Medical software can make open heart surgery safer by helping doctors visualize the blood vessels in the heart without invasive tests. The National Institute for Health and Care Excellence (NICE), UK, has just recommended Heartflow FFRct for use in patients with stable coronary artery disease (CAD) — a software medical device that calculates fractional flow reserve (FFR) using standard coronary CT angiography scans (cCTA).
This method can help diagnose heart conditions in patients with chest pain and suspected angina with non-invasive techniques.
According to NICE, 36,000 people could benefit from the new technology every year, saving the NHS around £7.7m (€9m; $10.2m) by avoiding invasive procedures, treatments and diagnostic techniques.
Patients with suspected stable coronary artery disease (CAD) need a cCTA scan, some other imaging or invasive procedure to create future treatment plans. The device uses standard data obtained from cardiac computed tomography angiography images, which the scientists used to develop a 3D model of the patient’s blood vessels.
These images are used to estimate fractional flow reserve, which is a technique used in coronary catheterization to determine blood flow pressure differences in arteries, with the results being available within 48 hours. Currently, fractional flow reserve is measured using a catheter invasively by placing a pressure wire across a narrow artery.
The manufacturer of the HeartFlow FFRct said that using this new technology would minimize the need for revascularization in some patients, which is the process of restoration of an organ that has suffered ischemia, because it identifies more accurately whether stenoses are ischaemic than coronary angiography alone.
An evaluation of the evidence by NICE’s medical technologies advisory committee agreed with this. Heartflow FFRct will be cheaper by 214 pounds due to a reduced price of 700 pounds per test than the current treatment pathway for all functional imaging tests (SPECT, MRI, and ECHO), according to the committee’s statement.
The consultation closes on 26 September, 2016.
Carole Longson, Director of the NICE Centre for Health Technology Evaluation, said, “Accurately diagnosing the cause of chest pain is important for ensuring that the affected person receives appropriate care and treatment.
The preliminary view of the independent committee is that HeartFlow FFRct is innovative, and using it in practice may simplify the series of tests used to diagnose the condition. Based on the evidence that the committee considered, they concluded that the device is highly accurate in diagnosing coronary artery disease and that it has the potential to reduce the need for invasive coronary investigations—which is good news for the patient.”
Most adults with congenital disease are asymptomatic; therefore, imaging and functional tests are used to assess the disease progression of disease and monitor residual lesions such as ventricular function or valve regurgitation. Several advanced imaging techniques are already in place.
These imaging techniques include echocardiography, also known as transthoracic echocardiography (TTE) and is the most common technique for routine assessment and surveillance of adults with congenital heart disease. TTE can make a detailed qualitative assessment of ventricular function, and Doppler echocardiography assesses the severity of haemodynamic or valve lesions. Tricuspid regurgitation jet can be used to estimate right heart pressures. TTE is conducted during each clinical review. With TTE, ultrasound has to penetrate between ribs and through the chest wall, therefore fat and well defined heavy chest muscles are a barrier to good image quality.
If TTE images are of poor resolution and lack detail, transoesophageal echocardiography (TOE) can be an alternative, where the ultrasound probe is placed within the esophagus canal, with little or no barrier to ultrasound penetration. TOE may require general anesthesia, and therefore everyone looking to undergo this operation should talk to a general anesthesiologist first.
Cardiovascular magnetic resonance imaging (CMRI) is another imaging technique being used extensively. CMRI provides 3D and 4D imaging which is capable of taking real time blood flow images. It is accurate for defining morphology and quantifying ventricular function. If CMRI is contraindicated owing to the presence of metallic implants or implantable electronic devices (pacemakers, defibrillators), then computed tomography (CT) is an alternative for providing 3D images.
CT includes current CT scanners, electron beam CT (EBCT), and multi-slice spiral CT. It has a fast image acquisition time which reduces scan time and therefore radiation dose. CT only provides qualitative, observational data rather than quantitative data such as volumes and fractional data. CT uses ionizing radiation and must be used judiciously as patients potentially require several scans over their lifetime.
These imaging techniques can assess repaired or newly presenting congenital heart disease. Although many of these imaging devices are available in most hospitals, the skills and specialization required to assess and diagnose on the basis of these images are only available in congenital heart disease specialty units. With the latest imaging discovery, HeartFlow has managed to develop a method to improve diagnosis of coronary artery disease for heart surgery using non-invasive methodology.