Current readings: neurocognitive impairment and clinical implications after cardiac surgery

The earliest reports of cardiac surgery literatures reported evidence of neurocognitive decline, highlighted in the 1995 statement of Consensus on assessment of neurobehavioral outcomes after cardiac surgery. Until now, the magnitude and clinical importance of neurocognitive outcomes continues to fluctuate and lack clarity. The aim of this review is to evaluate the contemporary status of neurocognitive outcomes in relation to pre-existing impairment, revascularization strategy, broader cardiovascular pathophysiological processes, and any longer-term clinical implications. Five studies published between 2009 and 2013 were reviewed. A meta-analysis did not find differences between on- and off-pump procedures. In other studies, there was evidence for extensive preoperative neurocognitive impairments. Additional 2 studies showed that longer-term neurocognitive impairment, including dementia, was not dissimilar to nonsurgical patients with cardiovascular disease. Currently, there is no convincing evidence to suggest that cardiac surgery, and cardiopulmonary bypass in particular, has a causal role in progression to dementia, or long-term deficit, independent of pre-existing neurocognitive impairments and cardiovascular disease.