Prognostic Value of Complementary Echocardiography and Magnetic Resonance Imaging Quantitative Evaluation for Isolated Tricuspid Regurgitation.

BACKGROUND

Isolated tricuspid regurgitation (TR) remains a management dilemma with poor outcomes. Echocardiography and cardiac magnetic resonance imaging (CMR) are valuable tools for evaluating TR, but their prognostic utility has rarely been studied together in this setting. We aimed to determine the prognostic value and thresholds for echocardiography and CMR parameters for isolated severe TR.

METHODS

Consecutive patients with isolated severe TR by echocardiography and undergoing CMR during January 2007 to June 2019 were studied. Echocardiography and CMR-derived quantitative parameters were analyzed for independent associations with and thresholds for predicting the primary end point of all-cause mortality during follow-up.

RESULTS

Among 262 patients studied, mean age was 62.8±15.6 years, 156 (59.5%) were females, 207 (79.0%) had secondary TR, and 87 (33.2%) underwent tricuspid valve surgery after CMR. There were 68 (26.0%) deaths during a mean follow-up of 2.5 years. Both CMR-derived tricuspid regurgitant fraction (per 5% increase) and right ventricle free wall longitudinal strain (per 1% decrease in magnitude) were independently associated with worse survival, with hazard ratios (95% CIs) of 1.15 (1.05-1.25) and 1.10 (1.04-1.17), respectively, along with right heart failure symptoms of 2.03 (1.14-3.60), while tricuspid valve surgery was borderline protective with 0.55 (0.31-0.997). Regurgitant fraction ≥30%, regurgitant volume ≥35 mL and right ventricle free wall longitudinal strain ≥-11% (by velocity vector imaging technique, which yields lower magnitude values than other conventional strain techniques) were the optimal thresholds for mortality during follow-up.

CONCLUSIONS

TR quantification by CMR and right ventricle free wall longitudinal strain by echocardiography were the key imaging parameters independently associated with reduced survival in isolated TR, incremental to conventional clinical factors. Clinically significant thresholds for these parameters were determined and may help guide decision-making for TR management.