Following the Heart: The History of the J-Curve in Stroke Risk

Reports of a J-shaped relationship between blood pressure and ischemic stroke are rare. The purpose of this study was to trace the published history of the J-curve theory as it relates to blood pressure, ischemic heart disease and eventually ischemic stroke. The J-curve publications on the relationship between Diastolic Blood Pressure (DBP) and ischemic stroke suggest that in certain populations, such as older adults, or hypertensives, a threshold for lowering blood-pressure may exist and may warrant consideration in order to insure adequate cerebral perfusion and stroke prevention. The cerebrovascular mechanisms possibly at play as risk factors for ischemic stroke when DBP is reduced are large and small vessel ischemic disease, reduced baro-receptor reactivity, reduced vasomotor reactivity, and sluggish auto-regulatory mechanism. The optimal diastolic blood-pressure for ischemic stroke-risk reduction ranged between 65 and 85 mm Hg. DBP levels below (as well as above) that range were associated with increased risk. More studies are needed.