Patients who received stress testing for staging purposes, cardiac rehabilitation evaluation, or preoperative testing before high-risk surgery were excluded. Data were analyzed from June to December 2020.

MAIN OUTCOMES AND MEASURES

The main outcome was the proportion of patients who underwent stress testing and had symptoms that were consistent with obstructive CAD, using definitions from the 2013 clinical practice guideline (Multimodality Appropriate Use Criteria for the Detection and Risk Assessment of Stable Ischemic Heart Disease). Secondary outcomes were the timing of stress testing (assessed using a cumulative incidence curve) and site-level variation in stress testing (assessed using multilevel logistic regression models).

RESULTS

A total of 3705 consecutive patients (mean [SD] age 66.3 [7.6] years; 3656 men [98.7%]; 437 Black individuals [11.8%], 3175 White individuals [85.7%], and 93 individuals [2.5%] of other races and ethnicities [Asian, Hispanic or Latinx, or unknown]) had elective PCI. Of these patients, 916 (24.7%) received a stress test within 2 years, among whom 730 (79.7%) had symptoms that were consistent with obstructive CAD at the time of stress testing. Visual inspection of a cumulative incidence curve for stress testing showed no rapid increases in stress testing at 6 months or 1 year after PCI, which might coincide with routine clinical visits. The proportion of symptomatic patients who underwent stress testing at each VA site ranged from 67.7% to 100%, with no significant site-level variation in stress testing.

CONCLUSIONS AND RELEVANCE

Results of this study suggest that most veterans who underwent stress testing within 2 years after elective PCI had symptoms that were consistent with obstructive CAD. Therefore, measuring low-value stress testing using only administrative claims data may overestimate its prevalence, and concerns about overuse of post-PCI stress testing may be overstated.

Characterizing and quantifying low-value diagnostic imaging internationally: a scoping review

BACKGROUND

Inappropriate and wasteful use of health care resources is a common problem, constituting 10-34% of health services spending in the western world. Even though diagnostic imaging is vital for identifying correct diagnoses and administrating the right treatment, low-value imaging-in which the diagnostic test confers little to no clinical benefit-is common and contributes to inappropriate and wasteful use of health care resources. There is a lack of knowledge on the types and extent of low-value imaging. Accordingly, the objective of this study was to identify, characterize, and quantify the extent of low-value diagnostic imaging examinations for adults and children.

METHODS

A scoping review of the published literature was performed. Medline-Ovid, Embase-Ovid, Scopus, and Cochrane Library were searched for studies published from 2010 to September 2020. The search strategy was built from medical subject headings (Mesh) for Diagnostic imaging/Radiology OR Health service misuse/Medical overuse OR Procedures and Techniques Utilization/Facilities and Services Utilization. Articles in English, German, Dutch, Swedish, Danish, or Norwegian were included.

RESULTS

A total of 39,986 records were identified and, of these, 370 studies were included in the final synthesis. Eighty-four low-value imaging examinations were identified. Imaging of atraumatic pain, routine imaging in minor head injury, trauma, thrombosis, urolithiasis, after thoracic interventions, fracture follow-up and cancer staging/follow-up were the most frequently identified low-value imaging examinations. The proportion of low-value imaging varied between 2 and 100% inappropriate or unnecessary examinations.

CONCLUSIONS

A comprehensive list of identified low-value radiological examinations for both adults and children are presented. Future research should focus on reasons for low-value imaging utilization and interventions to reduce the use of low-value imaging internationally.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42020208072.

Cardiac Stress Testing After Coronary Revascularization

Unless prompted by symptoms or change in clinical status, the appropriate use criteria consider cardiac stress testing (CST) within 2 years of percutaneous coronary intervention (PCI) and 5 years of coronary artery bypass grafting (CABG) to be rarely appropriate. Little is known regarding use and yield of CST after PCI or CABG. We studied 39,648 patients treated with coronary revascularization (29,497 PCI; 10,151 CABG) between April 2004 and March 2012 in Alberta, Canada. Frequency of CST between 60 days and 2 years after revascularization was determined from linked provincial databases. Yield was defined as subsequent rates of coronary angiography and revascularization after CST. Post PCI, 14,195 (48.1%) patients underwent CST between 60 days and 2 years, while post CABG, 4,469 (44.0%) patients underwent CST. Compared with patients not undergoing CST, patients undergoing CST were more likely to be of younger age, reside in an urban area, have higher neighborhood median household income, but less medical comorbidities. Among PCI patients undergoing CST, 5.2% underwent subsequent coronary angiography, and 2.6% underwent repeat revascularization within 60 days of CST. Rates of coronary angiography and repeat revascularization post-CST among CABG patients were 3.6% and 1.1%, respectively. Approximately one-half of patients undergo CST within 2 years of PCI or CABG in Alberta, Canada. Yield of CST is low, with only 1 out of 38 tested post-PCI patients and 1 out of 91 tested post-CABG patients undergoing further revascularization. In conclusion, additional research is required to determine patients most likely to benefit from CST after revascularization.

Use of High-Sensitivity Cardiac Troponin for the Exclusion of Inducible Myocardial Ischemia: A Cohort Study

BACKGROUND

Many patients with coronary artery disease (CAD) are routinely referred for surveillance stress testing despite recommendations against it.

