Dr Rajaram Anantharaman, Senior Consultant Cardiologist and Lead for TAVR, Frontier Lifeline Hospital, Chennai provides detailed insights into what experts have learnt from SARS-CoV2 so far and what precautions people most susceptible to it to should take
Coronavirus Disease 2019 (COVID-19) is caused by Severe acute respiratory syndrome coronavirus 2(SARS-CoV2) which first occurred in Wuhan, Hubei province in China in December 2019 and rapidly spread to rest of the world. On January 30, 2020 WHO declared the SARS-CoV2 outbreak as a Public Health Concern of International Concern.
SARS-CoV2 is an enveloped virus with segmented, single stranded, positive-sense RNA genome. Its genome is 96.2 per cent identical to bat coronavirus, which strongly suggest bats may have been the initial zoonotic host. SARS-CoV2 uses angiotensin-converting enzyme 2 (ACE2) protein for cell entry. ACE2 is abundantly present in lung alveolar cells and in heart, arteries, kidneys and intestine. ACE2 has lung protective function, hence viral binding to these receptors deregulates lung protective pathway leading to severe lung injury and fibrosis. Due to above even though fever, cough and viral pneumonia are predominant symptoms in COVID-19 presentation, cardiac manifestations including myocarditis, arrhythmias, myocardial infarction and heart failure are seen. Increased prevalence and case fatality rates are seen in chronic cardiovascular disease, hypertension and diabetic patients. Clinical severity of COVID-19 is reported as mild in 81.4 per cent, severe 13.9 per cent and critical 4.7 per cent
Transmission of 2019-nCoV is likely to occur through large droplets, which could provide an explanation for the initial infection at the wet fish market in Wuhan. In recent reports, the median time from onset of symptoms to first hospital admission was 7·0 days (minimum to maximum 4·0–8·0), to shortness of breath was 8·0 days (5·0–13·0), to ARDS was 9·0 days (8·0–14·0), to mechanical ventilation was 10·5 days (7·0–14·0), and to intensive care unit (ICU) admission was 10·5 days.
Patients with chronic CVD and their risks due to COVID-19
- Number of studies in the currently available literature shows a strong association between pre-existing CVD and severe COVID-19
- The prevalence of hypertension, cardiac / cerebrovascular disease and diabetes in COVID-19 patients are 17.1 per cent, 16.4 per cent and 9.7 per cent respectively.
- Increased case fatality rates are seen in patients with CVD (10.5 per cent), diabetes (7.3 per cent), hypertension (6.0 per cent), all are considerably higher than the overall case fatality rate of 2.3 per cent.
- As CVD patients are older, immunodeficient due to other associated comorbidities like DM and hyperlipidemia, higher ACE2 expression with hypertension, CVD has been postulated to increase susceptibility to COVID-19 with increased fatality.
COVID-19 positive patients and cardiovascular complications
- The current literature is suggesting increased CV complications due to SARS-CoV2 including myocardial injury, arrhythmias, acute coronary syndromes, myocarditis and cardiogenic shock and death.
- Myocardial injury with raise in troponin levels are seen in majority of the patients affected by COVID-19, and such injury occurs in 7-17 per cent of hospitalised patients, more in patients admitted to ICU (225 vs 2 per cent) and in patients who died (59 per cent vs 1 per cent).
- Among patients with COVID-19 who died. 7 per cent were due to myocarditis with circulatory failure, and in 33 per cent myocarditis as additional contributing factor.
- Apart from enzyme raise seen with the myocardial injury due to COVID-19, ECG and echocardiographic changes were also noted. Case reports of overlapping symptomatology between ACS and COVID-19 have been reported from Italy, where a patient presenting with acute MI was shown to have non-obstructive coronaries and subsequently tested positive for COVID-19.
- Like other acute respiratory syndromes, there is increased inflammatory response and haemodynamic changes, which may confer risk for atherosclerotic plaque rupture in susceptible patients.
- Higher incidence of cardiac arrhythmias and cardiac arrest were reported in
- hospitalised COVID-19 patients, and more so in ICU than non-ICU patients (44.4 per cent vs 6.9 per cent). This might be due to hypoxia, metabolic disarray, neurohormonal and inflammatory response with or without prior CVD.
