This briefing describes the regulated use of the technology for the indication specified, in the setting described, and with any other specific equipment referred to. It is the responsibility of healthcare professionals to check the regulatory status of any intended use of the technology in other indications and settings. Readers should note that administering drugs such as abciximab using ClearWay RX may be outside their UK marketing authorisation.
Atrium Medical, part of the Atrium Maquet Getinge group, received a CE mark for the ClearWay RX in March 2010. It is a class III medical device.
The ClearWay RX is a rapid exchange perfusion balloon catheter for localised delivery of diagnostic or therapeutic agents within coronary or peripheral vessels. It is a low pressure catheter which incorporates a thin, semi-compliant microporous PTFE balloon material. It allows for selective and controlled infusion of therapeutic drugs at very low pressures. The catheter is narrow (0.014" guidewire compatible), allowing access consistent with routine PCI practice, and is compatible with 6–7 Fr guide catheters (depending on the size of the balloon). Radiopaque markers are located within the balloon treatment zone to assist in catheter placement under fluoroscopy. The ClearWay RX catheter is available in 1.0–4.0 mm balloon diameters and in balloon lengths of 10–50 mm. Longer balloons allow a larger blood clot to be treated in a single procedure, and are used in coronary artery bypass grafts.
The ClearWay RX balloon has an atraumatic tip, which is intended to reduce the potential for additional damage to diseased vessels. The catheter is designed to optimise drug delivery by occluding blood flow and infusing the drug directly at the site of the stenosis. These combined actions are designed to allow the drug to be delivered with minimal dilution and to increase drug residence time while the balloon is inflated. This results in a higher localised drug concentration compared with intravenous delivery, without increasing systemic load beyond the initial bolus delivered, with the intention of limiting adverse events such as bleeding complications.
ClearWay RX is indicated for use by interventional cardiologists trained in surgical, angiographic and PCI techniques, in specialised settings such as catheterisation labs in coronary care units. Standard visualisation procedures would be used, such as X‑ray fluoroscopy.
ClearWay RX is only intended to be used for the localised perfusion of various diagnostic and therapeutic agents into the coronary (and peripheral) vasculature. It is not intended for use in percutaneous transluminal angioplasty or stent deployment, or in the neurovasculature. The scope of this briefing is the delivery of thrombolytic drugs to coronary arteries.
After addressing risk factors (for example smoking, hyperlipidaemia, obesity and hyperglycaemia), symptoms of a blocked artery may be treated with beta-adrenergic blockers, nitrates, calcium-channel blockers, antiplatelet agents and statins. If medical management fails or is inappropriate, the usual options are surgical coronary artery bypass grafting or percutaneous transluminal coronary angioplasty, usually involving a bare metal or drug-eluting stent inserted where the vessel is stenotic. In recent years, filters and aspiration devices, as well as drug strategies such as glycoprotein IIb/IIIa inhibitors, have been tested to prevent thrombus micro-embolisation. The drugs can be given intravenously or via the coronary arteries using a coronary catheter.
Other drug-eluting balloon catheters are available and in use in the NHS (Waksman and Pakala 2009). NICE is aware of the following CE‑marked device that appears to fulfil a similar function to the ClearWay RX:
GENIE local drug delivery catheter (Acrostak Corporation).
The list price of 1 ClearWay RX balloon catheter is £600 excluding VAT. A guidewire is needed to deliver the device, but because a guidewire would be needed for a PCI anyway, the cost is not included here. ClearWay RX balloon catheters are single use but can be used several times in the same patient during a single procedure.
The ClearWay RX would be used in hospital patients having angiographic procedures to aid in the dissolution of blood clots in coronary arteries that are continuing to cause symptoms and may cause further myocardial damage, following acute coronary syndrome events. It can also be used in cases of no-reflow through the coronary artery. It would be used as an alternative to systemic administration of the therapeutic agents which are intended to break down the clot.
All 3 specialist commentators noted that there is limited evidence to support the use of ClearWay RX. One specialist commentator said that it is possible that any reduction in blood clot burden with ClearWay RX may have been a result of physical displacement, pushing clot fragments distally away from the lesion. Demonstrating this point, there is no evidence of the ClearWay RX using abciximab compared with the ClearWay RX using saline.
Two specialist commentators said that the Infuse AMI trial has often been quoted as good evidence for the effectiveness of ClearWay RX, but the trial does not provide information on the comparative effectiveness of different routes of drug administration.
One specialist commentator stated that, with a reduction in the routine use of thrombectomy (clot aspiration) following the TASTE and TOTAL trials, and a reduction in use of the intravenous anticoagulant bivalirudin following the HEAT-PPCI trial, the incidence of residual blood clots may rise, increasing the need for alternative strategies such as ClearWay RX. However, they also noted that residual blood clots are relatively uncommon, and alternative methods of dissolving them already exist (such as administering the agent directly into the coronary artery using a guide catheter or giving the agent intravenously).
One specialist commentator noted that it can be difficult to deliver drugs into a vessel where no-reflow is present and that ClearWay RX can be used for this. They did, however, state that it is often better to give glycoprotein inhibitors to patients at risk before no-reflow develops.
One specialist commentator stated that it is currently unclear whether reducing blood clot burden, or even an improvement in microvascular perfusion or myocardial blush grade, translates into favourable clinical outcome. This is demonstrated by a recent systematic review of thrombectomy compared with no intervention in STEMI (Elgendy et al. 2015).
One specialist commentator stated that the cost of 1 ClearWay RX catheter is equivalent to the cost of multiple angioplasty balloon catheters.
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Coronary heart disease is more common in people over the age of 65 years and affects more men than women. Age and sex are protected characteristics under the Equality Act 2010.