UPFRONT | News and events HEART HEALTH Acting quickly after heart attack symptoms start can be a heart saver The longer the time between when heart attack symptoms start and a patient has an artery-clearing percutaneous coronary intervention (PCI), the more damage to the heart muscle, according to new research published in Circu-lation: Cardiovascular Inter-ventions, an American Heart Association journal. A heart attack happens about every 40 seconds in the U.S., and the most common heart attack is caused by a complete blockage in a coro-nary artery, called ST-eleva-tion myocardial infarction (STEMI). STEMI patients are most often treated with PCI, also known as angio-plasty with stent, in which a catheter with a deflated bal-loon is inserted into the narrowed heart artery. Sub-sequently, the balloon is in-flated, which clears the ob-struction and restores blood flow. A stent is then inserted to keep the artery open. “We know the time to opening the blocked coro-nary artery with PCI in heart attack patients is an impor-tant indicator for how a pa-tient does after their heart attack. There are two meas-ures 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; second is door-to-balloon time, the time from hospital arrival to PCI,” said study author Gregg W. Stone, M.D., direc-tor of academic affairs at Mount Sinai Heart Health System in New York City. “We focused on heart attack size, or damage, with both time measures and found symptom-to-balloon time was by far the more impor-tant.” Stone and colleagues ana-lyzed the data from 10 rand-omized controlled trials that followed more than 3,100 STEMI patients enrolled after PCI between 2002-2011. Patients’ hearts were assessed within between 3-12 days after PCI to measure the size of the heart attack, and some studies also in-cluded measures of ejection fraction (a measure of the percentage of blood the heart is able to pump with each contraction) and TIMI flow (a measure of blood flow in the coronary artery). All pa-tients had clinical follow-up data for at least six months, with a median follow-up of 341 days after PCI. The study found: • Symptom-to-balloon time was more strongly associ-ated with heart attack size and patients’ clinical health after heart attack than door-to-balloon time. • The median symp -tom-to-balloon time was 185 minutes. The median door-to-balloon time was 46 minutes. • Symptom-to-balloon time represented approximately 80% of the total time from symptom onset to treat-ment of the artery. • The size of the heart attack increased with longer symptom-to-balloon times, whereas longer door-to-balloon times were not notably related to heart attack size. • Older age, female sex, ar-terial hypertension, diabe-tes and left circumflex ar-tery as the culprit vessel were associated with longer symptom-to-bal-loon time. • For every 60-minute delay in symptom-to-balloon time, the one-year rate of death or hospitalization for heart failure was increased by 11%. In contrast, there was no relationship be-tween delays in door-to-balloon time and these clinical results. “Health care teams have worked to reduce door-to-balloon times and are achiev-ing excellent results with a median time of 46 minutes. 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 out-comes,” Stone said. “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. We must emphasize efforts to increase public awareness of heart attack symptoms and shorten the time it takes for patients to access emergency care.” These findings are ex-tremely important and par-ticularly relevant right now, said American Heart Associ-ation president Mitchell S.V. Elkind, M.D., M.S., FAHA, FAAN, professor of neurol-ogy and epidemiology at Vagelos College of Physicians and Surgeons. “During the peaks of the COVID-19 pandemic, hospi-tals are reporting fewer peo-ple coming into the emer-gency room for heart attack and stroke symptoms --indi-cating people aren’t calling 911, or they are delaying or avoiding critical care,” Elkind said. “This concerns us be-cause we know it’s very un-likely that there are fewer heart attacks or strokes oc-curring. These findings em-phasize how crucial it is to call 911 at the first sign of a heart attack or stroke – quick treatment can be the differ-ence between life and death.” Among the limitations of this analysis, detailed infor-mation about the intensity of chest pain or other heart at-tack signs and symptoms, or about the time from symp-tom onset to PCI was not available from the clinical trials’ data. Journal Reference: Björn Redfors, Reza Mohebi, Gennaro Giustino, Shmuel Chen, Harry P. Selker, Hol-ger Thiele, Manesh R. Patel, James E. Udelson, E. Mag-nus Ohman, Ingo Eitel, Christopher B. Granger, Akiko Maehara, Ziad A. Ali, Ori Ben-Yehuda, Gregg W. Stone. Time Delay, Infarct Size and Microvascular Ob-struction After Primary PCI for ST-Segment Elevation Myocardial Infarction. Cir-culation: Cardiovascular In-terventions, 2021; DOI: 10.1161/CIRCINTERVEN-TIONS.120.009879 — American Heart Association. www.Cndoctor.ca 8 Chiropractic and Naturopathic Doctor January/Febuary 2021
Chiropractic + Naturopathic Doctor January-February 2021: Page 8
