Factors Related to Percutaneous Coronary Intervention among Older Patients with Heart Disease in Rural Hospitals: A Retrospective Cohort Study
Round 1
Reviewer 1 Report
The paper "Factors Related to Percutaneous Coronary Intervention Among Older Patients With Heart Disease in Rural Hospitals: A Retrospective Cohort Study" by Yamane and colleagues is a very well written report describing correlation between catheterization and clinical variables in rural cohorts. The article is formally correct and conveys relevant insights which may help future clinical decision on the management of coronary intervention, including decisions of tertiary hospital transfer.
I have only a few observations for the authors:
- Abstratc: "ECG changes might correlate with the indication for emergency catheterization". The authors should clearly state whether they observe a significant correlation, indicating the results of the test, without resorting to vague terms such as "might correlate". Or, the authors could remove the sentence altogether, given that they already state the OR for ECG changes in the previous sentence, and indicate (in my opinion, correctly) a role of ECG in affecting decisions for transfer.
- Lines 64-69: the authors mention the tendency to avoid intensive treatment for older people, given their relatively reduced life expectancy. While this may be true, and undoubtedly one of the aspects of ageism, the authors do not provide any reference or previous studies that describe the phenomenon. Indeed, the current manuscript proves, at least in the investigated cohorts, that ageism seems not to affect decisions, and could become a well cited work on the subject. Nevertheless, several works exist describing the phenomenon, and I think the authors must cite a few (https://www.nature.com/articles/s43587-020-00004-4 is a recent one, but the authors can and should include examples that are even closer to the field of coronary intervention).
- Lines 70-71: the sentence could improved with an increase in formality and clarity. "Effective transfer of older patients with suspected acute coronary syndrome from rural hospitals to tertiary medical institutions, regardless of aging societies and ageism, is important". Why is it important? Are tertiary hospitals less rural and more specialized? (This latest question can be answered by defining more clearly "tertiart hospitals" in line 50.
- Lines 82-84: the authors should summarized the cohort used by describing here its patient size, in order to have an immediate idea of the order of magnitude of the study at the beginning of the Methods section.
- Line 139: the citation for the R software used to perform the statistical analysis should point at a paper describing R. For example, there is a recent review on it on Life (PMID 35629316).
- Table 1: the table is really informative and I thank the authors for constructing it. Given the small (n=71) sample size, it would have been hard to find significant variables. However, the authors have at least two demographic characteristics that seem to be borderline significant: brain infarction and myocardial infarction; I think this should be discussed in the results.
- Table 1: some variables are not abbreviated, some are abbreviated, with apparently no consistency. For example: Brain infarction is not, while Myocardial infarction is (MI). The authors should not abbreviate names that are already short enough, for clarity (e.g. MI, DM). In order to fit in a single line, the variable "Time from onset to transfer (hours), median (IQR)" could be abbreviated to "Hours from onset to transfer, median (IQR)". Also, the order of the variables seems erratic: partially alphabetic, partially based on p-values sorting, partially random.
- Line 232: "age may not be a strong indicator for emergency catheterization in aged societies". I concur with the sentence, and indeed the authors provide evidence for this statement in their work. However, can _perceived_ age be an indicator for emergency catheterization? This can be due to cultural reasons, and also to pervasive medical literature describing age as a correlate to cardiac catheterization (https://pubmed.ncbi.nlm.nih.gov/19463511/). Maybe the authors can widen their discussion on this point.
Author Response
Responses to the reviewers’ comments
Thank you for reviewing our manuscript and providing suggestions for its improvement. We have revised the relevant contents based on the reviewers’ comments. A point-by-point response to the comments is provided below. Our revisions are indicated in red font here and in the manuscript. We hope that the revised manuscript meets the journal’s requirements and can now be considered for publication.
The paper "Factors Related to Percutaneous Coronary Intervention Among Older Patients With Heart Disease in Rural Hospitals: A Retrospective Cohort Study" by Yamane and colleagues is a very well written report describing correlation between catheterization and clinical variables in rural cohorts. The article is formally correct and conveys relevant insights which may help future clinical decision on the management of coronary intervention, including decisions of tertiary hospital transfer.
