Peri-operative renal function and outcome after orthotopic heart transplantation.

BACKGROUND

Renal insufficiency is an established risk factor in patients undergoing cardiovascular surgery. We sought to evaluate the relationship between renal function and outcomes after orthotopic heart transplantation (OHT).

METHODS

We conducted a retrospective review of 622 adults who underwent 628 consecutive OHTs between 1994 and 2001 at our institution. The recipients were divided into either normal (Group 1) or impaired (Group 2) pre-operative renal function. Impaired renal function was defined as creatinine clearance (CrCl) < 40 ml/min (Cockroft-Gault formula). Meanwhile, patients in Group 1 (normal) were defined by CrCl > or = 40 ml/min. The primary end points of the study were early and late mortality. The secondary end point included post-operative renal failure defined by the requirement of dialysis or renal allograft in the early post-operative period. The Kaplan-Meier method was used to determine actuarial survival.

RESULTS

Early mortality was 7% (38/531) in Group 1 and 17% (16/96) in Group 2 (p = 0.002). Similarly, the death rate per 100 patient-years was 4.8 and 8.1 for the groups, respectively (p = 0.03). Nine percent of patients in Group 1 required post-operative dialysis (49/531), whereas 32% of recipients in Group 2 required this intervention (31/96) (p < 0.001). Early mortality was 41% for patients requiring post-operative dialysis and 3% for those not requiring such intervention (p < 0.001). Early mortality after post-operative dialysis was 41% (20/49) in Group 1 and 42% (13/31) in Group 2 (p = 0.2).

CONCLUSIONS

CrCl < 40 ml/min is a useful marker for increased post-operative renal failure and mortality. Recipients who require post-operative dialysis have greatly increased mortality regardless of pre-operative CrCl. Dialysis in patients after heart transplantation carries a prohibitive risk. Dialysis as a bridge to renal transplantation may reduce this high mortality rate.