OBJECTIVE

To determine whether low levels of resting high-sensitivity cardiac troponin I (hs-cTnI) can identify persons without inducible myocardial ischemia.

DESIGN

Observational study.

SETTING

A university-affiliated hospital network.

PATIENTS

Persons with stable CAD: 589 in the derivation group and 118 in the validation cohort.

MEASUREMENTS

Presence of inducible myocardial ischemia was determined by myocardial perfusion imaging with technetium-99m single-photon emission computed tomography during either treadmill or pharmacologic stress testing. Resting plasma hs-cTnI was measured within 1 week of the stress test, and the negative predictive value (NPV) for inducible ischemia was calculated. The derivation cohort was followed for 3 years for incident cardiovascular death and myocardial infarction.

RESULTS

In the derivation cohort, 10 of 101 patients with an hs-cTnI level below 2.5 pg/mL had inducible myocardial ischemia (NPV, 90% [95% CI, 83% to 95%]) and 3 of 101 had inducible ischemia involving at least 10% of the myocardium (NPV, 97% [CI, 92% to 99%]). In the validation cohort, 4 of 32 patients with an hs-cTnI level below 2.5 pg/mL had inducible ischemia (NPV, 88% [CI, 71% to 96%]) and 2 of 32 had ischemia of 10% or greater (NPV, 94% [CI, 79% to 99%]). After a median follow-up of 3 years in the derivation cohort, no adverse events occurred in patients with an hs-cTnI level below 2.5 pg/mL, compared with 33 (7%) cardiovascular deaths or incident myocardial infarctions among those with an hs-cTnI level of 2.5 pg/mL or greater.

LIMITATION

The data may not be applicable to a population without known CAD or to persons with unstable angina, and the modest sample sizes warrant further validation in a larger cohort.

CONCLUSION

Very low hs-cTnI levels may be useful in excluding inducible myocardial ischemia in patients with stable CAD.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Population-Based Study on Patterns of Cardiac Stress Testing After Percutaneous Coronary Intervention

BACKGROUND

The appropriate use criteria considers cardiac stress testing within 2 years after percutaneous coronary intervention (PCI) to be rarely appropriate, unless prompted by symptoms or change in clinical status. Little is known about the patterns of cardiac stress testing after PCI in the single-payer Canadian healthcare system, where mechanisms for reimbursement are different from the United States.

METHODS AND RESULTS

Frequency and timing of cardiac stress testing within 2 years of PCI performed between April 2004 and March 2013 in Ontario, Canada, was determined from linked provincial databases. Subsequent rates of coronary angiography and revascularization after stress testing were ascertained. Of the 112 691 patients with PCI, 67 442 (59.8%) underwent at least 1 stress test, with 38 267 (34.0%) undergoing repeat stress testing (ie, >1 stress test) within 2 years. Patients who underwent stress testing were younger, had less medical comorbidities, were more likely to reside in urban areas, and had higher incomes. Spikes in incidence of repeat stress testing were observed at 3 to 4 months, 6 to 7 months, and 12 to 13 months after the prior stress test. Of those tested, only 5.9% underwent subsequent coronary angiography, and only 3.1% underwent repeat revascularization within 60 days of stress testing.

CONCLUSIONS

More than half of all patients undergo cardiac stress testing within 2 years of PCI, with one third undergoing repeat stress tests. Only 1 of 30 tested patients underwent repeat revascularization. These findings reinforce the appropriate use criteria recommendations against routine stress testing after PCI. Further work is needed to aid with the selection of patients most likely to benefit from stress testing after PCI.

Stress testing after percutaneous coronary interventions: a population-based study

BACKGROUND

Routine stress testing is commonly used after percutaneous coronary intervention (PCI) to detect in-stent restenosis or suboptimal procedure results; however, recent studies suggest that such testing is rarely indicated. Our main objectives were to assess temporal trends in utilization of stress testing and to determine factors associated with its use.

METHODS

We conducted an observational study involving all patients who had undergone PCI in Ontario, Canada, from Apr. 1, 2004, to Mar. 31, 2012. The main outcome was stress testing within 2 years after PCI. We constructed multivariable logistic regression models to determine factors associated with the use of stress tests.

RESULTS

Our cohort consisted of 128 380 patients who underwent PCI procedures. The 2-year rate of stress testing declined significantly, from 68.1% among patients who underwent PCI in 2004 to 60.4% in 2012 (p < 0.001). Similar reductions were observed regardless of patients' risk of restenosis and type of stent received. Patients who were older or had diabetes mellitus, prior myocardial infarction, heart failure or other comorbidities were significantly less likely to undergo stress testing. In contrast, patients with higher income and those whose PCI was performed in a nonteaching hospital were significantly more likely to undergo stress testing.

INTERPRETATION

We observed a decrease in the use of stress testing after PCI procedures over time. However, stress tests were not performed in accordance with patients' higher baseline risk of adverse outcomes or risk of restenosis. Instead, many nonclinical factors, such as patients' socioeconomic status and hospitals' teaching status, were associated with higher use of stress tests.