New Expert Statement on Arrhythmias and Cognitive Function

Patrice Wendling

March 19, 2018

BARCELONA — Patients with atrial fibrillation (AF) could reduce their risk for dementia by taking oral anticoagulation therapy, according to the first expert consensus statement on arrhythmias and cognitive function.

The document was presented here at the European Heart Rhythm Association (EHRA) 2018 meeting and issued by the EHRA, Heart Rhythm Society, Asia Pacific Heart Rhythm Society, and Latin American Heart Rhythm Society. The guidelines were also published in Europace and Heart Rhythm .

"The most important thing we wanted to achieve was awareness for the physician that this problem exists," lead author, Nikolaos Dagres, MD, Heart Centre Leipzig, Germany, told | Medscape Cardiology. "To be aware that the association between arrhythmias and cognitive impairment and management of these patients is important and to understand how we can reduce cognitive decline."

AF is associated with a higher risk for cognitive impairment and dementia, even in the absence of stroke, he noted. Notably, the risk for silent strokes is twofold higher in AF, and accumulation of these strokes contributes to brain injury and cognitive impairment.

In addition, treatment of AF with catheter ablation may lead to silent infarcts and potential cognitive decline.

"We looked specifically at cognitive function, and there is good evidence that anticoagulation in patients who have an indication does not only prevent strokes, it prevents cognitive impairment, and that the quality of anticoagulation is also important," Dagres said.

Research has shown that the risk for dementia is increased in patients with AF who receive delayed warfarin therapy or who are poorly maintained within the therapeutic range on warfarin. Some evidence also suggests that novel oral anticoagulants (NOACs) could provide enhanced prevention of cognitive dysfunction compared with warfarin because of their association with lower stroke rates and less therapeutic variability, but this effect is not yet proven, he said.

Dagres pointed out that no randomized trials are devoted to cognitive outcomes in patients with arrhythmias and that most of the evidence had to be derived from observational studies, secondary outcomes in other randomized trials, or expert opinion.

As a result, none of the recommendations in the document carry a strong endorsement that physicians "should do this" or "should not do this," as indicated by a green or red heart, respectively. Instead, all recommendations are labeled with a yellow heart, indicating physicians "may do this."

The recommendations also apply to patients with clinical AF and not those with short durations of AF detected via remote monitoring, Dagres said.

One of the key recommendations for patients with clinical AF is that any change in appearance, behavior, or functioning reported by the patient or family should prompt the physician to the need to conduct a formal assessment. Although several tools are available for cognitive assessment, there is no consensus on the approach.

The report, however, does feature a table comparing 12 common assessment tools, including, for example, the two-step General Practitioner Assessment of Cognition and the Informant Questionnaire for Cognitive Decline in the Elderly, which have been validated in large populations.

It also notes that MRI is the preferred imaging modality for assessment of cognitive impairment but cautions that findings need to be interpreted in the clinical context because of uncertain correlation with symptoms or psychometric test performance. Positron emission tomography also may be helpful in differentiating some types of dementia.

Other recommendations to prevent cognitive dysfunction in AF include the following:

  • Apply appropriate anticoagulation in patients with AF and stroke risk factors;

  • Consider NOAC instead of vitamin K antagonists when oral anticoagulation it to be used for the prevention of stroke in AF;

  • In patients with AF managed with long-term VKA, a high anticoagulation time in therapeutic range may be beneficial for optimal prevention of new-onset dementia;

  • General health measures, such as prevention of smoking, hypertension, obesity, diabetes, and sleep apnea, and appropriate control of all risk factors may reduce concomitant risk for AF and stroke, with a putative benefit on cognitive function; and

  • Prevention of cognitive dysfunction in AF may include general measures proposed for vascular dementia or Alzheimer's disease.

For patients undergoing AF ablation, the experts point out that a recent AF ablation consensus statement highlights the use of transesophageal echocardiography to screen for pre-existing thrombus and that emerging evidence supports uninterrupted anticoagulation to perform AF ablation. "This practice is likely to gain increasing acceptance, particularly as reversal agents become more widely available for all NOACs," they write.

Even fewer data exist for patients undergoing ablation of ventricular arrhythmias, although a recent study identified a new silent stroke in 7 of 12 patients having ventricular tachycardia ablation. Most of the patients underwent ablation via a retrograde transaortic approach, although it is unknown whether the risk would be lower with use of a transseptal approach.

New acute brain lesions were also detected in 12 of 23 patients after left atrial appendage occlusion, but there was no apparent impact on cognitive testing, the authors note. Procedural stroke, typically related to air embolism, also has been reported with the Watchman device (Boston Scientific) in the PROTECT trial, although the impact on long-term cognition is unknown.

Finally, and perhaps most telling about the paucity of data in this area, the experts highlight no fewer than 17 knowledge gaps and areas for further research. These include the effect of rhythm control and cardiac resynchronization therapy on cognitive function, effective strategies for cognitive surveillance, and the time course of cognitive impairment in patients with AF.

"We need to see in AF patients, because this is the major group that is affected, if these recommendations based on observational evidence are supported by large randomized trials," Dagres said.  

Dagres reported no relevant financial relationships.

European Heart Rhythm Association (EHRA) 2018. Presentation 661. Presented March 19, 2018.

Europace. Published online March 18, 2018. Full text

Heart Rhythm. Published online March 18, 2018.  Abstract  

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