Cognitive Impairment Could be Linked to Chronic Heart Failure

A study has shown that patients suffering from heart-failure are four times more likely to develop cognitive impairment than those who are not heart failure patients.

Dr Mary Sauvé, from the University of California Davis Medical Centre, led the research which compared 50 heart failure patients to 50 community controls. Age, gender and intelligence were taken into consideration when comparing patients.

Throughout the study, neuropsychologists tested six cognitive functions in participants: orientation, attention, memory, executive function, motor speed and reaction time. Dr Sauvé confirmed that these tests have been carried out before in previous research and have proved to be very sensitive.

The results showed that 46% of the heart failure patients had mild or severe shortfalls in terms of memory, learning attention and/or reaction times. This is compared to 8% of similar cases in the controlled group, which were mostly milder memory loss.

The evidence strongly suggests that cognitive impairment is closely related to heart failure (odds ratio 4.47; 95% CI 1.75-11.43; p<0.002). Dr Sauvé also records in the research that the level of cognitive shortfall in these cases is also relative to depressed learning. The significance of cognitive impairment in patients was not linked with duration of suffering from heart failure, depression, anxiety or physical functioning.

Dr Sauvé said: "The cognitive impairments in this sample of community-dwelling HF patients were consistent with the prevalence, type, and severity of impairments found in hospitalized end-stage HF patients awaiting transplant." She went on to say that this research does conclude that heart failure is associated with cognitive impairment and that ischemic cardiomyopathy is also a factor in developing cognitive impairment with heart failure.

Dr Christopher O’Connor from the Duke Heart Centre said of the association: "It's completely under-recognized and under-appreciated. This could be a major cause of poor adherence to medication, poor adherence to lifestyle interventions, and a subsequent major reason for hospitalizations." He also recognised that this impairment may be a sign of common depression in heart failure patients.

Dr Ponrathi Athilingam from the University of Rochester won the Heart Failure Society of America 2008 Nursing Investigator Award for her study on cognitive screening in heart failure patients. She said: "Most research studies have been done in HF patients before and after cardiac transplantation and indicate that cognitive dysfunction is reversible [posttransplant and] that the changes are subtle... Hence, it becomes difficult to identify these subtle cognitive changes during a short clinic visit. Furthermore, current HF guidelines do not call for routine cognitive screening for HF patients."

She added: "Finally, the most commonly used test, the Mini Mental Status Examination, has been proven by several studies - including my own - to be insensitive in identifying subtle cognitive symptoms among HF patients... Dr Sauvé's contribution to science is timely and very appropriate in an area where research is scant and more is needed."

Dr Sauvé said that it is essential to recognize these results as a high number of those heart failure patients also suffering from cognitive impairment live alone: "What it means in clinical practice is that when you give these patients verbal instructions, you also need to provide written materials because of patient difficulties with information requiring attention, learning, and memory functions; that you include the family in the discussion whenever possible; and that patients and families need to have a direct line to call if they are getting into trouble or become confused about the instructions."

"Patients living alone are at higher risk for non-adherence to both medication schedules and dietary restrictions... They need frequent follow-up, either by home-health services or a telephone intervention instituted from the clinic or physician's office to prevent adherence issues, a major cause of rehospitalization in HF patients," she concluded.

L.W.