PONE-D-21-33226Outcome of cardiac surgery following recent COVID-19 infection in unvaccinated patientsPLOS ONE

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Reviewer #1: Yes

Reviewer #2: Partly

Reviewer #3: Yes

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Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: I Don't Know

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Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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5. Review Comments to the Author

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Reviewer #1: Dear the authors of the manuscript entitled "Outcome of cardiac surgery following recent COVID-19 infection in unvaccinated patients"

I was glad reading this manuscript which reported the outcomes of cardiac surgery in patients with previous infection of COVID-19.

I do agree with the authors about the importance of this study despite the limited numbers of patients included in this study, however it could be an addition to the literature discussing this issue

I have couple of points here to mention:

1. The period of in-hospital stay was longer than the counterpart patients, is there any explanation?..Is there any reporting of the period and amount of chest tube drainage? Because we noticed a prolonged periods of chest tube drainage in such patients after cardiac surgery

2. Do you utilize chest ct Scan before cardiac surgery to make sure that these patients are ready to undergo surgery?

3. Was there any special management protocols for patients during the cardiac surgery procedure, that is different from the other patients,? ie anticoagulation protocol, steroid,and antibiotic regimenens?

Thank you

Reviewer #2: This observational and descriptive report was done in a busy cardiac center with a large sample size, which was a highly selected cohort from referral and preop selection. It might be too premature to draw the interim conclusion that cardiac surgery in such patients because there were obvious selection biases. There are several issues here.

1. Even with preop COVID testing, how could there were 0.5% still receiving cardiac surgery in which there some elective cases? Please explain. Were they missed so still undergoing non-emergent cardiac surgery? In a well-managed hospital, unless life-threatening, there should 0% non-emergent cardiac surgery in this pandemic. Please justify and explain.

2. This study was done in the national specialized heart center which has the best faculty, staff, and facilities to achieve the non-inferior outcomes in a highly selected cohort. There are lots of lower-level cardiac surgery centers and they may not achieve this good outcome. If the denied COVID cases had received the cardiac surgery, the outcomes might have not been so favorable. If the data were collected in multi-centers, regional data, national data, or even international data registries, the conclusion would be much more convincing. The authors please explain or justify their highly selected patients could represent the real world.

3. Most of the presented were adult coronary cases, which were just a part of "cardiac surgery" which includes valve, aortic, root, transplant, congenital, etc. There were no pediatric or transplant cases. The data shown were mostly coronary cases and hence were not representative for "cardiac surgery". Please revise the Title to better reflect the case characteristics.

Therefore, the authors need to justify why there were still non-emergent COVID cases undergoing cardiac surgery, explain the case being representative to the outside world, revise the title to reflect the case majority of adult and coronary cases (no pediatric, no transplant), etc.

Reviewer #3: During such a difficult times of pandemic, in time of uncertanty regarding the influence of the still novel COVID-19, such kind of research makes it easier to health care professionals to conduct their daily activities and provide best possible care. This paper outlines the most important factors regarding treating COVID-19 patients having a cardiovascular ongoing disease. The importance of the research also lies under the fact that not much work has been done in this direction, there is not enough data, so the level of frustration is high when treating patient with COVID-19 previous infection. This paper will help health care professionals treating such kind of patients on a daily basis, the information provided can help predict outcomes after cardiac surgery in this group of patients. A lot of opinions has been heard, but not many are evidence based and statistically strong enough to take into consideration. It is clear from this work that cardiac surgical procedures could be safely done in pre-operative Covid-19 infection group after a period of recovery, and success rate is higher in the asymptomatic or mild category of infection.

This study assessed well the safety and outcomes of the cardiac surgery in the pre-operative Covid positive group. All the patients went through a strict selection criteria, every patient was Covid screened before surgeries. Out of 2368 patients 12 patients were identified as a pre-operative covid positive patients who went through a period of recovery. This paper shows that cardiac surgical procedure outcomes are better in a group of patients where more than 4 weeks has passed after the infection, and also the results are better in asymptomatic or mild category. The timeframe here is very important, because this will help the team the decide and choose the most appropriate timing for the surgery, of course taking into consideration the severity of the condition. Covid infection can halt the surgery timing, thus increasing the mortality, this was addressed in this paper, which is important. In my opinion 12 patients is enough to get some sentence of what is going on with covid patients undergoing cardiac surgical procedure, but seeing more patients in the study would strengthen the results.

The paper merits publication , is well-written and well organized.

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Reviewer #1: Yes: Salah Eldien Altarabsheh

Reviewer #2: Yes: Robert J. Chen, MD, MPH

Reviewer #3: No

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Outcome of adult cardiac surgery following recent COVID-19 infection in unvaccinated patient population in a national tertiary centre

PONE-D-21-33226R1

Dear Dr.Nur Aziah Ismail

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

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Kind regards,

Alessandro Leone, MD

Academic Editor

PLOS ONE

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