Study: Change the way you care for acute MI patients

If primary angioplasty is not available at your facility, are acute myocardial infarction (AMI) patients transferred so that they can receive this lifesaving intervention?

According to a new study, AMI patients who were transferred in order to receive primary angioplasty had a 40% decrease in death and major complications, as compared with patients who were not transferred and received thrombolytics.1

"The study concluded it was worth the extra time to get heart attack patients to hospitals that are able to perform primary angioplasty on an emergent basis, 24 hours a day, seven days a week," explains Marli Bennewitz, RN, BSN, chest pain center coordinator at St. Jude Medical Center in Fullerton, CA.

To improve care of AMI patients, consider the following items:

• Understand how angiography and percutaneous coronary interventions (PCIs) work.

Coronary angiography assesses for narrowing or blockage of the coronary arteries, says Steven D. Glow, RN, MSN, FNP, nursing faculty at Salish Kootenai College in Pablo, MT. A sheath is inserted into the femoral or radial artery, and a catheter is threaded up the aorta into the coronary artery system, he explains.

Radiopaque dye is injected into each coronary artery, and real-time imaging allows visualization of coronary artery blood flow, says Glow. "Data gained from this procedure are used to determine if the patient needs PCI," he says.

If PCI is needed, catheters with interventional devices are inserted through the sheath placed for angiography, says Glow.

There are four types of PCIs:

Balloon angioplasty: A balloon-tipped catheter is advanced to the location of coronary artery narrowing and is inflated, which compresses the plaque against the walls of the artery. The balloon is removed, and the lumen of the artery is reassessed.

Stenting: A small, expandable metallic or drug-coated device may be used in addition to the balloon angioplasty to hold the lumen of the artery open. When the angioplasty balloon is inflated, the stent opens up and locks, and the wire mesh stent opens the coronary artery and remains there permanently, says Glow.

"The newest stents, just recently available in the U.S., are drug-eluting stents," she says. Medicated coatings are used to decrease the chance of reocclusion of the artery due to scarring at the stent site, Bennewitz explains.

Rotational atherectomy: This procedure breaks up or carves out hard plaque narrowing a coronary artery. The pieces of plaque are suctioned out with the catheter to avoid embolization.

Brachytherapy: Radiation therapy at the site of a stent prevents or shrinks scar tissue.

All of these diagnostic and therapeutic procedures involve the use of radiopaque iodine dye, says Glow.

"Many people experience a warm or flush feeling when the dye is injected," he says. "The dye is eliminated by the kidneys, so clients with renal problems are at increased risk for complications."

• Know what to do if you don’t have capabilities for primary angioplasty.

Unfortunately, not all U.S. hospitals have cardiac catheterization lab capabilities, notes Bennewitz.

If you do have a cath lab, you must expedite the patient’s arrival for this lifesaving angioplasty procedure, she urges. Otherwise, know which hospital in your area you would transfer to and understand your transfer procedures, says Bennewitz.

• Know indications for this intervention.

There are no clearly defined contraindications to primary angioplasty, unlike with intravenous thrombolytics, says Bennewitz. "Rarely, you might have a patient with no access site or borderline renal failure who might not be the best candidates," she adds.

• Reduce door-to-balloon times.

"It is important for every ED nurse to remember the old saying we used when thrombolytics were first introduced: time is muscle,’" says Bennewitz.

To decrease the time from door-to-balloon at St. Jude Medical Center, a paramedic pre-hospital electrocardiogram (ECG) program was implemented in 1999, she reports. "The paramedic trucks are equipped with portable 12-lead ECG machines, which enables us to identify an AMI before the patient arrives," says Bennewitz. "We also have pre-printed consents to make informed consenting easier."

There is a team approach among the cardiologist, ED physicians and nurses, and cath lab staff, stresses Bennewitz. "Everyone is aware our goal is to get that AMI patient to the cath lab as soon as possible and in the best condition possible," she says.

• Reduce delays.

To cut delays once the patient arrives in the cath lab, remove the patient’s underwear and socks beforehand, and make sure there are at least two intravenous lines started, recommends Bennewitz.

Also, make sure a blood urea nitrogen/creatinine level has been obtained and is available for review prior to the procedure, says Glow. Patients may be allergic to the iodine-based dyes used for this diagnostic test, so ask about known allergies to intravenous iodine, shellfish, and any allergic reactions after the client’s previous diagnostic imaging studies, he advises.

"Depending on the severity of the previous reaction and the need for the procedure, premedication with diphenhydramine or methylprednisilone may be ordered," he says.

Reference

1. Andersen HR, Nielsen TT, Rasmussen K, et al. A comparison of coronary angioplasty with fibrinolytic therapy in acute myocardial infarction. N Engl J Med 2003; 349:733-742.

Sources

For more information, contact:

  • Marli Bennewitz, RN, BSN, Chest Pain Center Coordinator, St. Jude Medical Center, 101 E. Valencia Mesa Drive, Fullerton, CA 92832. Telephone: (714) 992-3000, ext. 3463. Fax: (714) 992-3109. E-mail: mbennewi@sjf.stjoe.org.
  • Steven D. Glow, RN, MSN, FNP, Nursing Faculty, Salish Kootenai College, P.O. Box 117, 52000 N. Hwy 93, Pablo, MT 59855. Telephone: (406) 275-4922. Fax: (406) 275-4806. E-mail: Steve_Glow@skc.edu.