Tricuspid annular dilatation (TAD) is an independent predictor of all-cause mortality in patients with severe aortic stenosis undergoing transcatheter aortic valve implantation (TAVI), a study published in JACC: Cardiovascular Interventions has found.
The study, authored by Simon Deseive (Munich University Hospital, Munich, Germany) et al, looked at maximal septo-lateral diameter measurements of the tricuspid annulus in consecutive patients with 3D multi-slice computed tomography (MDCT) datasets undergoing transfemoral TAVI procedures at Munich University Hospital between January 2013 and December 2016.
Writing in the study’s introduction, Deseive and colleagues note that secondary tricuspid regurgitation is often caused by left-sided heart disease including impaired left ventricular function, mitral or aortic valve disease. Secondary tricuspid regurgitation, they note, which is associated with increased mortality, is not a valvular pathology but is the result of TAD in combination with impaired right ventricular (RV) function and altered RV geometry. Consequently, current guidelines underline the importance of TAD on patient outcomes.
In patients with symptomatic severe aortic stenosis, they add, TAVI is the treatment of choice in most patients with moderate or high surgical risk, and is likely to be an increasingly favoured option in low surgical risk patients. They add that current evidence suggests right ventricular dysfunction and enlargement as well as tricuspid regurgitation are predictors of adverse outcomes in patients with severe aortic stenosis undergoing TAVI, but note that accurate and reproducible assessment of tricuspid regurgitation and TAD with 2D and 3D echocardiography is often difficult due to limited or insufficient acoustic windows.
“Pre-procedural cardiac CT, which is routinely performed for prosthesis selection and assessment of vascular access routes, permits acquisition of high-resolution 3D datasets of the entire heart. Those datasets can be angulated exactly in the tricuspid annulus allowing for precise measurements of its dimensions including the maximum septo-lateral diameter,” the study team notes.
Through the study, the researchers sought to investigate the prevalence of CT-derived TAD and its impact on procedural outcomes and two-year mortality in addition to echocardiographic parameters in a consecutive cohort of patients undergoing TAVI for severe aortic stenosis. The main endpoint of the analysis was all-cause mortality, and procedural endpoints were defined according to the Valve Academic Research Consortium-2 (VARC-2) criteria, including device-failure and its components, conversion to open surgery, significant pericardial effusion, procedural myocardial infarction, permanent pacemaker Implantation, any stroke within 24 hours and 30 days and all-cause mortality at 30 days.
Of a total 1,137 patients undergoing TAVI, Deseive and colleagues found that TAD was present in 446 (39.2%). Patients with tricuspid annular dilatation had a 99% higher mortality in univariable analysis and 78% higher mortality in multivariable analysis, they note, which included clinical and echocardiographic parameters. Continuous net reclassification improvement revealed incremental prognostic value of tricuspid annular dilatation to a baseline model of clinical and echocardiographic parameters (0.204, p<0.01) and the Society of Thoracic Surgeons (STS) Score (0.209, p<0.001). The difference in mortality was not driven by procedural outcomes, they suggest.
Discussing the findings, Deseive et al suggests that the analysis demonstrates, that CT-derived TAD is a “strong and independent predictor for mortality in this large consecutive cohort of patients undergoing TAVI for severe aortic stenosis and provides incremental prognostic value over clinical and echocardiographic assessment of patients. More than one third of the investigated patients were found to have TAD—a fact that underlines the clinical importance of this entity.”
