Evidence for the use of Rivaroxaban following an EKOS procedure for PE

Contents

1. Introduction

1.1 Therapeutic problem………………………………………………………..

2. Literature Search

3. Guidelines

4. Critical evaluation of the literature

4.1 Appraisal of Paper 1 – Kelley

et al


¹⁷

4.2 Appraisal of Paper 2 – Schreinlechner

et al


¹⁸

5. Discussion

6. Recommendation

7. References

1. Introduction

Pulmonary embolism (PE) is a condition caused by a blocked blood vessel occluding blood flow into the lungs. It usually occurs when a blood clot formed in a blood vessel elsewhere moves and obstructs the pulmonary arterial system. This obstruction is known as an emboli, resulting in a severe respiratory dysfunction since the lung area affected is no longer perfused.

^1,2

The therapy choice will depend on several factors; the severity of the condition, contraindication to a particular treatment, the presence of comorbidities, the licenced indication of the drug and patient’s preference.

¹

Specialists will usually make clinical decisions on the treatment choice (

Figure 1

) and the duration of treatment.

¹

Pharmacological treatment is preferred in haemodynamically stable patients.  If the patient is not haemodynamically stable, mechanical interventions such as thrombectomy might be required.

³

In the past years, novel endovascular procedures have emerged to revolutionise thrombosis treatment. Some of these non-surgical procedures use a combination of pharmacological and mechanical treatment with a catheter-directed thrombolysis.

⁴

Figure 1:

Summary of Pulmonary Embolism treatment options.

Platelets are activated when a blood vessel wall is broken and they start to aggregate in the injured area. The activated platelets trigger the initiation of the clotting cascade to stop the bleeding. Fibrinogen, a soluble plasma protein, will become fibrin as final result of this cascade.

⁵

Fibrin is an insoluble

protein

displayed in long fibrous chains that entangle more platelets and other blood cells.

⁶

This builds up a mesh that gradually hardens forming a blood clot.

Fibrin interfere the flow of thrombolytic drugs to the blood clot core, requiring higher doses to be effective. The acoustic pulse field created by ultrasound waves weakens fibrin formation unravelling the mesh blood clot. This technique allows more thrombolytic agent to reach effectively the entire clot.

⁷

It aims to reduce treatment time and the dose of thrombolytic agent required in catheter-directed thrombolysis (CDT) alone.

³

These techniques use an ultrasound enhanced catheter directed thrombolysis (UE-CDT) also known as ultrasound-assisted catheter-directed thrombolysis (USAT). One of these devices is branded as EkoSonic

^™

Endovascular system (EKOS

^™

), which gives name to this procedure. EKOS

^™

uses high frequency, low energy ultrasonic waves in a catheter that contains a thrombolytic agent infusion to target a specific area (

Figure 2

)

⁷

. This combination of ultrasound waves and a catheter-directed thrombolysis therapy is currently used to dissolve blood clots for the treatment of PE, Deep Vein Thrombosis (DVT) and Peripheral Arterial Occlusions.

⁸

Figure 2:

Ekosonic Ultrasonic Endovascular Thrombolysis system

⁹

.

1.1 Therapeutic problem

The cardiology team within the Trust have been prescribing Rivaroxaban PE treatment dose following an EKOS procedure. Rivaroxaban is an oral anticoagulant licensed in the UK for the treatment of PE and is not licensed for patients with PE who have had an intervention such as EKOS

¹⁰

. Thrombolysis is associated with a risk of haemorrhagic complications including stroke. This risk could potentially increase in patients who receive antithrombotic treatment following a thrombolysis therapy intervention.

The aim of this therapeutic review is to appraise the available evidence in order to assess the safety and appropriateness of Rivaroxaban following an EKOS procedure. This will allow for an informed recommendation to be made as to whether the cardiology team should continue to prescribe it under these circumstances.

2. Literature Search

A search was conducted using tertiary sources (Micromedex, UpToDate, DynaMed Plus, Martindale) to gain an overview of the therapeutic area. An extensive literature research was undertaken on Cochrane Library, EMBASE, and Medline databases via NHS Evidence’s Healthcare Databases Advanced Search (HDAS) to identify relevant papers (Tables 1-4). After completion of the literature search as per Figure 3,  three papers were identified for critical analysis (Table 5). The MeSH browser and EMTREE were used to match the search terms on Medline and Cochrane (Table 6).

