Costs of unstructured investigation of unexplained syncope: insights from a micro-costing analysis of the observational PICTURE registry

Management of Patients With Unexplained Syncope: Derivation and Validation of a Simplified 2-Step Diagnostic Approach

BACKGROUND

The aim of this study was to develop a structured 2-step approach, based on noninvasive diagnostic criteria, that led to an electrophysiology study in patients with unexplained syncope.

METHODS AND RESULTS

Two independent cohorts were used: the derivation cohort with 665 patients based on electronic health record data to develop our 2-step diagnostic approach, and the validation cohort based on 160 prospectively screened patients, presenting with unexplained syncope episodes. Noninvasive electrocardiographic and imaging markers and an electrophysiology study-based invasive assessment were combined. A positive diagnostic approach according to our study's prespecified criteria resulted in a decision to proceed with a permanent pacemaker/implantable cardioverter-defibrillator. The primary end point was the time until the event of recurrent syncope (syncope-free survival). Number needed to treat was calculated for patients with a positive diagnostic approach. The number of patients with unexplained syncope and borderline sinus bradycardia needed to treat was 5, and the number of patients with unexplained syncope and bundle branch block needed to treat was 3 over a mean follow-up of ≈4 years. After the structured 2-step approach, the primary outcome occurred in 14 of 82 (17.1%) with a pacemaker/implantable cardioverter-defibrillator and 19 of 57 (33%) with a negative approach, with a mean follow-up of ≈2.5 years (29.29±12.58 months, P=0.03).

CONCLUSIONS

The low number needed to treat in the derivation cohort and the low percentage of syncope recurrence in the validation cohort supports the proposed 2-step electrophysiology-inclusive algorithm as a potentially low-cost, 1-day, structured tool for these patients.

Clinical predictors of cardiac syncope in patients with unexplained syncope after the implantation of an insertable cardiac monitor

Syncope prognosis is related to both its etiology and comorbidities, with cardiac syncope (CS) having higher risks for mortality and cardiovascular events than syncope of non-cardiac causes. Although a novel insertable cardiac monitor (ICM) is an effective diagnostic tool for unexplained syncope, decision regarding ICM implantation with a high pre-test likelihood of CS should contribute to economic cost reduction and avoidance of unnecessary complications. This study aimed to investigate clinical factors associated with CS after ICM implantation in patients with unexplained syncope. This retrospective observational study included 31 consecutive patients with ICM implantation for syncope between September 2016 and August 2021. The initial examinations for syncope included a detailed history, physical examination, blood tests, 12-lead electrocardiograms, and transthoracic echocardiography. Of the 31 patients, 13 (41.9%) experienced recurrent CS during follow-up (676 ± 469 days). Among several clinical factors, syncope-related minor injuries (p = 0.017) and higher brain natriuretic peptide (BNP; p = 0.043) levels were significantly associated with CS. Moreover, multivariable analysis showed that both syncope-related minor injuries (odds ratio, 11.2; 95% confidence interval, 1.4-88.4; p = 0.022) and BNP higher than 64.0 pg/mL (odds ratio, 7.0; 95% confidence interval, 1.1-44.2; p = 0.038) were independent predictors of CS after ICM implantation. In conclusion, a history of minor injury secondary to syncope and higher BNP levels were independent CS predictors in patients receiving ICM for syncope. These results emphasized the utility of ICM implantation early in the diagnostic journey of patients presenting with CS predictors requiring specific treatments.

Clinical applications of heart rhythm monitoring tools in symptomatic patients and for screening in high-risk groups

Recent technological advances have facilitated and diversified the options available for the diagnosis of cardiac arrhythmias. Ranging from simple resting or exercise electrocardiograms to more sophisticated and expensive smartphones and implantable cardiac monitors. These tests and devices may be used for varying periods of time depending on symptom frequency. The choice of the most appropriate heart rhythm test should be guided by clinical evaluation and optimized following accurate characterization of underlying symptoms, 'red flags', risk factors, and consideration of cost-effectiveness of the different tests. This review provides evidence-based guidance for assessing suspected arrhythmia in patients who present with symptoms or in the context of screening, such as atrial fibrillation or advanced conduction disturbances following transcatheter aortic valve implantation in high-risk groups. This is intended to help clinicians choose the most appropriate diagnostic tool to facilitate the management of patients with suspected arrhythmias.

