Industry standards steer development of cardiac diagnostic tools
Manufacturer and medics draw up universal standards for eTRACKING and Wave Intensity devices
A leading UK medical professor is collaborating with ultrasound supplier, Hitachi Aloka Medical, to establish new industry standards for the development and evaluation of diagnostic tools that examine how the heart interacts with larger arteries.
In one of the first link-ups of its kind, Professor Alan Fraser of the Institute of Molecular and Experimental Medicine at the Cardiff University School of Medicine will work with the manufacturer to draw up universal clinical standards and validation techniques that will help to improve the accuracy and safety of future diagnostic systems.
The move comes after cardiologists from 13 centres across Europe collaborated in an ETIC study, co-ordinated from Cardiff, to pool results from eTRACKING of carotid arteries using Hitachi Aloka Medical’s vascular transducers.
The equipment looks for increased arterial stiffness, particularly in arteries located close to the heart, like the carotid, which cause increased pressure and load to be placed on the heart. This process is understood to occur because increased arterial stiffness, which is measured by eTRACKING, modifies the timing of wave reflections. For example, during ventricular ejection a forward pressure wave is generated which is then reflected back from the arterial tree. In patients with increased arterial stiffness, the reflected wave travels more quickly back to the heart, meaning that when it arrives the aortic valve has not had a chance to close, so the central systolic blood pressure and LV afterload are both increased. This causes the heart muscle to increase in size. Over time, the heart’s increased muscle mass will also cause slow relaxation of the heart muscle and difficulty in filling.
When developing its diagnostic tool, experts at Hitachi Aloka Medical studied the interactions between the heart and reflected waves and can now estimate the local direction and amplitude of waves in an artery – wave intensity – via simultaneous recordings of diameter (with pressure) and velocity. The results give clinicians new insights into how arteries and ventricles interact, especially in the presence of arterial disease.
Establishing industry standards and normal values for each manufacturer will help clinicians enormously in establishing quickly what is and is not a diagnostically significant result in an individual patient
Together, these two new diagnostic tools – eTRACKING and Wave Intensity – provide powerful new systems for understanding the effects of drugs on altering the interactions between the heart and arteries. It is now possible to discriminate between the peripheral and central effects of drugs, which will help clinicians to choose treatments for patients that are most likely to reduce the risk of heart failure. Drugs that modify the timing, as well as the amplitude, of reflected waves may be most effective in reducing stress on the heart, experts believe.
Commenting on how the guidelines will help as new systems reach the market, Professor Fraser said: “Ultrasound machines from different manufacturers, and even different models from the same manufacturer, often give different values for the same measurements. Establishing industry standards and normal values for each manufacturer will help clinicians enormously in establishing quickly what is and is not a diagnostically significant result in an individual patient. It surprises me that more manufacturers have not adopted a progressive and open approach to validating new diagnostic tools."