Tilt testing is more cost-effective than implantable loop recorder monitoring as a means of directing pacing therapy in people with recurrent episodes of suspected vasovagal syncope that affect their quality of life or present a high risk of injury

Economic value of insertable cardiac monitors in unexplained syncope in the United States

INTRODUCTION

Early use of insertable cardiac monitor (ICM) is recommended for patients with unexplained syncope following initial clinical workup, due to its superior ability to establish symptom-rhythm correlation compared with conventional testing (CONV). However, ICMs incur higher upfront costs, and the impact of additional diagnoses and resulting treatment on downstream costs and outcomes is unclear. We aimed to evaluate the cost-effectiveness of ICM compared with CONV for the diagnosis of arrhythmia in patients with unexplained syncope, from a US payer perspective.

METHODS

A Markov model was developed to estimate lifetime costs and benefits of arrhythmia diagnosis with ICM versus CONV, considering all related diagnostic and arrhythmia-related treatment costs and consequences. Cohort characteristics and costs were informed by original claims database analyses. Risks of mortality, syncopal recurrence, injury due to syncope and quality of life consequences from syncopal events were identified from the literature.

RESULTS

ICM was less costly and more effective than CONV. Most of the observed US$4532 cost savings were attributed to reduced downstream diagnostic testing. For every 1000 patients, ICM was projected to yield an additional 253 arrhythmia diagnoses and lead to treatment in an additional 168 patients. The ICM strategy resulted in overall improved outcomes (0.30 quality-adjusted life years gained), due to a reduction in syncope recurrence and injury resulting from arrhythmia treatment. The results were robust to changes in the base case parameters but sensitive to the model time horizon, underlying probability of syncope recurrence and prevalence of arrhythmias.

CONCLUSIONS

Our model projected that early ICM for the diagnosis of unexplained syncope reduced long-term costs, and led to an improvement in overall clinical outcomes by shortening time to arrhythmia treatment. The cost of ICM was outweighed by savings arising from fewer downstream diagnostic episodes, and the increased cost of treatment was counterbalanced by fewer syncope-related event costs.

Analysis of Heart Rate Variability Before and During Tilt Test in Patients with Cardioinhibitory Vasovagal Syncope

BACKGROUND

Cardioinhibitory vasovagal response is uncommon during the tilt test (TT). Heart rate variability (HRV) by use of spectral analysis can distinguish patients with that response.

OBJECTIVE

To compare the HRV in patients with cardioinhibitory vasovagal syncope (case group - G1) with that in patients without syncope and with negative response to TT (control group - G2).

METHODS

64 patients were evaluated (mean age, 36.2 years; 35 men) and submitted to TT at 70 degrees, under digital Holter monitoring. The groups were paired for age and sex (G1, 40 patients; G2, 24).

RESULTS

In G1, 21 patients had a type 2A response and 19 had type 2B, with mean TT duration of 20.4 minutes. There was a greater low frequency (LF) component (11,6 versus 4,5 ms2, p=0.001) and a lower low/high frequency ratio in the supine position (3,9 versus 4,5 ms2, p=0.008) in G1, with no difference during TT between the groups. Applying the receiver operating characteristic curve for cardioinhibitory response, the area under the curve was 0.74 for the LF component in the supine position (p = 0.001). The following were observed for the cutoff point of 0.35 ms(2) for the LF component: sensitivity, 97.4%; specificity, 83.3%; positive predictive value, 85.3%; negative predictive value, 96.9%; and positive likelihood ratio, 5.8.

CONCLUSION

HRV in the supine position allowed identifying patients with syncope and cardioinhibitory response with a high negative predictive value and likelihood ratio of 5.8.

The Current Indication for Pacemaker in Patients with Cardioinhibitory Vasovagal Syncope

The most frequent cause of syncope is vasovagal reflex. It is associated with worse quality of life, depression, fatigue and physical injury. Recurrence of vasovagal syncope is an aggravating, reaching the rate of 69%. Initial step and pharmacological treatment may not work, especially in patients with recurrent syncope without prodrome. These patients can present cardioinhibitory response with asystole. Studies were designed to analyses the effectiveness of pacemaker for prevention of syncope. In this review, nonrandomized clinical trials, open-label randomized, double-blind randomized, placebo-controlled, and studies based on tilt test or Implantable Loop Recorder findings will be discussed.

Sudden unexpected death in epilepsy genetics: Molecular diagnostics and prevention

Epidemiologic studies clearly document the public health burden of sudden unexpected death in epilepsy (SUDEP). Clinical and experimental studies have uncovered dynamic cardiorespiratory dysfunction, both interictally and at the time of sudden death due to epilepsy. Genetic analyses in humans and in model systems have facilitated our current molecular understanding of SUDEP. Many discoveries have been informed by progress in the field of sudden cardiac death and sudden infant death syndrome. It is becoming apparent that SUDEP genomic complexity parallels that of sudden cardiac death, and that there is a pauci1ty of analytically useful postmortem material. Because many challenges remain, future progress in SUDEP research, molecular diagnostics, and prevention rests in international, collaborative, and transdisciplinary dialogue in human and experimental translational research of sudden death.

Financial impact of adopting implantable loop recorder diagnostic for unexplained syncope compared with conventional diagnostic pathway in Portugal

Background

To estimate the short- and long-term financial impact of early referral for implantable loop recorder diagnostic (ILR) versus conventional diagnostic pathway (CDP) in the management of unexplained syncope (US) in the Portuguese National Health Service (PNHS).

Methods

A Markov model was developed to estimate the expected number of hospital admissions due to US and its respective financial impact in patients implanted with ILR versus CDP. The average cost of a syncope episode admission was estimated based on Portuguese cost data and landmark papers. The financial impact of ILR adoption was estimated for a total of 197 patients with US, based on the number of syncope admissions per year in the PNHS. Sensitivity analysis was performed to take into account the effect of uncertainty in the input parameters (hazard ratio of death; number of syncope events per year; probabilities and unit costs of each diagnostic test; probability of trauma and yield of diagnosis) over three-year and lifetime horizons.

Results

The average cost of a syncope event was estimated to be between 1,760€ and 2,800€. Over a lifetime horizon, the total discounted costs of hospital admissions and syncope diagnosis for the entire cohort were 23% lower amongst patients in the ILR group compared with the CDP group (1,204,621€ for ILR, versus 1,571,332€ for CDP).

Conclusion

The utilization of ILR leads to an earlier diagnosis and lower number of syncope hospital admissions and investigations, thus allowing significant cost offsets in the Portuguese setting. The result is robust to changes in the input parameter values, and cost savings become more pronounced over time.