The novel coronavirus is primarily regarded as a respiratory illness, causing pneumonia and acute respiratory distress that require mechanical ventilation for patients with severe infections. However, recently published research and anecdotal evidence from direct experience now indicate that the virus can also affect the heart, causing myocarditis, acute arrhythmias, and heart block. Emerging evidence indicates that coronavirus infection can underlie a clinical presentation of myocardial infarction in patients with no vascular blockages.
These recent findings highlight a rapidly evolving body of evidence about how to best diagnose and treat patients with cardiac symptoms during the coronavirus pandemic. "We're learning about this virus in real time," says Brian Houston, MD, Assistant Professor of Medicine in the Division of Cardiology at the Medical University of South Carolina (MUSC). "We know that there are patients who present with symptoms that look like myocardial ischemia who turn out to have COVID-19, but reports on the frequency of cardiac presentation vary drastically. Evidence from Wuhan, China puts it at about 7% of patients, but another study puts it closer to 25%. We don't know if those differences are due to the tests or sampling methodologies used, or because the patient populations were different."
Even just a few months ago, care protocols for patients presenting with cardiac symptoms followed clear cut guidelines. But, the ease of transmission and virulence of coronavirus has thrown healthcare providers into uncharted territory. "We're all collaborating and learning from each other about how to make the best decisions regarding needed procedures while also trying not to needlessly expose other patients or caregivers to this virus," says Jeffery Winterfield, MD, Associate Professor of Medicine, Hank & Laurel Greer Endowed Chair in Electrophysiology, and Director of the MUSC Electrophysiology Program. "We're working through some of our operating principles and practices, and re-evaluating and making assessments everywhere we can."
Because MUSC uses a team-based, multi-disciplinary model of care, providers are well-positioned to rapidly share the latest information across departments. System-wide communication channels are already in place and MUSC physicians are accustomed to discussing insights and developing new processes of care with colleagues from all areas in the chain of care. "Right now, we're getting at least two daily group emails from leadership addressing important points. We're also having bi-weekly, regimented phone calls for the Department of Cardiology where each section updates the others, and the heart failure section is having daily, online meetings to share information and ideas," says Houston. "I feel like the entire MUSC community has been very open to learning and working together to keep up with this rapidly changing landscape of information."
A central issue is that, while shortening time-to-treatment is critical for patients with cardiac compromise, conducting procedures without knowing whether a patient is infected risks exposing staff and other patients to the virus. "The issue is deciding how to best protect the whole community," says Winterfield. "We know that about a third of patients can transmit it even though they are asymptomatic. So, they unknowingly pose a significant risk to everyone who's in contact with them. Another concern is that, when we take a patient into the EP (electrophysiology) lab, in many instances we need to perform procedures that involve anesthesia and possibly intubating the patient which can transmit much smaller virus particles than what's in your breath. Those smaller particles can hang in the air for hours after the procedure, and it's very difficult to clear those suspended particles. We need to be responsible about how much we may be exposing others who come into that room afterwards."
Although MUSC can process its own coronavirus tests and a new, rapid test was recently approved by the Food and Drug Administration, delayed results remain a stumbling block to clinical decision-making for cardiac patients. Houston explains, "Getting in-house testing here at MUSC was a real paradigm shift in terms of diagnosing and treating COVID-19 patients. But, it still takes 12 to 24 hours to get results which is not fast enough when you have a patient with severe cardiac symptoms. For them, we need to get those results much faster to help determine the best treatment, keep our staff healthy, and avoid wasting PPE (personal protective equipment). The five-minute test that was approved recently hasn't been distributed yet–so that's not happening on the ground."
Winterfield agrees that improved testing is crucial, "Point-of-care testing with rapid turn-around would be a game-changer. It would let us take escalated precautions with the patients who are positive and better utilize our PPE. But there's also a lot we don't know about the tests. For example, we don't know their negative predictive value–what does a negative test result tell you? It may be that someone tests negative because it's early in the course of their disease, and they have low infectivity. We also don't know what percentage of results are false negatives."
The pandemic has not only changed processes of care for patients with acute cardiac symptoms, but also for those with chronic heart conditions. Like other healthcare centers worldwide, MUSC has limited elective procedures to reduce the risk of exposing staff and patients to infection and minimize PPE use. "Our Arrhythmia Center is only treating the most urgent cases right now, such as people with unstable tachycardia (very fast heart rate)or bradycardia (very slow heart rate). Most other procedures are being delayed as much as is reasonably possible," says Winterfield.
While heart transplants are not considered an elective procedure, those are also being postponed if possible. When one is conducted, the MUSC transplant team has developed additional protocols to protect organ recipients, donors, and staff. "We're weighing transplant decisions very carefully, because it's putting a patient through a high risk procedure that requires immune suppression therapy during an infectious disease pandemic," explains Houston. "There's also a donor-side risk to consider–we don't want a donor who's infected with COVID–and we need to be careful with resource use. Transplants use gloves, masks, gowns, and beds. All of that has to be weighed against the risk to the patient of dying from cardiac disease due to delaying or foregoing the surgery during this time. For more stable patients we're holding off on the transplant. If they're very sick and can't wait, we have to really make sure that neither the donor nor the recipient is infected, and that we're balancing the good of the patient and the good of whole."
In addition to managing current case loads and realigning care processes to ensure no one is needlessly exposed to a risk of infection, physicians at the MUSC Heart and Vascular Center are already collaborating on new studies to better understand how the novel coronavirus affects the heart. Winterfield says, "We've been approached by several other institutions to help plan studies to look at the heart tissue and try to figure out the mechanisms of damage." The Heart Failure Team is also collaborating to study the virus. "We know next to nothing about patients with LVADs (Left Ventricular Assist Devices) who get COVID," says Houston. "I'm very interested in working with other organizations to develop a registry of LVAD patients, and the transplant team is doing the same thing. We're already discussing how to safely obtain myocardial tissue from COVID patients that we can study."