Acting Quickly is Essential After Heart Attack Symptoms Begin
Researchers found that the amount of time between the onset of heart attack symptoms and an artery-clearing percutaneous coronary intervention was an important target for public education efforts.
The longer the time between the onset of heart attack symptoms and an artery-clearing percutaneous coronary intervention (PCI), the more damage occurs to the heart muscle, according to new research published in Circulation: Cardiovascular Interventions.
With a heart attack occurring approximately every 40 seconds in the United States, the most common heart attack is caused by a complete blockage in a coronary artery, called ST-elevation myocardial infarction (STEMI). Patients with STEMI heart attacks are most often treated with PCI, also called an angioplasty with a stent, in order to clear the obstruction and restore blood flow.
“We know the time to opening the blocked coronary artery with PCI in heart attack patients is an important indicator for how a patient does after their heart attack,” said study author Gregg W. Stone, MD, director of academic affairs at Mount Sinai Heart Health System, in a press release. “There are 2 measures for this time. One is symptom-to-balloon time, which is before the patient arrives to the hospital after symptoms start, to when that patient has a PCI. [The] second is door-to-balloon time, the time from hospital arrival to PCI.”
Stone said their team focused on heart attack damage with both time measures and found that symptom-to-balloon time was more important. The investigators analyzed data from 10 randomized controlled trials that followed more than 3100 STEMI patients enrolled after PCI between 2002 and 2011. Patients’ hearts were assessed within 3 to 12 days after PCI to measure the size of their heart attack, and some studies also included measurements of ejection fraction.
According to the study, the investigators found that the median symptom-to-balloon time was 185 minutes whereas the median door-to-balloon time was 46 minutes, making symptom-to-balloon time approximately 80% of the total time from symptom onset to treatment of the artery. Notably, the size of the heart attack increased with longer symptom-to-balloon times, whereas longer door-to-balloon times were not significantly related to heart attack size.
“Health care teams have worked to reduce door-to-balloon times and are achieving excellent results with a median time of 46 minutes,” Stone said in the press release. “While we shouldn’t become complacent and relax our current standards of rapidly performing PCI as soon as possible after the patient reaches the hospital, this study suggests that major efforts to further shorten door-to-balloon times by 10 or 20 minutes might not translate to better PCI outcomes.”
Older age, female sex, arterial hypertension, diabetes, and left circumflex artery as the culprit vessel were associated with longer symptom-to-balloon times, according to the researchers. Furthermore, for every 60-minute delay in symptom-to-balloon time, the 1-year rate of death or hospitalization for heart failure was increased by 11%. In contrast, the study found no relationship between delays in door-to-balloon time and these clinical results.
“Our analysis indicates the more important and meaningful focus should be to shorten the delays from symptom onset to arrival at hospitals that can perform PCI,” Stone said. “We must emphasize efforts to increase public awareness of heart attack symptoms and shorten the time it takes for patients to access emergency care.”
American Heart Association President Mitchel S.V. Elkind, MD, MS, FAHA, FAAN, said these findings are very important and relevant right now, adding in the press release that the COVID-19 pandemic has had a huge impact on the number of patients presenting to emergency departments with heart attack symptoms.
“During the peaks of the COVID-19 impact, hospitals are reporting fewer people coming into the emergency room for heart attack and stroke symptoms—indicating people aren’t calling 911, or they are delaying or avoiding critical care,” Elkind said in the press release. “This concerns us because we know it’s very unlikely that there are fewer heart attacks or strokes occurring. These new findings emphasize just how crucial it is to call 911 at the first sign of a heart attack or stroke, because getting quick treatment can be the difference between life and death.”
Acting Quickly After Heart Attack Symptoms Start Can Be A Heart Saver [news release]. American Heart Association; January 14, 2021. https://newsroom.heart.org/news/acting-quickly-after-heart-attack-symptoms-start-can-be-a-heart-saver?preview=afde. Accessed April 20, 2021.