Targeted Blood-pressure Management and Acute Kidney Injury After Coronary Artery Bypass Surgery

Impact of Targeted Blood-pressure Management on Incidence of Acute Kidney Injury After Off-pump Coronary Artery Bypass Surgery: A Randomized Controlled Trial

Acute renal injury (AKI) is a common complication after cardiac surgery and is associated with worse outcomes. It is now realized that intraoperative hypotension is an important risk factor for the development of AKI. In a recent randomized controlled trial of patients undergoing major noncardiac surgery, intraoperative individualized blood-pressure management reduced the incidence of postoperative organ dysfunction. The investigators hypothesize that, for patients undergoing off-pump CABG, targeted blood-pressure management during surgery may also reduce the incidence of postoperative AKI.

Acute renal injury (AKI) is a common complication after cardiac surgery. In patients undergoing noncardiac surgery, intraoperative hypotension may lead to hypoperfusion of important organs and result in organ injuries such as AKI, myocardial injury, and stroke. The development of organ injuries is associated with wose outcomes including higher 30-day or even 1-year mortality. In a recent randomized controlled trial, patients undergoing major noncardiac surgery received either individualized (systolic blood pressure [SBP] maintained within 10% of the reference level) or standard (SBP maintained above 80 mmHg or within 40% of the reference level) blood-pressure management strategy during surgery. The results showed that individualized blood-pressure management reduced the incidence of postoperative organ dysfunction. Intraoperative hypotension is very common during off-pump coronary artery bypass grafting (CABG) surgery. The investigators hypothesize that, for patients undergoing off-pump CABG, good blood-pressure management with norepinephrine may also reduce the incidence of postoperative AKI. The purpose of this study is to investigate the effect of targeted blood-pressure management during off-pump CABG surgery on the incidence of postoperative AKI.

Inclusion Criteria:

• Age ≥ 50 years;
• Scheduled to undergo off-pump CABG surgery.

Exclusion Criteria:

• Refuse to participate;
• Untreated or uncontrolled severe hypertension (systolic blood pressure ≥180 mmHg or diastolic blood pressure ≥110 mmHg);
• Chronic kidney disease with a glomerular filtration rate < 30 ml/min/1.73 m2 or end-stage renal disease requiring renal-replacement therapy;
• Inability to communicate during the preoperative period because of coma, profound dementia, language barrier, or end-stage disease;
• Requirement of vasopressors/inotropics to maintain blood pressure before surgery;
• Second or emergency surgery;
• Expected survival of less than 24 hours.