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.

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.

The prognostic value of pre-operative coronary evaluation in kidney transplanted patients.

Aims: Non-invasive coronary assessment using single-photon emission computerized tomography (SPECT) testing for potential cardiac ischemia is an essential part of the evaluation of kidney transplant candidates. We aimed to examine the prognostic value of preoperative SPECT test results in kidney transplanted patients. Methods and results: We retrospectively analyzed the pre-surgical nuclear SPECT test results in a registry of kidney transplanted patients. Follow-up at 1 month and 1 year recorded major adverse cardiac events (MACE) including non-fatal myocardial infarction, all-cause mortality and hospitalization due to cardiovascular disease following the renal transplantation. Of 577 patients available for analysis, 408 (70.9%) patients underwent nuclear SPECT test pre-transplant and 83 (20.3%) had abnormal results with either evidence of ischemia or infarct. A significantly higher incidence of post-operative MACE at 1 month was evident among patients with abnormal SPECT test compared to patients with no evidence of ischemia (10.8 vs. 4.3% respectively; P = 0.019). Differences were mostly derived from significantly increased rates of myocardial infarction events (8.4 vs. 1.8%; P = 0.002). Yet, MACE rate was not statistically different at 1 year (20.5 vs. 13.1%; P = 0.88). Importantly, the prognostic impact of an abnormal SPECT was significantly attenuated for all outcomes following multivariable adjusting for conventional cardiovascular risk factors and coronary revascularization. Conclusion: Pre-surgical cardiac risk assessment of kidney transplant candidates with nuclear SPECT test was found to be predictive of post-operative MACE, yet apparently, its prognostic value was significantly attenuated when adjusted for cardiac risk factors.

Immune Response to Third Dose BNT162b2 COVID-19 Vaccine Among Kidney Transplant Recipients-A Prospective Study.

Immune response to two SARS-CoV-2 mRNA vaccine doses among kidney transplant recipients (KTRs) is limited. We aimed to evaluate humoral and cellular response to a third BNT162b2 dose. In this prospective study, 190 KTRs were evaluated before and ∼3 weeks after the third vaccine dose. The primary outcomes were anti-spike antibody level >4160 AU/ml (neutralization-associated cutoff) and any seropositivity. Univariate and multivariate analyses were conducted to identify variables associated with antibody response. T-cell response was evaluated in a subset of participants. Results were compared to a control group of 56 healthcare workers. Among KTRs, we found a seropositivity rate of 70% (133/190) after the third dose (37%, 70/190, after the second vaccine dose); and 27% (52/190) achieved levels above 4160 AU/ml after the third dose, compared to 93% of controls. Variables associated with antibody response included higher antibody levels after the second dose (odds ratio [OR] 30.8 per log AU/ml, 95% confidence interval [CI]11-86.4, p < 0.001); and discontinuation of antimetabolite prior to vaccination (OR 9.1,95% CI 1.8-46.5, p = 0.008). T-cell response was demonstrated in 13% (7/53). In conclusion, third dose BNT162b2 improved immune response among KTRs, however 30% still remained seronegative. Pre-vaccination temporary immunosuppression reduction improved antibody response.