The risk of cardiovascular disease is not increasing over time despite aging and higher comorbidity burden of kidney transplant recipients

Background — Cardiovascular death remains the leading cause of mortality in kidney transplant recipients. Cardiovascular events are associated with significant morbidity. However, current trends in cardiovascular events after kidney transplantation are poorly understood.

Methods — We conducted a retrospective study using healthcare databases in Ontario, Canada, to determine whether the incidence of cardiovascular events after kidney transplantation has changed from 1994 to 2009. Our primary endpoint was a 3-year composite outcome of post-transplant death or major cardiovascular event (myocardial infarction, coronary angioplasty, coronary artery bypass graft surgery, stroke).

Results — Recipients (n = 4954) were older and had more baseline comorbidity in recent years. A total of 445 recipients (9.0%) died or experienced a major cardiovascular event within 3 years of transplantation. There was no significant change in the incidence of the composite outcome or death-censored cardiovascular events over time (P = 0.41 and 0.92, respectively). After adjusting for age, sex, and comorbidities, the risk of death or major cardiovascular event steadily declined across the years of transplant (2006-2009 adjusted hazard ratio, 0.70; P = 0.009; referent 1994-1997). When recipients were matched on age, sex, and date of cohort entry to members of the general population and to the chronic kidney disease population, the risk was lowest in the general population and highest in the chronic kidney disease population.

Conclusion — Despite transplant centers accepting recipients who are older with more comorbidities in recent years, the 3-year cumulative incidence of death or major cardiovascular event has remained stable over time.