Limitations and strengths
There were limitations and strengths in this study’s design and running,
as follows. The most accurate way to evaluate chambers’ volumes and
strains is cardiac magnetic resonance imaging (CMR)
(21). Although it was better to evaluate
the heart condition with CMR, echocardiography is still the most
accessible and inexpensive way to carry out the global cardiac status
(7). So, in case of having access and
enough budgets to perform CMR for research purposes, it would be more
reliable to perform this study with CMR, which would probably lead to
higher inter-and intra- observer reproducibility. Another noteworthy
limitation is the limited sample size. It was a single-center cohort of
health care workers, and the COVID-19 pandemic, by its nature of being
highly contagious, made it difficult to provide a sample of patients
with proper size in different clinical COVID-19 severity groups that may
have affected the present results.
Moreover, as the participants were all health care workers and thus
aware of alarm signs and symptoms ending to severe COVID-19, they
received proper care right away. Consequently, there were fewer patients
with cytokine storm and severe COVID-19 pneumonia to measure the impact
on the cardiopulmonary system. The bright point of the current study is
considering patients without cardiac indication for echocardiography
which provides evidence for silent long-term effects of COVID-19 on the
cardiovascular system. On the other hand, having a population bare of
known cardiac problems excludes the impact of the baseline cardiac
complications on the outcomes of the patients. Another novelty of the
current study is the duration of the follow-up period (6 months), which
is not practiced in any other similar study. It is of note that the
participants of this cohort were all young, otherwise healthy, without
any history of cardiac disease, and still productive people working as
healthcare staff. Hence, the considered response to COVID-19 systemic
implications was assessed to be the response of a healthy heart to
sepsis. Thus, it can practically be generalizable to the non-complicated
heart response to the COVID-19 crisis. The current results may not
present the outcomes of aged or, to any extent, previously damaged
hearts against the multi-system-involving COVID-19 infection.