People who suffered a stroke or transient ischemic attack (TIA or mini-stroke) were found to be at a high risk of suffering a second event for at least five years following their hospitalization.

Patients are usually considered to be at high risk of experiencing a subsequent stroke or mini-stroke for about 90 days following the original incident, but this new research suggest the risk window is much larger, the Heart and Stroke Foundation of Canada reported. The findings suggest these patients have almost a 10 percent risk of having a repeated stroke over the next year.

"This high long-term risk was surprising and shows that we need to develop better strategies and interventions for these patients to prevent as many of these serious problems as we can," said Dr. Richard Swartz, director of the University of Toronto stroke program and leader of the study.

To make their findings the researchers looked at 34,000 patients discharged from hospital following a stroke or TIA between the years of 2003 and 2011. Patients who passed away or had another serious medical event in the 90 days following their stroke were then excluded from the sample; about 30 percent of the patients were excluded through this method.

Out of the remaining 24,000 patients, 9.3 percent had a repeat stroke or TIA, had a major medical event (such as a heart attack), or died over the following years. Death was the most common event, and occurred in about 5.1 percent of the participants in the first year, the risk remained at 5 percent if the following four years.

"We now need to identify ways to determine which people, among those who have made it through the riskiest period, remain most at risk for serious events so we can develop appropriate preventive interventions," Dr. Swartz said.

The researchers have already developed a quick test that could be used to evaluate cognitive decline in stroke or TIA patients. The findings suggest patients who suffered this stype of event should be monitored for a period longer than 90 days.

"If it's not feasible, due to lack of resources, to follow patients longer in stroke clinics, we must do more to educate patients, their families and their family physicians and nurse practitioners to be more alert to the ongoing risks," said Ian Joiner, director of stroke for the Heart and Stroke Foundation. "Even those who seem to recover very well after a stroke or TIA must be followed closely."

The research was done at the Institute for Clinical Evaluative Sciences (ICES) using data from the Ontario Stroke Registry (formerly known as the Registry of the Canadian Stroke Network).