Right heart chambers geometry and function in patients with the atrial and the ventricular phenotypes of functional tricuspid regurgitation

Abstract

Aims Atrial functional tricuspid regurgitation (A-FTR) is a recently defined phenotype of functional tricuspid regurgitation (FTR) associated with persistent/permanent atrial fibrillation. Differently from the classical ventricular form of FTR (V-FTR), patients with A-FTR might present with severely dilated right atrium and tricuspid annulus (TA), and with preserved right ventricular (RV) size and systolic function. However, the geometry and function of the right ventricle, right atrium, and TA in patients with A-FTR and V-FTR remain to be systematically evaluated. Accordingly, we sought to: (i) study the geometry and function of the right ventricle, right atrium, and TA in A-FTR by two- and three-dimensional transthoracic echocardiography; and (ii) compare them with those found in V-FTR. Methods and results We prospectively analysed 113 (44 men, age 68 ± 18 years) FTR patients (A-FTR = 55 and V-FTR = 58) that were compared to two groups of age- and sex-matched controls to develop the respective Z-scores. Severity of FTR was similar in A-FTR and V-FTR patients. Z-scores of RV size were significantly larger, and those of RV function were significantly lower in V-FTR than in A-FTR (P < 0.001 for all). The right atrium was significantly enlarged in both A-FTR and V-FTR compared to controls (P < 0.001, Z-scores > 2), with similar right atrial (RA) maximum volume (RAVmax) between A-FTR and V-FTR (P = 0.2). Whereas, the RA minimum volumes (RAVmin) were significantly larger in A-FTR than in V-FTR (P = 0.001). Conclusion Despite similar degrees of FTR and RAVmax size, A-FTR patients show larger RAVmin and smaller TA areas than V-FTR patients. Conversely, V-FTR patients show dilated, more elliptic and dysfunctional right ventricle than A-FTR patients.

The atrial secondary tricuspid regurgitation is associated to more favorable outcome than the ventricular phenotype

“…Moreover, A-STR patients had a 2.7 lower risk of death for any cause and HF hospitalization compared to V-STR patients. Regarding the different echocardiographic remodeling observed in the 2 population, interesting results regarding RA, TA, and RV remodeling were found, in line with previous evidence ( 8 , 20 , 37 ).…”

“…Recently, a study from our group sought to analyze the TV geometry in a cohort of patients with any degree of TR compared with a control cohort and classified in A- and V-STR on the base of an echocardiographic definition ( 20 ). Contrary to our results, in that study, A-STR patients showed larger RAV min compared to V-STR.…”

“…Not surprisingly, the most recent guidelines about the management of heart valve diseases suggest that A-STR should be separated from the other forms of STR ( 12 , 13 ) since the mechanisms underlying these two STR phenotypes have been hypothesized to be different ( 14 ). Notwithstanding, the recently published studies, including STR patients, do not distinguish between the A-STR and the “ventricular” STR (V-STR) phenotypes ( 15 – 19 ) and, to the best of our knowledge, only one echocardiographic study examined the differences in geometry of the right heart structures between patients with A-STR and V-STR ( 20 ). Furthermore, since A-STR has long been under-recognized as a distinct phenotype of STR, its prognosis and prognostic predictors remain to be clarified, especially in comparison with V-STR, in which the prognosis is also associated with the underlying RV function and/or associated left heart conditions ( 18 , 19 , 21 ).…”

Reference ranges of tricuspid annulus geometry in healthy adults using a dedicated three-dimensional echocardiography software package

“…Our findings also showed a significant correlation of 3DE TA parameters with maximal RA maximal volume. This is not an unexpected result because it has been proven that an enlarged RA secondary to atrial fibrillation favors TA dilatation and the occurrence of functional TR (2,3,(43)(44)(45)(46)(47). Moreover, we demonstrated that RA maximal volume was independently associated with TA 3D area both at end-diastole and midsystole.…”

The Dysfunctional Right Ventricle in Dilated Cardiomyopathies: Looking from the Right Point of View

“…The adverse RV remodeling may result from any of the aforementioned conditions: pressure overload (pulmonary arterial hypertension, PAH), volume overload (significant tricuspid regurgitation, TR), primary myocardial disease, or a combination of them [ 10 , 19 ]. For example, in DCM patients affected by hereditary muscular dystrophies [ 20 ], RV longstanding volume overload and dysfunction [ 21 ] can develop in the context of a direct atrial myopathic process that contributes to the development of AF, and consecutive atrial secondary TR [ 22 , 23 ].…”