EPIDEMIOLOGY AND PREDICTORS OF CARDIAC BYPASS ASSOCIATED AKI IN A MIDDLE-INCOME CARIBBEAN COUNTRY

Abstract Background and Aims AKI is a common and resource intensive complication of cardiopulmonary bypass surgery (CPB) in high income-countries occurring in up to one third of surgeries performed. However, little is known of its incidence and impact in the small island developing states of the Caribbean. We describe the incidence, risk factors and outcomes of AKI following CPB at a referral cardiac centre in Jamaica. Method A review of the Medical Records of adult patients (aged ≥ 18 years) with no prior ESRD or dialysis requirement undergoing CPB at the University Hospital of the West Indies, Mona between January 1, 2016 to June 30, 2019 inclusive was undertaken. Demographics, pre-operative status, intraoperative and post-operative data were abstracted. The primary outcome was all-cause 30-day mortality. AKI was defined as meeting the KDIGO criteria based on the peak serum creatinine measurement obtained within 72 hours post-operatively. Multivariable logistic regression was used to examine the risk factors for and impact of AKI on all-cause mortality. Results Of the 259 persons who underwent CPB in the study period, 211 (58% men, mean age 58.1±12.9 years, median± IQR Euro-score II of 1.4 ± 1.4) met inclusion criteria. AKI occurred in 37.3 % (80) of patients with 43.8% (35) KDIGO I, 32.5% (26) KDIGO II and (19) 23.7% KDIGO III. Renal replacement therapy was required in 3.2% (7) of patients. In a multivariable logistic regression model, baseline CKD (eGFR<60mL/min/1.732m2; odds ratio, 95%CI: 5.32,1.72-15.90), Prolonged bypass time (1.73,1.21-2.48; per hour), intraoperative PRBC transfusion (2.33,1.08-5.03) and elevated 24-hour post-operative Neutrophil/Lymphocyte ratio>18 (3.00, 1.07-8.35) were associated with an increased risk of AKI. AKI after CPB resulted in greater hospital (23.6 versus 14.6 days, p<0.001) and ICU stay (8.1 versus 3.3 days, p<0.001) and a 6-fold increase in 30-day mortality after adjusting for age and sex (HR, 95 CI: 6.40, 2.38-17.25). (see Figure 1 Kaplan Meier survival estimates for AKI) Conclusion The occurrence of AKI following CPB is comparable to that reported in the literature and is associated with poor short-term outcomes. Larger multicentre prospective studies to predict risk, identify interventions to reduce mortality and assess long term complications of AKI following CPB in Caribbean countries are needed.