Older Singles at Increased Risk for Acute Coronary Syndrome

AARHUS, Denmark, July 13 -- Living alone can have dire implications for the heart.

Women over age 60 and men older than 50 who live alone have a two- to three-fold higher risk for unstable angina, myocardial infarction, or sudden cardiac death, according to researchers here.

In a study of all residents of Aarhus ages 30 to 60, only 7.7% of the population was made up of men over age 50 living alone, but they accounted for two-thirds of all patients who died within 30 days of a diagnosis of the acute coronary syndrome, said Kirsten Melgaard Nielsen, Ph.D., and colleagues, of the Aarhus Sygehus University Hospital here.

Similarly, women older than 60 living alone constituted only 5.4% of the study cohort, but accounted for 34% of acute coronary syndrome patients dying within a month of diagnosis, the investigators reported in the August issue of the Journal of Epidemiology and Community Health.

"About one of three acute coronary syndrome patients will die within 30 days of the diagnosis. High age and single living are the strongest predictors of acute coronary syndrome," Dr. Nielsen and colleagues wrote.

"By use of comparatively simple information from a population register, groups with excessive high risk of acute coronary syndrome and high risk of dying from acute coronary syndrome are identifiable," they added. "Such groups may be targets for complementary high-risk preventive strategies, which may be comparatively cost-effective as they entail only small parts of the resident population."

The investigators took advantage of Denmark's comprehensive population and health care registries, which contain information on virtually every Danish resident from cradle to grave.

The goal of the study was to identify sociodemographic risk factors in the population that are associated with a first episode of acute coronary syndrome, including unstable angina, myocardial infarction, sudden cardiac death, or a combination.

They identified a total of 138,290 residents of Aarhus who were representative of 5% of the entire Danish population of men and women between the ages of 30 and 69. They collected information on the each cohort members' age, gender, social background, and cause of death, when appropriate.

From April 1, 2000, through March 31, 2002, there were 457 incident cases of acute coronary syndrome, and 189 sudden cardiac deaths in patients without a history of acute coronary syndrome.

On a multiple logistic regression analysis, the authors determined that age and single living were positively associated with incident acute coronary syndrome in both sexes, with women older than 60 and men older than 50 who were living alone at especially high risk.

"They constituted only 5.4% and 7.7% of the source population, respectively, but they accounted for 34.3% and 62.4% of acute coronary syndrome patients dying within 30 days," the authors wrote.

For women older than 60, the odds ratio for ACS, including sudden cardiac death, was 5.0 (95% confidence interval, 3.4-6.7, P<0.001), and for all women living alone the odds ratio was 2.3 (95% CI, 1.7-3.0, P<0.001).

For men older than 50, the odds ratio for acute coronary syndrome including sudden cardiac death was 7.9 (95% CI, 6.2 to 10.1, P<0.001), and for all men living alone the odds ratio was 2.9 (95% CI, 2.4-3.5, P<0.001).

People who live alone are more likely to have risk factors for acute coronary syndrome such as smoking, obesity, and high cholesterol, the authors suggested. In addition, people of solitary habitation have less frequent physician visits and fewer calls for emergency medical services, either because of reluctance or inability to call for help during an acute episode of illness. Some people may also be socially isolated because of their illnesses.

"Single living is associated with an increased risk of acute coronary syndrome," the authors wrote. "Thus, risk groups identified by use of information on their age and family structure may be targets for future more focused and cost effective preventive strategies."