"I had not expected that unsuccessful marriage would be of this statistical importance," said Goldbourt, a professor of epidemiology and preventive medicine at Tel Aviv University in Israel.

The new research has several limitations, he said, including a lack of data on nonfatal vs. fatal strokes and on participants' medical treatment after the first five years of the initial study. Women also weren't included.

While the effects of marital status and success may be similar in women, "there are still differences, and research on women is clearly needed," Goldbourt said.

The research is a snapshot of Israel from more than four decades ago, he said. "How much this reflects associations between being happily or relatively happily married and stroke-free survival in other populations, at later times, is not readily deduced."

Author disclosures can be found on the abstract.

Source: American Heart Association