Risk factors should also be targeted in every case. Hypertension should be treated with a goal of lower than 140/90 mm Hg (or 130/80 mm Hg in diabetics and those with renal disease). Studies have shown that patients who are discharged with a blood pressure lower than 140/90 mm Hg are more likely to maintain this blood pressure at one-year follow-up.16 The choice of medication is less well studied, but drugs that act on the renin-angiotensin-aldosterone system and thiazides are generally preferred.15 Treatment with a statin is recommended after cerebrovascular ischemic events, with a goal LDL under 100. This reduces risk of secondary stroke by about 20%.17
(click for larger image)Table 3. Risk reduction goals and benefits
At discharge, it is also important to counsel patients on their role in preventing strokes. As with many diseases, making lifestyle changes is key to stroke prevention. Encourage smoking cessation and an increase in physical activity, and discourage heavy alcohol use. The association between smoking and the risk for first stroke is well established. Moderate to high-intensity exercise can reduce secondary stroke risk by as much as 50%18 (see Table 3). While light alcohol consumption can be protective against strokes, heavy use is strongly discouraged. Emerging data suggest obstructive sleep apnea (OSA) may be another modifiable risk factor for stroke and TIA, so screening for potential OSA and referral may be needed.15
Back to the Case
When Mr. G arrived at the ED, his symptoms had resolved. Based on the history of expressive aphasia and right-sided weakness, he most likely had a TIA in the left MCA territory. Hemorrhage was ruled out with a non-contrast head CT. His pacemaker precluded obtaining an MRI. CTA revealed diffuse atherosclerotic disease without evidence of carotid stenosis. His ABCD2 score was six given his age, blood pressure, weakness, and symptom duration, and he was admitted for an expedited workup. His sodium and glucose were within normal limits. His hemoglobin A1c was 6.5%, his LDL was 120, and his international normalized ratio (INR) was therapeutic at 2.1. His TIA may have been due to AF, despite a therapeutic INR, because warfarin does not fully eliminate the stroke risk. It might also have been caused by intracranial atherosclerosis.
Two days later, the patient was discharged on atorvastatin at 80 mg, and his lisinopril was increased for blood pressure control. For his age group, A1c of 6.5% was acceptable, and he was not initiated on glycemic control.
Bottom Line
TIAs are diagnosed based on patient history. Urgent initiation of secondary prevention is important to reduce the short-term risk of stroke and should be implemented by the time of discharge from the hospital.
Dr. Zeng is a hospitalist in the department of internal medicine at Vanderbilt University Medical Center in Nashville, and Dr. Douglas is associate professor in the department of neurology at the University of California at San Francisco.