Under the unprecedented pressures of the global coronavirus disease 2019
(COVID-19) pandemic, there is an urgent requisite for successful
strategies to safely deliver cardiac surgery. Severe acute respiratory
syndrome coronavirus 2 (SARS-CoV-2) was first described in early
December 2019, and the rapid spread and emergence of this virus has
caused significant disruptions in the delivery of healthcare services
worldwide.1,2 In particular, provision of cardiac
surgery has been disproportionally affected due to reallocation of
intensive care resources, such as ventilators.2Additionally, patients with pre-existing cardiovascular disease are
likely to have comorbidities which are associated with poorer clinical
outcomes in confirmed SARS-CoV-2 cases.3,4 Despite
this, Yandrapalli and colleagues have reported the first case of a
successful coronary artery bypass graft (CABG) operation in a patient
with asymptomatic SARS-CoV-2 infection, which offers insights into how
cardiac surgery could be adapted to solve the challenges of this
pandemic.5
In response to the burden of COVID-19 on healthcare systems in the
United Kingdom (UK), elective cardiac surgeries have been delayed owing
to the redistribution of intensive care resources and the unquantifiable
risk of acquiring COVID-19.2 Likewise, cardiac surgery
services have undergone structural remodelling into a centralised system
in an attempt to continue provisions of emergency surgery alongside
hospital management of COVID-19 patients.2Unsurprisingly, most cardiac surgery units across the globe have seen a
sharp decline in surgeries as a result, and one unit reported an 83%
reduction in cardiac index cases between 23rd March to
4th May 2020.2 Similar models have
been used in Europe to manage healthcare services and increase intensive
care capacity. For example in the Lombardy region of Italy, 16 out of 20
cardiac surgical units discontinued services and all urgent cases have
been consequently diverted to the remaining four units for centralised
services.6 Whilst these measures have been beneficial
for supporting the focused management of COVID-19 patients, it is
important to reflect upon the future consequences of delayed elective
cardiac surgery. Indeed, such patients are likely to have progressive
conditions and further work is needed to investigate the long-term
impact of COVID-19 on mortality and morbidity in this cohort.
The case report by Yandrapalli and colleagues highlight the importance
of routine SARS-CoV-2 testing for all patients requiring cardiac
surgery, especially for detecting asymptomatic or subclinical
infections.5 Active SARS-CoV-2 infection may
precipitate an overproduction of early response proinflammatory
cytokines in post-operative period, leading to unfavourable surgical
outcomes.7,8 Moreover, preliminary studies have shown
that patients with established cardiovascular diseases may have a
greater risk of increased SARS-CoV-2 infection severity and
prognosis.9 Taken together, assessment for active
infection is crucial for risk stratification. In addition, clinicians
should consider the threshold for surgery when selecting patients for
cardiac surgery. An international, multi-centre cohort study by
COVIDSurg Collaborative which included 1128 confirmed SARS-CoV-2
patients undergoing a broad range of surgeries revealed that 30-day
mortality risk was significantly associated with the patient
demographics of male sex, an age of 70 years or older, and poor
preoperative physical health status.10 Collectively,
the risks and benefits of cardiac surgery should be carefully considered
in such patients due to higher mortality risk.10Alternative therapeutic procedures with rapid discharge, such as
percutaneous intervention or medical therapy, may be more appropriate to
reduce SARS-CoV-2 related mortality and nosocomial infection
risk.11
Current evidence is limited for postoperative outcomes in cardiac
surgery cases. In the aforementioned cohort study by COVIDSurg
Collaborative, the 30-day mortality rate was 23.8%.10In addition, the study reported that 51.2% of patients had
postoperative pulmonary complications, which was associated with a
higher mortality rate of 38.0%.10 In another case
report describing an emergency CABG operation, the asymptomatic patient
succumbed to pulmonary complications arising from a SARS-CoV-2 infection
confirmed postoperatively.12 The authors acknowledge
that the undiagnosed infection may have triggered a refractory
pathological response after cardiac surgery. Indeed, recent literature
has suggested that patients with SARS-CoV-2 are at higher risk of
developing thromboembolisms, possibly mediated by the interaction with
angiotensin-converting enzyme 2 (ACE2) receptors.13Similarly, there is a consensus that SARS-CoV-2 has direct adverse
effects on the myocardium due to high expression of
ACE2.14 As such, SARS-CoV-2 can potentially trigger
multisystem complications which require vigilant monitoring, especially
in patients requiring cardiopulmonary bypass and at high risk of
developing thromboembolisms. Cardiac surgery patients represent a
vulnerable patient population, and this cohort may experience worse
outcomes with SARS-CoV-2 infection based on the current available
evidence. In the latest recommendation, UK currently advises all
patients who are listed for elective cardiac surgery to self-isolate for
14 days prior to surgery date, in a measure to limit and contain the
exposure of such cohort to the smallest possibilities of acquiring
COVID-19.
Currently, the future of cardiac surgery after the pandemic is unclear
as the evidence is still emerging. However, the lessons learnt from
these unprecedented times can be taken forward to inform future service
planning. Moving forwards, routine screening of patients for SARS-CoV-2
infection will undoubtedly play a key role in identifying asymptomatic
or subclinical infections. The preoperative UK National Health Service
testing recommendations should be broadened so that all patients
undergoing cardiac surgery are screened, given the higher risk of
postoperative complications in this population. Similarly, repeat
testing is important for monitoring patients for concomitant infections.
Alongside changes to hospital protocol, service delivery will inevitably
shift. The successful application of telemedicine during the pandemic
has already been reported in the delivery of oncology
services.15 Moreover, the benefits of telecardiology
outside of the COVID-19 era have been previously reported, and
cardiology services will likely embrace the utilisation of telemedicine
for managing outpatient consultations.16 Units will
also have to address the vast backlog of surgeries caused by
cancellation of elective cardiac operations in a sustainable manner,
with adequate hospital space and personal protective equipment
availability.17 In order to resume success services,
planning for this eventuality should begin now and patients at
significant mortality risk due to delayed surgery need to be
prioritised.
Ultimately, clear guidelines should be implemented to ensure safe
resumption of surgical services, whilst also reassuring patients
concerned about safety.3 Whilst the future trajectory
of this pandemic is uncertain, the insights from the impact of COVID-19
on cardiac surgery will undoubtedly shape the future delivery of cardiac
surgery.