New MHVI Program Improves Diagnosis and Management
Specialists at MedStar Heart & Vascular Institute (MHVI) have launched a new program to help diagnose and treat infiltrative cardiomyopathies earlier, in hopes of giving patients a greater chance for a longer, and improved, quality of life.
Infiltrative cardiomyopathies (CM) represent a group of acquired and inherited diseases characterized by the deposition of abnormal biological substances within the heart that ultimately lead to cardiac dysfunction.
These diseases result in symptoms of heart failure (breathlessness, lower extremity swelling, exercise intolerance, fatigue) as well as symptoms related to electrical disturbances (lightheadedness, palpitations, syncope), such as ventricular/atrial arrhythmias and even sudden cardiac death. Recognizing the disease in its early stages is essential to improve outcomes.
Designed to improve the diagnosis and treatment of all forms of infiltrative heart diseases, the new program—the first of its kind in the area—is directed by Farooq Sheikh, MD, FACC, a heart failure specialist in the Advanced Heart Failure (AHF) Program, and Selma Mohammed, MD, PhD, director of Heart Failure Research, both at MedStar Washington Hospital Center. Reflecting the systemic nature of these diseases, these two doctors work with colleagues in advanced heart failure, as well as specialists in cardiac electrophysiology, rheumatology, radiology, hematology/oncology, pulmonary medicine, genetic medicine, neurology, pathology, and more.
Two of the most common and challenging forms of infiltrative cardiomyopathies are cardiac sarcoidosis (CS) and cardiac amyloidosis (CA). Recent progress in imaging tools and technology has made identifying these diseases much easier and more accurate than before, often meaning the difference between life and death.
Sarcoidosis is a multisystem disease characterized by the accumulation of inflammatory cells within various organs, resulting in the pathologic finding of non-caseating granulomas. Increasingly, specialists are recognizing that cardiac involvement is a major cause of morbidity and mortality with sarcoidosis and much more prevalent than previously realized. In fact, the first international guidelines for the diagnosis and treatment of CS were only released in 2014.
“The annual incidence of sarcoidosis in the United States is estimated at 10 to 40 per 100,000 individuals, with a three-fold higher risk in African-Americans,” explains Dr. Sheikh.
“Approximately 30 percent of all sarcoidosis patients will experience cardiac involvement; however, clinically overt cardiac disease may only manifest in approximately 5 percent of cases. That means that the majority of CS patients have silent or asymptomatic disease, which has traditionally led to late or absent diagnoses and treatment.”
Over the last few years, however, cardiac MRI (CMR) and cardiac Positron Emission Tomography (PET) have emerged as the most effective and reliable imaging modalities for detecting CS. Cardiac PET imaging has also been shown to be useful in assessing the CS patient's response to immunosuppressive therapy.
“On their own, neither ECGs nor echocardiograms are specific enough to pick up the presence of cardiac sarcoidosis,” says Dr. Sheikh. “Even endomyocardial biopsy has a detection rate of less than 25 percent. By contrast, CMR and PET imaging have proven to be much more sensitive in detecting CS. These tests also serve as prognostic tools, predicting which patient is most likely to develop adverse cardiac events in the future, including heart failure, electrical conduction disease, ventricular tachycardia, and even death.”
While steroids remain the cornerstone immunosuppressive treatment, newer immunosuppressive therapies have been evaluated as steroid-sparing treatments, including biologic agents targeting TNFalpha (Tumor Necrosis Factor). For patients with Stages B to D heart failure, medical management remains an essential treatment approach. Finally, advanced CS care includes implantable cardiac defibrillators, monitoring for conduction disease and, in the most severe cases, mechanical circulatory support such as left ventricular assist device (LVAD) therapy and cardiac transplantation.
Amyloidosis is a systemic disease in which abnormal and even seemingly normal proteins deposit in organs and tissues, disrupting their function. Once considered rare, cardiac amyloidosis (CA) is now recognized as an under-appreciated cause of heart failure. Just like cardiac sarcoidosis, the diagnosis of cardiac amyloidosis requires biopsy evidence of amyloid deposits in the heart.
Two forms of amyloid generally infiltrate the heart: AL (immunoglobulin light chain, previously known as primary amyloidosis) and transthyretin (ATTR). Transthyretin (ATTR) amyloidosis further encompasses two distinct disease states: hereditary or familial amyloidosis (ATTR-mutant), which is due to a mutation in the transthyretin gene, and a non-genetic form seen in elderly individuals (ATTR-wild type, formerly known as senile systemic amyloidosis).
The incidence of AL cardiac amyloidosis remains relatively stable at around 3,000 new cases per year. However, recent data demonstrates that transthyretin CA is a frequent yet largely unnoticed cause of several cardiovascular diseases, including heart failure with preserved ejection fraction (HFpEF), atrial fibrillation, and aortic stenosis. It is particularly more widespread than previously expected among those individuals older than 70 and African Americans.
The past decade has seen a revolution in the diagnostic and treatment strategies for cardiac amyloidosis. The MHVI Infiltrative Cardiomyopathy Program has adopted a systematic approach to evaluate patients with suspected CA, which harnesses state-of-the-art tools for the diagnosis and treatment of the disease. This has included involvement in the Patisiran EAP Study, a phase 3 clinical trial assessing the utility of RNA interference in the treatment of hereditary amyloidosis.
OUTLOOK FOR THE FUTURE
Through the MHVI Infiltrative Cardiomyopathy Program, Drs. Sheikh and Mohammed anticipate developing a nationally recognized center of excellence on both the clinical and research fronts that hopefully will yield new knowledge that can lead to disease-specific therapies for infiltrative CM patients. Meanwhile, they are focused on capturing more patients with suspected infiltrative heart disease early in the process when treatments can help manage disease progression. Dr. Sheikh will begin to see patients at our MedStar Union Memorial Hospital site this fall, as part of our continuing effort to expand access to the MHVI network.
“Infiltrative cardiomyopathies and related heart diseases are a group of conditions in which the heart is basically an innocent bystander, struck down by an outof-control systemic illness,” Dr. Sheikh says. “Throughout the MHVI network, we have the full complement of tools, technologies, and talent at our fingertips to identify infiltrative cardiomyopathies, assess the threat, and intervene accordingly, giving patients their best hope for enhanced longevity and an improved quality of life.”
For more information on the Infiltrative Cardiomyopathy Program, please call Farooq Sheikh, MD, FACC, or Selma Mohammed, MD, PhD, at 202-877-8085. To schedule an appointment at MedStar Washington Hospital Center, call 202-877-4698. At MedStar Union Memorial Hospital, call 410-554-6550.