17β-Estradiol Does Not Designate Non-Sex-Specific Early Ventricular Arrhythmia in Acute Myocardial Infarction, in Contrast to C-Reactive Protein

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

I read with interest the paper entitled ”17β-estradiol indicates non-sex-specific early ventricular arrhythmia in acute myocardial infarction”. The study is a single-center, observational analysis of 86 acute myocardial infarction (AMI) patients. The manuscript investigates whether endogenous 17β-estradiol (E2) and the E2/testosterone ratio are associated with early ventricular arrhythmias in patients with acute myocardial infarction. The topic is clinically relevant, at the intersection of sex hormones, inflammation, and ventricular arrhythmogenesis in AMI. However, I have the following comments:
- the study is clearly underpowered (only 11 ventricular arrhythmias events)
- some key analyses are at best exploratory
- important methodological limitations are not yet fully acknowledged
- the title and conclusions currently overstate the strength of the evidence and need to be substantially adjusted.

The following aspects should be reconsidered:

1) The central claim, implied by the title, is that E2 “indicates” non-sex-specific early VA in AMI. In the main analysis, however, E2 shows only a trend, not a statistically significant association with VA, and it is not an independent predictor in multivariable models.

2) E2 correlates with markers of myocardial infarction severity and inflammation (CRP, WBC, cardiac enzymes) and with reduced EF, suggesting that it may simply track overall AMI severity, which is itself associated with VA risk. Thus, E2 may be a surrogate marker of the severity of AMI and systemic inflammation, rather than an independent arrhythmogenic factor, in absence of statistically significant association.

3) Only 11 patients experienced VA, yet multivariable logistic regression for VA includes multiple variables. This defies the usual rules of thumb (≥10 events per variable) and leads to vicious estimates. The multivariable models should be presented and interpreted as exploratory only, not as confirmatory.

4) Several conclusions rely on p-values in the 0.05–0.10 range in a small cohort with high risk of type I error.

5) It should be clearly stated if all the women included in the study are at menopausal status, and also that the “non-sex-specific” results would only apply in this circumstance. 

6) QT parameters are measured on an admission ECG (before PCI/conservative therapy), but the exact timing of hormone and CRP sampling relative to symptom onset and reperfusion is not entirely clear. Please specify exact timing of hormone and inflammatory marker sampling relative to AMI onset and PCI, or acknowledge this as a limitation, as changes over time are not captured.

7) Other limitations which should be mention are the single-center design and the need of external validation. 

Comments on the Quality of English Language

1) The language requires careful editing by a fluent English speaker or professional service to correct grammar, phrasing, and some unclear sentences such as: “as tendency higher,” “marker of plasma endogenous E2”, “makes diminishes the statistical powered of this analysis”.

2) At line 16 "E2" should be put between brackets "(E2)", instead of commas.

2) The information on pages 12-13 is duplicated.

3) Sometimes decimals are written with commas vs points in the same table or text - please standardize.

4) Some abbreviations are not defined at their first appearance (IKr, IKs, APD, ICaL, and IK1).

5) In the legend of the tables "*" and "**" should be defined more clearly and separately.

Author Response

1/. ‘……E2 shows only a trend, not a statistically significant association with VA……’

Answer: The title of the manuscript is changed based on the tendency for association reached.

2/.  ‘ E2 correlates with markers of myocardial infarction severity and inflammation (CRP, WBC, cardiac enzymes) and with reduced EF, suggesting that it may simply track overall AMI severity,..’

Answer: This explanation of the results is added to   Discussion and  Conclusions.

3/. ‘Only 11 patients experienced VA, yet multivariable logistic regression for VA includes multiple variables. This defies the usual rules of thumb (≥10 events per variable) and leads to vicious estimates…….. ‘

Answer: The exploratory nature of our multivariable models has been additionally addressed in Limitiations

4/. ‘Several conclusions rely on p-values in the 0.05–0.10 range in a small cohort with high risk of type I error.’

Answer: The above has been added as one limitation of the study

5/. ‘It should be clearly stated if all the women included in the study are at menopausal status,….’

Answer: All women in the study are with postmenopausal status.

