Predicting Right Ventricular Function and Strain Using Indices of Right Heart Size and Hemodynamics in Functional Tricuspid Regurgitation

Background:

Right ventricular (RV) systolic function is evaluated using TAPSE, FAC and RV strain among other parameters. RV strain is a more sensitive predictor of RV dysfunction in functional tricuspid regurgitation (FTR). Based on this, FTR patients can be divided into those in whom with all three parameters are normal (NNN), those in whom all three parameters are abnormal (LLL) and those in whom only RV strain is reduced (NNL). We examined the ability to predict these groups using indices of RV and RA size and right heart Doppler hemodynamics.

Methods:

We analyzed echo data from 302 patients with severe FTR (115 male, mean age 72±14 years). Normal values of TAPSE, FAC and RV strain were >1.6 cm, >35% and <24%, respectively. We used a random decision forest model with resampling to predict group classification using 13 variables including LVEF. The area under the curves (AUCs) were calculated using a multiclass method, and variable importance was estimated.

Results:

257 (85%) of the 302 patients with severe FTR had abnormal RV strain compared to 157 (52%) with abnormal TAPSE, and 160 (53%) with abnormal RV FAC. The average AUC was 0.87 with the lowest for NNL-classification (Figure 1a). End-systolic RV area and S’ were the most important predictors followed by LVEF (Figure 1b).

Conclusion:

In FTR, indices of RV and RA size or right heart hemodynamics does not predict subclinical RV dysfunction (NNL), defined as normal TAPSE and FAC but abnormal RV strain. However, indices of right heart size and hemodynamics reliably predict NNN and LLL groups. Measurements of RV strain in these groups may not have incremental diagnostic value but may have prognostic value in the LLL group.