P1623MAJOR ADVERSE CARDIOVASCULAR EVENTS (MACE) AFTER KIDNEY TRANSPLANTATION: A POPULATION-COHORT ANALYSIS OF ENGLISH TRANSPLANT CENTRES
Authors: Anderson Benjamin , Evison Felicity , Gallier Suzy , Ferro Charles , Sharif Adnan 
Published: June 2020

Abstract

Background and Aims
Due to a high burden of cardiovascular disease in end-stage kidney failure, candidates for kidney transplantation must undergo cardiac screening to determine their ‘cardiac fitness’ to proceed with surgery even when asymptomatic and in the absence of robust evidence. MACE rates within the first year after kidney transplantation in North American centres are reported at between 7.0% and 8.7% but data from an European cohort is lacking. Therefore, the aim of this population-cohort analysis was to determine the MACE rate within the first year after kidney transplantation for all kidney transplant recipients in England.

Method
We obtained data from every kidney transplant procedure performed in England between 1st April 2002 and 31st March 2018. Data was extracted from Hospital Episode Statistics using administrative ICD-10 and OPCS-4 codes, with linkage to the national death registry for mortality data (including causality). We excluded age ≤18, repeat transplant in same period, multi-organ transplant and residence outside England. MACE was defined as any hospital admissions with myocardial infarction, stroke, unstable angina, heart failure, any coronary revascularisation procedure and/or any cardiovascular-related death. Univariable and multivariable logistical regression analyses were conducted to investigate the odds for MACE after kidney transplantation.

Results
After exclusions, we had a cohort of 30,325 kidney transplant recipients for analysis. MACE events occurred in 781 kidney transplant recipients within the first-year post-transplantation (2.6% of all kidney transplant procedures). Of these 781 MACE events, 201 occurred during the index admission for kidney transplantation surgery (representing 25.7% of all first-year MACE events and 0.7% of all kidney transplant procedures). Predictors of long-term mortality on Cox regression include; age, non-White ethnicity, socio-economic deprivation, deceased donor, pre-existing diabetes, increased Charlson score, previous cardiac history and MACE within the first year (HR 2.59; 95% CI 2.34-2.88, p&lt;0.001). Kidney transplant recipients who suffered a non-fatal MACE within the first year had 1-, 3-, 5- and 10-year patient survival of 80.5%, 70.2%, 54.5% and 38.6%, compared to 97.4%, 94.4%, 90.7% and 78.4% for kidney transplant recipients not developing MACE within the first year post-transplant (p&lt;0.001). Kidney transplant recipients having MACE events during the index admission compared to subsequent admissions were differentiated by age, sex and previous cardiac history but had similar patient survival (p=0.283).

Conclusion
MACE events within the first year after kidney transplantation are associated with increased mortality risk in England but MACE rates are significantly lower at 2.6% than those reported in North America. This is despite similar cardiac screening strategies, which may reflect different patient demographics and kidney failure care. In the context of the increased debate concerning the utility of cardiac screening asymptomatic kidney transplant candidates, understanding baseline MACE rates can shape the design of clinical trials exploring non-inferiority of cardiac screening versus non-screening before joining the waiting list (which differs methodologically from the CARSK study). However, renal physicians and surgeons will need to determine the upper boundary of the 95% confidence interval for the hazard ratio of MACE risk in any future clinical trial.