Monitoring and diagnosis of intermittent arrhythmias: evidence-based guidance and role of novel monitoring strategies

Technological advances have made diagnosis of heart rhythm disturbances much easier, with a wide variety of options, including single-lead portable devices, smartphones/watches to sophisticated implantable cardiac monitors, allowing accurate data to be collected over different time periods depending on symptoms frequency. This review provides an overview of the novel and existing heart rhythm testing options, including a description of the supporting evidence for their use. A description of each of the tests is provided, along with discussion of their advantages and limitations. This is intended to help clinicians towards choosing the most appropriate test, thus improving diagnostic yield management of patients with suspected arrhythmias.

Diagnostic sensitivity and cost per diagnosis of ambulatory cardiac monitoring strategies in unexplained syncope patients

Diagnosing cardiac pauses that could produce syncopal episodes is important to guide appropriate therapy. However, the infrequent nature of these episodes can make detection challenging with conventional monitoring (CM) strategies with short-term ECG monitors. Insertable cardiac monitors (ICMs) continuously monitor for arrhythmias but present a higher up-front cost. It is not well understood whether these higher costs are offset by the costs of repeat evaluation in CM strategies. We simulated the likelihood of diagnostic success and cost-per-diagnosis of pause arrhythmias with CM strategies compared to ICM monitoring. ICM device data from syncope patients diagnosed with pause arrhythmias was utilized to simulate patient pathways and diagnostic success with CM. We assumed that detected true pause episodes (≥5 seconds) were symptomatic and prompted a hospital encounter and further evaluation with CM. Subsequent true pause episodes in yet-undiagnosed patients triggered additional rounds of CM. Costs of monitoring were accrued at each encounter and represent the U.S. payer perspective. Cost per diagnosed patient was calculated as the total costs accrued for all patients divided by the number of patients diagnosed, across 1,000 simulations. During a mean 505±333 days of monitoring ICM detected 2.4±2.7 pause events per patient, with an average of 109±94 days until the first event. CM was projected to diagnose between 13.8% (24-hour Holter) and 30.2% (two 30-day monitors) of the ICM-diagnosed patients. Total diagnostic costs per ICM-diagnosed patient averaged $7,847, whereas in the CM strategies average cost-per-diagnosis ranged from $12,950±2,589 with 24-hour Holter to $32,977±14,749 for two 30-day monitors. Relative to patients diagnosed with pause arrhythmias via ICM, CM strategies diagnose fewer patients and incur higher costs per diagnosed patient.

Safety and outcome of nurse-led syncope clinics and implantable loop recorder implants

BACKGROUND

Implantable loop recorders (ILRs) are effective in achieving symptom-rhythm correlation. Data on the diagnostic yield of ILRs, on nurse-led syncope clinics, and on nurse-led ILR implants are limited.

OBJECTIVE

We evaluated the safety and efficacy of our nurse-led syncope clinic and nurse-led ILR implants.

METHODS

A retrospective study of all consecutive patients undergoing nurse-led ILR implantations was performed between April 2016 and April 2018. Patients were referred from both nurse-led and physician-led clinics. Data were collected on baseline demographic characteristics, referral source, symptom-rhythm correlation, ILR findings, and subsequent changes to management. All ILRs were enrolled into remote monitoring with automatic arrhythmia detection, and all immediate (≤24 hours) ILR implant complications were recorded. Comparisons were made between nurse-led and physician-led clinics and subsequent outcomes.

RESULTS

A total of 432 patients with an ILR were identified: 164 (38%) from nurse-led and 268 (62%) from physician-led clinics; 200 (46%) were women (mean age 66.5 ± 18.2 years; mean follow-up duration 28.9 ± 9.5 months). Primary ILR indications were syncope (n = 251 [58%]), presyncope (n = 33 [7%]), palpitation (n = 39 [9%]), cryptogenic stroke (n = 78 [18%]), and other reasons (n = 31 [7%]). No immediate ILR implant complications occurred. Overall, 156 patients (36%) had a change in management as a direct result of ILR findings, with no overall differences between nurse-led and physician-led clinics (35% vs 36%; P = .7). More patients had newly diagnosed atrial fibrillation in physician-led clinics (15% vs 7%; P = .01), and more patients had pacemaker implants for bradycardia in nurse-led clinics (23% vs 13%; P < .01).

