Measuring the effectiveness of a revised clinical practice guideline for the pre-hospital management of supraventricular tachycardia

Evaluation of the prehospital use of a Valsalva assist device in the emergency treatment of supraventricular tachycardia (EVADE SVT): study protocol for a stepped wedge cluster randomised controlled trial

INTRODUCTION

Patients with episodes of supraventricular tachycardia (SVT), a common heart arrhythmia, are often attended by ambulance services. International guidelines advocate treatment with the Valsalva manoeuvre (VM), but this simple physical treatment has a low success rate, with most patients requiring conveyance to hospital. The Valsalva Assist Device (VAD) is a simple device that might help practitioners and patients perform a more effective VM and reduce the need for patients to be taken to hospital.

METHODS AND ANALYSIS

This stepped wedge cluster randomised controlled trial, conducted within a UK ambulance service, compares the current standard VM with a VAD-delivered VM in stable adult patients presenting to the ambulance service with SVT. The primary outcome is conveyance to hospital; secondary outcomes measures include cardioversion rates, duration of ambulance care and number of subsequent episodes of SVT requiring ambulance service care. We plan to recruit approximately 800 patients, to have 90% power to detect an absolute reduction in conveyance rate of 10% (from 90% to 80%) between the standard VM (control) and VAD-delivered VM (intervention). Such a reduction in conveyance would benefit patients, the ambulance service and receiving emergency departments. It is estimated potential savings would pay for devices for the entire ambulance trust within 7 months.

ETHICS AND DISSEMINATION

The study has been approved by the Oxford Research Ethics Committee (reference 22/SC/0032). Dissemination will be through peer-reviewed journal publication, presentation at national and international conferences and by the Arrhythmia Alliance, a patient support charity.

TRIAL REGISTRATION NUMBER

ISRCTN16145266.

Effectiveness of the modified Valsalva manoeuvre in adults with supraventricular tachycardia: a systematic review and meta-analysis

BACKGROUND AND IMPORTANCE

Cardiac arrhythmia, specifically paroxysmal supraventricular tachycardia (SVT), accounts for a substantial proportion of emergency medical services resources utilisation. Reconversion requires increasing the atrioventricular node's refractoriness, which can be achieved by vagal manoeuvres, pharmacological agents or electrical cardioversion. There are multiple variants of vagal manoeuvres, including the Valsalva manoeuvre (VM). While the effectiveness of the standard VM has already been systematically reviewed, there has been no such analysis for the modified VM.

OBJECTIVES

Compare the effectiveness of the modified VM versus the standard VM in restoring the normal sinus rhythm in adult patients with supraventricular tachycardia.

DESIGN

Systematic review with meta-analysis of published randomised controlled trials.

OUTCOME MEASURES

The primary outcome was the reconversion to a sinus rhythm. Secondary outcomes included: medication use, adverse events, length of stay in the emergency department and hospital admission.

MAIN RESULTS

Five randomised controlled trials were included, with a combined total of 1181 participants. The meta-analysis demonstrated a significantly higher success rate for reconversion to sinus rhythm when using the modified VM compared to the standard VM in patients with an SVT (odds ratio = 4.36; 95% confidence interval, 3.30-5.76; P < 0.001). More adverse events were reported in the modified VM group, although this difference is NS (risk ratio = 1.48; 95% confidence interval, 0.91-2.42; P = 0.11). The available evidence suggests that medication use was lower in the modified VM group than the standard VM group. However, medication use could not be generalised across the different studies. None of the included studies showed a significant difference in length of stay in the emergency department. Only one study reported on hospital admission, with no significant difference between the two groups.

CONCLUSIONS

The available evidence is highly suggestive to support the use of the modified VM compared to the standard VM in the treatment of adult patients with SVT. Meta-analysis showed a higher success rate, required less medication use, and resulted in an equal number of adverse events. However, these results cannot be regarded as definitive in the absence of higher-quality studies.

A Novel Calcium Channel Blocker: Etripamil: What is the Future of Intranasal Drug Delivery in the Treatment of Cardiac Arrhythmias?