Due to the small number of hits on these databases, it was not necessary to apply limitations to the search, such as date or language restriction. The full text of the remaining studies were then assessed using the inclusion criteria (Table 7).

Table 1:

EMBASE search (conducted on 16/06/2019)

Search	Search term	Results
1	RIVAROXABAN/	14,993
2	“LUNG EMBOLISM”/	85,593
3	“INTRAVASCULAR ULTRASOUND”/	14,447
4	“BLOOD CLOT LYSIS”/	38,207
5	(2 AND 3 AND 4)	20
6	(3 AND 4)	282
7	(EkoSonic).af	153
8	(ekos).af	371
9	(ultrasound-assisted catheter-directed thrombolysis).af	80
10	(ultrasound enhanced catheter directed thrombolysis).af	8
11	(acoustic pulse thrombolysis).af	13
12	(3 OR 8 OR 9 OR 10 OR 11 OR 12)	15,027
13	(5 OR 6 OR 12)	15,027
14	(1 AND 13)	55

Table 2:

MEDLINE search (conducted on 16/6/2019)

Search	Search term	Results
1	RIVAROXABAN/	2,624
2	“PULMONARY EMBOLISM”/	37,263
3	“ULTRASONICS THERAPY”/	9,297
4	“THROMBOLYTIC THERAPY”/	22,698
5	(2 AND 3 AND 4)	24
6	(3 AND 4)	239
7	(ekosonic).af	34
8	(ekos).af	79
9	(ultrasound-assisted catheter-directed thrombolysis).af	72
10	(ultrasound enhanced catheter directed thrombolysis).af	22
11	(acoustic pulse thrombolysis).af	22
12	(7 OR 8 OR 9 OR 10 OR 11)	179
13	(5 OR 6 OR 12)	392
14	(1 AND 13)	1

Table 3:

Cochrane Library search (conducted on 16/06/2019)

Search	Search term	Results
1	MeSH descriptor: [Rivaroxaban] this term only	371
2	MeSH descriptor: [Pulmonary Embolism] this term only	927
3	MeSH descriptor: [Ultrasonic therapy] this term only	865
4	MeSH descriptor: [Thrombolytic therapy] this term only	1653
5	(2 AND 3 AND 4)	0
6	(3 AND 4)	0
7	(EkoSonic).af	4
8	(ekos).af	18
9	(ultrasound-assisted catheter-directed thrombolysis).af	14
10	(ultrasound enhanced catheter directed thrombolysis).af	1
11	(acoustic pulse thrombolysis).af	6
12	#1 AND (#3 OR #7 OR #8 OR #9 OR #10 OR #11)	0

Table 4:

Key for search strategy with definitions

Command	Definition
/	Indicates the Search term is mapped to thesaurus
AND	Boolean Logic- requires both search terms to be in each result. This narrows the search.
OR	Boolean Logic – requires at least one of terms to be in each result. This broads the search.
af.	Stands as “any field” used for free-text searches when the term is not recognised by thesaurus

Figure 3.

Literature search strategy using EMBASE, Medline and Cochrane Library.

Table 6:

Explanation of search terms

Strategy decision	Rationale
“Ultrasonic therapy” used as MeSH term instead of “Ultrasonics”	The Medline scope note for “ultrasonics” confirmed is only referred to the discipline (education, history, etc.) The more appropriate term would be “ultrasonic therapy” as it refers to ultrasound waves used exclusively as treatment with “ultrasonic therapies” as synonym. The scope notes were also analysed to ensure any pre-2015 terms indexed for were identified. Ultrasonic therapy was established as a MeSH descriptor in 1966 with no other indexes prior to this date.
“Thrombolytic therapy” used as MeSH term instead of “Fibrinolysis”	The Medline scope note for “fibrinolysis” confirmed is only referred to the natural enzymatic dissolution of fibrin. The more appropriate term would be “thrombolytic therapy” as it refers to the use of infusions of fibrinolytic agents to destroy thrombi. The scope notes were also analysed to ensure any pre-1989 terms indexed for were identified. Thombolytic therapy was established as a MeSH descriptor in 1989 with previous indexes such as fibrinolysis (1966-1989). Since the therapeutic review is focused on a very novel technique, the search was conducted using only the latest index.
Only used “intravascular ultrasound” as similar term to EKOS	EMBASE scope notes for “intravascular ultrasound” did include other terms found on my preliminary search such as IVUS.
Amplify search results	Most terms of the search couldn’t be exploded therefore the indication (PE) was not included in some of the search to amplify results. This exemption allows to capture results for DVT which are the most common cause of PE.
Other free terms were used but not altered the search results in any of the databases.	Plural nor the use of hyphens between words or capital letters altered the results . Other terms from preliminary research were also tried as a free-text search such as “ekosonic endovascular system” and didn’t change the results either.

