Comparison of the Treatment Efficacy of Rosuvastatin versus Atorvastatin Loading Prior to Percutaneous Coronary Intervention in ST-Segment Elevation Myocardial Infarction

Reviewer 1

Comment

Author Response

Text Insertion (if applicable)/ section

The introduction can be made more succinct to focus on the study question. Please reduce it to a single paragraph that introduces the study question.

we briefly conducted the introduction of the manuscript

Introduction

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Please report missing values in the dataset.

We completed the missing parts.

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Why was multivariable logistic regression used in a RCT?

Multivariable linear regression analysis was used to determine the effect of the interventions on the main outcome measures as adjusted for the effect of other confounding factors.

Logistic regression is described in the study methods; however, I don’t see the results from the regression model in the results.

Missed logistic regression results have been added as they were lost unintentionally.

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Table 3

How many patients were lost to follow up?

56 patients who were lost to be follow up because of referral to fibrinolytic therapy rather than primary PCI

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Do you have data on the race/ethnicity of the individuals?

All populations included in the current study are Egyptians

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please provide p values for direct comparison of

Atorvastatin vs. rosuvastatin.

done

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Reviewer 2

 Comments

Author Response

Text Insertion (if applicable)/ section

1. In the abstract the loading dose of rosuvastatin is not mentioned.

We added the loading dose of rosuvastatin missed in the abstract.

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2. Some numbers are not clear in the figures.

Done

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3. In figures 1-3 how was subgroup analysis performed? Which correction was applied? Between groups comparisons were performed using ANOVA or Kruskal Wallis?

done

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4. In the statistical analysis section it is mentioned that a multivariate linear regression analysis was performed. However, no respective results are mentioned

Missed logistic regression results have been added as they were lost unintentionally.

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Table 3

5. Why was CK-MB and not hs-troponin measured?

We used peak CK-MB for enzymatic infarct size evaluation as peak CK-MB is considered the most powerful enzymatic predictor of infarct size [1, 2]. It is not used for early detection and diagnosis of STEMI; furthermore, CK-MB is the best enzyme test used for detection of re-infarction incidence [3-5].

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6. Did the authors evaluate an interobserver variability for CTFC?

No, as it was the same observer who evaluated CTFC for all individuals and he was blinded to the randomization assignment. Besides; the lower incidence of intra-observer and even inter-observer variations and according to previous studies, that variations are non-significantly differ among observers or the same observer [6-9].

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7. How is the conclusion supported by the results of the study? In all three analyses (figure 1-3) there was no difference between high dose of rosuvastatin or atorvastatin.

In figure 2 regarding the CTFC, There is a statistically significant difference between Atorvastatin and Control (p-value =0.003). Differences between Rosuvastatin and Atorvastatin and between Rosuvastatin and Control are not statistically significant. And as a result, that’s may give superiority to atorvastatin over rosuvastatin as atorvastatin could reach significance compared to control, while rosuvastatin failed to achieve that significance improvement in CTFC. Beside; the sensitivity of the CTFC parameter compared to TIMI flow grade and STR.

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Reviewer 1

Comment

Author Response

Text Insertion (if applicable)/ section

1. In response to my earlier comment to report missing values in the dataset. The authors responded “We completed the missing parts”

This response is not adequate. My question was about missing value analysis in the dataset?

We apologize about the previous confused response as there were some invisible numbers on the related figures.

The current study has no missing values for all of the analyzed variables; as we had a complete dataset for all the variables observed related to the entire 99 individuals included in the study.

2. Were there any missing values in any of the variables in the dataset?

3. If there were missing values in any of the variables, was a missing value analysis done to see if they are missing at random or not?

No, there were not any missing values in any of the variables in the dataset.

4. In the regression analysis, were any variables used that had missing data?

No, there were not any variables used in regression analysis that had missing data.

5. The lost to follow up of 55 patients with a study sample size 99 is a major concern and deserve a specific mention in the limitation section

There was a misunderstanding of the previous comment “how many patients were lost to follow up” as the entire 99 eligible individuals of the study totally followed up and had no missing data. The mentioned number of patients (56) was excluded from 155 initially selected patients as they were not eligible for the current study. Briefly, the answer there were no any patients lost to follow up.

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