Background: Presence of severe tricuspid regurgitation (TR) has a significant impact on assessment of right ventricular function (RVF) in transthoracic echocardiography (TTE). High trans-valvular pendulous volume leads to backward-unloading of the right ventricle. Consequently, established cut-offs for normal systolic performance may overestimate true systolic RVF.
Methods: A retrospective analysis was performed entailing all patients who underwent TTE at our institution between 1 January 2013 and 31 December 2016. Only patients with normal left ventricular systolic function and with no other valvular lesion were included. All recorded loops were re-read by one experienced examiner. Patients without severe TR (defined as vena contracta width ≥7 mm) were excluded. All-cause 2-year mortality was chosen as the end-point. The prognostic value of several RVF parameters was tested.
Results: The final cohort consisted of 220 patients, 88/220 (40%) were male. Median age was 69 years (IQR 52-79), all-cause two-year mortality was 29%, median TAPSE was 19 mm (15-22) and median FAC was 42% (30-52). In multivariate analysis, TAPSE with the cutoff 17 mm and FAC with the cutoff 35% revealed non-significant hazard ratios (HR) of 0.75 (95%CI 0.396-1.421, p = 0.38) and 0.845 (95%CI 0.383-1.867, p = 0.68), respectively. TAPSE with the cutoff 19 mm and visual eyeballing significantly predicted survival with HRs of 0.512 (95%CI 0.296-0.886, p = 0.017) and 1.631 (95%CI 1.101-2.416, p = 0.015), respectively.
Conclusions: This large-scale all-comer study confirms that RVF is one of the main drivers of mortality in patients with severe isolated TR. However, the current cut-offs for established echocardiographic parameters did not predict survival. Further studies should investigate the prognostic value of higher thresholds for RVF parameters in these patients.
Keywords: FAC; GLS; RVF; TAPSE; TR.