While acute MI (AMI) occurs suddenly, patients who reach the hospital have a better chance of surviving compared with those who don’t; however, the fatal coronary events outside the hospital are increasing significantly, particularly among younger patients, according to a study in the Jan. 4/11 issue of Circulation.
“[I]t has been suggested that improved management of AMI has only contributed to a modest 6 to 8 percent improvement in observed survival trends,” the authors wrote. And while there has been a reported decrease in the number of patients affected by CHD [coronary heart disease], often those who experience a sudden fatal event without reaching the hospital are left out of the data.
To better understand the trends in cases associated with a fatal major coronary event that occurs out of hospital for these patients, Kerstin Dudas, PhD, of the University of Gothenburg in Göteborg, Sweden, and colleagues identified 384,597 cases of a first major coronary event (out-of-hospital coronary death or hospitalization for AMI) that occurred in Sweden from 1991 to 2006—111,319 patients died outside of the hospital, while 36,552 patients died within the hospital or within 28 days of hospitalization.
During the five-year span, the researchers reported that the number of major coronary events decreased from 30.5 percent to 25.6 percent. In addition, there was an even larger decrease in 28-day case fatality in hospitalized cases.
Dudas et al found that the out-of-hospital deaths to overall case fatality increased among younger individuals aged 35 to 54 years old, with no more than 10.8 percent of deaths occurring in hospitalized cases between 2003 and 2006. For those between the ages of 35 and 54, one in five did not survive their first major coronary event beyond 28 days. For those aged 75 to 84 years of age, the rate of those dying outside the hospital increased to 34.8 percent—one in two survived in the short term. One in four deaths occurred inside the hospital.
Older age and the female sex were associated with a lower risk of out-of-hospital death; however, with each successive calendar year, the risk increased.
The total rates of 28-day case fatality decreased by 4.1 percent, from 42.8 percent from 1991 to 1994 to 32.4 percent from 2003 to 2006. In addition, the number of hospitalized patients with AMI who died within 28 days decreased from 12.3 percent to 6.8 percent. Among those admitted to the hospital, the corresponding decrease in case fatality was from 17.7 percent to 9.1 percent.
Out-of-hospital case fatality decreased from 30.5 percent to 25.6 percent. And for patients who were under 55 years old, 15.7 percent died outside the hospital, while 1.9 percent died in the hospital.
Population mortality rates associated with a first-ever major coronary event in Sweden declined from 245 per 100,000 to 131 per 100,000 between 1991 and 2006. The researchers attributed this decline to a decrease in the rates of out-of hospital deaths that went from 169 to 106 per 100,000 and the rates of death that occurred within 28 days of hospitalization for AMI—from 76 per 100,000 to 25 per 100,000.
“There is a need for more knowledge about CHD deaths that occur out of the hospital,” the authors urged. “An increasing proportion of fatal coronary events occur in the out-of-hospital setting and beyond the reach of advanced hospital care. It is therefore of concern that the time from onset of chest pain to arrival at the hospital has not improved despite community education efforts.”
In addition, the authors offered that future efforts are needed to educate patients on the importance of seeking hospital treatment as soon as the symptoms of major coronary events occur.
The study was funded by the Swedish Heart and Lung Foundation, the Swedish Research Council and the Swedish Council for Working Life and Social Research.