Noninvasive imaging helps predict heart attacks

March 14, 2017

Noninvasive 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 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 ."

A combination of invasive coronary angiography (ICA) and 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," Dr. 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 , 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 , 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," Dr. 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: 15 of the 16 centers in the trial had never done the procedure before, according to Dr. Chen, and all were all able to learn it effectively.

Explore further: Head-to-head comparison of non-invasive coronary artery imaging

More information: "Prognostic Value of Combined CT Angiography and Myocardial Perfusion Imaging versus Invasive Coronary Angiography and Nuclear Stress Perfusion Imaging in the Prediction of Major Adverse Cardiovascular Events: The CORE320 Multicenter Study" Radiology, 2017.

Related Stories

Head-to-head comparison of non-invasive coronary artery imaging

August 29, 2016
For patients presenting for the first time with suspected coronary artery disease (CAD) clinicians have had a number of non-invasive diagnostic tests to choose from, but little evidence for which is best.

MRI stronger predictor of major adverse cardiovascular events than standard scan

May 9, 2016
Cardiovascular magnetic resonance (CMR) is a stronger predictor of risk for major adverse cardiovascular events (MACE) than single-photon emission computed tomography (SPECT) at 5 years follow-up. The findings are published ...

CT perfusion imaging better IDs CAD than SPECT

August 11, 2014
(HealthDay)—Computed tomographic (CT) perfusion imaging shows higher overall diagnostic performance than single photon emission computed tomography (SPECT) perfusion imaging for the diagnosis of coronary artery disease ...

CT angiography and perfusion to assess coronary artery disease: The CORE320 study

August 28, 2012
A non-invasive imaging strategy which integrates non-invasive CT angiography (CTA) and CT myocardial perfusion imaging (CTP) has robust diagnostic accuracy for identifying patients with flow-limiting coronary artery disease ...

Advanced CT imaging proves as accurate as invasive tests to assess heart blockages, study shows

November 19, 2013
An ultrafast, 320-detector computed tomography (CT) scanner that shows both anatomy within coronary arteries and blood flowcan accurately sort out which people need – or don't need – an invasive procedure to identify ...

Study examines unnecessary angiography rates among strategies to guide care of suspected CHD

August 29, 2016
In a study published online by JAMA, John P. Greenwood, Ph.D., of the University of Leeds, Leeds, United Kingdom, and colleagues examined whether among patients with suspected coronary heart disease (CHD), cardiovascular ...

Recommended for you

Low-salt and heart-healthy dash diet as effective as drugs for some adults with high blood pressure

November 22, 2017
A study of more than 400 adults with prehypertension, or stage 1 high blood pressure, found that combining a low-salt diet with the heart-healthy DASH diet substantially lowers systolic blood pressure—the top number in ...

Stroke patients may have more time to get treatment, study finds

November 22, 2017
Patients and doctors long have relied on a simple rule of thumb for seeking care after an ischemic stroke: "Time is brain."

Cases of heart failure continue to rise; poorest people worst affected

November 22, 2017
The number of people being diagnosed with heart failure in the UK continues to rise as a result of demographic changes common to many developed countries, new research by The George Institute for Global Health at the University ...

Some cancer therapies may provide a new way to treat high blood pressure

November 20, 2017
Drugs designed to halt cancer growth may offer a new way to control high blood pressure (hypertension), say Georgetown University Medical Center investigators. The finding could offer a real advance in hypertension treatment ...

Could this protein protect people against coronary artery disease?

November 17, 2017
The buildup of plaque in the heart's arteries is an unfortunate part of aging. But by studying the genetic makeup of people who maintain clear arteries into old age, researchers led by UNC's Jonathan Schisler, PhD, have identified ...

Raising 'good' cholesterol fails to protect against heart disease

November 16, 2017
Raising so-called 'good' cholesterol by blocking a key protein involved in its metabolism does not protect against heart disease or stroke, according to a large genetic study of 150,000 Chinese adults published in the journal ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.