Segment Elevation Myocardial Infarction (STEMI)


Segment Elevation Myocardial Infarctions (STEMIs) are a type of heart attack caused by the sudden blockage of a major coronary artery. For 25 years, clinical research has focused on ways to quickly open these blocked arteries, which reduces the chance of death.

This was accomplished first by clot-dissolving thrombolytic drugs that are ineffective 33 percent of the time and can cause life-threatening bleeding. After using the drugs, another heart attack caused by re-occlusion often happens. Restoring blood supply to the heart muscle with immediate coronary angioplasty and stenting can be better than thrombolytic therapy for treatment of STEMIs.

To provide a coronary angioplasty, the best STEMI care, a medical center must have 24/7 interventional cardiology facilities and personnel, as well as cardiac surgery backup. UTMC is one of just 43 medical centers that can provide this care, so if you live within 30 minutes of the hospital, you can get angioplasty within 90 minutes. Eighty-nine percent of UTMC patients in 2009 achieved the 90-minute door-to-balloon benchmark, compared to a state average of 82 percent and a national average of 79 percent.

There’s controversy about the best treatment for STEMI patients who do not have easy access to medical centers that can perform coronary angioplasties. Each 10-minute delay in treatment results a 1 percent higher chance of dying from a heart attack. There are programs to improve access to care by creating regional STEMI centers. In Tennessee, the Cardiac System of Care Task Force is identifying how to set up STEMI networks. The Heart Lung Vascular Institute has been a regional STEMI referral center for more than a decade.

UTMC’s system of care for STEMI patients in rural East Tennessee began in 1999 with a rapid transport protocol allowing patients with STEMIs in rural emergency departments to be transferred directly to the center. The LIFESTAR dispatch center became the communication hub for coordinating STEMI care by calling in the catheterization lab team the moment a STEMI patient was identified.

The UT LIFESTAR team went a step further in 2005 with a program to train local EMS providers to recognize the EKG of STEMI patients in the field, and call for aeromedical transport from the patient’s location to an interventional center. This has been an enormous step forward in improving time to treatment.