**10. Cardiac surgery during the COVID-19 pandemic**

The COVID-19 pandemic posed serious challenges not only to modern cardiac surgery, but to medicine in general. As a result of the epidemic situation, the planned admission to hospitals and elective operations were stopped, and some of the health facilities were transformed into COVID-19 centers. Our hospital has developed a special algorithm for admission of patients in need of urgent or emergent cardiac surgery.

The epidemic situation has led to a reduction in hospital admissions. One of the reasons is certainly the fear of intra-hospital infection and transmission of COVID-19. The other reason is the postponement of elective operations. According to statistics, the number of hospitalized patients with acute coronary syndrome has decreased by 30%. If we consider that the mortality from COVID-19 is about 3% and the mortality from untreated STEMI reaches 30%, then the fear seems unjustified [81]. Important in this case, from a cardiac surgery point of view, is the definition of the concepts of elective and emergency admission and treatment, as well as treatment in accelerated and urgent order, as well as the nosological units to the respective groups:


While the first two groups may remain on the waiting list, for the next three the waiting time is shortened according to the disease (24 hours, 6 hours and as soon as possible in case of urgent, emergency and life-saving surgery, respectively). The functioning of such a system requires particularly good communication and collaboration between GPs, specialized outpatient and inpatient care, proper categorization of patients and optimal timing of treatment.

Unfortunately, there is still no formal international protocol or guidelines for optimal timing of cardiac surgery in patients with active COVID-19 infection. Since the beginning of the pandemic, 18 patients with identified COVID-19 infection pre- or postoperatively have undergone cardiac surgery (4.9% of all operated patients). The results of the operative treatment are excellent, as the intraoperative and early (up to 7th day) postoperative mortality is zero. Late postoperative mortality was 44%, with no patients dying from cardiovascular disease. It is noteworthy, contrary to expectations, that it is not the complexity of surgical treatment that is the leading risk factor for the complicated postoperative period in patients with

*Post COVID-19 Conditions and the Cardiovascular System DOI: http://dx.doi.org/10.5772/intechopen.99197*

proven COVID-19, but the development of viral pneumonia. Interstitial changes typical of COVID-19 pneumonia (ground-glass opacities, vascular enlargement, bilateral abnormalities, lower lobe involvement, and posterior predilection) have been demonstrated by CT scan in 75% of the deaths, with respiratory failure being the leading cause of death.

The question how long after recovery from a COVID-19 infection can a patient be transferred to surgery also remains open. Several studies on the subject are currently conducted. The data collected so far from 116 countries on 140,231 patients may finally show some resolve [82]. 2.2% of the patients included in the study were diagnosed preoperatively with COVID-19 infection. Mortality is highest in the first 7 weeks after the illness.

Thus, with surgical treatment 0-2 weeks, 3-4 weeks, and 5-6 weeks after COVID-19, the 30-day mortality was 4.1%, 3.9% and 3.6%, respectively. In surgical treatment after the seventh week, the results were the same as in patients without COVID-19 infection (1.5%). The estimated 30-day postoperative mortality in patients without COVID-19 infection was 1.5%. It should be borne in mind, however, that these are not specific studies in the field of cardiac surgery, but concern surgery in general. Probably the specific risk for cardiac surgery patients would be higher if we consider the complicated procedure of cardiac surgery, the aging of the population and the polymorbidity of the Bulgarian population. The role of the Heart team is crucial and the preparation of precise general hospital protocols and individual approach to each patient are extremely important for achieving good results.
