Beijing, China—Could a remedy to help hypertensive adults with a low platelet count avoid a first stroke be sitting on drugstore shelves?

A study published online by the Journal of the American College of Cardiology suggests that could be the case. It reports that those patients who took a combined daily pill of both folic acid and enalapril realized a 73% reduction in their risk of first stroke versus patients who took only enalapril daily.

An earlier published report from the China Stroke Primary Prevention Trial (CSPPT) determined that folic acid treatment could reduce first stroke risk by 21% on average in hypertensive adults by lowering total homocysteine levels; elevated levels are a risk factor for vascular disease. The current study from Chinese researchers is touted as the first and largest of its kind to examine the possible effects of elevated homocysteine levels and platelet count together on first stroke.

For the study, researchers analyzed 10,789 CSPPT participants, i.e., men and women aged 45 to 75 years who had hypertension or were on antihypertensive medication, dividing them into two groups. Excluded were patients with a history of stroke or other major cardiovascular diseases.

Participants were randomly assigned to either a combined daily oral dose of 10-mg enalapril and 0.8-mg folic acid, or, in the second group, to a daily dose of enalapril only.

Over the median follow-up period of 4.2 years, 210 first strokes occurred in the enalapril-only group, and 161 first strokes in the enalapril-folic acid group.

“Our analysis has shown that baseline low platelet count and elevated homocysteine can jointly increase the risk of first stroke,” explained senior author Yong Huo, MD, director of the Heart Center of Peking University First Hospital in China. “If the findings are further confirmed by prospective trials, we can raise the prospect that we can identify patients at high risk of developing first stroke by measuring both platelet and homocysteine, and we can remarkably lower stroke risk among this subgroup of patients with folic acid—a simple, safe and inexpensive treatment.”

The risk of first stroke dropped from 5.6% to 1.8% among patients with low platelet count and high homocysteine levels, according to the report, but folic acid had no apparent effect among those with high platelet count and low homocysteine levels.

Writing in an accompanying editorial, J. David Spence, MD, director of the Stroke Prevention and Atherosclerosis Research Centre at Robarts Research Institute in Canada, and Vladimir Hachinski, CM, MD, DSc, a professor at Western University, note, “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.

“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,” Spence and Hachinski add.