Table 7:

Exclusion and inclusion criteria for identification of relevant studies

Characteristic	Criteria
Publication type	Relevant, prospective double-blind randomised controlled trials (RCTs) were preferable due to the high quality of evidence and decreased risk of bias. However, a preliminary search revealed it was unlikely to identify RCTs (or even non-randomised trials, cohort and case-controlled studies). Case series or reports, although prone to several limitations, were therefore accepted to evaluate the use of Rivaroxaban for PE following an EKOS procedure. Abstracts were excluded where no clinical outcomes were reported. Conference abstracts were also excluded because of the difficulty of appraising study methodology and data.
Participant	Adults preferably diagnosed with PE who had an ultrasound enhanced catheter directed thrombolysis.
Intervention	Rivaroxaban treatment dose for PE
Comparator	Comparisons of Rivaroxaban prophylaxis dose vs Rivaroxaban PE treatment dose were desirable but not essential.
Outcome measures	Articles were retrieved if the abstract contained information relevant to the safety and/or efficacy.
Exclusion criteria	Studies were excluded from analysis if ultrasound was used as a diagnostic tool, other co-morbidities/medical conditions were involved, did not focus on treatment, other surgical interventions combined with EKOS or based on children population.

3. Guidelines

A search for local, national and international guidelines was conducted using NHS Evidence and DynaMed Plus. The guidelines available (Table 8) illustrated very limited information about this therapeutic area, which highlights the need for further investigations regarding the therapeutic plan for patients with intermediate-high risk PE.

⁹

None of these guidelines mention a specific anticoagulation regime plan post CDT or USAT. Due to the lack of recommendations for the use of Rivaroxaban for PE following an EKOS procedure an analysis of primary literature is required to determine if there is sufficient evidence to support its use.

Table 8.

Guidance relating to the use of Rivaroxaban following an USAT for PE.

Organisation	Guidance	Recommendations
Local trust guidelines 12	Acute pulmonary embolism pathway	Aligned to European Society of Cardiology (ESC) guidelines (see below)
NICE (The National Institute for Health and Care Excellence) 1	Pulmonary embolism – Clinical Knowledge Summary (CKS)	CDT and anticoagulation therapies are both contemplated as treatment options. It doesn’t describe under what conditions one or the other or both are preferred. Treatment choice will depend on several factors and the specialists input.
British Thoracic Society guidelines (BTS) 13	BTS guidelines for the management of suspected acute pulmonary embolism	Thrombolysis therapy is only first line treatment in massive PE. Thrombolysis treatments do not mention the new catheter techniques.
European Society of Cardiology (ESC) guidelines 11	Guidelines on the diagnosis and management of acute pulmonary embolism: The Task Force for Diagnosis and Management of Acute Pulmonary Embolism of the ESC	Systemic thrombolysis is not first choice treatment for patients with intermediate-high-risk PE, but it is recommended for those patients showing clinical signs of haemodynamic decompensation. The greatest benefit is shown when thrombolysis therapy is started as early as possible, ideally within 48 hours of symptom onset. From this group of patients those who have an increased risk of bleeding if full dose systemic thrombolysis is administered then percutaneous CDT or USAT techniques such as EKOS procedure should be considered as an alternative to surgery. This treatment could potentially avoid life-threatening complications from PE but also aggravate the risk of a bleeding incident. There are not recommendations regarding post-thrombolysis anticoagulation therapy following this procedure.
American College of CHEST physician guidelines 14	Antithrombotic Therapy for VTE disease (February 2016)	Systemic thrombolysis is preferred to CDT for the treatment of PE associated with hypotension unless patient has a higher risk of bleeding with the systemic thrombolytic therapy or this one has failed previously or patient is at imminent risk of becoming haemodynamically unstable. The use of USAT could be considered on a individual basis depending on patient’s clinical condition. There are not recommendations regarding post-thrombolysis anticoagulation therapy following this procedure.

4. Critical evaluation of the literature

Three papers were deemed suitable for review from the literature search: a review, a case series and a retrospective observational cohort study. The STROBE tool

¹⁵

(to support observational studies) and CASP tool

¹⁶

(for analysing cohort studies) were used to appraise the papers. Principles of the CASP tool were used as a guide to appraise review paper.

