A Clearer Picture for Acute Chest Pain

Heart-related chest pain may be optimally diagnosed with cardiac magnetic resonance imaging

(RxWiki News) Traditionally, acute chest pain meant a hospital stay for evaluation. Using a stress cardiac MRI in the emergency department offers an alternative that may improve outcomes for patients.

A stress cardiac MRI is a medical imaging technique used to evaluate the blood flow in heart arteries and look for blockages. Doctors at one medical center recently compared approaches for treating patients with acute chest pain.

They found that patients evaluated with stress cardiac MRI in an emergency department had reduced hospital readmissions, heart procedures and additional cardiac testing, compared to patients admitted for inpatient hospital care.

"Know the diagnostic benefits of getting a cardiac MRI."

Chadwick Miller, MD, director of clinical research and executive vice-chair of Emergency Medicine at Wake Forest Baptist Medical Center in Winston-Salem, North Carolina, and colleagues followed 105 older patients who came to the center with acute chest pain.

The patients had many risk factors for coronary disease or they may have had prior health problems. Their average age was 56 years old. About 30 percent had a history of diabetes, and 20 percent were already known to have coronary artery disease.

Patients were randomized to receive care in the observation unit of the Emergency Department (ED) with cardiac MRI or in the hospital as an admitted patient (note that the Emergency Department is also commonly known as the ER). The observation unit of the Emergency Department is designed for short stays. These stays are longer than a typical emergency room visit but shorter than a hospital admission.

After following patients for 90 days, Dr. Miller and his team observed significant reductions in three “adverse events” among the patients in the Emergency Department group compared to those who received usual inpatient care.

These events were hospital readmissions, need for additional cardiac testing, and revascularization procedures. Revascularization reestablishes blood flow to the heart muscle, which is being blocked by a clogged or narrowed artery.

Comparing the inpatient group to the Emergency Department group, cardiac testing after discharge occurred in 17 percent vs. 4 percent, re-hospitalization in 23 percent vs. 8 percent and revascularization occurred in 15 percent vs. 2 percent.

"This clinical trial is encouraging, because it seems to have shown that cardiac MRI for the evaluation of certain patients hits a trifecta of positive outcomes. Any diagnostic method that shows potential to reduce unnecessary hospital admissions, reduce the amount of testing and procedures needed by patients, and also save patients and hospitals money deserves more research and attention," said Dr. Fouad Azoury, a cardiothoracic surgeon with the St. John Providence Health System. 

Some of the common procedures for revascularization are balloon angioplasty, stenting and bypass. With angioplasty, a catheter with a tiny balloon is carefully threaded through the coronary artery to the blockage, then inflated to widen the opening and increase blood flow to the heart.

With stenting, a stainless steel mesh tube is placed at the site of narrowed coronary artery and it pushes against the artery walls, keeping it open. With a bypass, a piece of vein is surgically grafted above and below the blocked area of a coronary artery to deliver blood flow around the blockage.

Dr. Miller told dailyRx News, “With cardiac MRI in the Emergency Department, we’re getting high quality imaging information early on about whether the patient needs to undergo revascularization procedures. We’re getting imaging information that’s informative to the type of intervention the patient may benefit from.”

This study built on previous Wake Forest research finding that patients with chest pain managed in an observation unit with cardiac MRI experienced a reduction in care costs of about $2,100 per patient per year.

"I look forward to seeing if these results can be replicated in larger trials," said Dr. Azoury. 

"What's exciting about this is not only can we reduce events that are important to patients, but we can reduce costs as well," Dr. Miller said. "What we think is happening is that the cardiac MRI is more accurately selecting patients who will benefit the most from having invasive procedures done. It's a win-win."

This study was published in June in the journal JACC: Cardiovascular Imaging. The study was funded by the National Institutes of Health's National Heart, Lung, and Blood Institute.

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Review Date: 
June 14, 2013