Effects of 'mini stroke' can shorten life expectancy

"People experiencing a TIA won't die from it, but they will have a high risk of early stroke and also an increased risk of future problems that may reduce life expectancy," said Melina Gattellari, Ph.D., senior lecturer at the School of Public Health and Community Medicine in The University of New South Wales, Sydney and Ingham Institute in Liverpool, Australia.

"Our findings suggest that patients and doctors should be careful to intensely manage lifestyle and medical risk factors for years after a transient ischemic attack."

The statistical analysis is the first to comprehensively quantify the impact of hospital-diagnosed TIA on life expectancy.

Researchers identified 22,157 adults hospitalized with a TIA from July 2000 to June 2007 in New South Wales, Australia, and tracked their medical records for a minimum two years (median 4.1 years). They gathered death registry data for the area through June 2009 and compared death rates in the study population to those in the general population. Median ages were 78 for female patients and 73 for male patients; 23.9 percent were younger than 65 and 19.4 percent were older than 85.

At one year after hospitalization, 91.5 percent of TIA patients were still living, compared to 95 percent expected survival in the general population. At five years, survival of TIA patients was 13.2 percent lower than expected -- 67.2 percent were still alive, compared to an expected survival of 77.4 percent.

By the end of the study, at the nine-year mark, survival of TIA patients was 20 percent lower than expected.

Increasing age was associated with an increasing risk of death compared to the matched population. TIA had only minimal effect on patients younger than 50, but significantly reduced life expectancy in those older than 65. Compared to patients younger than 50, relative risk of death for patients 75-84 was 7.77 times higher and 11.02 times higher for those 85 and older.

"We thought the reverse may be true -- that survival rates in older TIA patients would be more like other older people, who, although not affected by TIA, are affected by other conditions that may influence their survival," Gattellari said. "But even a distant history of TIA is major determinant of prognosis; certainly, the risks faced by TIA patients go well beyond their early stroke risk."

Researchers also examined TIA patients' medical records for other common health risks:

• Congestive heart failure was associated with 3.3 times more risk of dying.
• Atrial fibrillation was associated with twice the risk of dying.
• Prior hospitalization for stroke meant 2.63 times the risk of dying compared to patients without it; further, this effect grew over time, peaking at 5.01 times more risk three years after TIA admission.

In general, adults with a history of TIA can maximize their chances of living a long life by adopting healthy lifestyle habits, such as exercising daily, maintaining a healthy weight, quitting smoking and eating healthy, Gattellari said.

Co-authors are Chris Goumas, M.P.H.; Frances Garden, M.Biost.; and John M. Worthington, M.B.B.S. Author disclosures are on the manuscript.The Clinical Excellence Commission and the Commonwealth Department of Health and Ageing partly funded the study.