The following studies were appraised to help determine the role for Rivaroxaban in the treatment of PE following EKOS procedure.

4.1 Appraisal of Paper 1 – Kelley

et al


<sup>1


7</sup>

A total of 76 patients aged 18 years and above were retrospectively selected to receive either a DOAC or VKA following USAT for VTE. The methodology of this study is vague (Table 9). Whilst the exclusion criteria are clearly stated, the requirements for the eligibility criteria were not described.

It is difficult to determine whether or not the cohort was representative of the population who actually received treatment following USAT procedure over two years because this information is not provided. It is unknown if it is a small or relevant sample size, which increases the risk of selection bias in the study and prevents generalisation of the results.

The treatment groups were evenly balanced in most baseline characteristics, however DOACs were more commonly prescribed in patients with PE, and VKA was preferred for patients with VTE. The fact that the treatment groups had different diagnosis could potentially lead to biased general conclusions.

There is no description of the actual USAT procedure for any groups. There is no mention whether the thrombolysis therapy doses used were steady for both groups. Patients receiving higher doses of thrombolytic agent are more likely to suffer bleeding events affecting the primary outcome.

DOACs appear to have similar safety/efficacy profile as VKA following USAT. The DOACs have a slightly higher rate of a 90-day bleeding or recurrent thrombotic event compared to VKAs with no significant difference (9.5% vs 5.9% respectively, P=0.686). Three months may not be sufficient to expect a measurable outcome of the intervention.

The use of DOAC therapy for VTE post-USAT was not associated with higher rates of bleed/recurrent VTE compared to VKA. There is limited evidence to suggest the dose of Rivaroxaban is safe and appropriate for clinical practice.

Table 9.

Summary of paper 1 appraisal.

Type of study	Retrospective observational cohort study
Study design	Objective : The use of DOAC therapy post-USAT for VTE, including DVT and PE. Recruitment: not stated Time frame : 1 st January 2014 to 1 st May 2016
Sample size	76 patients, however only 20 patients received Rivaroxaban.
Patient population	Mean age VKA group = 55 years Mean age DOAC group = 59 years No age range provided which affects the validity of the study to extrapolate to other ages. 53% males in VKA group and 48% males in DOAC group (n=34 and n=42 respectively) Inclusion criteria : Age of 18 years and over who had a documented VTE. No specific details of the inclusion criteria were stated. Exclusion criteria : patients who were pregnant, incarcerated or involved in any active research.
Baseline Characteristics	Demographic characteristics were similar in both groups. DOACs group had generally better mean renal function than VKA (95.7 mL/min vs 87.7 mL/min, respectively). No ethnicity data provided.
Co-morbidities	Patients compromised a few comorbidities calculated by Charlson Comorbidity Index (CCI). However, the co-morbidities aren’t stated, although this may have affected the likelihood to bleed on anticoagulation treatment. There were more patients on concomitant antiplatelet therapy (clopidogrel, prasugrel and ticagrelor) in the VKA group compared to the DOAC group (35% and 29% respectively, p=0.739).  This therapy is likely to increase the risk of bleeding, and therefore alter the results.
Treatment intervention	USAT device used wasn’t specified. There is no statistically significant difference in the average time from admission to USAT (25.3 and 32 hours in the DOAC and VKA group respectively, p=0.667).  The patients’ condition could have worsened during this time period contributing to future complications, clouding the results. Average time from USAT to oral anticoagulation in both groups = 49 hours Rivaroxaban 15 mg twice daily for 21 days or Apixaban 10 mg twice daily for 7 days or Dabigatran (dose not specified). All followed by maintenance dose respectively. These doses were chosen because it reflects real-world practice rather than evidence based.
Measure of outcomes	Primary outcomes: 1) 90-day incidence of major and minor bleeding post-procedure based on TIMI bleed score 2) 90-day incidence of recurrent VTE between patients receiving DOAC vs VKA. Secondary outcome: Time to hospital re-admission. The reason for re-admissions is not documented. Monitoring of patients in each group varies; VKA entails more vigorous monitoring compared to DOACs allowing patients to be more likely identified and re-admitted into hospital. This outcomes measure seems reasonable but neglects the data about the number of patients who might not have been selected because of death.
Outcomes	DOACs appear to have slightly higher rates of bleeding and thrombotic events compared to VKA (9.5% vs 5.9% respectively). There was no statistically significant difference for the composite of these endpoints (p = 0.686) Time to readmission for the composite endpoint was slightly longer in DOAC group vs. VKA (21.25 days vs 17.5 days) There was no statistically significant difference either ( p = 0.845)
Statistics	Confidence interval not stated and p > 0.05

