Things We Do For No Reason: Echocardiogram in Unselected Patients with Syncope

Appropriate use of transthoracic echocardiography in the investigation of general medicine patients presenting with syncope or presyncope

STUDY PURPOSE

Routine transthoracic echocardiography (TTE) in patients with syncope or presyncope is resource-intensive. We assessed if risk thresholds defined by a validated risk score may identify patients at low risk of cardiac abnormality in whom TTE is unnecessary.

STUDY DESIGN

We conducted a retrospective study of all general medicine patients with syncope/presyncope presenting to a tertiary hospital between July 2016 and September 2020 and who underwent TTE. The Canadian Syncope Risk Score (CSRS) was used to categorise patients as low to very low risk (score -3 to 0) or moderate to high risk (score ≥1) for serious adverse events at 30 days. A cut-point of 0 was used to calculate the sensitivity, specificity, positive and negative predictive values (PPV and NPV) for CSRS and the odds ratio (OR) of a clinically significant finding on TTE in patients with CSRS ≥1 compared with all patients.

RESULTS

Among 157 patients, the CSRS categorised 69 (44%) as very low to low risk in whom TTE was normal. In 88 patients deemed moderate to high risk, TTE detected a cardiac abnormality in 24 (27%). A CSRS ≥1 yielded a sensitivity of 100% (95% CI 85.7% to 100%), specificity of 51.1% (95% CI 42.3% to 59.8%), PPV of 26.5% (95% CI 26.3% to 30.1%) and NPV of 100% (95% CI 92.5% to 100%) for cardiac abnormalities and doubled the odds of an abnormality (OR=2.05, 95% CI 1.08 to 3.87, p=0.028).

CONCLUSION

In general medicine patients with syncope/presyncope, using the CSRS to stratify risk of a cardiac abnormality on TTE can almost halve TTE use.

Current best practices in emergency evaluation and management of syncope

ABSTRACT

Syncope is a common medical presentation that can cost the US healthcare system up to $2.4 billion dollars annually. Much of this cost can be mitigated with proper evaluation and management in the urgent care setting, as well as appropriate use of a risk stratification system.

ACR Appropriateness Criteria® Syncope

Syncope and presyncope lead to well over one million emergency room visits in the United States each year. Elucidating the cause of syncope or presyncope, which are grouped together given similar etiologies and outcomes, can be exceedingly difficult given the diverse etiologies. This becomes more challenging as some causes, such as vasovagal syncope, are relatively innocuous while others, such as cardiac-related syncope, carry a significant increased risk of death. While the mainstay of syncope and presyncope assessment is a detailed history and physical examination, imaging can play a role in certain situations. In patients where a cardiovascular etiology is suspected based on the appropriate history, physical examination, and ECG findings, resting transthoracic echocardiography is usually considered appropriate for the initial imaging. While no imaging studies are considered usually appropriate when there is a low probability of cardiac or neurologic pathology, chest radiography may be appropriate in certain clinical situations. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Predictors of Clinically Significant Echocardiography Findings in Older Adults with Syncope: A Secondary Analysis

BACKGROUND

Syncope is a common reason for visiting the emergency department (ED) and is associated with significant healthcare resource utilization.

OBJECTIVE

To develop a risk-stratification tool for clinically significant findings on echocardiography among older adults presenting to the ED with syncope or nearsyncope.

DESIGN

Prospective, observational cohort study from April 2013 to September 2016.

SETTING

Eleven EDs in the United States.

PATIENTS

We enrolled adults (=60 years) who presented to the ED with syncope or near-syncope who underwent transthoracic echocardiography (TTE).

MEASUREMENTS

The primary outcome was a clinically significant finding on TTE. Clinical, electrocardiogram, and laboratory variables were also collected. Multivariable logistic regression analysis was used to identify predictors of significant findings on echocardiography.

RESULTS

A total of 3,686 patients were enrolled. Of these, 995 (27%) received echocardiography, and 215 (22%) had a significant finding on echocardiography. Regression analysis identified five predictors of significant finding: (1) history of congestive heart failure, (2) history of coronary artery disease, (3) abnormal electrocardiogram, (4) high-sensitivity troponin-T >14 pg/mL, and 5) N-terminal pro B-type natriuretic peptide >125 pg/mL. These five variables make up the ROMEO (Risk Of Major Echocardiography findings in Older adults with syncope) criteria. The sensitivity of a ROMEO score of zero for excluding significant findings on echocardiography was 99.5% (95% CI: 97.4%-99.9%) with a specificity of 15.4% (95% CI: 13.0%-18.1%).

CONCLUSIONS

If validated, this risk-stratification tool could help clinicians determine which syncope patients are at very low risk of having clinically significant findings on echocardiography.

REGISTRATION

ClinicalTrials.gov Identifier NCT01802398.

Variation in diagnostic testing for older patients with syncope in the emergency department

BACKGROUND

Older adults presenting with syncope often undergo intensive diagnostic testing with unclear benefit. We determined the variation, frequency, yield, and costs of tests obtained to evaluate older persons with syncope.

METHODS

We conducted a prospective, multicenter observational cohort study in 11 academic emergency departments in the United States of 3686 patients aged ≥60 years presenting with syncope or presyncope. We measured the frequency, variation, yield, and costs (based on Medicare payment tables) of diagnostic tests performed at the index visit.

RESULTS

While most study rates were similar across sites, some were notably discordant (e.g., carotid ultrasound: mean 9.5%, range 1.1% to 49.3%). The most frequently-obtained diagnostic tests were initial troponin (88.6%), chest x-ray (75.1%), head CT (42.5%) and echocardiogram (35.5%). The yield or proportion of abnormal findings by diagnostic test ranged from 1.9% (electrocardiogram) to 42.0% (coronary angiography). Among the most common tests, echocardiogram had the highest proportion of abnormal results at 22.1%. Echocardiogram was an outlier in total cost at $672,648, and had a cost per abnormal test of $3129.

CONCLUSION

Variation in diagnostic testing in older patients presenting with syncope exists. The yield and cost per abnormal result for common tests obtained to evaluate syncope are also highly variable. Selecting tests based on history and examination while also prioritizing less resource intensive and higher yield tests may ensure a more informed and cost-effective approach to evaluating older patients with syncope.