Use of antihypertensive medication and formation of de novo intracranial aneurysms

Background and purpose: Hypertension is a risk factor for subarachnoid hemorrhage and is also considered a risk factor for saccular intracranial aneurysm (sIA) formation. However, there is little direct evidence that antihypertensive medication will reduce sIA formation. Methods: The impact of antihypertensive medication on de novo sIA formation was studied in an angiographically followed cohort of 1419 patients. Patients were identified from our population-based Kuopio Intracranial Aneurysm Database, and data on the purchases of antihypertensive medication were obtained from a national registry. Univariate and multivariate analyses were used to investigate the risk factors. Results: Of the 966 sIA patients who were prescribed with antihypertensive medication, 841 patients used the medication regularly; 20 of them had de novo sIA. One hundred and twenty-five patients used the medication irregularly and 12 of them developed de novo sIAs. Four hundred and fifty-three patients did not use antihypertensive medication even though 27 of them had a diagnosis of hypertension, and 10 of them developed de novo sIAs. In the multivariate analysis antihypertensive medication did not significantly reduce de novo sIA formation (hazard ratio [HR] 1.60, 95% confidence interval [CI] 0.84–3.06). Age at primary diagnosis (HR: 0.95, 95%: CI 0.93–0.98) and smoking history (HR: 5.53, 95% CI: 2.77–11.05) were significant risk factors for de novo sIA formation. Also, irregular usage of antihypertensive medication was a significant risk factor (HR: 3.84, 95% CI: 1.59–9.29) for de novo sIA formation. Conclusions: Antihypertensive agents were not associated with a reduction of de novo sIA formation, but irregular use of antihypertensive agents was associated with an increased risk of de novo sIA formation.