Preoperative cerebral hypoperfusion in the left, not in the right, hemisphere is associated with cognitive decline after cardiac surgery

• Published in: Psychosomatic medicine Vol. 74; no. 1; pp. 73 - 80
• Main Authors: Messerotti Benvenuti, Simone, Zanatta, Paolo, Longo, Carolina, Mazzarolo, Anna Paola, Palomba, Daniela
• Format: Journal Article
• Language: English
• Published: United States Lippincott Williams & Wilkins Ovid Technologies 01-01-2012
• Subjects: Blood Flow Velocity; Cardiac surgery; Cardiac Surgical Procedures - adverse effects; Cerebrovascular Circulation - physiology; Cerebrum - blood supply; Cerebrum - diagnostic imaging; Cerebrum - physiopathology; Circulatory system; Cognition & reasoning; Cognition Disorders - epidemiology; Cognition Disorders - etiology; Cognition Disorders - physiopathology; Cognitive impairment; Female; Functional Laterality; Heart surgery; Humans; Incidence; Logistic Models; Male; Memory, Short-Term; Middle Aged; Middle Cerebral Artery - diagnostic imaging; Middle Cerebral Artery - physiopathology; Neuropsychological Tests - statistics & numerical data; Neuropsychology; Postoperative period; Predictive Value of Tests; Preoperative; Preoperative Period; Risk Factors; Short term; Surgery; Ultrasonography, Doppler, Transcranial
• ISSN: 0033-3174; 1534-7796
• DOI: 10.1097/PSY.0b013e3182383a94

Postoperative cognitive decline (POCD) is a frequent complication after cardiac surgery. Although intraoperative events are risk factors for POCD, the role played by preoperative hypoperfusion in cognitive decline has not yet been investigated. It is also unknown whether the impact of preoperative hypoperfusion in the left or right middle cerebral arteries (MCAs) can differentially account for POCD. The main aims of this study were to investigate whether preoperative cerebral hypoperfusion was associated with early POCD and whether lateralized hypoperfusion would differentially affect POCD in patients after cardiac surgery.
Bilateral MCA continuous transcranial Doppler (TCD) sonography was preoperatively performed at rest in 31 right-handed patients who underwent cardiac surgery to detect cerebral blood flow (CBF) velocity. All patients completed a neuropsychological evaluation to assess attention, short-term memory, working memory, and psychomotor function before surgery and at discharge. POCD was defined using the standard deviation method. Logistic regression was used to investigate the association between hypoperfusion and POCD, controlling for common preoperative risk factors.
Fourteen patients (45%) exhibited POCD. Cerebral hypoperfusion in the left MCA selectively predicted the incidence of POCD (odds ratio = 0.90, p < .02), whereas CBF velocity in the right MCA was unrelated to POCD (odds ratio = 1.07, p = .39).
Patients who underwent cardiac surgery with reduced CBF velocity in the left MCA preoperatively are at greater risk for POCD. Left cerebral hypoperfusion may also represent an independent predictor of POCD in these patients. TCD evaluation may have substantial clinical benefits for the detection of patients at high risk of POCD after cardiac surgery.