6/. ‘QT parameters are measured on an admission ECG (before PCI/conservative therapy), but the exact timing of hormone and CRP sampling relative to symptom onset and reperfusion is not entirely clear. …….’

Answer: The hormone and inflammatory marker sampling have been carried out within 6 hours of PCI or in the cases of nonobstructive CAD within the first 48 hours of the hospital stay.

 

Comments on the Quality of English Language.

Answer: The text was edited by MDPI Editing Service  

 

Reviewer 2 Report

Comments and Suggestions for Authors

The paper potentially addresses an interesting phenomenon, however there are many glaring issues with the data presentation.  It is misleading to denote ** for trend and * for significance.  Usually, the more significant, the more stars!  By some reason there is also an "NS" designator... Well, p=0.806 corresponds to "non-significant", why is there a separate "NS" category?  Figure 1 is weird and redundant: the Y axis represents CRP in units of concentration, and QTcmax in milliseconds ?  Another strange and redundant one: "Figure 2. Early ventricular arrhythmia and its covariates" - what are the X and Y axes?  Somehow X and Y axes represent OR?  The paper needs to be completely rewritten.  There is still a chance to present the data properly.

Author Response

1/. It is misleading to denote ** for trend and * for significance. Usually, the more significant, the more stars! 

Answer: I agree.

2/. By some reason there is also an "NS" designator... Well, p=0.806 corresponds to "non-significant", why is there a separate "NS" category? 

Answer: NS – stands for lack of significance due to very few cases : below 7 cases; p-0.806 is the insignificant result of statistically comparable groups (each including 7 cases and more).

3/. Figure 1 is weird and redundant: the Y axis represents CRP in units of concentration, and QTcmax in milliseconds ?  Another strange and redundant one: "Figure 2. Early ventricular arrhythmia and its covariates" - what are the X and Y axes?  

Answer: The figures has been edited by the MDPI editing service for a previous submission of this manuscript for the journal Int J Med Sci, MDPI

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for submitting the revised version of your manuscript. I have reviewed your point-by-point responses and the updated text, and I find that the manuscript has been substantially improved and that the previous concerns have been satisfactorily addressed. I therefore recommend acceptance for publication in its current form.

Author Response

The changes in Figure 1 are attached as pdf file to this one. Indeed, I have ignored your remark regrading these figures because I found it difficult to understand this remark thoroughly.

The significant associations (those with p<0.05) have been marked with stars and those with propensity for significance -  with one star.

The abbreviations in all tables legends' were written in full.

The word 'indicate' in the Title was altered with the synonym 'designate'.   

Dec 24th, 2025 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors did not make any significant changes to the manuscript.  It is inadequate to respond to my comment that mixing various units on the same graph is meaningless by saying "Answer: The figures has been edited by the MDPI editing service for a previous submission of this manuscript for the journal Int J Med Sci, MDPI".  I believe the editing service isn't responsible for the scientific soundness of the figures...

Author Response

The changes in Figure 1 are attached as pdf file to this one. Indeed, I have ignored your remark regrading these figures because I found it difficult to understand this remark thoroughly.

The significant associations (those with p<0.05) have been marked with stars and those with propensity for significance -  with one star.

The abbreviations in all tables legends' were written in full.

The word 'indicate' in the Title was altered with the synonym 'designate'.   

Dec 24th, 2025 

Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

Comments and Suggestions for Authors

I believe the authors still do not thoroughly understand the issue with their manuscript.  The "modified" figure 1 now simply does not show numbers on the Y axis.  Still, placing the measurements of different units on the same graph is rather meaningless.  Think about it: the bars for WBC are lower than E2 or QT... But how can you compare these things, the proverbial apples to oranges :-) ? I suspect the authors wanted to show the comparison of blue and yellow bars with each other, but i'm not sure...  This information is already in the table; the figure is wrong and redundant.

Also, what is the meaning of Figure 2?  On the right side there is odds ratio and p value...but what is on the X-axis?

 

Author Response

Dear Reviewer 2, 

I have done my best to modify figures 1 and 2 according to you remarks.

The  new figures are included in the resubmitted manuscript.