Defining an Intraoperative Hypotension Threshold in Association with Stroke in Cardiac Surgery

Area of Science:

• Cardiology
• Neurosurgery
• Anesthesiology

Background:

• Stroke is a significant complication following cardiac surgery, leading to disability and mortality.
• Identifying modifiable risk factors for perioperative stroke is crucial for improving patient outcomes.

Purpose of the Study:

• To evaluate the association between the severity and duration of intraoperative hypotension and the incidence of postoperative stroke in patients undergoing cardiac surgery.

Main Methods:

• A retrospective cohort study analyzed 7,457 adult patients undergoing cardiac surgery with cardiopulmonary bypass.
• Intraoperative hypotension was defined by minutes with mean arterial pressure (MAP) below specific thresholds (<55, 55-64, 65-74 mmHg).
• Logistic regression with propensity score adjustment examined the association between hypotension and postoperative ischemic stroke.

Main Results:

• Postoperative stroke occurred in 1.5% of patients (111/7,457).
• Sustained MAP < 64 mmHg during cardiopulmonary bypass was strongly associated with increased stroke risk.
• Older age, hypertension, combined surgery, emergent status, prolonged bypass, and new-onset atrial fibrillation were also linked to stroke.

Conclusions:

• Intraoperative hypotension is a potentially modifiable risk factor for perioperative stroke.
• Targeting mean arterial pressure during cardiopulmonary bypass may be a key strategy to reduce stroke incidence.