Mortality rates are lowering due to appropriate treatment, lifestyle changes
According to the American Heart Association, about 250,000 Americans suffer an ST-elevation myocardial infarction, or STEMI, each year. These occur when a cholesterol plaque ruptures and a blood clot forms within an artery leading to the heart muscle, completely obstructing the flow of blood. A potentially large area of the heart may be affected by the resultant injury.
“We’ve come to realize the most direct way and the most expeditious way to treat a STEMI is to admit the patient directly to the cath lab” –Dr. Kevin Scully
“Unfortunately, a number of these patients die within the first hours of a ST-elevated myocardial infarction, usually from ventricular tachy arrhythmia,” said Dr. Kevin Scully with Lexington Cardiology at Baptist Health. “ST-elevated myocardial infarctions do the most damage and are associated with a high risk of sudden cardiac death.”
Because quick intervention can lessen damage done to the heart by a myocardial infarction, it is vitally important that a victim be transported to a hospital as soon as possible, preferably by ambulance.
“It’s better to summon EMS, have them assess the patient and make the diagnosis and appropriately triage and take the patient to the nearest facility that hopefully can do a coronary-based intervention,” Scully said.
While en route to the hospital, the patient can receive an EKG. These days, STEMI patients are usually taken directly to the heart cath lab where the attending cardiologist will put in a stent and open the occluded infarct-related artery.
“We’ve come to realize the most direct way and the most expeditious way to treat a ST-elevated myocardial infarction is to admit the patient directly to the cath lab,” Scully said. “We remove the clot and repair the ruptured plaque with balloon surgery or a stent, and that’s where our main focus is now.”
There is only a narrow window of time before the heart is irreparably damaged after a cardiac event.
“The goal with all of this is to attempt to keep the time from when the EMS arrives to the time they have a balloon opening up the occluded artery under 90 minutes,” Scully said. “That’s kind of a universal standard. Certainly the American College of Cardiologists and the American Heart Association have worked hard to really make sure that’s feasible and encourage that treatment.”
Any delay could lead to death at a later date from sudden cardiac arrest, Scully said. “We want to prevent all those long-term results if we can,” he said. “That’s why the emphasis is on trying to promptly recognize, diagnose and treat an ST-elevation myocardial infarction.”
Hospitals are graded on how well they are reaching that 90-minutes-or-less goal and how well they are doing all the appropriate triage, making appropriate diagnoses and providing appropriate treatment for STEMI patients.
“Without question, if you do that, you have excellent results and low mortality,” Scully said. “In the past, 15 to 20 percent of people with ST-elevated myocardial infarctions died even when they got to the hospital because we did not have effective methodology to limit the muscle damage. Then people developed subsequent heart damage and arrhythmias and things of that nature. Nowadays that mortality’s been reduced to around 4 to 5 percent.”
Scully said there are fewer incidences of STEMI these days. “A lot of that is due to hygienic measures: fewer people smoke, more people evaluate and treat their hypertension, more people are on statin drugs to lower their risk of their high cholesterol levels; more people are paying attention and appropriately exercising and working to control their diabetes mellitus,” he said. “All those appropriate therapeutic lifestyle changes have played a role. It’s always better if you have any symptoms that suggest myocardial infarction to promptly seek help and get evaluated.”
By Tanya J. Tyler, Associate Editor