The prevalence, incidence, management and risks of atrial fibrillation in an elderly Chinese population: a prospective study.

BACKGROUND: There is limited information on prevalent and incident atrial fibrillation in Chinese. We aimed to investigate the prevalence, incidence, management and risks of atrial fibrillation in an elderly Chinese population. METHODS: In a population--based prospective study in elderly (≥ 60 years) Chinese, we performed cardiovascular health examinations including a 12-lead electrocardiogram at baseline in 3,922 participants and biennially during follow-up in 2,017 participants. We collected information on vital status during the whole follow-up period. RESULTS: The baseline prevalence of atrial fibrillation was 2.0 % (n = 34) in 1718 men and 1.6 % (n = 36) in 2204 women. During a median 3.8 years of follow-up, the incidence rate of atrial fibrillation (n = 34) was 4.9 per 1000 person-years (95 % confidence interval [CI], 3.4-6.9). In univariate analysis, both the prevalence and incidence of atrial fibrillation were higher with age advancing (P < 0.0001) and in the presence of coronary heart disease (P ≤ 0.02). Of the 104 prevalent and incident cases of atrial fibrillation, only 1 (1.0 %) received anticoagulant therapy (warfarin). These patients with atrial fibrillation, compared with those with sinus rhythm, had significantly higher risks of all-cause (n = 261, hazard ratio [HR] 1.87, 95 % CI, 1.09-3.20, P = 0.02), cardiovascular (n = 136, HR 3.78, 95 % CI 2.17-6.58, P < 0.0001) and stroke mortality (n = 44, HR 6.31, 95 % CI 2.81-14.19, P = 0.0003). CONCLUSIONS: Atrial fibrillation was relatively frequent in elderly Chinese, poorly managed and associated with higher risks of mortality.

Brachial-ankle pulse wave velocity as a predictor of mortality in elderly Chinese.

Pulse wave velocity (PWV) is a measure of arterial stiffness and predicts cardiovascular events and mortality in the general population and various patient populations. In the present study, we investigated the predictive value of brachial-ankle PWV for mortality in an elderly Chinese population. Our study subjects were older (≥60 years) persons living in a suburban town of Shanghai. We measured brachial-ankle PWV using an automated cuff device at baseline and collected vital information till June 30, 2013, during follow-up. The 3876 participants (1713 [44.2%] men; mean [±SD] age, 68.1±7.3 years) included 2292 (59.1%) hypertensive patients. PWV was on average 17.8 (±4.0) m/s and was significantly (P<0.0001) associated with age (r=0.48) and in unadjusted analysis with all-cause (n=316), cardiovascular (n=148), stroke (n=46), and noncardiovascular mortality (n=168) during a median follow-up of 5.9 years. In further adjusted analysis, we studied the risk of mortality according to the decile distributions of PWV. Only the subjects in the top decile (23.3-39.3 m/s) had a significantly (P≤0.003) higher risk of all-cause mortality (hazard ratio relative to the whole study population, 1.56; 95% confidence interval, 1.16-2.08), especially in hypertensive patients (hazard ratio, 1.86; 95% confidence interval, 1.31-2.64; P=0.02 for the interaction between PWV and hypertension). Similar trends were observed for cardiovascular, stroke, and noncardiovascular mortality, although statistical significance was not reached (P≥0.08). In conclusion, brachial-ankle PWV predicts mortality in elderly Chinese on the conditions of markedly increased PWV and hypertension.

A functional common polymorphism of the ABCB1 gene is associated with chronic kidney disease and hypertension in Chinese.

