Multivariable risk scores for predicting short-term outcomes for emergency department patients with unexplained syncope: A systematic review

Risk-stratification tools for emergency department patients with syncope: A systematic review and meta-analysis of direct evidence for SAEM GRACE

OBJECTIVES

Approximately 10% of patients with syncope have serious or life-threatening causes that may not be apparent during the initial emergency department (ED) assessment. Consequently, researchers have developed clinical decision rules (CDRs) to predict adverse outcomes and risk stratify ED syncope patients. This systematic review and meta-analysis (SRMA) aims to cohere and synthesize the best current evidence regarding the methodological quality and predictive accuracy of CDRs for developing an evidence-based ED syncope management guideline.

METHODS

We conducted a systematic literature search according to the patient-intervention-control-outcome question: In patients 16 years of age or older who present to the ED with syncope for whom no underlying serious/life-threatening condition was found during the index ED visit (population), are risk stratification tools (intervention), better than unstructured clinical judgment (i.e., usual care; comparison), for providing accurate prognosis and aiding disposition decision for outcomes within 30 days (outcome)? Two reviewers independently assessed articles for inclusion and methodological quality. We performed statistical analysis using Meta-DiSc. We used GRADEPro GDT software to determine the certainty of the evidence and create a summary of the findings (SoF) tables.

RESULTS

Of 2047 publications obtained through the search strategy, 31 comprising 13 CDRs met the inclusion criteria. There were 13 derivation studies (17,578 participants) and 24 validation studies (14,845 participants). Only three CDRs were validated in more than two studies. The San Francisco Syncope Rule (SFSR) was validated in 12 studies: positive likelihood ratio (LR+) 1.15-4.70 and negative likelihood ratio (LR-) 0.03-0.64. The Canadian Syncope Risk Score (CSRS) was validated in five studies: LR+ 1.15-2.58 and LR- 0.05-0.50. The Osservatorio Epidemiologico sulla Sincope nel Lazio (OESIL) risk score was validated in five studies: LR+ 1.16-3.32 and LR- 0.14-0.46.

CONCLUSIONS

Most CDRs for ED adult syncope management have low-quality evidence for routine clinical practice use. Only three CDRs (SFSR, CSRS, OESIL) are validated by more than two studies, with significant overlap in operating characteristics.

Role of Artificial Intelligence in Improving Syncope Management

Syncope is common in the general population and a common presenting symptom in acute care settings. Substantial costs are attributed to the care of patients with syncope. Current challenges include differentiating syncope from its mimickers, identifying serious underlying conditions that caused the syncope, and wide variations in current management. Although validated risk tools exist, especially for short-term prognosis, there is inconsistent application, and the current approach does not meet patient needs and expectations. Artificial intelligence (AI) techniques, such as machine learning methods including natural language processing, can potentially address the current challenges in syncope management. Preliminary evidence from published studies indicates that it is possible to accurately differentiate syncope from its mimickers and predict short-term prognosis and hospitalisation. More recently, AI analysis of electrocardiograms has shown promise in detection of serious structural and functional cardiac abnormalities, which has the potential to improve syncope care. Future AI studies have the potential to address current issues in syncope management. AI can automatically prognosticate risk in real time by accessing traditional and nontraditional data. However, steps to mitigate known problems such as generalisability, patient privacy, data protection, and liability will be needed. In the past AI has had limited impact due to underdeveloped analytical methods, lack of computing power, poor access to powerful computing systems, and availability of reliable high-quality data. All impediments except data have been solved. AI will live up to its promise to transform syncope care if the health care system can satisfy AI requirement of large scale, robust, accurate, and reliable data.

Comparison of syncope risk scores in predicting the prognosis of patients presenting to the emergency department with syncope

BACKGROUND

Various scores have been derived for the assessment of syncope patients in the emergency department (ED).

AIM

We aimed to compare the effectiveness of Canadian Syncope Risk Scores (CSRS), San Francisco Syncope Rules (SFSR), and Osservatorio Epidemiologico sulla Sincope nel Lazio (OESIL) risk scores in predicting the risk of major adverse cardiac events (MACE) and mortality among syncope patients within 30 days of the initial ED visit.

METHODS

We performed a prospective, observational case series study of adults (≥ 18 years) with unexplained syncope/near-syncope who presented to ED. Demographic characteristics of the patients and clinical and laboratory data were recorded in the standard data collection form of the study. Our primary outcome was a 30-day mortality.

