Assessment of Optimal Stent Implantation with the Use of Optical Coherence Tomography in Patients with Coronary Artery Disease

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study aims to evaluate whether OCT could improve PCI outcome for patients with CAD, as compared to angiography alone. This retrospective study included 73 vessels from 64 patients. All patients underwent OCT imaging to guide the stent implantation in PCI procedure. Post-PCI OCT imaging was performed to assess the stenting performance. In the Results Section, the authors claimed that OCT evaluation demonstrated that 41.09% (30/73) of the vessels were suboptimally stented after angiography-guided PCI. The presentation of the manuscript is very confusing. Actually, According to the Methods Section, the PCI was guided by OCT, thus no angiography-guided PCI was performed in this study. I do NOT know where the angiography-guided PCI data come from. Furthermore, I did not see any clinical significance of this study. More specific comments are below.

(1) In Section 2.2, the authors clearly stated that “All PCI procedures were preceded by OCT imaging”. And OCT information was later used for PCI guidance. So no angiography-guided PCI were done. How did the authors get the data that 30/73 of the vessels were suboptimally stented after angiography-guided PCI, as shown in Table 5?

(2) OCT-guided stent optimization. In the Methods Section, no information on how to optimize the stent implantation based on OCT image. Actually this is the main contribution of this manuscript, but no information was provided for this procedure.

(3) What is the clinical significance of this study? Previous studies have shown that OCT resulted in a larger minimum stent area than angiography guidance for PCI procedure (see Ref. Ali et ai., N Engl J Med 2023;389:1466-1476). Compared to the reference, what is the additional value of this manuscript to guide clinical practice?

(4) The introduction is too short. No introduction why the authors would like to perform such a study? What is the clinical significance of this study? Any previous similar studies? And the novelty of this study?

Author Response

This study aims to evaluate whether OCT could improve PCI outcome for patients with CAD, as compared to angiography alone. This retrospective study included 73 vessels from 64 patients. All patients underwent OCT imaging to guide the stent implantation in PCI procedure. Post-PCI OCT imaging was performed to assess the stenting performance. In the Results Section, the authors claimed that OCT evaluation demonstrated that 41.09% (30/73) of the vessels were suboptimally stented after angiography-guided PCI. The presentation of the manuscript is very confusing. Actually, According to the Methods Section, the PCI was guided by OCT, thus no angiography-guided PCI was performed in this study. I do NOT know where the angiography-guided PCI data come from. Furthermore, I did not see any clinical significance of this study. More specific comments are below.

• In Section 2.2, the authors clearly stated that “All PCI procedures were preceded by OCT imaging”. And OCT information was later used for PCI guidance. So no angiography-guided PCI were done. How did the authors get the data that 30/73 of the vessels were suboptimally stented after angiography-guided PCI, as shown in Table 5?

ANSWER

We appreciate the reviewer’s comment and acknowledge that the terminology used in the manuscript may have caused confusion. All procedures in this study were performed with angiographic guidance complemented by OCT imaging.

We added figure 2 to describe better the workflow.

Post-PCI OCT was systematically performed after an angiographically acceptable result to evaluate appropriateness of stent implantation (expansion, apposition, edge pathology, and lesion coverage) and these findings represent the focus of our work.

The reported rate of 41.09% suboptimal stent implantation reflects findings detected by post-PCI OCT that were not apparent on angiography, thereby highlighting the incremental diagnostic value of OCT beyond angiography alone. We have revised the Methods, Results, and Tables/Figures to clarify this workflow and avoid ambiguity.

 

• OCT-guided stent optimization. In the Methods Section, no information on how to optimize the stent implantation based on OCT image. Actually this is the main contribution of this manuscript, but no information was provided for this procedure.

ANSWER

We agree with the reviewer that this is a critical aspect of the study. Accordingly, we have added a dedicated subsection in the Methods (2.3) describing the study workflow and OCT-guided stent optimization protocol.

Briefly, post-PCI OCT findings were interpreted according to the EAPCI consensus criteria, and optimization strategies were tailored to the underlying mechanism of suboptimal implantation. These included post-dilatation with NC balloons for underexpansion, NC OR SC balloons for malapposition, additional stent implantation for significant edge dissections or residual plaque burden, and conservative management for limited tissue protrusion when appropriate. This protocol is now explicitly described in Section 2.3.

 

• What is the clinical significance of this study? Previous studies have shown that OCT resulted in a larger minimum stent area than angiography guidance for PCI procedure (see Ref. Ali et ai., N Engl J Med 2023;389:1466-1476). Compared to the reference, what is the additional value of this manuscript to guide clinical practice?

ANSWER

While large, randomized trials have demonstrated that intravascular imaging improves procedural outcomes compared with angiography alone, the specific clinical value of systematic post-PCI OCT assessment and subsequent optimization in routine practice remains insufficiently characterized.

This study highlights that a substantial proportion of angiographically satisfactory PCIs (41%) remain suboptimal by OCT predefined criteria, despite contemporary practice and pre-PCI OCT use. Moreover, Post-PCI OCT provides actionable information, leading to targeted optimization strategies that increased the rate of optimal stent implantation to >90%. Thus, these findings emphasize that post-PCI OCT is not merely diagnostic but interventional, directly influencing procedural decision-making and final PCI quality and might support a wider acceptance of intravascular imaging guidance.

