Objective: To evaluate the association between tricuspid regurgitation (TR) severity measured near intensive care unit (ICU) admission and 365-day all-cause mortality in echocardiography-selected adult ICU patients.

Methods: This secondary analysis linked Medical Information Mart for Intensive Care-IV (MIMIC-IV) version 3.1 with MIMIC-IV-echocardiogram. Adults with transthoracic echocardiography from 24 hours before to 72 hours after ICU admission and documented TR severity were included. None/trivial and mild TR were combined as the low-grade reference group; moderate and severe TR were compared with this group. Multiple Cox regression analyses evaluated 28-, 90-, and 365-day mortality. Sodium-adjusted and biomarker-availability analyses evaluated additional laboratory information.

Results: The cohort included 16 991 patients: 12 417 (73.1%) had low-grade, 3467 (20.4%) moderate, and 1107 (6.5%) severe TR. Crude mortality increased across TR severity at 28 days (15.1%, 24.5%, and 32.7%), 90 days (20.3%, 32.5%, and 42.7%), and 365 days (27.2%, 42.9%, and 53.4%). Compared with low-grade TR, 365-day multiple-adjusted estimates were hazard ratio (HR) = 1.32, P < .001, 95% CI: 1.24-1.41 for moderate TR and HR = 1.67, P < .001, 95% CI: 1.52-1.83 for severe TR; 28- and 90-day estimates were directionally consistent, and sodium-adjusted estimates were similar.

Conclusion: Moderate and severe TR on early echocardiography were associated with higher 1-year mortality in echocardiography-selected adult ICU patients. This observational association remained consistent after sodium adjustment but should not be interpreted as a treatment effect.