Improved technology may obviate need for drug when assessing patients for a coronary stent

A new method for measuring narrowing in the coronary arteries may allow patients to be assessed for a stent without having to take a drug with unpleasant side effects. Currently fractional flow reserve (FFR) involves inserting a wire into the artery to measure changes in blood pressure. This is sometimes used in addition to an angiogram to give a more clinically accurate measurement to help make the decision to insert a stent. However, FFR requires the patient to be given a drug such as adenosine to dilate blood vessels, which can cause unpleasant side effects including facial flushing and shortness of breath. Although there is good evidence that FFR is useful, it is done in only 5-10 per cent of cardiac stenting procedures because it is costly, time-consuming and some patients cannot receive adenosine, such as patients with certain heart conduction diseases. Now, researchers at Imperial College London, UK have developed a way to measure narrowings in the arteries instantaneously, using the same instruments as FFR but without the need for a drug. The new investigational method, termed the instant wave-Free Ratio could benefit patients by making it easier to determine whether a stent is the best option.Like FFR, iFR works by inserting a wire into the coronary artery to measure blood pressure on either side of the narrowing. However it is possible to obtain a measurement during a particular time in the heart