News | Computed Tomography (CT) | September 03, 2015

Non-Invasive FFR-CT Reduces Invasive Tests in Chest Pain Patients

Sixty-one percent of patients in PLATFORM trial had invasive tests canceled following FFR-CT analysis

FFR-CT, HeartFlow, PLATFORM trial, ESC 2015, ICA, fractional flow reserve, computed tomography

Image courtesy of HeartFlow

September 3, 2015 — Results of the PLATFORM trial indicate fractional flow reserve computed tomography (FFR-CT) can obviate the need for invasive tests in up to 61 percent of patients with chest pain and suspected coronary artery disease. The results were presented at the European Society of Cardiology (ESC) Congress 2015.

FFR-CT estimates blood flow and pressure in the coronary artery using images from computed tomography angiography (CTA).

“This approach significantly reduced the need for unnecessary invasive coronary angiography (ICA) which, although it is the gold standard for investigating chest pain, comes with the risk and costs of an invasive procedure,” said lead investigator Pamela Douglas, M.D., the Ursula Geller Professor at the Duke Clinical Research Institute, Duke University School of Medicine.

“The message is that for stable chest pain patients in whom elective ICA is recommended, consideration should be given to performing this new test first.”

When used alone, CTA can identify an abnormal narrowing (stenosis) in the coronary arteries but it cannot quantify how much this actually obstructs blood flow. Therefore “many patients who have blockages that are not interfering with blood flow may end up undergoing ICAs that show no evidence of obstructive coronary artery disease (CAD) and could possibly have been avoided, “ explained Douglas.

Other commonly used non-invasive tests for CAD, such as myocardial perfusion stress imaging or stress echocardiography, may tell whether blood supply to the heart tissue is adequate but cannot determine whether a specific blockage is obstructing blood flow, she said.

The current standard for assessing the significance of coronary artery narrowing is conventional FFR, which is invasive, involving insertion of a wire into the coronary artery.

But by using computer simulations to calculate blood flow, non-invasive FFR-CT can give a comprehensive evaluation of a patient’s chest pain without the need for an invasive procedure.

The PLATFORM study included 584 chest pain patients (average age 60.9 years) from 11 test centers in Europe.

Patients were evaluated using either FFR-CT, via the HeartFlow FFR-CT Analysis software from HeartFlow (n=297), or conventional testing (n=287) to see if FFR-CT  could reduce the rate of ICAs that show no obstructive CAD.

Patients were divided into those in whom “usual care” would dictate a non-invasive investigation such as stress testing or conventional CTA (n=204) and those who would have proceeded straight to an invasive ICA (n=380).

In both groups patients were then allocated to receive either usual care (invasive or non-invasive) or FFR-CT — defined as CTA with the addition of FFR when appropriate.

Among patients already scheduled for an ICA, 73 percent in the usual care group underwent ICA only to find no significant blockages, compared to 12 percent in the FFR-CT group. Furthermore, 61 percent of patients in the FFR-CT group had the ICA cancelled based on the FFR-CT results.

While FFR-CT reduced the number of patients who underwent an ICA that found no significant disease, there was no difference between the two groups in the rate of revascularization procedures, such as stenting and coronary artery bypass surgery.

No clinical adverse events were reported at the 90-day follow-up in patients whose physicians chose to cancel ICAs based on FFR-CT guided strategy

“The study shows that CTA plus FFR-CT more effectively triages patients for invasive procedures than usual care strategies,” said Douglas.

“Although FFR-CT is a relatively new technique, PLATFORM demonstrates that it is feasible and safe with high utility in busy clinical settings.” 

FFR-CT from HeartFlow received CE Mark in 2010 and received U.S. Food and Drug Administration clearance in November 2014. The technology has been evaluated in four large, clinical trials enrolling a total of more than 1,100 patients

For more information: www.escardio.org

Related Content

Chief among the myriad practical updates to minimize risks for patients and imaging personnel alike is a tiered approach for delaying both outpatient and inpatient cross-sectional interventional procedures

For procedural delays that will not adversely affect patient outcome, Fananapazir and colleagues proposed the following tiered approach for both outpatient and inpatient scenarios: urgent procedures, procedures that should be performed within 2 weeks, procedures that should be performed within 2 months, and procedures that can safely be delayed 2 or 6 months. Courtesy of American Journal of Roentgenology (AJR)

News | Coronavirus (COVID-19) | June 05, 2020
June 5, 2020 — An...
Early diagnosis of cancer is one of the highest-priority problem for the healthcare system, because it is critical for overall treatment success and saving patients' lives. Diffusion-weighted magnetic resonance imaging (DWI) may be used to detect a malignancy in various tissues and organs. It has the advantage of providing insight into the diffusion of water molecules in body tissues without exposing patients to radiation.

DWI of the phantom with polyvinylpyrrolidone (PVP) solutions (b value 500 s/mm2). Image courtesy of Kristina Sergunova et al.

