One of six research sites nationwide selected by the American Heart Association
The American Heart Association recently selected Northwestern Medicine as one of six centers to be part of a new, grant-funded national network dedicated to researching and understanding the causes of atrial fibrillation, the most common type of irregular heartbeat.
At Northwestern, a $3.7 million grant will fund research specifically on how atrial fibrillation develops and how it causes stroke, the leading cause of serious, long-term disability in the United States. The new knowledge base this network discovers is expected to provide a basis to generate more effective ways to treat and prevent atrial fibrillation.
“Our selection by the American Heart Association is a testament to the depth and breadth of the expertise, infrastructure and collaborative spirit present at Northwestern Medicine Bluhm Cardiovascular Institute,” said Rod Passman, MD, professor of Medicine in the Division of Cardiology and of Preventive Medicine, and a cardiac electrophysiologist at Northwestern Memorial Hospital. “We anticipate this award will allow Northwestern to continue its leadership role in atrial fibrillation research and facilitate further contributions to the prevention and treatment of this disease.”
Passman will serve as the center director at Northwestern for the Atrial Fibrillation Strategically Focused Research Network.
“The work to be led by Dr. Passman here at Northwestern is of major importance as it addresses a true compelling need within the scope of heart disease,” said Clyde Yancy, MD, MSc, chief of Cardiology and Magerstadt Professor of Medicine, and the vice dean for Diversity and Inclusion. “As well, this award now aligns with four other similar American Heart Association Strategically Focused Research Networks and positions Northwestern in unprecedented territory as the holder of five strategically focused research networks representing an aggregate research investment by the American Heart Association in Northwestern of over $15 million. With these resources we intend to change the trajectory of heart disease in this country.”
Atrial fibrillation occurs when the heart’s upper chamber beats out of synch with the lower chamber. Symptoms include palpitations, shortness of breath and fatigue, but for many with atrial fibrillation few if any symptoms are experienced. As one of the leading causes of stroke, atrial fibrillation represents an important public health challenge. An estimated 6.1 million or more Americans were living with AFib as of 2010, making it the most common heart abnormality in the United States, according to the American Heart Association. That number is expected to rise to 12.1 million by 2030.
“Establishing these centers with leading investigators from renowned institutions is an important step in discovering biological, genetic and behavioral connections affecting the occurrence and impact of atrial fibrillation and stroke related to this common arrhythmia,” said American Heart Association Chief Science Officer Rose Marie Robertson. “Bringing together the best science while empowering patients to be active participants in their own care should significantly improve the quality of life for those who suffer from atrial fibrillation.”
In its entirety, the Atrial Fibrillation Strategically Focused Research Network will allow the American Heart Association to enhance the understanding of the causes, biology, pathophysiology and epidemiology of atrial fibrillation with a goal to improve patient outcomes.
Project Descriptions
Three project comprise the new Atrial Fibrillation Strategically Focused Research Network: a clinical study, a population-level epidemiological study and a basic science investigation. Below are snapshots of the three projects and their primary investigators.
Project 1: Clinical Study
Passman will lead the clinical study. The scientific premise of this project is based on the emerging concept of the atrial myopathy as the underlying substrate for atrial fibrillation and stroke, and our ability to use cutting-edge cardiovascular magnetic resonance (CMR) methods to measure left atrial stasis, fibrosis, size and function. The first aim of this proposal, is to determine whether the addition of CMR metrics of left atrial myopathy will provide incremental value in the prediction of successful ablation – a surgical procedure to treat atrial fibrillation’s irregular heart rhythm – above traditional risk factors alone. The second aim of the clinical study is to test whether patients who maintain sinus rhythm following ablation experience “reverse remodeling,” as defined by improvement in CMR metrics of left atrial structure and function. Lastly, the investigators intend to take their extensive research on the molecular mechanisms of atrial fibrillation (performed in large animal models) and apply it to human disease. As such, in the part of the clinical study, the investigators will assess whether regions of high inflammation in the atrium can be detected using changes in local intracardiac electrograms.
Project 2: Population
Philip Greenland, MD, the Harry W. Dingman Professor of Cardiology and director of the Center for Population Health Sciences, and a professor of Preventive Medicine in the Division of Epidemiology, will lead the population study. In this observational epidemiologic study, the investigators will build on an existing cohort of well-characterized older adults who have participated for years in the Multi-Ethnic Study of Atherosclerosis (MESA). They will perform advanced 4D flow CMR imaging to further characterize the physiological substrate of atrial myopathy and atrial fibrillation. Greenland and his collaborators will study novel structural and functional MRI measures including atrial 4D blood flow and its association with atrial fibrillaiton and clinically defined ischemic stroke and silent cerebral infarction detected by brain MRI, even in the absence of documented AF. While the existing MESA study is designed to assess the association of clinical factors, including presence or absence of AF, with brain imaging findings, we will also be able to evaluate in this Center grant the additional information obtained from advanced cardiac MRI and the atrial myopathy. This will allow us to determine the importance of atrial 4D flow and LA structural abnormalities on AF prevalence, ischemic stroke risk, and subclinical cerebral infarction prevalence even in the absence of AF.
Project 3: Basic Science
Rishi Arora, MD
, associate professor of Medicine in the Division of Cardiology will lead the basic science project. The molecular mechanisms that underlie the origin of atrial fibrillation are not well understood. In this project, the investigators will determine whether inflammation and oxidative stress are major mechanisms underlying atrial fibrillation. To determine the precise role of inflammation on the genesis of atrial fibrillation, the investigators will use a highly novel gene therapy approach in clinically relevant large animal models of the disease. Specifically, they will use this gene-based approach to selectively target molecular signaling pathways involved in causing inflammation in the fibrillating atrium. As part of this translational project, Arora and his collaborators will assess whether regions of enhanced inflammation in the atria can be accurately detected by using characteristics of intra-cardiac electrograms. Lastly, the investigators will assess whether regions of enhanced tissue edema or inflammation on cardiac imaging correlate with regions of high inflammation in two complementary large animal models of atrial fibrillation.
The Northwestern Medicine Bluhm Cardiovascular Institute is part of the Northwestern Medicine health system, with multiple sites of care in Chicago and the region. Northwestern Medicine is the shared strategic vision of Northwestern Memorial HealthCare and Northwestern University Feinberg School of Medicine.
For more information, or to make an appointment with a cardiovascular specialist, call (312) NM-HEART or visit heart.nm.org.
To learn more about Northwestern Medicine, visit http://news.nm.org/about-northwestern-medicine.html.
The American Heart Association is devoted to saving people from heart disease and stroke – two of the leading causes of death in the world. We team with millions of volunteers to fund innovative research, fight for stronger public health policies, and provide lifesaving tools and information to prevent and treat these diseases. The Dallas-based association is one of the world’s oldest and largest voluntary organizations dedicated to fighting heart disease and stroke. To learn more or to get involved, visit heart.org or call any of the group’s offices around the country.