4.2 Appraisal of Paper 2 – Schreinlechner

et al


<sup>1


8</sup>

This is a case series study, considered a lower grade of evidence, as it is only an initial exploration of an issue related to a proposed evaluation. This case series’ objective reports the use of Rivaroxaban following USAT in 5 patients (Table 10). Although a clear timeline is established, the methodology of identifying eligible patients with a confirmed diagnosis of symptomatic intermediate high-risk PE is not stated. This potentially introduces a selection bias that represents a threat to the validity of the study. The internal validity of the study is also very low due to the lack of a comparator group and no statistical analysis.

Four of the patients are aged over 70 with identical diagnosis – extensive pulmonary emboli with central involvement of the main pulmonary arteries; four out of five cases were bilateral occlusions. This reduces generalisability of the results to younger patients or those ones with not so severe diagnosis.

No recurrent thromboembolic events or bleeding episodes were reported during the 3 month follow up period; this data is not reflective of a wider population and may be down to chance. There are several limitations to this paper, which make it difficult to replicate the results to clinical practice.

Table 10.

Summary of paper 2 appraisal.

Type of study	Case series
Study design	Objective : Evaluate the efficacy and safety of DOAC treatment after USAT Recruitment : not stated Time frame : 1 st January 2014 to 1 st May 2016
Sample size	5 patients
Patient population	Mean age = 73 years. Age range 51-82 years 3 males and 2 females.  No exclusion criteria nor inclusion criteria stated.
Baseline Characteristics	Some demographic characteristics not described such as ethnicity, weight or creatinine clearance.
Co-morbidities	Patient 1: prior DVT and PE, CKD stage III Patient 2: he medical history is not stated. Patient 3: coronary artery bypass grafting Patient 4: pneumonia left lower lobe Patient 5: prior DVTs (twice), bladder cancer, COPD The co-morbidities are varied and this could have influenced the outcomes.
Treatment intervention	All cases used EKOS as USAT device.  Rivaroxaban 15 mg twice daily for 21 days followed by maintenance dose of 20 mg daily was prescribed post-procedure for all patients. However, the thrombolytic agent dose for the procedure was different: 20 mg for patients ≤ 75 years with bilateral PE (Patient 3 and 5) 15 mg for patients > 75 years with bilateral PE (Patient 1 and 2) 10 mg for patient 4 because it was not bilateral PE.
Measure of outcomes	Primary or secondary outcomes not stated due to the descriptive nature of the study rather than an analytical design with a comparator arm. The diagnostic parameters are well described.The outcomes measure used were: – echocardiography: right ventricular function improvement using RV/LV ratio – physical capacity: no assessment method described – recurrent thromboembolic events – bleeding episodes: no assessment method described
Outcomes	Significant improvement of right ventricular function showed on 3 months follow-up echochardiography but decreased compared to baseline. Improved physical capacity in all patients. No recurrent VTE or bleeding episodes were reported.
Statistics	Confidence interval and p value not stated.

4.3 Appraisal of Paper 3 – Mohsen Sharifi



¹⁹

This paper reviews the most important literature in regards to percutaneous endovenous intervention (PEVI) such as USAT or CDT over conventional treatment of VTE. While this review also discusses the post-procedure anticoagulation treatment from the author’s perspective, it doesn’t address a clearly focused aim.

Most relevant studies, especially the randomized clinical trials (RCTs) mentioned in this paper, the author didn’t assess the quality of them. The author reviews all the studies available based on his experience from clinical practice considering the evidence currently available.

Over 100 patients were treated with Rivaroxaban 20 mg daily 2 hours after PEVI with no bleeding or other complications observed. EKOS procedure is categorised as USAT, which falls under PEVI umbrella, but the author has not specified the sample size of patients who had USAT. This lower dose of Rivaroxaban was selected as patients requiring thrombolysis were excluded from the trials that contributed to license Rivaroxaban. A lower anticoagulant dose is sensible when tissue plasminogen activator is been given to minimise bleeding risk.  Bleeding rate with low dose rivaroxaban was <1% which the author compares to the bleeding rate of 2.2% in the TORPEDO trial

²⁰

which uses a higher dose. There is no mention of what outcomes were measured and the monitoring involved.

