Discussion
We present a case of a successful CABG surgery in a patient with asymptomatic SARS-CoV-2 infection presenting with acute coronary syndrome and with multi-vessel severe CAD requiring urgent surgery. We thoroughly evaluated the patient to identify active COVID-19 infection by assessing for common inflammatory markers and CT findings associated with COVID-19. After confirming the absence of subclinical COVID-19, we proceeded with the CABG operation with a favorable outcome and without post-operative COVID-19 manifestations.
To the best of our knowledge, there are no published reports of CABG operation in patients with pre-operatively confirmed SARS-CoV-2 infection. In a report of post-operatively diagnosed COVID-19 after CABG for an acute coronary syndrome, the patient succumbed to severe pneumonia.1 In accordance with the United Kingdom National Health Service recommendations, the patient was not initially tested for the SARS-CoV-2 at presentation (15 days prior to surgery) as he did not have COVID-19 symptoms and had normal inflammatory markers.1 A chest CT scan at presentation showed mild chronic obstructive pulmonary disease. The patient developed pneumonia on postoperative day 1 with severe hypoxia and fever. Chest radiography showed bilateral consolidation and bronchial-alveolar lavage was positive for SARS-CoV-2. The authors recognized that undiagnosed or potentially concomitant COVID-19 infection might precipitate a catastrophic pathologic response refractory to standard treatments after cardiac surgery which might pose a challenge to clinicians.1 In a case series if eleven patients with COVID-19 infection diagnosed after lung cancer surgery, three patients expired in the immediate post-operative period.3 In two other reports of emergency thoracic surgery (embolectomy for pulmonary embolism and acute type A aortic dissection repair) and post-operatively diagnosed COVID-19 , the patients had a complicated post-operative course and eventually died from multiorgan dysfunction.2,4 A review of a pre-operative CT chest in one of these patients showed signs consistent with COVID-19 lung lesions.2
The key takeaway points from our case presentation are: 1) Routine testing for the SARS-CoV-2 in all patients who require cardiac surgery to identify asymptomatic/subclinical infection. 2) In asymptomatic SARS-CoV-2 infection, assessing for subclinical active infection (with inflammatory markers and CT chest) helps to identify patients at higher risk of developing post-operative complications. This is especially important for patients requiring cardiopulmonary bypass as subclinical pneumonia can result in severe hypoxia and complicate weaning from cardiopulmonary bypass. 3) Careful monitoring of all SARS-COV-2 positive patients postoperatively for development of COVID-19. Nasal swab testing with reverse transcriptase-polymerase chain reaction to detect the SARS-CoV-2 RNA has only 70% sensitivity. Any clinical change to suggest active COVID-19 in the pre- or post-operative period should prompt repeat swab testing or chest CT imaging to improve risk stratification. Chest CT screening has a higher sensitivity (98%) than nasal swab for SARS-CoV-2 infection as CT findings occur earlier.5Post-intubation bronchoalveolar lavage can be considered.
As we move forward in this pandemic, we need to continue to provide appropriate medical care for patients with asymptomatic or subclinical SARS-COV-2 infection who require cardiac surgery. Careful screening strategies, standard guideline recommendations and hospital level protocols are required to identify higher risk patients who are at greater risk of post-surgical morbidity and mortality.