Strokes can be either ischemic or hemorrhagic in nature. Ischemic strokes may occur due to narrowing of the cerebral vessels, secondary to calcification, and, among prevalent dialysis patients in 2011, were much more common than hemorrhagic strokes.
Unlike admission rates for other diagnoses of cardiovascular disease, those for stroke have clearly decreased, with no interference wrought by the advent of MS-DRGs. In both the incident and prevalent dialysis patient populations, rates have decreased by 20 percent or more. Because of the catastrophic nature of stroke and its consequences on physical function and quality of life, this decline is an important sign of progress. Regional variation in the incidence of stroke has been also limited. Particularly striking is the decline in incidence of stroke during the first year of dialysis among incident patients in the East South Central area, which includes most of the so-called Stroke Belt states; there, the first-year admission rate for stroke was cut in half between 2003 and 2010.
Among incident dialysis patients, the admission rate for stroke declined during the entire first year of dialysis between 2003 and 2010, with a particularly large decrease during the second month of dialysis. It remains true, however, that the risk of stroke is elevated during the first three months of dialysis, relative to the remainder of the first year. Early stroke is therefore a possible target for quality improvement.
Seasonality is not apparent in the incidence of stroke among prevalent dialysis patients, although epidemiologic studies have suggested that ischemic strokes and hemorrhagic strokes may follow different seasonal patterns, with the risk of hemorrhagic stroke actually peaking during the spring season.
Regarding hemorrhagic stroke specifically, there are some published data suggesting iatrogenic risk associated with warfarin exposure, particularly among patients with atrial fibrillation. Little is known about regional and facility-level variation in the use of warfarin and novel oral anticoagulants; use of the latter remain rare, but may grow in coming years, as randomized trials of their use in hemodialysis patients are completed.