COVID-19 and the Heart (Part 3)

Individuals with pre-existing heart disease

Patients with pre-existing heart disease such as history of stents in the coronaries, history of bypass surgery, history of heart attack or stroke and history of congestive heart failure are at highest risk of dying from COVID-19. It is therefore imperative that those patients use utmost caution in wearing masks and social distancing. For those patients the mortality can be as high as 18%. COVID-19 can exacerbate the underlying condition for those patients. By causing undue stress on the heart with development of fever, tachycardia, dehydration, shortness of breath, those patients can suffer from what is known as demand ischemia and a subsequent heart attack. Demand ischemia refers to lack of sufficient blood flow to the heart muscle as a result of undue demand placed on an already vulnerable heart in the setting of stress.  This can lead to eventual cutoff of blood supply to a part of the heart or all of it leading to a heart attack and heart failure.

For those more vulnerable patients presenting to the emergency room, emergency department physicians often decide to admit the patient to the hospital to observe them. As part of their initial laboratory workup, several blood tests are performed to risk stratify the patient.  These include an enzyme called troponin I which is a marker for injury to the heart muscle. If troponin I is elevated, it means that the cells of the heart are already exhibiting signs of injury.  Another important blood test is hs-crp (high sensitivity c reactive protein ) which is a marker of inflammation. The higher the number the higher the inflammation. D-Dimer is a third blood test often used to assess a patient’s risk. If elevated, your doctor may suspect a pulmonary embolism and request a CT scan of the lung to rule it out.  A normal D-Dimer is quite reassuring however. Other tests routinely completed on cardiac patients with COVID-19 are electrocardiogram, chest x-ray, complete blood count and an assessment of kidney and liver function.