Tricuspid Regurgitation and Kidney Transplant Recipient Outcomes.

RATIONALE & OBJECTIVE: Kidney function can be adversely affected by significant tricuspid regurgitation (TR) owing to effects on cardiac output and systemic venous congestion. However, the impact of significant TR on short- and long-term kidney function following a kidney transplant remains uncertain.

STUDY DESIGN: Retrospective observational cohort.

SETTING & PARTICIPANTS: Kidney transplant recipients from a single center between 2016 and 2019.

EXPOSURE: Significant TR, defined by at least moderate regurgitation, on echocardiogram before kidney transplantation.

OUTCOMES: Primary end points included the estimated glomerular filtration rate (eGFR) at the following 3 time points: 2 weeks, 3 months, and 1 year after transplantation. Secondary end points included major adverse cardiac events including nonfatal myocardial infarction, all-cause mortality, and hospitalization owing to cardiovascular disease.

ANALYTICAL APPROACH: Propensity score matching was performed in 1:3 ratio between patients treated with significant TR and controls, within a caliper 0.05 standard deviation of the propensity score, to analyze for the primary end point.

RESULTS: Among 557 kidney transplant recipients, 26 (5%) exhibited significant TR pretransplantation. According to propensity score matching analysis, with 1:3 ratio between 24 patients with significant TR and 72 controls, the presence of significant TR was associated with a lower eGFR posttransplantation. Specifically, the mean eGFR was 41.2 mL/min/1.73 m2 compared to 53.3 mL/min/1.73 m2 at 2 weeks ( P  < 0.01), 50.0 mL/min/1.73 m2 versus 60.3 mL/min/1.73 m2 at 3 months ( P  < 0.01), and 49.4 mL/min/1.73 m2 versus 61.2 mL/min/1.73 m2 at 1 year ( P  < 0.01). Delayed graft function was observed in 41.7% of the patients with significant TR compared to 12.5% of those without significant TR ( P  < 0.01). No patients with significant TR required dialysis after 1 year. 1-year major adverse cardiac events were nonsignificantly higher among patients with significant TR (20.8% vs 8.1%; P  = 0.16).

LIMITATIONS: Retrospective design and relatively small TR population.

CONCLUSIONS: The presence of significant TR among kidney transplant recipients was associated with a lower eGFR at 2 weeks, 3 months, and 1 year following transplant, although all remained dialysis independent at 1 year.