Hypertension and atrial fibrillation (AF) are two major public health problems worldwide. Hypertension is an important risk factor for AF, and the combination of which could significantly increase the risk of cardiovascular adverse events, and result greater disability rate and mortality.

Hypertension can stimulate cardiomyocytes apoptosis, drive renin-angiotensin-aldosterone system (RAAS) activation, lead to left ventricular hypertrophy (LVH) and finally result in the structure remodeling of the atrium, which can trigger AF development through influence on myocardial electrical activity. Previous studies have found that angiotensin receptor blockers (ARB) seem to be more efficient in preventing AF when hypertension combined heart failure or LVH, but not completely clear in others with hypertension.

Azilsartan is a new ARB, it replaces the tetrazole ring of the traditional ARB with the oxadiazole ring, which making it binds to the angiotensin type 1 (AT1) receptor more tightly, dissociate more slowly, and has a stronger antihypertensive effect. It was reported that Azilsartan could inhibit cell proliferation, reduce inflammation and oxidative stress. However, whether Azilsartan can reduce the risk of AF in hypertensive patients, and the possible corresponding mechanism is still unclear.

Accordingly, the investigators designed this study intending to evaluate the effect of Azilsartan on the incidence of AF in hypertensive patients combined with LVH, and to explore the possible mechanism. This study is a practical, multicenter randomized controlled research method, the investigators will include 400 patients with hypertension and LVH who meet the inclusion criteria in Beijing Tsinghua Changgung Hospital and other centers. The patients would be divided into the Azilsartan group and conventional treatment group randomly, and be followed up regularly for 12 months. The incidence of AF in the two groups would be compared through the flexible intelligent ECG monitoring system, and the optimal blood pressure control, also the left ventricular hypertrophy and left atrial function would be evaluated.

This study will provide evidence for the use of Azilsartan in blood pressure control and lower risk for AF patients with hypertension and LVH. It will be benefit for improving prognosis of patients with hypertension combined LVH, reducing the incidence of AF, and achieving good social economic effects.

Inclusion Criteria:

• Age ≥ 18 years.
• Satisfied the diagnostic criteria for hypertension in the 2020 International Society of Hypertension Global Practice Guidelines for Hypertension.
• Blood pressure control fails to meet one of the following conditions: office blood pressure ≥ 140/90mmHg; ambulatory blood pressure monitoring daytime average blood pressure ≥ 135/85mmHg or nighttime average blood pressure ≥ 120/70mmHg; home monitoring blood pressure ≥ 135/85mmHg.
• Echocardiography shows that the left ventricular wall thickness is ≥11 mm, or the left ventricular mass index (LVMI) is >95 g/m2 (female), 115 g/m2 (male).

Exclusion Criteria:

• Secondary hypertension.
• Confirmed diagnosis of persistent atrial fibrillation.
• Severe liver and kidney disease (eGFR<30 mL/min/1.73m2), severe lung disease, malignant tumor and mental illness history.
• Pregnant women, women of childbearing age who plan to become pregnant during the study or who cannot use effective contraception during the study
• Illness leading to life expectancy <12 months.
• Not signed informed consent.