News | Magnetic Resonance Imaging (MRI) | June 02, 2020
June 2, 2020 — Early diagnosis of cancer is one of the highest-priority problem for the healthcare system, because it
Largest case series (n=30) to date yields high frequency (77%) of negative chest CT findings among pediatric patients (10 months-18 years) with COVID-19, while also suggesting common findings in subset of children with positive CT findings

A and B, Unenhanced chest CT scans show minimal GGOs (right lower and left upper lobes) (arrows) and no consolidation. Only two lobes were affected, and CT findings were assigned CT severity score of 2. Image courtesy of American Journal of Roentgenology (AJR)

News | Coronavirus (COVID-19) | May 29, 2020
May 29, 2020 — An investigation published open-access in the ...
a Schematic of the system. The entire solid tumour is illuminated from four sides by a four-arm fibre bundle. A cylindrically focused linear array is designed to detect optoacoustic signals from the tumour. In vivo imaging is performed in conical scanning geometry by controlling the rotation and translation stages. The sensing part of the transducer array and the tumour are submerged in water to provide acoustic coupling. b Maximum intensity projections of the optoacoustic reconstruction of a phantom of pol

a Schematic of the system. The entire solid tumour is illuminated from four sides by a four-arm fibre bundle. A cylindrically focused linear array is designed to detect optoacoustic signals from the tumour. In vivo imaging is performed in conical scanning geometry by controlling the rotation and translation stages. The sensing part of the transducer array and the tumour are submerged in water to provide acoustic coupling. b Maximum intensity projections of the optoacoustic reconstruction of a phantom of polyethylene microspheres (diameter, 20 μm) dispersed in agar. The inset shows a zoomed-in view of the region boxed with a yellow dashed line. In addition, the yellow boxes are signal profiles along the xy and z axes across the microsphere centre, as well as the corresponding full width at half-maximum values. c Normalized absorption spectra of Hb, HbO2 and gold nanoparticles (AuNPs). The spectrum for the AuNPs was obtained using a USB4000 spectrometer (Ocean Optics, Dunedin, FL, USA), while the spectra for Hb and HbO2 were taken from http://omlc.org/spectra/haemoglobin/index.html. The vertical dashed lines indicate the five wavelengths used to stimulate the three absorbers: 710, 750, 780, 810 and 850 nm. Optoacoustic signals were filtered into a low-frequency band (red) and high-frequency band (green), which were used to reconstruct separate images.

News | Breast Imaging | May 26, 2020
May 26, 2020 — Breast cancer is the most common cancer in women.
A new technique developed by researchers at UC Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The team created a probe that generates two magnetic resonance signals that suppress each other until they reach the target, at which point they both increase contrast between the tumor and surrounding tissue

A new technique developed by researchers at UC Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The team created a probe that generates two magnetic resonance signals that suppress each other until they reach the target, at which point they both increase contrast between the tumor and surrounding tissue. Image courtesy of Xiandoing Xue, UC Davis

News | Magnetic Resonance Imaging (MRI) | May 26, 2020
May 26, 2020 — Researchers at the University of California, Davis offers a...
Researchers from Tokyo Metropolitan University have surveyed the amount of gadolinium found in river water in Tokyo. Gadolinium is contained in contrast agents given to patients undergoing medical magnetic resonance imaging (MRI) scans, and it has been shown in labs to become toxic when exposed to ultraviolet rays. The researchers found significantly elevated levels, particularly near water treatment plants, highlighting the need for new public policy and removal technologies as MRI become even more commonp

Samples were taken along rivers around Tokyo. Measurements of rare earth element quantities indicate a clearly elevated amount of gadolinium compared to that in natural shale. Graphics courtesy of Tokyo Metropolitan University

News | Magnetic Resonance Imaging (MRI) | May 26, 2020
May 26, 2020 — Researchers from Tokyo Metropolitan...
Remote reading of imaging studies on home picture archiving and communication systems (PACS) workstations can contribute to social distancing, protect vulnerable radiologists and others in the hospital, and ensure seamless interpretation capabilities in emergency scenarios, according to an open-access article published ahead-of-print by the American Journal of Roentgenology (AJR).

Srini Tridandapani, M.D., Ph.D.

News | PACS | May 21, 2020
May 21, 2020 — 
Examples of chest CT images of COVID-19 (+) patients and visualization of features correlated to COVID-19 positivity. For each pair of images, the left image is a CT image showing the segmented lung used as input for the CNN (convolutional neural network algorithm) model trained on CT images only, and the right image shows the heatmap of pixels that the CNN model classified as having SARS-CoV-2 infection (red indicates higher probability). (a) A 51-year-old female with fever and history of exposure to SARS-

Figure 1: Examples of chest CT images of COVID-19 (+) patients and visualization of features correlated to COVID-19 positivity. For each pair of images, the left image is a CT image showing the segmented lung used as input for the CNN (convolutional neural network algorithm) model trained on CT images only, and the right image shows the heatmap of pixels that the CNN model classified as having SARS-CoV-2 infection (red indicates higher probability). (a) A 51-year-old female with fever and history of exposure to SARS-CoV-2. The CNN model identified abnormal features in the right lower lobe (white color), whereas the two radiologists labeled this CT as negative. (b) A 52-year-old female who had a history of exposure to SARS-CoV-2 and presented with fever and productive cough. Bilateral peripheral ground-glass opacities (arrows) were labeled by the radiologists, and the CNN model predicted positivity based on features in matching areas. (c) A 72-year-old female with exposure history to the animal market in Wuhan presented with fever and productive cough. The segmented CT image shows ground-glass opacity in the anterior aspect of the right lung (arrow), whereas the CNN model labeled this CT as negative. (d) A 59-year-old female with cough and exposure history. The segmented CT image shows no evidence of pneumonia, and the CNN model also labeled this CT as negative.  

News | Coronavirus (COVID-19) | May 19, 2020
May 19, 2020 — Mount Sinai researchers are the first in the country to use...