Stroke Risk

Special MRI scan could identify stroke risk in people with atrial fibrillation

Howard LeWine, M.D.

Chief Medical Editor, Harvard Health Publishing

Atrial fibrillation is a heart rhythm disorder that affects millions of people. It can lead to potentially disabling or deadly strokes. Researchers from Johns Hopkins University School of Medicine adding motion-tracking software to standard MRI heart scans of 149 men and women with atrial fibrillation. The scans revealed specific changes in the muscles of the left atrium that increased stroke risk in some of the volunteers. These changes were not associated with age or other risk factors for stroke. This could help many people with this condition to avoid taking warfarin or other clot-preventing medications for life. But it is much too early to include MRI as part of the standard evaluation of people with atrial fibrillation — not to mention that such scans would significantly increase the cost of these evaluations. For now, doctors will continue to use standard tools to help determine stroke risk.

Bleeding risk from new blood thinner Pradaxa higher than first reported

Howard LeWine, M.D.

Chief Medical Editor, Harvard Health Publishing

The FDA’s approval in 2010 of the blood-thinner dabigatran (Pradaxa) got many doctors excited. It was at least as effective as warfarin for preventing stroke-causing blood clots, and possibly caused fewer bleeding side effects. In addition, it is easier to use. Since then, studies of Pradaxa have slightly dampened the enthusiasm for the new drug. For example, a new study from the University of Pittsburgh showed that Pradaxa cause more episodes of serious bleeding (9%) than warfarin (6%). The bleeding sites tended to differ. Bleeding in the stomach and intestines was slightly higher among Pradaxa users. Bleeding in the head was slightly higher among warfarin users. Black patients and those with chronic kidney disease were more likely to bleed from Pradaxa.

Flu shot linked to lower heart attack, stroke risk

Getting the flu shot may do more than protect against the flu and its lingering aftermath. It also lowers a person’s odds of a having heart attack, stroke, heart failure, or other major cardiac event—including death—by about a third over the following year. What’s the connection between flu and cardiovascular problems? The body mounts an impressive immune response against the flu. That causes a lot of inflammation, which destabilizes cholesterol-filled plaque inside blood vessels. Plaque rupture can cause a heart attack or stroke. Experts recommend a flu shot for everyone six months of age and older. It is especially important for those who face the highest risk of complications: young children; adults over age 50; those of all ages with serious health conditions such as cardiovascular disease, asthma or other lung disease, liver or kidney disease, or diabetes; and those who care for young children or other individuals at high risk of flu complications.