CONCLUSION

Nurse-led ILR implantation was safe and effective. Nurse-led syncope clinics achieved good symptom-rhythm correlation with resultant significant changes to management in comparison to physician-led clinics. Larger prospective studies are needed to evaluate their longer-term impact.

Do implantable loop recorders impact the survival of patients with recurrent unexplained syncope?

Aim: This study compares the outcomes of patients who receive an implantable loop recorder (ILR) for unexplained syncope to a control group without the diagnostic device in German claims data. Methods  and materials: Patients with ILR were matched to a control group based on prior syncope events, age, gender and Charlson Comorbidity index (CCI). Survival, syncope hospitalizations, treatment and costs were compared. Results/conclusion: Four hundred and twelve ILR patients were matched with controls, mean age was 68, mean CCI was 2.7, 42% females. ILR patients lived on average 1.2 years longer than patients in the control group. Twenty-five percent of ILR patients received a therapeutic device compared with 5% in the control group. ILRs might help to diagnose and treat patients with positive impact on survival.

Burden of recurrent syncope and injuries and the usefulness of implantable cardiac monitors: insights from a nationwide longitudinal cohort analysis

Aim: The study assesses the burden and costs of recurring unexplained syncope and injuries and the effectiveness of implantable loop recorders. Methods: The English national hospital database (Hospital Episode Statistics) was retrospectively analyzed. Results: 12,002 patients were identified with repeated syncope hospitalizations. 25% of patients were hospitalized at least once again for syncope, 9% of the patients were hospitalized at least once for an injury, causing substantial costs. In the second analysis: 10,902 patients implanted with an implantable cardiac monitor were tracked. By year 3, hospitalizations due to syncope had dropped by 60% versus pre-implantable cardiac monitor (ICM) levels. Conclusion: This study shows a high rate of recurrent syncope admissions and a parallel burden of hospitalizations for injuries. Use of an ICM appears to reduce syncope hospitalizations.

[Management of syncope in clinical practice : What has changed according to the new ESC guidelines 2018?]

Syncope is a common problem in clinical practice, which affects approximately 1% of patients admitted to European emergency departments. The clinical practice guidelines for the diagnosis and management of syncope published by the European Society of Cardiology (ESC) are based on the newest scientific data in the field and have provided clinical cardiologists with a structured therapeutic approach for affected patients over many years. The previous ESC guidelines on syncope were published in 2009 and are compared to the most recent edition, which was published in 2018. This review summarizes the most important innovations with respect to the diagnostic principles and treatment of syncope. The initial assessment of the patient and the risk stratification in the emergency department are the focus of the review. Another important topic that is adequately covered in the current guidelines is the rising significance of implantable loop recorders for the evaluation of unexplained syncope and the assessment of potential indications for a definitive treatment with a pacemaker or implantable cardioverter defibrillator (ICD). Additional changes involve the evidence level with respect to the use of other diagnostic (ECG monitoring, tilt testing) and therapeutic measures (indications for pacemaker implantation, catheter ablation of tachycardiac rhythm disorders).

[Indications for loop recorder implantation for syncope]

Implantable loop recorder with discontinuous ECG recording enables monitoring of heart rhythm over several years. Consequently, in patients with recurrent syncope it is possible to record an ECG during the next syncopal event to obtain symptom-ECG correlations. In patients with recurrent syncope of unknown origin, the implantation of a loop recorder leads to an earlier diagnosis and an asystole is more often detected as the cause of the recurrent syncope. In addition, the loop recorder identifies patients who will benefit from pacemaker implantation. An established indication for early implantation of a loop recorder is given in patients with recurrent syncope and no high-risk marker, e. g., reduced left ventricular function, valve disease, history of myocardial infarction or ECG findings such as bifascicular block, pre-excitation, long QT syndrome or an epsilon wave. These patients should receive a complete cardiological work-up with the aim of detecting the underlying heart disease. Patients with no conclusive findings should also receive a loop recorder. A relative indication is given for patients with recurrent syncope and injuries in order to predict the effect of pacemaker implantation. Possible indication is given for patients with transient loss of consciousness to rule out an arrhythmogenic origin.

