Antihypertensive drugs and relevant cardiovascular pharmacotherapies and the risk of incident dementia in patients with atrial fibrillation

Background: Atrial fibrillation (AF) and dementia are predominant among the elderly; patients with AF have an increased dementia risk. We aimed to study if prescribed antihypertensive drugs and cardiovascular pharmacotherapies are associated with a lower relative risk of dementia. Methods: All included patients were ≥45 years and diagnosed with AF in primary care; 12,096 (6580 men and 5516 women) in Sweden. We excluded patients with a dementia diagnosis before onset of AF. Cox regression was used (hazard ratios, HRs, and 95% confidence interval, CI) with adjustments for sex, age, socioeconomic factors and co-morbidities. Results: Incident dementia occurred in 750 patients (6.2%) during an average of 5.6 years of follow-up (a total of 69,214 person-years). Patients prescribed thiazides HR 0.81 (95% CI 0.66–0.99) and warfarin HR 0.78 (95% CI 0.66–0.92) had a lower risk of dementia than patients without these drugs. The use of 1–4 of the different antihypertensive drug classes (thiazides, beta blocker, vessel active calcium channel blockers or renin angiotensin aldosterone (RAAS) blockers) were associated with a reduction of incident dementia; HR 0.80 (95% CI 0.64–1.00) for one to two drugs, and HR 0.63 (95% CI 0.46–0.84) for three or four drugs, versus having no prescribed antihypertensive drugs. The combination of a RAAS-blocker and a thiazide was significant, HR 0.70 (95% CI 0.53–0.92), versus not having that particular combination prescribed, while RAAS-blockers or thiazides separately were not significant. Conclusion: Prescribed antihypertensive drugs, including thiazide/RAAS-blocker combination therapy and use of warfarin, were associated with a decreased incidence of dementia.