MedWire News: The weaker protection against stroke seen with beta blockers relative to other antihypertensive agents is confined to ischemic stroke, a study suggests.

“We also found that poor compliance with antihypertensive pharmacotherapy was an important risk factor in stroke development, for both ischemic and hemorrhagic type,” say Jung-Der Wang (National Taiwan University, Taipei) and colleagues.

The researchers studied a cohort of 29,759 patients with newly diagnosed uncomplicated hypertension, 1078 of whom suffered stroke during an average follow-up of 38.8 months.

Overall, and in contrast to previous studies, the risk for stroke did not differ according to the type of antihypertensive patients were taking. The increased stroke risk with beta blockers (by 27% relative to other antihypertensives) emerged only when the analysis was restricted to ischemic stroke.

“Our findings indicated that outcomes research might provide additional evidence for improving clinical guidelines, as the processes in randomized clinical trials might not be able to take care of all conditions in the daily practices of clinicians,” Wang et al comment in the Journal of Hypertension.

“For all types of stroke among these low-risk, uncomplicated hypertensive patients in our study, the control of their hypertension seemed to be a more important factor than the choice of antihypertensive agent.”

Based on prescription claim rates, patients were compliant with their medication regimen 42.1% of the time, on average. The risk for stroke increased with decreasing medication compliance, by 1.5, 1.8, and 1.9 fold for compliance of 40–69%, 20–39%, and less than 20%, compared with at least 70%.

Male gender, older age, and the presence of diabetes or heart disease also raised stroke risk, after accounting for confounders.

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