RESULTS

A total of 421 patients (mean age 50.9 ± 20.8, 51.5% male) were enrolled. The rate of MACE development in the 30-day follow-up of the patients was 12.8% (n = 54). While 20.2% (n = 85) of the patients were hospitalized, two of the patients died in the emergency room and the 30-day mortality was 5.5% (n = 23). CSRS was found to have the highest predictive power of mortality (AUC: 0.869, 95% CI 0.799-0.939, p < 0.001). If the cut-off value of CSRS was 0.5, the sensitivity was found to be 82.6% and the specificity was 81.9%. Also CSRS (OR: 1.402, 95% CI: 1.053-1.867, p = 0.021) was found to be an independent predictor of the 30-day mortality.

CONCLUSION

The CSRS may be used as a safety risk score for a 30-day risk of MACE and mortality after discharge from the emergency department.

Risk stratification tools for patients with syncope in emergency medical services and emergency departments: a scoping review

BACKGROUND

Patients with a syncope constitute a challenge for risk stratification in (prehospital) emergency care. Professionals in EMS and ED need to differentiate the high-risk from the low-risk syncope patient, with limited time and resources. Clinical decision rules (CDRs) are designed to support professionals in risk stratification and clinical decision-making. Current CDRs seem unable to meet the standards to be used in the chain of emergency care. However, the need for a structured approach for syncope patients remains. We aimed to generate a broad overview of the available risk stratification tools and identify key elements, scoring systems and measurement properties of these tools.

METHODS

We performed a scoping review with a literature search in MEDLINE, CINAHL, Pubmed, Embase, Cochrane and Web of Science from January 2010 to May 2022. Study selection was done by two researchers independently and was supervised by a third researcher. Data extraction was performed through a data extraction form, and data were summarised through descriptive synthesis. A quality assessment of included studies was performed using a generic quality assessment tool for quantitative research and the AMSTAR-2 for systematic reviews.

RESULTS

The literature search identified 5385 unique studies; 38 were included in the review. We discovered 19 risk stratification tools, one of which was established in EMS patient care. One-third of risk stratification tools have been validated. Two main approaches for the application of the tools were identified. Elements of the tools were categorised in history taking, physical examination, electrocardiogram, additional examinations and other variables. Evaluation of measurement properties showed that negative and positive predictive value was used in half of the studies to assess the accuracy of tools.

CONCLUSION

A total of 19 risk stratification tools for syncope patients were identified. They were primarily established in ED patient care; most are not validated properly. Key elements in the risk stratification related to a potential cardiac problem as cause for the syncope. These insights provide directions for the key elements of a risk stratification tool and for a more advanced process to validate risk stratification tools.

Development of practice recommendations based on the Canadian Syncope Risk Score and identification of barriers and facilitators for implementation

BACKGROUND

Wide variations in emergency department (ED) syncope management exist. The Canadian Syncope Risk Score (CSRS) was developed to predict the probability of 30-day serious outcomes after ED disposition. Study objectives were to evaluate the acceptability of proposed CSRS practice recommendations among providers and patients, and identify barriers and facilitators for CSRS use to guide disposition decisions.

METHODS

We conducted semi-structured interviews with 41 physicians involved in ED syncope and 35 ED patients with syncope. We used purposive sampling to ensure a variety of physician specialties and CSRS patient risk levels. Thematic analysis was completed by two independent coders with consensus meetings to resolve conflicts. Analysis proceeded in parallel with interviews until data saturation.

RESULTS

The majority (97.6%; 40/41) of physicians agreed with discharge of low risk (CSRS ≤ 0) but opined that 'no follow up' changed to 'follow-up as needed'. Physicians indicated current practices do not align with the medium-risk recommendation to discharge patients with 15-day monitoring (CSRS = 1-3; due to lack of access to monitors and timely follow-up) and the high-risk recommendation (CSRS ≥ 4) to potentially discharge patients with 15-day monitoring. Physicians recommended brief hospitalization of high-risk patients due to patient safety concerns. Facilitators included the CSRS-based patient education and scores supporting their clinical gestalt. Patients reported receiving varying levels of information regarding syncope and post-ED care, were satisfied with care received and preferred less resource intensive options.

CONCLUSION

Our recommendations based on the study results were: discharge of low-risk patients with physician follow-up as needed; discharge of medium-risk patients with 15-day cardiac monitoring and brief hospitalization of high-risk patients with 15-day cardiac monitoring if discharged. Patients preferred less resource intensive options, in line with CSRS recommended care. Implementation should leverage identified facilitators (e.g., patient education) and address the barriers (e.g., monitor access) to improve ED syncope care.