Cardiac consequences of COVID-19
This week’s expert:
A/Prof Raj Puranik , Clinical Cardiologist at Royal Prince Alfred Hospital and Westmead Children’s Hospital, Sydney
Drawn from Dr David Lim’s interview with Associate Professor Raj Puranikon the Healthed Podcast, ‘Going Viral’.
• Data from China have shown that although 80% of people with COVID-19 will have only mild symptoms, 5% will have a critical illness.
• In COVID-19, the primary cause of death is commonly respiratory failure, however significant cardiac manifestations are likely to be present.
• Also from China data, the overall fatality rate of COVID-19 was estimated to be 2.3%. However, among those who died, patients with cardiovascular disease were over-represented. For patients with CVD, the fatality rate was closer to 10%, for those with diabetes 7% and for those with hypertension the fatality rate was 6%
• The mechanism by which pre-existing CVD represents a higher risk of dying from COVID-19 relates to how the virus infects the body. The spike protein in the SARS-CoV-2 virus gains entry into multiple organs via the ACE2 receptor. Once in the cell the virus inhibits the expression of this enzyme which means this enzyme can no longer exert its protective effect on the heart and vascular system.
• We now know that people who have been on ACE inhibitors or ARBs must absolutely continue to take them. Their use has been associated with a reduced viral load in COVID-19 infection and better outcomes.
• The direct effects of SARS-CoV-2 infection on the cardiovascular system include an effect on the myocardium causing myocarditis and an activation of the clotting cascade which can result in an acute coronary syndrome such as a STEMI or coronary spasm.
• The indirect effects of SARS-CoV-2 on the cardiovascular system include the response of the heart to ongoing hypoxia (which can be an acute or late complication) or it can induce a hyperinflammatory state which can trigger a cytokine storm, possibly leading to cardiogenic shock.
• Acute coronary syndrome can be the first sign of COVID-19 infection.
• People with cardiac symptoms still need urgent assessment in hospital even in the midst of COVID-19. Patients reluctant to attend hospitals because of the risk of COVID-19 can be reassured measures have been put in place to ensure their safety including protocols that see patients undergoing a rapid COVID-19 screening test and a chest Xray prior to cardiac catheterisation.
• Interestingly recent research suggests that up to 40% of patients with COVID-19 who present with STEMI have non-obstructive coronary atherosclerosis (MINOCA). Despite ST-elevation on their ECG and high troponin levels, their symptoms are caused by myocarditis rather than atherosclerosis.
• A recent study published in JAMA suggests that the cardiac inflammation associated with a COVID-19 infection persists long after the respiratory effects have resolved. In this recent study, cardiac MRI revealed 80% of people still had evidence of cardiac inflammation 70 days post-infection. This was independent of the severity of the initial COVID-19 infection and any pre-existing comorbidities. However, this inflammation was not necessarily symptomatic and did not cause any adverse effects in this study.
• Nonetheless, the evidence of slow recovery from myocardial inflammation has clinical implications.
• Should patients with a history of COVID-19 infection present with new symptoms such as dyspnoea they should initially be re-tested for COVID-19. They should then be assessed with a full cardiac examination, an ECG and an echocardiogram.
• Cardiac inflammation can be present despite a normal ECG and echocardiogram. Consequently, given that the evidence suggests this cardiac inflammation can take up to six months to resolve, it is suggested, post-COVID, people gradually build up exercise capacity over 3-6 months to reduce the risk of developing cardiac arrhythmias even if they are asymptomatic.
• Finally, COVID-19 isolation has seen a reduction in face-to-face GP consultations among patients with chronic cardiac disease particularly heart failure. The change in lifestyle courtesy of the pandemic has also potentially seen a lessening of control of cardiac risk factors in terms of weight, exercise, alcohol intake, fluid intake and in some cases compliance with medications. Telehealth consultations have been shown to be effective in helping patients maintain the required lifestyle changes and medication compliance to improve cardiac health outcomes, particularly among heart failure patients. Patients can be encouraged to keep a log book of weight, BP and fluid intake.
• Cardiac rehabilitation nurses at local hospitals can provide monitoring services via telehealth to cardiac patients in the community