Kidney Week

Abstract: TH-PO168

Relationship of Systolic Blood Pressure with GFR Decline in Kidney Transplant Recipients: The FAVORIT Trial

Session Information

• Transplantation: Cardiovascular and Metabolic Diseases
  October 25, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Transplantation

• 1802 Transplantation: Clinical

Authors

• Malhotra, Rakesh, UCSD, San Diego, California, United States

Rakesh Malhotra,

• Katz, Ronit, University of Washington, Seattle, Washington, United States

Ronit Katz,

• Weiner, Daniel E., Tufts Medical Center, Boston, Massachusetts, United States

Daniel E. Weiner,

• Levey, Andrew S., Tufts Medical Center, Boston, Massachusetts, United States

Andrew S. Levey,

• Cheung, Alfred K., University of Utah, Salt Lake City, Utah, United States

Alfred K. Cheung,

• Bostom, Andrew, Rhode Island Hospital, Providence, Rhode Island, United States

Andrew Bostom,

• Ix, Joachim H., UCSD , San Diego, California, United States

Joachim H. Ix,

Background

In chronic kidney disease, intensive systolic blood pressure (SBP) control reduces mortality, but increases rate of estimated glomerular filtration (eGFR) decline and acute kidney injury risk. The optimal blood pressure target in KTRs is uncertain. Prior observational studies from FAVORIT demonstrate lower mortality at lower SBP levels, but the relationship of SBP with kidney allograft function is largely unknown. We investigated the relationship of baseline SBP with risk of kidney allograft failure and eGFR slope during long-term follow-up among stable KTRs.

Methods

The FAVORIT trial, a multicenter, double-blind, randomized trial examining the effect of B-vitamin therapy on CVD and mortality, recruited KTRs who were at least 6 months post-transplant. SBP was measured at baseline, and subsequent eGFR values and kidney failure events were assessed. Cox proportional hazards and multivariable linear regression models were used to determine association of SBP with time to ≥50% eGFR decline or dialysis dependence, and annualized eGFR decline, respectively. Restricted cubic spline plots were developed to evaluate the functional form of the relationships. Models were adjusted for demographics, transplant characteristics, baseline eGFR, urine ACR and comorbidities.

Results

Among 3,598 KTRs, mean age was 52±9 years, mean baseline SBP was 136±20 mmHg and mean eGFR was 49±18 ml/min/1.73m². There were 369 ≥50% eGFR decline or dialysis dependence events during mean follow-up of 4.0±1.5 years. The relationships of SBP with both ≥50% eGFR decline or dialysis (SBP: P_nonlinearity = 0.2) and annualized eGFR slope (SBP: P_nonlinearity = 0.8) were linear without evidence of J or U shaped relationships (figure).

Conclusion

In a large sample of stable KTRs, we found no evidence of threshold at which lower baseline SBP was related to higher risk of eGFR decline. While reassuring in light of prior findings of mortality benefit at lower SBP, future trials are required to establish optimal BP targets in KTRs.

Funding

• NIDDK Support