Influence of functional tricuspid regurgitation on right ventricular function

Background. Although right ventricular (RV) function has been extensively studied during the past decade, few reports have described the influence of functional tricuspid regurgitation (TR) on RV function.

Methods. One hundred forty-two patients with left-side valvular heart disease associated with TR were enrolled in the study and divided into three groups according to tricuspid annular diameter: group 1 (n = 66), tricuspid annular diameter less than 40 mm; group 2 (n = 58), tricuspid annular diameter of 40 to 50 mm; and group 3 (n = 18), tricuspid annular diameter greater than or equal to 50 mm. In groups 2 and 3, the right heart parameters had deteriorated to the point that TR repair was necessary. The mean follow-up period was 102 months after the operation.

Results. In each of the three groups, as pulmonary arteriolar resistance index increased, RV forward stroke work index increased in a linear fashion. The slope of the linear regression line was progressively less in group 1, 2, and 3 preoperatively. Postoperatively, this line moved in a parallel manner in group 1 and became steeper in group 2, consequently becoming similar in both groups. However, in group 3, although the slope became steeper in spite of a remarkable decrease of TR, it remained less when compared with groups 1 and 2. In addition, the right heart parameters also improved, but still remained worse in group 3 than group 2; 7 patients undergoing a flexible annuloplasty have shown gradual aggravations in TR and late postoperative clinical manifestations.

Conclusions. Functional TR with severely dilated annulus may produce an irreversible deterioration of RV function. The preoperative relationship between pulmonary arteriolar resistance index and RV forward stroke work index, that is, RV systolic function to pressure afterload, might predict a postoperative fate of the right heart function.