Could being married protect you from cardiovascular death?
Study leader Dr. Arshed Quyyumi, a professor of medicine at Emory University in Atlanta, GA, says that he was "somewhat surprised" by the strength of the influence of marital status on heart patients.
In a new paper published in the Journal of the American Heart Association, he and his team remark that while there is good evidence to suggest that divorced people are more likely to die prematurely, it is not clear whether marital status makes a difference to cardiovascular outcomes in people with heart disease.
They also point out that "the definition of unmarried status is not always clear despite noted differences in the divorced or separated, widowed, and never-married groups."
Heart disease is the number one cause of death worldwide, claiming a total of 17.3 million lives every year. This number is expected to exceed 23.6 million by 2030.
In the United States — where it is the leading cause of death for both men and women — heart disease kills around 610,000 people per year, accounting for 1 in every 4 deaths.
Often, the first time that people discover that they have heart disease is when they experience a heart attack. In the U.S., some 735,000 people have heart attacks every year.
Recruiting those with coronary artery disease
For their study, Dr. Quyyumi and colleagues investigated 6,051 adult patients with "suspected or confirmed coronary artery disease" who had undergone cardiac catheterization, which is a diagnostic procedure for examining how well the heart is functioning.
The average age of the participants — 23 percent of whom were black and 64 percent were male — was 63 years. They underwent the heart procedure between 2003 and 2015, and they were followed for between 1.7 and 6.7 years, with most being followed for around 3.7 years.
When they underwent cardiac catheterization, 70 percent of the patients were diagnosed to have blockages, or obstructive coronary artery disease, and 8 percent presented with heart attack.
From information gathered in telephone interviews and medical records, the researchers found that 18 percent of the patients had died from all causes over the follow-up period, 11 percent had died from cardiovascular-related causes, and 4.5 percent had had heart attacks.
From questionnaires that the study participants had filled in at the outset, the scientists were able to determine that 68 percent of them were married, 14 percent were divorced or separated, 11 percent were widowed, and 7 percent had never married.
First to look at different unmarried groups
The primary outcome that Dr. Quyyumi and colleagues measured was the combined incidence of cardiovascular death or heart attack. They also analyzed two secondary outcomes: death from all causes, and cardiovascular death on its own.
They defined cardiovascular death as death that is caused by an "ischemic" event — including, for example, fatal heart attacks or strokes that result from restricted blood supply.
A statistical analysis of the data showed that the risk of dying during the follow-up was higher in the unmarried people than in the married ones.
Specifically, being unmarried was linked to a 24 percent increased risk of dying from any cause, a 45 percent increased risk of dying from cardiovascular disease, and a 52 percent increased risk of cardiovascular death or heart attack.
Further analysis of the risk of cardiovascular death or heart attack among the unmarried patients revealed that the risk was highest for those who had been widowed (71 percent higher), followed by those who had been divorced or separated (41 percent higher) and those who were never married (40 percent higher).
Doctors should consider marital status
The increased risks remained significant "even after extensive adjustment" to take into account other factors that might have an influence on the results, such as disease severity, use of medication, and socioeconomic status.
The team believes that its study is the first to specifically show that the risk of death in widowed, divorced, separated, or never-married patients with suspected or confirmed coronary artery disease is higher than in married patients.
But the researchers also point out that their study has some limitations and should be treated with caution.
For example, the data only covered patients treated at one medical facility, and also, there were no checks during the follow-up of changes in patients' marital status. There was also no account taken of whether or not patients were cohabiting.
Nevertheless, they suggest that perhaps clinicians ought to take into account marital status when deciding treatment and care of those with coronary artery disease.
They also call for further studies to find out whether "more aggressive treatment strategies" can reduce these risks for unmarried heart patients.
In this group of participants, compared with married people, those who were unmarried were more likely to be black women with high blood pressure, high cholesterol, or heart failure and less likely to smoke.
"Social support provided by marriage, and perhaps many other benefits of companionship, are important for people with heart disease."
Dr. Arshed Quyyumi