Those who had never been married had a heightened risk of dying from both heart disease (42 percent) and stroke (55 percent).
Divorce was associated with a 35 percent higher risk of developing heart disease for both men and women.
And widowed individuals were 16 percent more likely than married men or women to have a stroke, likely a result of stress-related theory, which suggests that losing a partner may have a negative impact on the emotional, behavioral and economic well-being of an individual.
Researchers reported no difference in the risk of death following a stroke between married and unmarried individuals. However, risk of death after a heart attack was significantly higher (42 percent) among those who had never married.
"Social causation theory suggests that individuals benefit from spousal support," study authors wrote. "For example, living with another person allows earlier recognition and response to warning symptoms, especially if a myocardial infarction becomes instantly disabling."
Studies have shown that unmarried patients had longer delays when seeking help, authors wrote in the report. These individuals are also twice as likely not to take prescribed medications, the strongest predictor of better outcomes.
Furthermore, greater financial resources from homes with dual incomes make quality healthcare more accessible.
The researchers note that there was no information on same sex partnerships or marriage quality in their report. The meta-analysis didn’t explore unmarried individuals living with someone, either.
Future work, the authors suggest, should focus on whether being married is a “surrogate marker” of other health conditions or whether marital status should be considered a risk factor alone.
Heart disease is the leading cause of death in the United States for both men and women, according to the Atlanta-based Centers for Disease Control and Prevention. Approximately 610,000 people die of heart disease in the country every year–that's 1 in every 4 deaths.
More than 350,000 Americans who may or may not have diagnosed heart disease suffer a cardiac arrest each year in areas other than a hospital. And about 90 percent of them die.