Chapter 7. Cerebrovascular Diseases
A 65-year-old right-handed woman with hypertension presented with a transient episode of inability to speak associated with right-sided weakness that resolved over a period of 2 hours. In the emergency department, her blood pressure (BP) was 180/95. Diagnostic neuroimaging revealed multiple subcortical old lacunar infarcts. Computed tomography (CT) angiogram of the head and neck showed high-grade stenosis of the left middle cerebral artery. Laboratory evaluations were significant for a low-density lipoprotein (LDL) level of 100 mg/dL and a hemoglobin A1c (HbA1c) of 5.5%. Which of the following is true regarding secondary stroke prevention in this patient?
(A) Ideal systolic blood pressure to achieve optimal secondary stroke prevention is between 120 and 140 mm Hg.
(B) Long-term treatment goal for blood pressure is 10 mm Hg reduction in systolic BP from the blood pressure measurement in the emergency department.
(C) LDL-cholesterol level less than 120 mg/dL or 20% reduction in LDL level from baseline should be sought.
(D) At least 1 hour of moderate-intensity physical exercise five times per week is recommended.
(E) Aggressive glycemic control will help to further reduce her risk of stroke.
(A) The patient in the vignette has marked hypertension. Hypertension is the single most important modifiable risk factor for both hemorrhagic and ischemic stroke. Studies have consistently shown a linear relationship between blood pressure and stroke risk such that no threshold exists where risk could not be further reduced. In prospective studies, every 10 mm Hg reduction in BP is associated with a 33% lowering of stroke risk in primary prevention. The PRoFESS trial reported that very low systolic BP (less than 120 mm Hg) after recent stroke was associated with increased risk of recurrent stroke compared with those with normal BP defined as 120 to 139 mm Hg. This data suggests that a goal BP of approximately 120 to 140 mm Hg (systolic) and 80 to 90 mm Hg (diastolic) may be ideal.
The patient in the vignette has a hemoglobin A1c (HbA1c) that is not consistent with a diagnosis of uncontrolled diabetes mellitus. Diabetes mellitus (DM) is currently defined as HbA1c greater than 6.5%. DM is a well-known risk for recurrent ischemic strokes (especially lacunar strokes). Although there is strong evidence that aggressive glycemic control reduces the microvascular complication of DM, aggressive glycemic control when the HbA1c is less than 6.5% has not been shown to demonstrate benefit.
Low-density lipoprotein (LDL)/cholesterol level lowering is the primary goal of dyslipidemia management following stroke. This is achieved primarily through the use of statins. A meta-analysis of statins in primary or secondary prevention of stroke found that for each ...