Summary

Advice

The technology described in this briefing is the MiraQ cardiac transit time flowmetry (TTFM) and high-frequency ultrasound (HFUS) system. It is used for intraoperative quality assessment of graft blood flow during coronary artery bypass graft (CABG) surgery for people with coronary heart disease.
The innovative aspect is the L15 HFUS imaging probe that is designed to improve near-field imaging and is applied directly to the cardiac tissue.
The intended place in therapy would be as an alternative to clinical assessment in people undergoing CABG surgery.
The main points from the evidence summarised in this briefing are from 4 studies (1 multicentre observational registry, 1 secondary analysis, 1 prospective study and 1 retrospective observational study) including a total of 1,134 people undergoing CABG surgery. They show that MiraQ cardiac with TTFM and HFUS may improve the quality and efficacy of the CABG procedure.
Key uncertainties around the evidence or technology are that there is limited UK NHS evidence and none of the studies included a comparator.
Experts advised that the main benefits of the technology are providing surgeons with detailed objective information about the graft condition and graft flow, and helping them detect the position of deep lying arteries during the procedure. These may reduce long-term graft failure, and the risk of bleeding and intraoperative complications.
Safety issues identified with the MiraQ system are that there have been incidences when flow measurement channels incorrectly indicated that the flow is too high or too low, which could cause surgeons to make unnecessary changes and potentially lead to graft failure. The instructions for use have been updated to address the problem.
The cost of the MiraQ cardiac TTFM and HFUS system is £81,550 per unit, the L15 imaging probe is £8,365 and the TTFM probe is £1,720 (excluding VAT). Standard care is clinical assessment of graft flow using a variety of techniques, which are selected based on surgeon preference.