In-Hospital Mortality and Major Adverse Cardiovascular Events after Kidney Transplantation in the United States

Kidney transplantation (KT) is the treatment of choice for end-stage kidney disease. Cardiovascular disease is a major determinant of morbidity and mortality in patients with KT. Temporal trends in perioperative cardiovascular outcomes after KT are understudied, especially in light of an aging KT waitlist population.

We performed a retrospective observational cohort study using the National Inpatient Sample for the years 2004-2013. All adult patients undergoing KT were identified using the appropriate International Classification of Diseases, 9th Revision, Clinical Modification codes. Demographic and hospital characteristics, discharge disposition, payer status, and major adverse cardiovascular events (MACEs) were summarized using summary statistics. Multivariate logistic regression was used to identify predictors of MACEs in the perioperative period of KT.

A total of 147,431 KTs were performed between 2004 and 2013. The mean age at KT went up from 48.1 to 51.8 years from 2004 to 2013. Medicare was the primary payer for 59.6% of the KTs. Overall average perioperative mortality was 0.5%, median length of stay was 5 days, and 6.5% of patients experienced an MACE, 78% of which were heart failures (HFs). Important predictors of perioperative MACEs were age ≥65 years (OR = 2.14), Medicare as primary payer (OR = 1.51), diabetes (OR = 1.46), recreational drug use (OR = 1.72), pulmonary circulation disorders (OR = 3.28), and malnutrition (OR = 1.91).

Despite increases in age at the time of KT, the absolute risk of perioperative MACEs has remained stable from 2004 to 2013. HF is a major component of postoperative MACEs in KT. Malnutrition and pulmonary hypertension are major nontraditional predictors of perioperative MACE outcomes.