RESUMO
INTRODUCTION: Despite the high prevalence of cognitive impairment or dementia post coronary artery bypass grafting (CABG), the incidence of cognitive impairment or dementia post-CABG in contemporary practice is currently unclear. Therefore, this paper aims to investigate the incidence and associated risk factors of cognitive impairment or dementia in patients post-CABG. METHODS: A systematic search across three databases (PubMed, SCOPUS and Embase) was conducted for studies published in or after 2013 that reported cognitive impairment or dementia post-CABG. Subgroup analyses and meta-regression by risk factors were performed to determine their influence on the results. RESULTS: This analysis included 23 studies with a total of 2620 patients. The incidence of cognitive impairment or dementia less than one month, two to six months, and more than twelve months post-CABG was 35.96% (95%CI: 28.22-44.51, I2=87%), 21.33% (95%CI: 13.44-32.15, I2=88%) and 39.13% (95%CI: 21.72-58.84, I2=84%), respectively. Meta-regression revealed that studies with more than 80% of the cohort diagnosed with hypertension were significantly associated with incidence of cognitive impairment or dementia less than one-month post-CABG. CONCLUSION: This meta-analysis demonstrates a high incidence of cognitive impairment or dementia in patients post-CABG in contemporary practice, particularly less than one month post-CABG. We found that hypertension was a significant risk factor in the short term (less than one month) follow-up period for cognitive impairment or dementia post-CABG. Future research should be done to assess strategies to reduce cognitive impairment post-CABG. .
RESUMO
Cognitive impairment (CI) shares common cardiovascular risk factors with acute myocardial infarction (AMI), and is increasingly prevalent in our ageing population. Whilst AMI is associated with increased rates of CI, CI remains underreported and infrequently identified in patients with AMI. In this review, we discuss the evidence surrounding AMI and its links to dementia and CI, including pathophysiology, risk factors, management and interventions. Vascular dysregulation plays a major role in CI, with atherosclerosis, platelet activation, microinfarcts and perivascular inflammation resulting in neurovascular unit dysfunction, disordered homeostasis and a dysfunctional neurohormonal response. This subsequently affects perfusion pressure, resulting in enlarged periventricular spaces and hippocampal sclerosis. The increased platelet activation seen in coronary artery disease (CAD) can also result in inflammation and amyloid-ß protein deposition which is associated with Alzheimer's Dementia. Post-AMI, reduced blood pressure and reduced left ventricular ejection fraction can cause chronic cerebral hypoperfusion, cerebral infarction and failure of normal circulatory autoregulatory mechanisms. Patients who undergo coronary revascularization (percutaneous coronary intervention or bypass surgery) are at increased risk for post-procedure cognitive impairment, though whether this is related to the intervention itself or underlying cardiovascular risk factors is debated. Mortality rates are higher in dementia patients with AMI, and post-AMI CI is more prevalent in the elderly and in patients with post-AMI heart failure. Medical management (antiplatelet, statin, renin-angiotensin system inhibitors, cardiac rehabilitation) can reduce the risk of post-AMI CI; however, beta-blockers may be associated with functional decline in patients with existing CI. The early identification of those with dementia or CI who present with AMI is important, as subsequent tailoring of management strategies can potentially improve outcomes as well as guide prognosis.