Symptomatic paroxysmal cardiac arrhythmias are common cardiac conditions that lead to a decreased quality of life, increased healthcare costs, and significant morbidity. Many cardiac arrhythmias increase in frequency with age, and as the elderly population continues to increase, so will the incidence and prevalence of cardiac arrhythmias. The long-term treatment options for patients with paroxysmal arrhythmias include ablation procedures and daily oral antiarrhythmics. Acute management entails vagal maneuvers, intravenous antiarrhythmics, and synchronized cardioversion. However, there are limited treatment options for patients with less frequent and less severe arrhythmias, ablation refractory disease, or who are poor candidates for ablative procedures, For abortive therapy, oral anti-arrhythmic medications are ineffective due to their slow onset of action and intravenous medications require treatment at an acute care facility, which is both costly and stressful to the patient. Etripamil is a novel intranasal non-dihydropyridine calcium channel blocker that has begun phase III clinical trials for the treatment of paroxysmal supraventricular tachycardias. Due to its intranasal mode of delivery, etripamil has a rapid onset of action, and could feasibly be administered by the patient themselves. Clinical phase II trials of etripamil in moderate to high doses demonstrated efficacy comparable to the standard of care, and took an average of 3 minutes from drug administration to conversion to sinus rhythm. In this article, we have conducted an extensive literature review of intranasal drug delivery, calcium channel blockers, and etripamil, to discuss the future possibilities of using this new medication.

Evaluation of pre-hospital use of a valsalva assist device in the emergency treatment of supraventricular tachycardia [EVADE]: a randomised controlled feasibility trial

BACKGROUND

The valsalva manoeuvre is an internationally recommended initial treatment for supraventricular tachycardia (SVT). The pre-hospital use of a valsalva assist device, to help deliver this manoeuvre, could improve cardioversion rates and reduce the need for patients to attend hospital.

METHODS

We conducted a randomised controlled feasibility trial comparing ambulance clinician use of a valsalva assist device versus standard care to treat adult patients presenting to an ambulance service in the south west of England. Eligible consenting participants were randomised 1:1 to device or standard care with trial procedures mirroring a proposed definitive trial.Feasibility was assessed upon ambulance clinician and participant recruitment rates and feedback, data completeness and potential future primary outcome rates.

RESULTS

Over a 6 months period (1 July to 31 December 2018), 276 (23%) of 1183 eligible ambulance clinicians were trained and they recruited 34 participants; approximately 10% of patients presenting with suspected SVT during that time. Seventeen participants were randomised to each arm and all underwent their allocated valsalva strain method. All trial data and 63/68 (93%) of pre and post-valsalva ECGs were available. Seven (21%) participants had ineligible initial rhythms on retrospective expert ECG review. Valsalva assist device use was associated with cardioversion and non-conveyance in 4 (24%) and 2 (12%) participants respectively. No participants assigned to standard care were cardioverted and all were conveyed. Participant feedback highlighted the challenges of retaining trial information during an SVT attack.

CONCLUSIONS

The trial achieved efficient clinician training, randomisation and data collection, and there was an encouraging effect signal associated with device use. However, trial design changes should be considered to address the relatively small proportion of eligible patients recruited and challenges identified with consent and confirmation of cardioversion as a primary outcome.

TRIAL REGISTRATION

The trial was registered with ClinicalTrials.gov (NCT03514628) on 2 May 2018.

Safety and efficacy of paramedic treatment of regular supraventricular tachycardia: a randomised controlled trial

INTRODUCTION

Supraventricular tachycardias (SVTs) are a common cause of acute hospital presentations. Adenosine is an effective treatment. To date, no studies have directly compared paramedic-with hospital-delivered treatment of acute SVT with adenosine.

METHOD

Randomised controlled trial comparing the treatment of SVT and discharge by paramedics with conventional emergency department (ED)-based care. Patients were excluded if they had structural heart disease or contraindication to adenosine. Discharge time, follow-up management, costs and patient satisfaction were compared.

RESULTS

Eighty-six patients were enrolled: 44 were randomised to paramedic-delivered adenosine (PARA) and 42 to conventional care (ED). Of the 37 patients in the PARA group given adenosine, the tachycardia was successfully terminated in 81%. There was a 98% correlation between the paramedics' ECG diagnosis and that of two electrophysiologists. No patients had any documented adverse events in either group. The discharge time was lower in the PARA group than in the ED group (125 min (range 55-9513) vs 222 min (range 72-26 153); p=0.01), and this treatment strategy was more cost-effective (£282 vs £423; p=0.01). The majority of patients preferred this management approach. Being treated and discharged by paramedics did not result in the patients being less likely to receive ongoing management of their arrhythmia and cardiology follow-up.

CONCLUSIONS

Patients with SVT can effectively and safely be treated with adenosine delivered by trained paramedics. Implementation of paramedic-delivered acute SVT care has the potential to reduce healthcare costs without compromising patient care.

TRIAL REGISTRATION NUMBER

NCT02216240.