Criteria Identified to Help Predict Survival Benefit From Combined Heart/Kidney Transplantation

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March 18, 2009 — Criteria have been identified that, when combined with a measure of kidney function, could help identify patients who are likely to receive a survival benefit from combined heart and kidney transplantation (HKT), according to the results of an analysis of the United Network for Organ Sharing Database reported in the March issue of Archives of Surgery.

"In the past, patients with endstage heart failure having concurrent renal disease were not considered candidates for heart transplantation," write Mark J. Russo, MD, MS, from Columbia University College of Physicians and Surgeons, in New York, NY, and colleagues. "The objective of this study was to define pretransplantation patient characteristics that predict posttransplantation survival following HKT. By analyzing all heart transplantations (including all HKT cases) performed in the United States during an 11-year period, this study is the first (to our knowledge) with sufficient power to define preoperative patient characteristics that predict post-HKT survival."

Using Kaplan-Meier survival functions, this time-to-event analysis used deidentified patient-level data for 19,373 heart transplant recipients from January 1, 1995, to December 31, 2005. Pretransplantation recipient characteristics associated with better long-term survival after HKT were identified with use of multivariate Cox proportional hazards regression analysis to calculate relative risks. Weights were assigned for each risk factor, allowing construction of a risk score.

HKT was performed in 264 (1.4%) of heart transplant recipients. Factors predicting reduced survival benefit were peripheral vascular disease, recipient age older than 65 years, nonischemic cause of heart failure, dependence on dialysis at the time of transplantation, and bridge to transplantation with use of a ventricular assist device.

After stratification by risk score, the 1-year survival rate was 93.2% in the lowest-risk HKT group and 61.9% in the highest-risk HKT group. Based on an earlier study demonstrating reduced survival rates of patients undergoing orthotopic heart transplantation with a preoperative estimated glomerular filtration rate (eGFR) of less than 33 mL/minute, the investigators further stratified patients by eGFR. The only group that had significantly better survival benefit vs isolated patients undergoing orthotopic heart transplantation with eGFRs and risk scores in the same range was low-risk patients with an eGFR of less than 33 mL/minute (P = .006).

"When patients were stratified by risk score and by diminished eGFR (< 33 mL/min), low-risk HKT recipients with a diminished eGFR had improved survival following HKT over isolated heart transplant recipients," the study authors write. "Only low-risk patients with combined kidney failure (eGFR, < 33 mL/min) and heart failure seem to gain a survival benefit from HKT."

Limitations of this study include use of creatinine clearance and eGFR, which are imperfect measures of kidney disease; inability to determine reversibility of kidney disease; variability in data entry; and lack of data regarding other outcome issues.

"Among patients with combined kidney failure (eGFR, < 33 mL/min) and heart failure, those classified by this risk stratification scheme as low risk should undergo HKT, while there is no demonstrable benefit for HKT over HTA [heart transplantation alone] in patients classified as high risk," the study authors conclude.

The Health Resources and Services Administration, US Department of Health and Human Services, and the National Institutes of Health supported this study. The views expressed in the article do not necessarily represent the views of the US Department of Health and Human Services or the National Institutes of Health, nor does the mention of trade names, commercial products, or organizations imply endorsement by the US government. The study authors have disclosed no relevant financial relationships.

Arch Surg. 2009;144:241-246.

Medscape Medical News © 2009  Medscape

Cite this: Laurie Barclay. Criteria Identified to Help Predict Survival Benefit From Combined Heart/Kidney Transplantation - Medscape - Mar 18, 2009.