A Population-Based Cohort Study Evaluating Outcomes and Costs for Syncope Presentations to the Emergency Department

OBJECTIVES

This study sought to examine outcomes and costs of patients with syncope admitted and discharged from the emergency department (ED).

BACKGROUND

ED visits for syncope are common, yet the impact on health care utilization is relatively unknown.

METHODS

A total of 51,831 consecutive patients presented to the ED with a primary diagnosis of syncope (International Classification of Diseases-9 code 780.2 and International Classification of Diseases-10 code R55) in Alberta, Canada from 2006 to 2014. Outcomes included 30-day syncope ED and hospital readmissions; 30-day and 1-year mortality; and annual inpatient, outpatient, physician, and drug costs, cumulative.

RESULTS

Of adults presenting to the ED, 6.6% were hospitalized and discharged with a primary diagnosis of syncope (Cohort 1), 8.7% were hospitalized and discharged with a primary diagnosis other than syncope (Cohort 2), and 84.7% were discharged home with a syncope diagnosis (Cohort 3). The 30-day ED revisits for syncope varied from 1.2% (Cohort 2) to 2.4% (Cohort 1) (p < 0.001), and readmission rates were <1% among cohorts. Short- and long-term mortality rates were highest for Cohort 2 and lowest for Cohort 3 (30-day mortality: Cohort 1 of 1.2%, Cohort 2 of 5.2%, Cohort 3 of 0.4%; p < 0.001) (1-year mortality: Cohort 1 of 9.2%, Cohort 2 of 17.7%, Cohort 3 of 3.0%; p < 0.001). Total cost of syncope presentations was $530.6 million (Cohort 1: $75.3 million; $29,519/patient, Cohort 2: $138.1 million; $42,042/patient, Cohort 3: $317.3 million; $9,963/patient; p<0.001).

CONCLUSIONS

Most patients with syncope presenting to the ED were discharged and had a favorable prognosis but overall costs were high compared with patients hospitalized. Further research is needed for cost-saving strategies across all cohorts.

The Cost-Effective Evaluation of Syncope

Syncope is a common clinical problem that carries a high socioeconomic burden. A structured approach in the evaluation of syncope with special emphasis on a detailed history, comprehensive physical examination that includes orthostatic vital signs, and an electrocardiogram, proves to be the most cost-effective approach. The need for additional testing and hospital admission should be based on the results of the initial evaluation and use of risk-stratification tools that help identify those syncope patients at highest risk for poor outcomes.

Insertable cardiac monitors in the diagnosis of syncope and the detection of atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

Insertable or implantable cardiac monitors (ICMs) continuously monitor the heart rhythm and record irregularities over 3 years, enabling the diagnosis of infrequent rhythm abnormalities associated with syncope and stroke. The enhanced recognition capabilities of recent ICM models are able to accurately detect atrial fibrillation (AF) and have led to new applications of ICMs for the detection and monitoring of AF.

METHODS AND RESULTS

Based on a systematic literature search, two indications were identified for ICMs for which considerable evidence, including randomized studies, exists: diagnosing the underlying cardiac cause of unexplained recurrent syncope and detecting AF in patients after cryptogenic stroke (CS). Three randomized controlled trials (RCTs) were identified that compared the effectiveness of ICMs in diagnosing patients with unexplained syncope (n = 556) to standard of care. A meta-analysis was conducted in order to generate an overall effect size and confidence interval of the diagnostic yield of ICMs versus conventional monitoring. In the indication CS, one RCT and five observational studies were included in order to assess the performance of ICMs in diagnosing patients with AF (n = 1129). Based on these studies, there is strong evidence that ICMs provide a higher diagnostic yield for detecting arrhythmias in patients with unexplained syncope and for detection of AF in patients after CS compared to conventional monitoring.

CONCLUSIONS

Prolonged monitoring with ICMs is an effective tool for diagnosing the underlying cardiac cause of unexplained syncope and for detecting AF in patients with CS. In all RCTs, ICMs have a superior diagnostic yield compared to conventional monitoring.