Effect of on-pump vs. off-pump coronary artery bypass grafting in patients with non-dialysis-dependent severe renal...

Area of Science:

• Cardiovascular Surgery
• Nephrology
• Clinical Outcomes Research

Background:

• On-pump coronary artery bypass (ONCABG) grafting poses risks for patients with poor renal reserve.
• Evidence on off-pump coronary artery bypass (OPCABG) benefits in high-risk renal patients is limited and controversial.
• Severe renal impairment (creatinine clearance < 50 mL/min) significantly increases perioperative morbidity and mortality.

Purpose of the Study:

• To compare early clinical outcomes between OPCABG and ONCABG in patients with severe renal impairment.
• To utilize propensity-matched cohorts from a large national registry for robust comparison.
• To assess the impact of surgical technique on mortality, stroke, dialysis, bleeding, and hospital stay.

Main Methods:

• Retrospective analysis of 8,628 patients with severe renal impairment undergoing isolated CABG (1996-2019) from the UK NACSA database.
• Propensity score matching (1:1 nearest neighbor) to create comparable cohorts for OPCABG (n=1,141) and ONCABG (n=1,141).
• Cluster-robust standard error regression used for outcome analysis, adjusting for baseline characteristics.

Main Results:

• No significant differences in in-hospital mortality, post-operative dialysis, or stroke rates between OPCABG and ONCABG groups.
• ONCABG group showed a higher rate of return to theatre for bleeding or tamponade (P > 0.02).
• OPCABG was associated with a shorter hospital length of stay by 1 day (P = 0.008).

Conclusions:

• OPCABG and ONCABG demonstrate comparable early mortality and stroke rates in patients with severe renal impairment.
• ONCABG is linked to an increased risk of bleeding complications requiring reoperation.
• OPCABG may offer a benefit in reducing hospital length of stay for this high-risk population.