Trends and Specific Causes of Cardiovascular Mortality after Kidney Transplantation in Finland

Abstract

Background Cardiovascular diseases are an important cause of mortality in patients who have undergone kidney transplantation, but the knowledge on trends of cardiovascular mortality and specific causes of cardiovascular death among these patients is scarce. Methods Our aim was to compare the cardiovascular mortality rates after kidney transplantation in Finland between 1990–1999, 2000–2009, and 2010–2019 using data from the Finnish Registry for Kidney Diseases. We analyzed 1-year and long-term cardiovascular mortality rates as well as the specific causes of cardiovascular death and the trends in them. Results In total, 4946 patients underwent first kidney transplantation in 1990–2019. During the follow-up time (median 8.3 years, interquartile range 4.0–14.5), there were 1392 deaths, of which 582 were cardiovascular deaths. In an unadjusted Cox regression model, the risk of long-term cardiovascular mortality was similar in the different periods. However, when adjusted for age, sex, duration of dialysis, and cause of kidney disease, the long-term cardiovascular mortality risk was significantly lower in 2000–2009 and 2010–2019 (hazard ratio 0.60 [95% confidence interval, 0.49 to 0.73] and hazard ratio 0.51 [95% confidence interval, 0.39 to 0.66], respectively) compared with 1990–1999. The results were similar regarding 1-year cardiovascular mortality. The distribution of different causes of cardiovascular death remained unchanged during the study period, with coronary artery disease accounting for 47% of deaths. During the first year after transplantation, pulmonary embolisms and arrhythmias were more common than in the long term. Conclusions Cardiovascular disease remained the most common cause of death in kidney transplant recipients, but adjusted cardiovascular mortality risk has decreased significantly during the past three decades. Coronary artery disease was the most frequent cause of cardiovascular death, and the proportion of coronary artery disease–related cardiovascular deaths increased after the first year after transplantation.