Effect Of Losartan On The Left Atrial Function And TGF-β1 In Hypertention Patients With Paroxymal Atrial Fibrillation

Objective We designed the present study to investigate the effect of losartan,a angotensin-receptor blocker,compared with felodipine on left atrial function and serum TGF-β1 in hypertension patients with paroxysmal atrial fibrillation(AF),to discuss the possible mechanisms and maintenance of atrial remodeling and the causes which can affect left atrial function.We aimed to search the possible approach to prevent and treat paroxysmal AF in hypertension patients.Methods 76 hypertension patients with paroxysmal AF were randomly divided into losartan group(n=38) and felodipine group(n=38).Losartan group was treated with losartan and felodipine group with felodipine except ACEI or ARB.Clinic blood pressure and a 24-hour ECG were evaluated every month;the patients were asked to report any episode of symptomatic AF and to perform an ECG as early as possible. Before the therapy and 4 weeks,12 weeks and 24weeks later,left atrial structure and function were observed in the both groups by echocardiography.TGF-β1 in the serum were measured respectively in patients before and after the treatment in both groups.In addition,the preventing recurrence of paroxysmal AF and the blood pressure control were examined and analyzed.Twenty cases of healthy adults were selected in the control group.Results Among the76 cases of hypertension patients with paroxysmal AF,no significant difference was observed between the 2 groups in the basic patient characteristics.No significant difference was found between the 2 groups in the blood pressure control(144±6.8 mmHg VS 140.5±6.5 mmHg,P＞0.05).The LAAPD LASID,LAVmax were significant decreased and the PVA,LAEF were increased in both groups after the treatment 12 weeks later.Compared to the felodipine group, the dimensions and maximal volumes of left atrium decreased more in losartan group, and the PVA,LAEF were significantly increased after 12 weeks.The maintenance of sinus rhythm in losartan group was greatly higher than felodipine group at the end of study(P＜0.05).The level of TGF-β1 in losartan group was significant lower than that in felodipine group 24 weeks later(P＜0.05).Conclusions The initiation of AF is a complex event involved in hypertensive heart disease and hypertension is a important risk fact of AF.Compared to felodipine, losartan was able to control blood pressure with good safety and tolerability.Losartan can prevent not only recurrence of paroxysmal AF in hypertension patients but also improving left atrial function.In reducing the recurrence of AF in patients with paroxysmal AF,and this might be related to possible favorable impact of angiotensinⅡreceptor blockers(ARB) on the atrial structural remodeling.It is confirmed that ARB can reverse atrial remodeling and prevent atrial fibrosis is probably the most critical process of atrial remodeling which was mediated by the rennin-angiotensin system(RAS).The study also demonstrated that the use of losartan seems more effective than felodipine in decreasing serum TGF-β1 in hypertensive patients with paroxysmal atrial fibrillation.These results could play an important and decisive role in the treatment and prevention of in hypertension patients with paroxysmal AF.