Weinrauch LA, et al. - Researchers determined the link between smoking status and clinical outcomes in kidney transplant recipients, given the rising number of patients either awaiting or having received a kidney transplant and the absence of smoking cessation as the criterion for transplantation in guidelines. Continued smoking was found to be related to >100% increased risk of non-cardiovascular death, 70% greater risk of all-cause mortality and a 50% greater risk of graft loss, a risk not seen in former smokers. These data confirmed the link between smoking and adverse clinical outcomes and recommended smoking cessation prior to kidney transplantation.

Methods

• Researchers performed this post hoc analysis of the Folic Acid for Vascular Outcome Reduction in Transplant trial, using Cox proportional hazards models to evaluate the links between smoking status, defined as never having smoked, formerly or currently smoking, and both all-cause mortality and graft survival.
• Fatal events were centrally adjudicated into prespecified categories: all-cause, cardiovascular and non-cardiovascular causes.
• Return to dialysis or retransplantation was used to define graft loss.

Results

• Data showed that among 4110 transplant recipients, there were 451 current smokers and 1611 former smokers.
• Researchers noted that the mortality rate per 100 patient-years was 4.0 (71 deaths) for smokers, 3.5 (226 deaths) for former smokers and 2.4 (116 deaths) for never smokers.
• They also observed that hazard ratio for mortality for current smokers was 1.70 (CI=1.26–2.29, p=0.001) and for former smokers was 1.21 (0.98–1.50, p=0.08) with 1.0 representing never smokers.
• As in each group (allp>0.3), the number of cardiovascular deaths was found to be similar, the differences between groups was driven by non-cardiovascular death rates.
• Increased hazard of non-cardiovascular death was reported for current smokers (2.39; 1.62–3.61, p<0.001) and former smokers (1.50; 1.12–2.01, p=0.007).
• Findings demonstrated kidney allograft failure to be seen more likely in current smokers vs in either former or never smokers (3.5, 2.1 and 2.0 per 100 patient-years, p<0.001, adjusted hazard ratio 1.49 and 1.05, respectively).