News | CT Angiography (CTA) | March 14, 2017

Noninvasive Imaging Helps Predict Heart Attacks

Radiology study finds CT angiography plus CT myocardial perfusion is equally effective as gold-standard invasive coronary angiography

CTA, CT angiography, predict heart attacks, Radiology study

March 14, 2017 — Noninvasive computed tomography (CT) angiography and stress tests can help predict which patients are likely to suffer a heart attack or other adverse cardiovascular event, according to a new study appearing online in the journal Radiology.

Cardiovascular disease is a leading cause of death worldwide. Bypass surgery or stent placement is often recommended in people with certain degrees of coronary arterial narrowing, or stenosis, but recent studies have shown that many of these patients do just as well with medical therapy. A key factor in treatment decisions is the hemodynamic significance of the lesion, meaning the degree to which the lesion is blocking blood from getting to areas of the heart.

“Previous studies show that a lesion is hemodynamically significant if there is a significant blood pressure drop corresponding to a big reduction in blood flow across the stenosis,” said study author João A.C. Lima, M.D., from Johns Hopkins Hospital and School of Medicine in Baltimore. “If plaque has those characteristics, the patient should be targeted for intervention, be it with a stent or downstream bypass surgery.”

A combination of invasive coronary angiography (ICA) and stress tests with single photon emission tomography (SPECT) myocardial imaging has been the gold standard for making these determinations, with ICA showing the blockages and SPECT the perfusion, or penetration of the blood into the tissue. However, ICA requires the use of a catheter that is threaded from a puncture point in the groin all the way up to the heart.

“Invasive angiography is generally safe, but it can cause vascular problems in a significant number of patients, most commonly at site of the puncture,” Lima said. “In rare cases, it can cause strokes or heart attacks. These risks are not trivial.”

The ICA/SPECT approach can also be expensive, as it often necessitates hospitalization for the patient.

“The traditional approach with invasive catheterization requires that patients go to the hospital, get a catheter inserted into their leg and go in for the nuclear SPECT study on a different day,” said study coauthor Marcus Chen, M.D., from the National Institutes of Health in Bethesda, Md. “Now with just one noninvasive test we can get two important but different pieces of information about the coronary arteries.”

The researchers set out to determine if combined CT angiography (CTA) and CT myocardial stress perfusion imaging (CTP) could demonstrate similar or superior ability to ICA/SPECT in predicting future adverse events.

They compared the invasive and noninvasive approaches in 379 patients who were referred for ICA from November 2009 to July 2011. The researchers looked at the ability of both techniques to predict whether or not a future major adverse cardiac event (MACE), such as a heart attack, revascularization, arrhythmia or hospitalization for chest pain or congestive heart failure would occur.

Fifty-one patients, or 13.5 percent, experienced one or more major adverse cardiac events, including 49 revascularizations, five myocardial infarctions, one cardiac death, nine hospitalizations for chest pain or congestive heart failure, and one arrhythmia.

Both techniques proved to have similarly high values for predicting MACE at two years after presentation and event-free survival. The two-year MACE-free rates for combined CT angiography and CT perfusion findings were 94 percent negative for coronary artery disease (CAD) versus 82 percent positive for CAD and were similar to combined ICA/SPECT findings (93 percent negative for CAD vs. 77 percent positive for CAD).

“The key finding of our study is that both techniques are equally effective in identifying which patients are going to have trouble down the road,” Lima said. “The noninvasive option should be a preferred or at least strongly considered option by cardiologists and radiologists managing these patients because it is safer and less expensive, and patients like it better.”

Obstacles remain before the noninvasive approach can achieve more widespread use, including the lack of a reimbursement code for stress CT perfusion. But the study indicates that the technique is relatively easy to incorporate into existing practices: Fifteen of the 16 centers in the trial had never done the procedure before, according to Chen, and all were all able to learn it effectively.

Watch the video "CT for Chest Pain Evaluation in The Emergency Department."

For more information: www.pubs.rsna.org/radiology

Related Content

Norwegian Study Confirms Benefits of Pressure-Based Breast Compression for Mammography
News | Mammography | May 22, 2017
Sigmascreening recently announced that a large independent Norwegian study further confirms Sigma’s hypothesis that...
Lantheus and GE Healthcare Sign Agreement for Worldwide Development, Commercialization of Flurpiridaz F-18
News | Radiopharmaceuticals and Tracers | May 22, 2017
May 22, 2017 — Lantheus Holdings Inc., parent company of Lantheus Medical Imaging Inc., and GE Healthcare announced t
ACR Select Extended to Cover Pediatric Imaging Indications and Exams
News | Clinical Decision Support | May 17, 2017
May 17, 2017 — Through the support of the American College of Radiology and the contribution of leading experts from
Seno Medical's Imagio Opto-Acoustic Breast Imaging System Proves Strong Predictor of Malignancy
News | Breast Imaging | May 16, 2017
Seno Medical Instruments Inc. recently announced that is Imagio opto-acoustic (OA/US) breast imaging system results...
Study Indicates Q-Collar May Help Protect Football Players' Brain Function
News | Neuro Imaging | May 15, 2017
A new study of high school football players adds to mounting evidence that the Q-Collar may help reduce brain injury...
FALCON Trial of Fluciclovine PET/CT Imaging Stops Recruitment after Successful Interim Analysis
News | Radiopharmaceuticals and Tracers | May 15, 2017
Blue Earth Diagnostics announced that the Trial Steering Committee recommended further recruitment be stopped in the...
Study Reveals Low Adoption of IAEA Recommendations for Reduced Nuclear Cardiology Radiation Exposure
News | Radiation Dose Management | May 12, 2017
A study in 65 countries has revealed low adoption of International Atomic Energy Agency (IAEA) recommendations to...
Arkansas Surgeon Reports Positive Findings From Use of BioZorb 3-D Marker
News | Radiation Therapy | May 12, 2017
A new research study concluded that use of the BioZorb surgical marker appears to provide better cosmetic outcomes and...
Large Nuclear Cardiology Laboratory Slashes Radiation Dose 60 Percent in Eight Years
News | Radiation Dose Management | May 11, 2017
A large nuclear cardiology laboratory in Missouri has slashed its average radiation dose by 60 percent in eight years,...
Overlay Init