After all, it is extremely difficult to determine if there is confirmation bias and the author only focused on those perspectives suited to his pre-existing views, while dismissing other papers that refute them. This paper can only be considered as anecdotal evidence.

5. Discussion

Systemic thrombolysis for the treatment DVT is usually problematic due to poor penetration into the blood clot. This contributed to the development of new devices that could overcome this obstacle like USAT. Systemic thrombolysis through a peripheral vein is very effective for PE treatment as the drug is fully gathered into the lungs due to the venous flow direction converging into the lungs.

²⁵

Furthermore, according to current guidelines, for patients with high-risk PE and shock or hypotension, systemic thrombolysis is preferred to USAT

¹¹

. In view of how NHS is increasingly focused in delivering cost effective care; it is very likely that the use of EKOS devices for PE treatment will still be very limited. Patient recruitment into large sample size studies will be difficult.

The lack of evidence about the use of Rivaroxaban treatment dose is not unforeseen given that patients receiving thrombolysis were excluded from the trials (EINSTEIN-PE) that established Rivaroxaban as licensed treatment for PE.

²³

The main objective of all the RCTs was to demonstrate no inferiority of USAT treatment versus conventional thrombolysis or anticoagulation therapy (PEITHO, ULTIMA, SEATTLE II and GUSTO) do not even mention what post-procedure anticoagulation treatment was used.

^22-25

ULTIMA trial acknowledges that the post-procedure anticoagulation treatment was left to discretion of the investigators.

²³

Papers 1 and 2 used the same dose of Rivaroxaban (15 mg twice daily) whilst Paper 3 used a lower dose (20 mg daily). Neither offer a justification of why PE treatment dose was preferred over prophylaxis dose.

^23,25

Case-reports are subject to a high probability of bias and are not a reliable form of evidence in comparison to RCTs or a meta-analysis. They are essential for the awareness of rare diseases and their management.

Paper 1 did not specify the USAT device whilst Paper 2 used the EKOS endovascular system. EKOS procedure uses of a fraction (10-20%) of the conventional dose of the thrombolytic agent. It is intuitive to believe this promptly improves the clinical condition of the patient without considerable increase in bleeding risk. Bleeding risk increases when combined thrombolysis with anticoagulation PE treatment. Further studies are needed to look at other dosing regimens and their effects with different thrombolysis therapy interventions.

All studies had a small sample size with no statistical significant measure stated. Prudent consideration is required when considering using Rivaroxaban following an EKOS procedure for PE because inappropriate use of may result in major bleeding complications.

6. Recommendation

There is no evidence available that specifically assesses the safety and efficacy of the use of Rivaroxaban. Anecdotal reports suggest that PE treatment dose is the most commonly used in practice. More robust and well-designed prospective double-blind RCTs that minimise bias are needed to demonstrate more strengthened conclusions from the data. After evaluation of the available evidence, the use of Rivaroxaban following an EKOS procedure for PE cannot be recommended due to a lack of high-quality evidence.

There may be a role for Rivaroxaban in conjunction with thrombolysis therapies to reduce VTE recurrent events. The evidence-base for this unlicensed use is currently limited to anecdotal reports. A reasonable recommendation would be to review and consider dose regime on an individual basis until further guidance is available. Taking into consideration patient’s factors like bleeding risk, co-morbidites, emboli resolution status after procedure as well as assessing the risk/benefit.

Rivaroxaban is a licensed medicine that in these cases will be used ‘off label’. Therefore, the consultant must complete a request form for the ‘off label’ use of a licensed medicine as per London North West University Healthcare Unlicensed Medicines policy. Clinical data, risk management, funding plan and any evidence to support this use must be endorsed with this form prior submission to Drug and Therapeutic Group (DTG).

DTG will review the application based on the evidence provided and will make a decision on individual basis. If Rivaroxaban is approved for this ‘off label’ use by the DTG, the cardiology team will be advised to discuss this limited evidence with their patients as well as possible side effects such as bleeding incidents or haemorrhagic stroke. If the patient still wished to trial this unlicensed use this should be initiated and monitored. Patient-centred approach should be taken when determining the appropriateness of the treatment with special consideration to treatment goal: prevent death and improving quality of life in the long term.

The consultant should then be encouraged to write a case-report, which may help corroborate future evidences.

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