Failure to take blood pressure-lowering medicines as directed greatly increases the risk of stroke and death in patients with high blood pressure, a new study finds.
"These results emphasize the importance of hypertensive [high blood pressure] patients taking their antihypertensive medications correctly in order to minimize their risk of serious complications such as fatal and non-fatal strokes," said study first author Dr. Kimmo Herttua, a senior fellow in the Population Research Unit at the University of Helsinki in Finland.
"Non-adherent patients have a greater risk even 10 years before they suffer a stroke. We have also found that there is a dose-response relationship, and the worse someone is at taking their antihypertensive therapy, the greater their risk," Herttua said.
For the study, published online July 17 in the European Heart Journal, researchers followed more than 73,000 hypertensive Finnish patients, aged 30 and up, from 1995 through 2007. They looked at how often prescriptions were filled for these patients each year to determine if they followed their medication regimens. During this time, more than 2,100 died from stroke and more than 24,500 were hospitalized with a stroke.
Compared to those who followed their medication schedule, patients who did not adhere to the schedule had nearly four times the risk of dying from a stroke in the second year after being prescribed their medicines and three times the risk in the 10th year.
In the actual year that non-adherent patients died from stroke, they had a 5.7-fold higher risk than adherent patients, the study found.
Patients who didn't take their blood pressure-lowering medications correctly had a 2.7-fold higher risk of hospitalization in the second year after being prescribed the drugs, and a nearly 1.7-fold higher risk in the tenth year, the study also found.
In the actual year that non-adherent patients were hospitalized with stroke, they had nearly twice the risk compared to adherent patients.
"As far as we know, this study is unique as it is the first study to follow patients over a long period of time, repeatedly checking how correctly they are taking their medications, and linking the trajectory of adherence with the risk of fatal and non-fatal stroke," Herttua said in a journal news release.
Blood pressure refers to the force of blood pushing against your artery walls. Over time, elevated blood pressure can cause serious problems.
The study had some limitations. The researchers couldn't be sure that patients were actually taking their drugs even though they had picked them up, and the registries did not offer information on body mass index (a calculation of body fat), smoking, alcohol consumption and resting blood pressure.