- More severe form of malignant tachyarrhythmias were seen in patients with fulminant myocarditis cardiogenic and mixed shock were the predominant reasons for fatality. Extracorporeal membranous oxygenation (ECMO) either venovenous for respiratory failure or venoarterial for associated cardiogenic component were used in critically ill COVID-19 patients, but the prognosis in this group was vey poor (83.3 per cent of patients who were treated with ECMO did not survive).
COVID-19 healthcare workers risks and safety measures
- As mode of transmission for COVID-19 is through droplets that are produced by cough or sneeze of the affected individual, HCW working in close proximity to the patients or undertaking procedures in close proximity are at higher risk of being exposed and procedures that produce aerosol are at the highest risk
- Currently available evidence from China shows HCW are at elevated risk of
- contracting the COVID-19 (3.8 per cent) and the Italian literature shows Interventional Cardiologists among one of the highest risk group
- WHO has recommended personal protective equipment (PPE) including face mask, eye protection, gown and gloves, and for those at highest risk while performing aerosol-generating procedures like trans-oesophageal echo, endotracheal intubation, cardiopulmonary resuscitation should use additional PPE including controlled or powered air purifying respirators (CAPR / PAPR).
- To minimise the risk for the HCW, all acute coronary syndromes (STEMI and NSTEMI) should be risk stratified (i.e. isolated inferior or lateral vs extensive Anterior STEMI) and triaged according to COVID-19 positive and probable groups.
COVID-19 drugs under evaluation and their cardiac risks
- Several anti-viral drugs (Ribavarin, Lopinavir / Ritonavir, Remdesevir) are currently being evaluated under trial protocol in COVID-19 positive patients with severe or critical illness. Majority of these drugs have unknown adverse effects or arrhythmogenic through various mechanisms including prolonged QT interval, hence close monitoring will be required
- Chloroquine / Hydroxychloroquine is another drug that has been used either as prophylactic agent or as therapeutic agent in China, the US and other countries including India. There is no RCT evidence for this apart from invitro and animal studies. It works by altering endosomal PH required for virus / cell fusion. The major adverse effects include direct myocardial toxicity, conduction abnormality and ventricular arrhythmias due to prolonged QT. Hence baseline ECG monitoring is essential and those with QTc > 450 msec should avoid taking this. This should be given under strict trial protocol and should not be taken without a physician’s prescription.
- Other drugs like Bevacizumab, Eculizumab, Fingolimod, Interferon, Pirfenidone are used only under strict trial protocol.
Lockdown and self-isolation and rapid response for COVID-19 and its implications on acute cardiac emergencies
- The lockdown and self-isolation is important to flatten the curve and reduce the community transmission of COVID-19, but the non COVID-19 acute cardiac emergencies like STEMI needing PPCI may be delayed due to the service provision priority given by the paramedical services, hospitals and cardiologists for COVID-19. Rather than delaying the reperfusion therapy, thrombolytic therapy early might be a suitable alternative in selected group of patients.
- We know from extensive literature that for STEMI patients early PPCI provides the best mortality and morbidity benefit, but due to the constraint on the services provision due to COVID-19 pandemic and the exposure risk for the HCW during the cardiac catheter laboratory procedure, a risk stratification based on the STEMI type (isolated inferior / lateral vs extensive anterior) and whether COVID-19 positive or probable based on clinical assessment is essential. There are national guidelines or consensus statements regarding the above from ACC / AHA / SCAI and ESC which can be used by individual service providers or hospitals to formulate their own protocol.
Advice for chronic CVD patients during this COVID-19 pandemic
- The prevalence of COVID-19 is high among patients with prior CVD, hypertension and diabetes. The fatality is also high among these group of patients.
- They should continue with all their guidelines directed cardiac medications that is already prescribed to them including ACE-I and ARB. All international societies have given guidelines on ACE-I and ARB and advised not to stop them.
- They should continue with their regular exercise programme (at least 30 minutes per day or 150 minutes per week total), this will increase their immunity.
- They should avoid contact with anyone who has travelled abroad within the last 14 days or have been in contact with COVID-19 patients.
- They should follow the self-isolation, social distancing and hand washing with soap strictly.
- If they develop fever, cough and respiratory symptoms including breathlessness, they should get SARS-CoV2 testing done early and seek their physicians advice over phone. Home quarantine for patients with mild symptoms and hospital admission for severe or ICU admission for critical symptoms has been advised.