I have only a few observations for the authors:
- Abstract: "ECG changes might correlate with the indication for emergency catheterization". The authors should clearly state whether they observe a significant correlation, indicating the results of the test, without resorting to vague terms such as "might correlate". Or, the authors could remove the sentence altogether, given that they already state the OR for ECG changes in the previous sentence, and indicate (in my opinion, correctly) a role of ECG in affecting decisions for transfer.
Response:
Thank you for your valuable feedback. We agree with the suggestion and have revised the sentence based on the suggestion as follows.
“In these patients, age, time from onset to transfer, and serum troponin level were not significantly related to emergency catheterization, while ECG changes correlated with the indication for emergency catheterization.” (Lines 21–24)
- Lines 64-69: the authors mention the tendency to avoid intensive treatment for older people, given their relatively reduced life expectancy. While this may be true, and undoubtedly one of the aspects of ageism, the authors do not provide any reference or previous studies that describe the phenomenon. Indeed, the current manuscript proves, at least in the investigated cohorts, that ageism seems not to affect decisions, and could become a well cited work on the subject. Nevertheless, several works exist describing the phenomenon, and I think the authors must cite a few (https://www.nature.com/articles/s43587-020-00004-4 is a recent one, but the authors can and should include examples that are even closer to the field of coronary intervention).
Response:
Thank you for pertinent comment. We agree with the suggestion and have added the references for the mentioned points as follows.
“Further, ageism may affect the decision of the intervention. Both medical professionals and laypeople tend to consider intensive interventions in older patients not meaningful and effective for their quality of life [13,14]. Ageism can affect the decision regarding interventions for older patients with heart disease [13,14]. An aging society may make it difficult to determine indications for emergency catheterization in older patients with increased serum troponin.” (Lines 66–71)
- Lines 70-71: the sentence could improve with an increase in formality and clarity. "Effective transfer of older patients with suspected acute coronary syndrome from rural hospitals to tertiary medical institutions, regardless of aging societies and ageism, is important". Why is it important? Are tertiary hospitals less rural and more specialized? (This latest question can be answered by defining more clearly "tertiary hospitals" in line 50.
Response:
Thank you for helpful suggestion. We agree with the suggestion and have added sentences to support our concept as follows.
“If ST elevation is simultaneously observed on a patient’s electrocardiogram (ECG), myocardial infarction caused by the obstruction of specific coronary arteries can be diagnosed, and the patient can be transported to tertiary hospitals in urban areas for emergency catheterization [9].” (Lines 49–52)
“Effective transfer of older patients with suspected acute coronary syndrome from rural hospitals to tertiary medical institutions, regardless of aging societies and ageism, is important for the sustainability of older people’s quality of life.” (Lines 72–74)
- Lines 82-84: the authors should summarized the cohort used by describing here its patient size, in order to have an immediate idea of the order of magnitude of the study at the beginning of the Methods section.
Response:
Thank you for valuable feedback. We agree with the suggestion and have added the information of patients’ size as follows.
“This retrospective cohort study enrolled a total of 71 patients >65 years old who visited the emergency department in a rural hospital and were transferred to tertiary hospitals.” (Lines 85–86)
- Line 139: the citation for the R software used to perform the statistical analysis should point at a paper describing R. For example, there is a recent review on it on Life (PMID 35629316).
Response:
Thank you for helpful feedback. We agree with the suggestion and have revised the sentence with the reference of EZR as follows.
“The presence of chest pain was not included in the logistic regression model because of the vagueness of symptoms in older people [6]. Patients with missing data were excluded. Statistical significance was set at p < 0.05. All statistical analyses were performed using EZR (Saitama Medical Center, Jichi Medical University, Saitama, Japan), which is a graphical user interface for R (The R Foundation, Vienna, Austria) [21].” (Lines 137–142)
- Table 1: the table is really informative and I thank the authors for constructing it. Given the small (n=71) sample size, it would have been hard to find significant variables. However, the authors have at least two demographic characteristics that seem to be borderline significant: brain infarction and myocardial infarction; I think this should be discussed in the results.
Response:
Thank you for your important suggestion. We agree with the suggestion and have included a discussion of the suggested results in the discussion part as follows.
