Global right ventricular (RV) dysfunction is an independent predictor of cardiovascular outcomes for patients undergoing transcatheter tricuspid valve repair (TTVR), new clinical data suggest.
The study, published online Monday and in the July 26 issue of JACC: Cardiovascular Interventions, investigated the clinical impact of RV function prior to TTVR in 79 patients using cardiac magnetic resonance (CMR) imaging.
Led by Karl-Patrik Kresoja, MD, form the Heart Center Leipzig at the University of Leipzig and Leipzig Heart Institute, Germany, the team behind the study reported that global RV dysfunction –as determined by the combined presence of both longitudinal and circumferential RV dysfunction using CMR – was associated with a composite risk factor of all-cause mortality and first heart failure (HF) hospitalization.
“Mere measurement of longitudinal function (TAPSE) is not sufficient to assess prognosis among these patients,” they said, noting that imaging markers of longitudinal function alone, assessed by either echocardiography or CMR, are not able to predict outcomes following TTVR
Kresoja and colleagues noted that by acknowledging the “complex role and interplay” of longitudinal and circumferential function, further research may further understanding of the interplay of RV failure, severe tricuspid regurgitation (TR), and the capability of the right ventricle to favorably respond to therapy.
The German team said the new study is the first to comprehensively analyze CMR-derived RV function and its relation to cardiovascular outcomes and the different contraction patterns of the right ventricle stressed by pathological loading conditions in patients undergoing TTVR for significant TR.
Within the study, global RV dysfunction was defined as CMR-derived RV ejection fraction (RVEF) of 45% or lower, while longitudinal RV dysfunction was defined as tricuspid annular plane systolic excursion (TAPSE) <17 mm on echocardiography. The primary outcome was a composite of all-cause mortality or first heart failure hospitalization.
Of 79 patients, 18 (23%) presented with global and 40 (51%) presented with longitudinal RV dysfunction, revealed Kresoja and colleagues, adding that the composite outcome occurred in 22 patients.
They found that global RV dysfunction, defined as the combined presence of both longitudinal and circumferential RV dysfunction using CMR, but not longitudinal RV dysfunction alone, was associated with the composite outcome (hazard ratio [HR]: 6.62; 95% confidence interval [CI]: 2.77-15.77; and HR: 1.30; 95% CI: 0.55-3.08, respectively).
Furthermore, the team stratified patients into three types of RV contraction: type I, TAPSE of 17 or greater and RVEF more than 45%; type II, TAPSE of less than 17 and RVEF of more than 45%; and type III, TAPSE less than 17 and RVEF 45% or lower.
Type III patients showed worse survival and outcomes, whereas there were no differences between types I and II, they said. The authors noted that compared with type I RV contraction, patients with type II RV contraction displayed increased circumferential strain, with a protection of RVEF despite reduced longitudinal strain.
“Patients with diminished longitudinal and circumferential strain resulting in reduced RV global function (type III) exhibited the worst outcome despite successful relief of volume overload,” they said.
Writing in an accompanying editorial comment, Nicole Karam, MD, PhD, from INSERM and the European Hospital Georges Pompidou, France, and Jörg Hausleiter, MD, from LMU Klinikum and the Munich Heart Alliance, Germany, said that despite the small sample size, the new study provides an interesting and in-depth analysis of RV function that highlights the limited value of two-dimensional, longitudinal strain – and therefore of TAPSE – while demonstrating a major prognostic role of a four-dimensional assessment of RV function, including both longitudinal and circumferential strain and RVEF, in predicting prognosis after TTVR.
“Accordingly, imaging techniques such as cardiac magnetic resonance imaging or 3-dimensional echo with the ability to quantify RVEF appear to be necessary to better characterize patients who are evaluated for TTVR,” they noted.
The editorialists added that at the patient level, the results underline the importance of not denying TTVR to patients with low TAPSE – because longitudinal dysfunction is frequently present but does not predict adverse outcome when compensation through circumferential strain is maintaining a normal RVEF.
“Accordingly, a 4-dimensional analysis of RV function is mandatory to distinguish patients in whom compensatory mechanisms are still sufficient (and who might be good candidates for catheter-based tricuspid interventions) from patients in whom RV damage is too severe and have reached an advanced, probably irreversible, state,” they said.
However, the expert commentators also noted that although the findings suggest that survival outcomes after TTVR are worse for patients with reduced RVEF, it is too early to make recommendations that those with reduced RVEF should be denied tricuspid interventional treatments. They added that it remains unclear whether such patients might benefit from symptomatic improvement and increased physical activity.
Kresoja K-P, Rommel K-P, Lücke C, et al, et al. Right Ventricular Contraction Patterns in Patients Undergoing Transcatheter Tricuspid Valve Repair for Severe Tricuspid Regurgitation. JACC Cardiovasc Interv 2021;14:1551-61.
Karam N, Hausleiter J. How Many Dimensions Do We Need to Assess RV Function Before Tricuspid Interventions?. JACC Cardiovasc Interv 2021;14:1562-4.
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