Tricuspid Regurgitation and Kidney Transplant Recipient Outcomes

Abstract

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. Plain-Language Summary: Significant tricuspid regurgitation (TR) is associated with increased mortality rates and kidney failure, but its impact on kidney transplant recipients is poorly investigated. We examined how significant TR diagnosed pretransplantation affects kidney function within the first posttransplant year in a retrospective cohort study. Among 24 patients with significant TR, there was a consistent pattern of lower kidney function at 2 weeks, 3 months, and 1 year following transplantation, compared to 72 matched controls based on a propensity score. Results were statistically significant at all time points within the first year after transplant. These findings suggest that selected individuals with significant TR are able to undergo successful kidney transplantation, although with worse kidney function following transplantation.

Keywords

• Chronic kidney failure
• heart failure
• kidney transplant
• tricuspid regurgitation
• venous congestion