The Correlations Of Clinical Risk Factors With Functional Tricuspid Regurgitation In Patients With Atrial Fibrillation

Background:Functional tricuspid regurgitation (FTR) refers to tricuspid regurgitation and blood reflux from right ventricle to right atrium secondary to the changes of spatial structure or function in heart chambers, in the absence of organic lesions of the tricuspid valve. FTR often occurs secondary to left-side heart disease or pulmonary hypertensive disease, sometimes accompanied with functional mitral regurgitation (FMR). Left atrial enlargement occurs as a consequence of isolated atrial fibrilliation (AF), which might contribute to FTR by changing spatial structure of cardiac fiber scaffold. It is rare reported that right atrial enlargement can also occur in AF patients. The mechanism of right atrial enlargement in FTR is still controversial. Therefore, it is helpful to interpret the potential mechanisms of AF on FTR by studying the relationship of atrial dimensions with FTR. Herein, a cross-sectional, retrospective study was designed to analyze clinical risk factors and echocardiographical parameters in AF patients and its correlation with FTR and FMR, trying to explore the etiology and pathological mechanisms of AF on FTR. Our data would contribute to screen the clinical predictors of FTR and supply with the references of FTR theory.Methods:AF patients were selected in the hospitalized database of Second Affiliated Hospital, Zhejiang University, School of Medicine, from May 2015 to October 2015. Entry into the study was based on the following criteria:(1) documentation of atrial fibrillation, whatever paroxysmal, persistent or chronic; (2) underwent transthoracic echocardiography examination more than once; (3) hospitalized patients with complete clinical medical records. The exclusion criteria showed as follows:(1) valvular heart disease; (2) structure abnormalities of tricuspid valve, such as congenital deformity, inflammation, trauma, carcinoid heart diseases, etc; (3) after heart valve replacement; (4) congenital heart diseases:(5) iatrogenic tricuspid regurgitation, such as pacemaker, implantable cardiac defibrillators (ICD), cardiac resynchronization therapy or with defibrillators (CRT/CRTD), myocardial biopsy, and radiation therap. Informed consent was obtained, medical records and echocardiography results met the criteria were collected. Clinical baseline data of AF patients were investigated, including age, sex, body mass index and complicated diseases. The incidences of FTR and FMR were evaluated, respectively, including those in the subgroups of both sex and age, and those complicated with hypertension, coronary atherosclerotic heart disease and dilated cardiomyopathy. Then, patients were divided into different groups according to the severity of valvular regurgitation. The correlations of FTR and FMR with clinical related risk factors and echocardiographic parameters were analyzed, respectively, including the subgroups in sex. Logistic regression analysis was applied to assess the correlation of the severity of FTR with heart chamber dimensions and cardiac function.Result:There were 841 AF patients met the criteria, with the average age was 69.2±12.1, 268 of them were elder than 75 (31.9%). In all the patients,544 were male and 297 were female.(1) In all the AF patients, the incidences of FTR and FMR were 23% and 9%, respectively. The concurrence of FTR and FMR was as higher as 54%. Among them, the incidence of moderate-to-severe FTR was 22.8%, especially in the AF patients elder than 70. Otherwise, the incidence of moderate-to-severe FMR was 13.1%, especially in the AF patients elder than 60. The incidence of both moderate-to-severe FTR and FMR were equal in male and female.(2) The incidence of functional valvular regurgitation was increased in the AF patients, as accompanied with coronary atherosclerotic heart disease, dilated cardiomyopathy, and ischemic cerebrovascular disease. The incidences of moderate-to-severe FTR and FMR were elevated in the AF patients with dilated cardiomyopathy, especially in male. However, the incidences of mild-to moderate FMR were increased in the AF patients with coronary atherosclerotic heart disease, especially in male.(3) In the AF patients, left atrial dimension, left ventricular ejection fraction and fractional shortening were statistically significant among the different severity groups of FTR (P<0.01). Furthermore, logistic regression was applied to assess the atrial dimensions and the severity of FTR. As a result, the present study showed that the moderate-to-severe FTR was significantly correlated with right atrium dimension (moderate FTR:OR 2.36; 95%CI 1.27 to 4.37; P<0.01; severe FTR:OR 4.83; 95% CI 2.45 to 9.54; P<0.01).Conclusion:In conclusion, the present study, a cross-sectional, retrospective design, showed that atrial enlargement may contribute to the pathological process of moderate-to-severe functional tricuspid regurgitation in atrial fibrillation patients, and right atrial dimension may be used as a predictor.