BACKGROUND: Permeability glycoprotein is encoded by the ATP-binding cassette B1 gene (ABCB1) and is an extruder of toxic metabolites in the kidney. A functional common polymorphism (C3435T, rs1045642) in the human ABCB1 gene has been found to be associated with allograft outcome in kidney transplant patients. In this study, we investigated the association of the C3435T polymorphism with renal function and blood pressure (BP) in 2 Chinese populations. METHODS: The discovery and replication populations were recruited from a mountainous area (Zhejiang Province) and a newly urbanized suburban area (Shanghai), respectively. We genotyped all subjects using the ABI SNapShot method. Chronic kidney disease (CKD) was defined as an estimated glomerular filtration rate <60 ml/min × 1.73 m(2) or 24-hour urinary albumin excretion ≥30 mg. RESULTS: In the discovery population of 1,987 subjects, after adjustment for covariables, TT homozygosity (n = 217) was associated with a higher risk of CKD (n = 369; odds ratio (OR) = 1.73; P = 0.003) and with higher systolic BP (+3.1 mm Hg; P = 0.03) and pulse pressure (+3.4 mm Hg; P = 0.001). These associations were dependent on age (Pint ≤ 0.05). In subjects aged ≥60 years (n = 374), the corresponding OR or difference was 2.40 for CKD, 15.1 mm Hg for systolic BP, and 12.4 mm Hg for pulse pressure (P < 0.001). In similar adjusted analyses in the replication population of 2,427 elderly (≥60 years) subjects, TT homozygosity was also associated with a higher risk of CKD (OR = 1.39; P = 0.02) and an enhanced association of hypertension with CKD (OR = 1.50; P = 0.04). CONCLUSIONS: The ABCB1 C3435T polymorphism might predict CKD, especially in the elderly.

Prevalence, awareness, treatment and control of hypertension in elderly Chinese.

We studied the prevalence, awareness, treatment and control of hypertension in an elderly Chinese population. The study subjects (age ≥60 years) were recruited from a suburban town of Shanghai from 2006 to 2008. We administered a standardized questionnaire to collect information on medical history, the use of medications and lifestyle. We measured blood pressure three times consecutively using a validated Omron 7051 oscillometric device (Kyoto, Japan) after the subjects had rested for at least 5 min in the sitting position. We defined hypertension as a blood pressure of at least 140 mm Hg systolic or 90 mm Hg diastolic or as the use of antihypertensive drugs. The 3949 participants (mean age of 68.3 years) included 2185 (55.3%) women, 182 (4.6%) obese subjects (body mass index ≥30 kg m(-2)) and 366 (9.3%) diabetic patients. The prevalence of hypertension was 59.4%. In the 2345 hypertensive patients, the awareness, treatment and control (<140/90 mm Hg) rates were 72.5%, 65.8% and 24.4%, respectively. In the 1542 treated hypertensive patients, 1196 (77.6%) used fixed-dose combinations of thiazide and reserpine or clonidine (n=1157, 75.0%) or of an angiotensin receptor blocker and hydrochlorothiazide (n=1) or free combinations (n=38, 2.5%), and 346 (22.4%) used a monotherapy of short-acting calcium channel blockers (n=217, 14.1%) or other classes of antihypertensive drugs (n=129, 8.3%). The corresponding control rates were 37.3% and 36.4%, respectively. In a stepwise logistic regression, the risk of uncontrolled hypertension was higher with older age (+10 years, odds ratio (OR) 1.19, P=0.03), female sex (OR 1.40, P=0.01), obesity (OR 2.35, P=0.0002) and heavy drinking (≥300 g per week, OR 2.18, P=0.0007). In conclusion, in elderly Chinese, the prevalence of hypertension is high. In spite of reasonably high awareness and treatment rates, the control rate remains low, most likely due to an unhealthy lifestyle and the underuse and/or underdose of antihypertensive drugs.

Effects of Various Antihypertensive Drugs on Arterial Stiffness and Wave Reflections.

We reviewed trials that tested the efficacy of antihypertensive drugs in reducing arterial stiffness and wave reflections as assessed by pulse wave velocity and augmentation index, respectively. Regardless of cross-over or parallel-group comparison design, placebo-controlled trials demonstrated that antihypertensive drugs were effective in reducing pulse wave velocity. In actively-controlled parallel-group comparison studies, this effect on arterial stiffness was more evident for angiotensin-converting enzyme inhibitors or angiotensin receptor blockers than other classes of antihypertensive drugs, particularly when brachial-ankle pulse wave velocity was measured. Regardless of cross-over or parallel-group comparison or placebo- or actively-controlled design, the reviewed trials showed that ß-blockers were inferior to all the other classes of antihypertensive drugs in reducing augmentation index. However, these studies had a small sample size and a short follow-up time and did not link the changes in measurements of arterial function with cardiovascular events. Whether the superiority or inferiority is clinically relevant for cardiovascular protection and prevention remains to be investigated.