Patients spared artery probe by 3D heart scan

ANEW high-definition 3D scanner is being used to pinpoint life-threatening blocked arteries around the heart – saving patients from risk of older diagnostic methods that involve a probe fed into the vessels.

The new technology, known as fractional flow reserve computed tomography (FFRCT), creates a detailed computer model of the heart from a standard CT scan image, which is similar to an X-ray.

It then uses complex calculations to work out the extent of blockages in the coronary arteries and whether they are restricting the flow of blood – all without the need for invasive intervention.

British cardiologists have been leading the way with the procedure in trials with angina sufferers at Southampton University Hospital. The accuracy of the test led them to revise plans in a third of cases where they had considered carrying out a heart stent angioplasty operation.

Currently, the gold standard diagnosis for coronary heart disease (CHD), in which the arteries supplying the heart become blocked with a build-up of a hard material known as plaque, is a procedure called an angiogram, or cardiac catheterisation. More than 100,000 Britons have the test each year, and it involves a long, thin, flexible tube called a catheter being inserted into an artery in the groin or wrist.

Doctors guide the catheter to the heart and inject a dye through it, which makes the heart and coronary arteries show up more clearly on X-rays.

Without adequate blood flow from the coronary arteries, the heart is starved of the oxygen and vital nutrients it needs to work properly, leading to a heart attack. The test clearly shows up blockages, flagging up the need for life-saving surgery, and is vital.

If the angiogram shows a narrowing of an artery, a pressure sensor can be inserted into the heart during the same procedure – known as a fractional flow reserve (FFR) test.

The FFR gives a precise reading of whether blood flow is significantly restricted, which is vital in deciding if a patient can be treated with medical therapy or if they require heart surgery.

CHD is Britain’s biggest killer, responsible for 73,000 deaths every year.

Alongside increasing the risk of a heart attack, CHD can cause angina, which is pain emanat- ing from the heart during even mild exertion.

The most common treatment is angioplasty, where a catheter – again fed through the arteries into the heart – is used to insert a flexible, expandible metal mesh tube called a stent, which widens the arteries and restores blood flow.

Stents remain in place to prevent re-narrowing of that artery.

However, angiograms carry a range of serious risks, so doctors must weight those up against the perceived benefits.

PROFESSOR Nick Curzen, a Southampton cardiologist who has been involved in the trials, said: ‘Any invasive test – even though it’s not actual surgery – still has a risk, which is why we have been searching for an alternative to an angiogram, which is the current gold standard.’

The risk of death from an angiogram is one in 1,000 and can be caused by a rupture of an artery, or a stroke or heart attack caused by fatty plaque breaking off during the test.

Prof Curzen said: ‘This new technology gives us a better picture. We are now moving into exciting new territory where we can discover important and accurate details without intervention.’