A 71-year-old Hispanic man with medical comorbidities of diabetes mellitus, hypertension, abnormal functioning bioprosthetic aortic valve (severe aortic stenosis), and chronic kidney disease was admitted with COVID-19 pneumonia confirmed with nasopharyngeal COVID-19 reverse-transcription-polymerase chain reaction (RT-PCR) test. The patient received tocilizumab, remdesivir and dexamethasone with marked signs of improvement. He was discharged home on a tapering dose of prednisone and home oxygen. He was readmitted 3 months later with fever and chills. His blood cultures grew methicillin-sensitive Staphylococcus aureus. He was started on intravenous antibiotics for 4 weeks but remained febrile with persistent bacteremia. An electrocardiogram showed third-degree heart block (Figure 10-1A). The patient underwent a transesophageal echocardiogram (TEE) for evaluation of endocarditis (Figure 10-1B). The TEE showed aortic valve vegetation with aortic root and aortomitral curtain thickening suspicious of abscess (Figure 10-1C). He underwent aortic root abscess drainage and implantation of a redo bioprosthetic aortic valve with transvenous pacemaker placement.
(A) ECG showing third-degree heart block. (B) TEE showed aortomitral curtain abscess. (C) Postoperative aortic valve.
The management strategies of COVID-19 infection are controversial and still evolving. Physicians should be mindful of the pros and cons of therapeutics and their appropriateness in select population groups. Immunization and development of antibodies against infection may have a promising future that is not yet known. The earlier data regarding the role of antibodies in COVID-19 infection showed that acquired immunity may have a protective role in avoiding disease and its complications, but the long-term effects beyond 6 months’ duration remains elusive. Antibodies such as IgM and IgA are short-lived, lasting 2-4 weeks compared with antibody IgG that may last up to 6 months. Antibody titers at 6 months may have a role in predicting the immunity against the infection. Ongoing research will continue to prove the beneficial effects of antibodies in the long term and its system-based effectiveness. The cardiovascular effects of these immunization techniques are not clear.
Active immunity in COVID-19 infection can be achieved using four strategies:
Whole virus. Whole virus in attenuated/killed form can trigger immunity. It can develop strong immunity but can cause disease in a weaker immune system. It requires cold chain for storage.
Protein subunit. A small subunit protein of virus is inoculated, which may generate immunity that can be weak or may not be completely protective.
Nucleic acid. Viral DNA/RNA is transferred to a human cell where it can generate antigen and antibodies with protective effects. It requires cold storage.
Viral vector. A nonpathogenic virus is introduced to create immunity ...