Perioperative outcomes among patients with end-stage renal disease following coronary artery bypass surgery in the USA

Abstract

Background: Patients with end-stage renal disease (ESRD) requiring chronic haemodialysis who undergo coronary artery bypass graft surgery (CABG) are at significant risk for perioperative mortality. However, the impact of changes in ESRD patient volume and characteristics over time on operative outcomes is unclear.

Methods: Using the Nationwide Inpatient Sample database (1988-03), we evaluated rates of CABG surgery with and without concurrent valve surgery among ESRD patients and outcomes including in-hospital mortality, and length of hospital stay. Multivariate regression models were used to account for patient characteristics and potential cofounders.

Results: From 1988 to 2003, annual rates of CABG among ESRD patients doubled from 2.5 to 5 per 1000 patient-years. Concomitantly, patient case-mix changed to include patients with greater co-morbidities such as diabetes, hypertension and obesity (all P < 0.001). Nonetheless, among ESRD patients, in-hospital mortality rates declined nearly 6-fold from over 31% to 5.4% (versus 4.7% to 1.8% among non-ESRD), and the median length of in-hospital stay dropped in half from 25 to 13 days (versus 14 to 10 days among non-ESRD).

Conclusions: Since 1988, an increasing number of patients with ESRD have been receiving CABG in the USA. Despite increasing co-morbidities, operative mortality rates and length of in-hospital stay have declined substantially. Nonetheless, mortality rates remain almost 3-fold higher compared to non-ESRD patients indicating a need for ongoing improvement.

Fig. 1

Flow diagram describing the selection criteria for discharges from core NIS data files from 1988 to 2003. Boxes A through D indicate the level of data after application of selection criteria at each step.

Fig. 2

Percentage and number of patients with ESRD receiving CABG from 1988 to 2003.

Fig. 3

Adjusted in-hospital mortality rates among patients with and without ESRD following CABG. Regression lines are shown for ESRD (straight line) and non-ESRD (dashed line) patients.

Fig. 4

Median length of hospital stay in days among survivors with and without ESRD following CABG with vertical bars indicating the confidence intervals. Regression lines are shown for ESRD (straight line) and non-ESRD (dashed line) patients.

Fig. 5

Percentage of post-CABG survivors with and without ESRD with non-routine discharge disposition from 1988 to 2003. Regression lines are shown for ESRD (straight line) and non-ESRD (dashed line) patients.