At the intersection of heart and brain
Leaders in cardiac monitoring and neurology pursue strategies to treat patients with AFib and stroke.
Atrial fibrillation and stroke are each serious health events — but combined, outcomes can be especially debilitating and complex.
At a session Sunday afternoon, experts will address the relationship between the two as well as the role of anticoagulation and monitoring strategies for detecting and treating AFib. The session “Atrial Fibrillation and Stroke: From Wearables and Implantables to Prevention and Outcomes — CRYSTAL Clear or Clear as Mud?” also will cover some of the latest research, new advancements and relevant guidelines.
Ten years ago, the American Heart Association published Guidelines for the Primary Prevention of Stroke, which include approaches to stratify risk and select treatments to mitigate stroke in patients with AFib. Since then, new studies and guidelines have further assessed therapeutic applications and defined management recommendations, said session speaker Rajesh Kabra, MD, FACC, FHRS.
For example, the CRYSTAL AF clinical trial demonstrated that more intensive monitoring with an implanted device after a stroke of undetermined cause resulted in discovery of more occult AFib, a finding that typically prompts initiation of anticoagulation to prevent future stroke.
“Several contemporary studies have also shown that a significant proportion of patients with AFib and a high risk of stroke do not receive anticoagulation due to perceived increased risk of bleeding,” said Kabra, who is director of clinical operations at the Kansas City Heart Rhythm Institute. “Clinical pathways need to be created so that these patients can be referred for alternative nonpharmacological therapy for stroke prevention using left atrial appendage closure devices.”
Patients should receive a comprehensive stroke assessment before beginning treatment with oral anticoagulation (OAC) to attempt to weigh their absolute risk of stroke with appropriate consideration of bleeding risk, said session speaker Cara Pellegrini, MD, FHRS.
“Those who have had a stroke are at particularly high risk of a repeat event, but it may not be from the same mechanism. Their secondary stroke prevention will likely include other pharmacologic targets in addition to OAC,” said Pellegrini, director of cardiac electrophysiology at the San Francisco VA Medical Center and professor of medicine at the University of California, San Francisco.
“The impact of initiating OAC upon discovery of subclinical AFib is about as unclear among those with and without a stroke history, though our current practice does not necessarily reflect that,” she said.
The use of implantable and wearable cardiac monitoring devices in diagnosing and managing AFib and preventing stroke has evolved. Implantables are smaller and have greater diagnostic capabilities, in part due to the use of artificial intelligence and machine learning in applying sophisticated algorithms to quickly process data and identify real-time actionable factors versus false alerts.
“Implantable loop recorders have significantly improved detection and management of AFib,” Kabra said. “A recent study (MONITOR AF) showed that use of ILRs resulted in early therapy, better rhythm control and decreased AFib-related complications.”
Implantables are still the “gold standard,” Pellegrini said, but wearable devices have also advanced in their ability to monitor cardiac vitals and AFib. Many of them are inexpensive, less intrusive and relatively easy to use.
“While patient-facing wearables often use surrogates other than an electrogram to diagnose AFib and don’t yet have the specificity of traditional monitoring modalities, their ubiquity and accessibility brings advantages in terms of personal health agency,” Pellegrini said.
The session’s moderators and speakers will also discuss the impact of other large, randomized studies — NOAH-AFNET 6 and ARTESIA — that examine the impact of OAC on device-detected AFib. They also will review recently published guidelines, including the 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation, the 2024 ESC Guidelines for the Management of Atrial Fibrillation, the 2024 ESC consensus statement on embolic strokes of undetermined source and the American Heart Association/American Stroke Association 2021 Guideline for the Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack.
“The totality of evidence shows that oral anticoagulants reduce stroke in device-detected atrial fibrillation, despite the fact that baseline risk is low, and the results of the two trials have been shown in a meta-analysis to be consistent,” said session speaker and cardiologist/electrophysiologist Jeff Healey, MD, MSc, FRCPC, FHRS.
Healey said multiple secondary analyses demonstrate that anticoagulant treatment provides the greatest benefits among:
• Patients with a CHA2DS2-VASc score of greater than four
• Patients with a history of stroke/TIA
• Patients with vascular disease (peripheral vascular disease, coronary artery disease, cerebrovascular disease)
Healey, professor of medicine, Yusuf Chair in Cardiology and director of cardiology at McMaster University in Hamilton, Ontario, points out that episode duration does not play a major role in determining who benefits from the therapy.
“I hope this session gives attendees a framework for compiling seemingly discrepant results and a better understanding of the continued gaps in knowledge — the nuances of which are not always transparent in discrete guideline recommendations,” Pellegrini said. “The more we can do to be selective and specific in who and how we screen, the more useful the data we generate will be.”