Ps-p06-11: late-onset hypertension as a contributing factor to the changes in the cha2ds2-vasc score and incident atrial fibrillation in the elderly

Background: Hypertension is closely associated with the risk of atrial fibrillation. However, hypertension is already prevalent in young adults, but atrial fibrillation usually only occurs in the elderly. In the present study, we investigated incident atrial fibrillation in relation to early- and late-onset hypertension in an elderly Chinese population. Methods: Our study participants were elderly (≧ 65 years) hypertensive residents, recruited from five community health centers in the urban area of Shanghai (n = 4161). Early- and late-onset hypertension were defined as the use of antihypertensive medication or elevated blood pressure (systolic/diastolic blood pressure ≧ 140/90 mmHg), respectively, at entry and during follow on at least 2 consecutive clinic visits. Atrial fibrillation was detected by a 30-second single-lead electrocardiography (ECG, AliveCor® Heart Monitor) and further evaluated with a regular 12-lead ECG. Results: During a median of 2.1 years follow-up, the incidence rate of atrial fibrillation was 7.60 per 1000 person-years in all study participants; it was significantly higher in patients with late-onset hypertension (n = 368) than those with early-onset hypertension (n = 3793, 15.76 per 1000 person-years vs. 6.77 per 1000 person-years, P = 0.007). After adjustment for confounding factors, the hazard ratio (HR) for the incidence of atrial fibrillation was 2.67 (95% confidence interval [CI] 1.04–6.87, P = 0.04) in patients with late-onset hypertension versus those with early-onset hypertension. The association was even stronger in those aged 75 years and over (HR 5.93, 95% CI 1.59–22.05, P = 0.008) and when patients with a duration of hypertension ≧ 5 years were considered as reference (HR 2.48, 95% CI 1.30–4.76, P = 0.006). Conclusions: Our study showed a significant association between late-onset hypertension and the incidence of atrial fibrillation in elderly Chinese.