Hypertensive adults with low platelet count who took a combined daily pill of both enalapril and folic acid saw a 73 percent reduction in their risk of first stroke compared to patients who took only enalapril daily, according to a study published May 7 in the Journal of the American College of Cardiology.

Xiangyi Kong, MD, et al., analyzed 10,789 participants from the China Stroke Primary Prevention Trial. Subjects were aged 45 to 75 years old and had hypertension or were on anti-hypertensive medication. The study excluded patients with a history of stroke or other major cardiovascular diseases. Participants were randomly assigned into two groups. In the first group, 5,408 patients received a combined daily oral dose of 10 mg enalapril and 0.8 mg folic acid, and in the second group, 5,381 patients received a daily dose of only the enalapril.

Among the total number of participants, 371 first strokes took place over a median follow up of 4.2 years. A total of 210 first strokes occurred in the enalapril-only group and 161 first strokes in the enalapril-folic acid group. The risk of first stroke reduced from 5.6 percent to 1.8 percent among patients with low platelet count and high homocysteine levels, creating a 73 percent risk reduction. However, the folic acid had no effect among those with high platelet count and low homocysteine levels.

According to the researchers, these findings show that baseline low platelet count and elevated homocysteine may jointly increase the risk of first stroke. They conclude that physicians can identify hypertensive adults at particular high risk of stroke and incorporate a folic acid supplement tailored to individual genetic, nutritional and clinical characteristics.

In an accompanying editorial, J. David Spence, MD, and Vladimir Hachinski, MD, note that, "Patients with lower platelet counts and higher homocysteine levels are more likely to have been at higher risk because they had vitamin B12 deficiency. Among folate-replete subjects, the main nutritional determinant of high homocysteine levels is B12 deficiency."

They further explain that, "the widespread belief that B vitamins do not reduce the risk of stroke is mistaken. This study not only invited confirmation of the benefit of B vitamins, but opens the door to wider applications."

Keywords: Vitamin B Complex, Folic Acid, Antihypertensive Agents, Enalapril, Platelet Count, Homocysteine, Hypertension, Dietary Supplements, Vitamin B 12 Deficiency, Stroke, Primary Prevention, Risk Reduction Behavior, China

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