Boston Scientific COMET Wire Validation Study (COMET)

Summary of Study Aims To assess, in a randomised fashion: performance of Boston Scientific Pressure Wire versus St Jude Pressure Wire performance of Boston Scientific Pressure Wire versus Boston Scientific Pressure Wire performance of St Jude Pressure Wire versus St Jude Pressure Wire

Given the following key points of evidence, the optimal management of chest pain patients who come to diagnostic coronary angiography would more often be achieved if there was concomitant data with regard to the presence of patient-specific and lesion-specific ischaemia: that it is the presence and extent of reversible myocardial ischaemia (RMI) that dominates over coronary anatomy as a predictor of near term cardiovascular events, as well as symptom relief that prognostic benefit after revascularisation is greatest in patients with the largest pre-procedure ischaemic burden that intra-coronary pressure wire (PW) data are strongly correlated with subsequent cardiac events despite the binary nature of the test that stenting of coronary lesions that are PW negative has a worse outcome than optimal medical therapy (OMT) that PW-directed percutaneous coronary intervention (PCI) in multivessel disease is associated with a better clinical outcome than angiogram-directed PCI despite fewer treated lesions and less stents that PW-directed PCI improves prognosis compared to OMT that mismatch exists in up to 30-40% of lesions encountered at angiography between the visual appearance of the severity of the lesion and whether the lesion is "ischaemic" (and therefore a target for revascularisation) according to PW. The availability of PW has been shown to have had a substantial effect on overall management of patients undergoing diagnostic coronary angiography (ie when options are still OMT/PCI and coronary artery bypass grafting (CABG) in several observation studies including RIPCORD and the French Registry. Yet, despite the seemingly persuasive data summarised here, the uptake of PW at the diagnostic stage of the patient pathway is still low. There are, as yet, no suitably powered randomised trials using the PW systematically at the stage of diagnostic angiography and comparing outcome with management based upon angiography alone. This is the gap that will be filled by RIPCORD2. RIPCORD2 will use the new Boston Scientific Pressure Wire (BSPW), which is currently undergoing first-in-man testing in Chile. The device has, of course, already been internally validated by Boston Scientific engineers and scientists, but the purpose of the COMET study is to provide independent and objective validation of the performance of BSPW using the performance of the St Jude Medical pressure wire (SJPW) as the reference, both using inter-wire and intra-wire measurements. Thus, not only will we assess the reproducibility of the measurements between the 2 wires, but the investigators will also compare reproducibility of measurements from 2 wires of the same manufacturer.

The study will involve the use of two pressure wires simultaneously in a coronary artery. The three randomisation groups will allow the comparison of pressure measurements between two different wires (BSPW vs SJPW) and will document consistency of readings within the same wire (BSPW vs BSPW or SJPW vs SJPW). Measurements will be undertaken using standard drug protocols. No additional drugs will be necessary for study purposes. The first wire allocated at randomisation will be passed to the target measurement position in the artery The second wire allocated at randomisation will be passed to exactly the same point in the vessel Positioning of the wires will be confirmed by X-rays Simultaneous measurements will be taken from the 2 pressure wires If there is a narrowing in more than one vessel the process will be repeated for each vessel. Once the measurement has been taken, both wires will be removed.

The study will involve the use of two pressure wires simultaneously in a coronary artery. The three randomisation groups will allow the comparison of pressure measurements between two different wires (BSPW vs SJPW) and will document consistency of readings within the same wire (BSPW vs BSPW or SJPW vs SJPW). Measurements will be undertaken using standard drug protocols. No additional drugs will be necessary for study purposes. The first wire allocated at randomisation will be passed to the target measurement position in the artery The second wire allocated at randomisation will be passed to exactly the same point in the vessel Positioning of the wires will be confirmed by X-rays Simultaneous measurements will be taken from the 2 pressure wires If there is a narrowing in more than one vessel the process will be repeated for each vessel. Once the measurement has been taken, both wires will be removed.

Inclusion Criteria >18yrs age Written informed consent Patients scheduled for diagnostic angiography (and/or "standby" angiography) Clinical requirement for pressure wire assessment Exclusion Criteria STEMI presentation Aorto-ostial disease Pregnancy CABG Contraindication to adenosine Creatinine >180umol/L Life threatening co-morbidity Severe valve disease