Refining tricuspid regurgitation grading: do mild-to-moderate and moderate-to-severe categories improve mortality prediction in heart failure patients?

Introduction Secondary tricuspid regurgitation (TR) commonly develops as a consequence of left heart failure (HF) leading to increased morbidity and mortality. Identifying patients at risk for severe adverse events is crucial in clinical practice, especially in the context of emerging interventional TR therapies. To enhance risk stratification, various TR grading schemes have been proposed, including a more granular classification of moderate TR that differentiates between mild-to-moderate and moderate-to-severe. Purpose The present study aimed to assess the prognostic value of this refined TR grading schema for mortality prediction in HF patients. Methods HF patients with reduced (HFrEF), mildly reduced (HFmrEF), or preserved ejection fraction (HFpEF) and a recent transthoracic echocardiography were prospectively enrolled in the registry. Follow-ups were conducted for up to 24 months. In the present subanalysis, only patients with TR categorized by the effective regurgitant orifice area (EROA) according to the following severity grades were included: none and mild, mild-to-moderate, moderate-to-severe, and severe TR as proposed by Dreyfus (EHJ CVI, 2024). Cox regression analysis with the reference group "none and mild TR" was used to assess the prognostic value of the different grading schemas. Results From 2020 to 2022, a total of 1,012 HF patients were enrolled and EROA measurements for TR grading were available in 970 patients. The mean age of the cohort was 74±11 years and 363 (37%) were women. 33% of patients (n=324) suffered from HFrEF, 20% (n=189) from HFmrEF, and 47% (n=457) from HFpEF. In the overall HF cohort, the distribution of TR grades was as follows: 15% (n=141) severe, 13% (n=121) moderate, 73% (n=707) mild or no TR. The moderate TR group was further subdivided into 7% (n=71) patients with mild-to-moderate and 5% (n=51) with moderate-to-severe TR. After 24 months, survival data was available in 968 patients (99.8%). The overall mortality reached 24% (n=230). A more severe TR was associated with an increased risk of mortality. Compared to patients with no or mild TR, those with moderate TR had a hazard ratio (HR) of 2.419 (95% confidence interval [CI] 1.473-2.921, p<0.001), while those with severe TR had a HR of 2.038 (95%CI 1.471-2.824, p<0.001). According to the new grading schema, a mild-to-moderate TR severity was associated with a HR of 2.065 (95% CI 1.349-3.162, p<0.001), a moderate-to-severe TR with a HR of 2.029 (95% CI 1.241-3.316, p=0.005), and a severe TR with a HR of 2.035 (95% CI 1.469-2.820, p<0.001). Conclusion In the present study, a higher severity of TR was associated with an increased risk of mortality. However, a more detailed differentiation of moderate TR did not improve risk stratification.