Background: Cardiovascular disease is a leading cause of death after renal transplantation (RTx), and the incidence is considerably higher than in the general population. Aim of this study was to evaluate the incidence of atherosclerotic cardiovascular complications after RTx, the prevalence of cardiovascular risk factors, prior to and following RTx, and the association between the risk factors and complications.
Patients and methods: Analysis of atherosclerotic cardiovascular diseases (coronary artery disease, cerebral and peripheral vascular disease) and cardiovascular risk factors before and after transplantation in 427 renal transplant recipients between 1987 and 1992 (mean age at transplantation 45 +/- 12 years, 58% male, 7% diabetics) with a mean posttransplant follow-up of 28 +/- 20 months.
Results: Following RTx 11.7% developed atherosclerotic cardiovascular diseases, the majority coronary artery disease (9.8%). The comparison of risk factors 12 months before and 24 months following transplantation showed: The prevalence of systemic hypertension (from 67% to 86%), diabetes mellitus (from 7% to 16%) and obesity with a body mass index > 25 kg/m2 (from 26% to 48%) had increased significantly whereas the number of smokers halved to 20%. The triglycerides decreased significantly (from 235 +/- 144 mg/dl to 217 +/- 122 mg/dl). The total and HDL cholesterol rose significantly (from 232 +/- 65 mg/dl to 273 +/- 62 mg/dl and from 47 +/- 29 mg/dl to 56 +/- 21 mg/dl, respectively). The LDL cholesterol increase was insignificant (from 180 +/- 62 mg/dl to 189 +/- 53 mg/dl). In the univariate analysis, cardiovascular diseases were significantly associated with male gender, age over 50 years, diabetes mellitus (DM), smoking, total cholesterol > 200 mg/dl, LDL cholesterol > 180 mg/dl, HDL cholesterol < 55 mg/dl, fibrinogen > 350 mg/dl, body mass index > 25 kg/m2, and more than 2 antihypertensive agents per day. The Cox proportional hazards model revealed DM with a relative risk (RR) of 4.3, age > 50 years (RR = 2.7), body mass index > 25 kg/m2 (RR = 2.6), smoking (RR = 2.5), and LDL cholesterol > 180 mg/dl (RR = 2.3) as independent risk factors.
Conclusions: The high incidence of cardiovascular disease following renal transplantation is mainly due to a high prevalence and accumulation of classical risk factors before and following transplantation. The treatment of the risk factors must be effective and introduced early in the course of renal failure, further, they must be continued following transplantation. Future prospective studies should evaluate the success of treatment regarding reduction of cardiovascular morbidity and mortality in this high risk population.