“In addition, as this study shows, higher rate of the presence of myocardial infarction in past medical history has a trend of non-performance of catheterization and high rate of brain stroke with performance of catheterization. This trend could be explained by the contents of information possessed by physicians in tertial hospitals. The physicians might know the prior history of coronary arterial catheterization among the patients with previous myocardial infarction and consider that patients with brain stroke might have higher risk of acute coronary syndrome.” (Lines 200–207)
- Table 1: some variables are not abbreviated, some are abbreviated, with apparently no consistency. For example: Brain infarction is not, while Myocardial infarction is (MI). The authors should not abbreviate names that are already short enough, for clarity (e.g. MI, DM). In order to fit in a single line, the variable "Time from onset to transfer (hours), median (IQR)" could be abbreviated to "Hours from onset to transfer, median (IQR)". Also, the order of the variables seems erratic: partially alphabetic, partially based on p-values sorting, partially random.
Response:
Thank you for productive feedback. We agree with the suggestion and have revised the table 1 based on the suggestion. The order of the variables is kept the same considering the order followed in previous articles related to CCI.
- Line 232: "age may not be a strong indicator for emergency catheterization in aged societies". I concur with the sentence, and indeed the authors provide evidence for this statement in their work. However, can _perceived_ age be an indicator for emergency catheterization? This can be due to cultural reasons, and also to pervasive medical literature describing age as a correlate to cardiac catheterization (https://pubmed.ncbi.nlm.nih.gov/19463511/). Maybe the authors can widen their discussion on this point.
Response:
Thank you for productive feedback. We agree with the suggestion and have added statements to describe why age was not related to the performance of emergency catheterization in the discussion part as follows.
“This study revealed that age was not an indication for emergency catheterization in older patients. Chronological age may be unrelated to health conditions [33]. Thus, age may not be a strong indicator for emergency catheterization in aged societies. When patients are older, difficulty in executing activities of daily living can be high and they may require intensive treatment to improve their conditions [33,34]. However, ageism may exist in developed countries, and medical professionals may have a prejudice that older people do not need intensive treatment [35]. Moreover, older patients and their families are usually hesitant in providing consent for intensive treatments [36,37]. Nevertheless, intensive treatment for older patients should not be avoided as many older people are biologically healthy. Many developed countries, including Japan has many older people living longer, and medical professionals and lay people might have realized that mortality may not be decided only by age [36,37]. So, the results of the present study show that ageism may not affect the administration of cardiac interventions in tertiary hospitals. However, the influence of ageism in rural hospitals should be investigated in future studies.” (Lines 244–258)
Reviewer 2 Report
The authors stated in the discussion of using AI to process ECG data. How this process was done or what has been done is not clear.
How univariate logistic regression was performed? What software was used for informatics analysis (statistics, regression, and others)?
Author Response
Responses to the reviewers’ comments
Thank you for reviewing our manuscript and providing suggestions for its improvement. We have revised the relevant contents based on the reviewers’ comments. A point-by-point response to the comments is provided below. Our revisions are indicated in red font here and in the manuscript. We hope that the revised manuscript meets the journal’s requirements and can now be considered for publication.
The authors stated in the discussion of using AI to process ECG data. How this process was done or what has been done is not clear.
Response:
Thank you for pointing this out. We agree with the suggestion and have included the details of the process in the discussion part as follows.
“Comparing the present and past ECGs could be vital for the detection of new ECG changes [30]. In addition, AI can analyze ECG based on their algorism, and the results may facilitate the interpretation of ECG results for accurate diagnosis of acute coronary syndromes [31,32].” (Lines 223–226)
How univariate logistic regression was performed? What software was used for informatics analysis (statistics, regression, and others)?
Response
Thank you for this important question. We agree with the suggestion and have revised the sentence with the reference of EZR as follows.
“The presence of chest pain was not included in the logistic regression model because of the vagueness of symptoms in older people [6]. Patients with missing data were excluded. Statistical significance was set at p < 0.05. All statistical analyses were performed using EZR (Saitama Medical Center, Jichi Medical University, Saitama, Japan), which is a graphical user interface for R (The R Foundation, Vienna, Austria) [21].” (Lines 137–142)
