Cognitive decline before and after incident coronary events

Reviewers

Romain Didier

Interventional cardiologist / Cardiologist

CHRU BREST SITE HOPITAL CAVALE BLANCHE - Brest, France

Mehdi Hadid

Interventional cardiologist

CHRU of Brest -

Our Comment

This joint review is part of the PCRonline GLOBAL Journal Club Initiative by selected members of the EAPCI/PCR Journal Club and PCR NextGen, and is based on the underlying idea of “Bringing peers together, exchanging ideas, towards a common standard of care”.

Why this study – the rationale/objective?

Previous studies have suggested that coronary heart disease (CHD) may be associated with accelerated cognitive decline. CHD could predispose to cerebrovascular damage, such as cerebral ischemic lesions, which has been reported to finally result in cognitive impairment and to be involved in the pathological cascade of vascular dementia and Alzheimer’s disease.

The cognitive function declines naturally with age, but patients experiencing CHD could have faster decline as compared to the general population and potentially further decline also after an acute coronary ischemic event.

The objective of this study was to compare, in a national representative cohort age 50 years, the average of cognitive decline: 1) between patients who had an incident of CHD and patients free of CHD; 2) and before and after an acute event in patients with CHD.

How was it executed – the methodology?

This study is the analysis of The English Longitudinal Study of Ageing (ELSA) which is a longitudinal study that collects multidisciplinary data from a representative sample of the English population aged of 50 years old and older.

This study included 7,888 participants with no history of stroke or incident stroke during follow-up. Participants underwent a cognitive assessment at baseline and at least 1 other time point. Incident CHD was identified as a diagnosis of myocardial infarction and/or angina during follow-up.

The cognitive assessment was performed in each time point with 3 tests (verbal memory, semantic fluency and temporal orientation). Participants were classified in two groups according to an occurrence or not of CHD.

What is the main result?

The median follow-up was 12 years, overall, 480 (5.6%) patients presented CHD events during the follow-up (254 myocardial infarction and 286 angina pectoris), and the median number of cognitive assessments was 7.

The mains results of this study were:

1. The global cognitive decline was higher in patients with history of CHD.
2. Before CHD diagnosis, the annual rate of cognitive decline was similar between patients free of CHD and patients where a CHD was secondarily diagnosed.
3. No short-term cognitive decline was observed in participants with CHD diagnosis after the event, but after the years following CHD diagnosis, global cognition, verbal memory, and temporal orientation scores declined significantly faster than they did before the event.

Critical reading and relevance for clinical practice

This study is one of the largest longitudinal with a long-term follow-up study investigating the progression of cognitive decline before and after the occurrence of CHD.

An interesting point highlighted by this study is that cognitive decline seems to be more pronounced only in patients with coronary symptoms. In other words, having many cardiovascular risk factors without having presented coronary symptoms seems not sufficient to lead to a faster cognitive decline compared to the reference population. Cerebral lesions are most probably the nidus of cognitive decline.

Of course in the interpretation of this study, we need to take into account that there is potential selection bias, as 1,644 participants (17.2%) were excluded from the present study because of loss of follow-up. In addition, the evaluation of cognitive function with a simple isolated task may not be enough to detect subtle changes after CHD. More elaborate neuropsychological assessment may yield more robust associations. Finally, after CHD, patients received frequently various treatments that could also contribute to the cognitive decline.

It is important to note that the present study does not address the cognitive decline after angiography and/or Trans-aortic valve implantation (TAVI). In fact, several data support the post-procedural occurrence of numerous cerebral defects in cerebral magnetic resonance imaging after TAVI, but the clinical translation in cognitive decline remain not fully explored.