 

• The introduction is too short. No introduction why the authors would like to perform such a study? What is the clinical significance of this study? Any previous similar studies? And the novelty of this study?

ANSWER

We agree with this comment, and we have revised the Introduction accordingly.

Reviewer 2 Report

Comments and Suggestions for Authors

I am grateful to the editor for the opportunity to review the manuscript by Alexandros Kaperonis et al., "Assessment of Optimal Stent Implantation Using Optical Coherence Tomography in Patients with Coronary Artery Disease." In this article, the authors present data on the use of optical coherence tomography to improve PCI procedure optimization in patients with coronary artery disease. The authors' data support the practical feasibility of this approach.
While reviewing the article, I had the following comments and questions:
1. The text of the article does not include the authors' full names, affiliations, or keywords.
2. The statement of the study objective in the ABSTRACT and in the Introduction section requires correction; it would be advisable to formulate it more clearly.
3. It is unclear from the text of the article who underwent OCT. Was this procedure routinely performed on everyone with OCT sensors? Or was this technique used in cases of technical difficulties or complications during PCI? Or was OCT used when suboptimal stent placement was suspected? These questions should be clarified, as they are important for the subsequent practical use of OCT in routine clinical practice.
4. The authors repeatedly emphasize that OCT was used to obtain clinically relevant information that is not available through angiography alone. However, I would still like to know what information was obtained with routine CAG and how it differed from the OCT data.
5. In Section 2.1. Study Population, the authors note that "we evaluated exclusively the non-culprit lesions after appropriate treatment of the culprit lesion during the acute phase" (lines 66-68).
In this regard, I have the following questions:
- Does this mean that all patients with STEMI had more than one vessel affected? And does this mean that multivessel stenting was routinely used in such cases? - 26% of patients had a single vessel lesion. If that vessel had a culprit lesion, how could there also be a vessel with non-culprit lesions?
- How did the authors identify culprit lesion and non-culprit lesions in cases of NSTEMI, unstable angina, and stable angina? This is often a challenging clinical task.
6. The reference list contains references primarily to publications older than 5 years (9) and older than 10 years (7). Only 4 references to recent publications (less than 5 years). Perhaps the research topic is no longer relevant if it is of no interest to other scientists? Otherwise, one should primarily consider publications from recent years that are widely represented (including in meta-analyses) (e.g., refs. 1-2, see below).
References:
1. Lin TY, Chen YY, Huang SS, Wu CH, Chen LW, Cheng YL, Hau WK, Hsueh CH, Chuang MJ, Huang WC, Lu TM. Comparison of angiography-guided vs. intravascular imaging-guided percutaneous coronary intervention of acute myocardial infarction: a real-world clinical practice. Front Cardiovasc Med. 2024 Aug 29;11:1421025. doi: 10.3389/fcvm.2024.1421025.
2. Khan SU, Agarwal S, Arshad HB, Akbar UA, Mamas MA, Arora S, Baber U, Goel SS, Kleiman NS, Shah AR. Intravascular imaging guided versus coronary angiography guided percutaneous coronary intervention: systematic review and meta-analysis. BMJ. 2023 Nov 16;383:e077848. doi: 10.1136/bmj-2023-077848.

Author Response

I am grateful to the editor for the opportunity to review the manuscript by Alexandros Kaperonis et al., "Assessment of Optimal Stent Implantation Using Optical Coherence Tomography in Patients with Coronary Artery Disease." In this article, the authors present data on the use of optical coherence tomography to improve PCI procedure optimization in patients with coronary artery disease. The authors' data support the practical feasibility of this approach.
While reviewing the article, I had the following comments and questions:
1. The text of the article does not include the authors' full names, affiliations, or keywords.

ANSWER

We agree with this comment, and we have revised the text.

2. 
   The statement of the study objective in the ABSTRACT and in the Introduction section requires correction; it would be advisable to formulate it more clearly.
   ANSWER

We agree with this comment, and we have revised the text.

3. It is unclear from the text of the article who underwent OCT. Was this procedure routinely performed on everyone with OCT sensors? Or was this technique used in cases of technical difficulties or complications during PCI? Or was OCT used when suboptimal stent placement was suspected? These questions should be clarified, as they are important for the subsequent practical use of OCT in routine clinical practice.

ANSWER

We appreciate the reviewer’s request for clarification. In our center, OCT was used routinely in a broad spectrum of patients undergoing OCT-guided PCI, including ACS and CCS, when technically feasible and not limited to bailout situations or procedural complications (ATHEROSCLEROSYS study).

This analysis represents a retrospective subset of a larger institutional OCT database, focusing specifically on patients in whom both pre-PCI and post-PCI OCT imaging were available, allowing detailed evaluation of stent optimization. OCT was primarily used for lesion characterization, vessel sizing, and plaque assessment, and post-PCI imaging was systematically performed to assess procedural results.

4. 
   The authors repeatedly emphasize that OCT was used to obtain clinically relevant information that is not available through angiography alone. However, I would still like to know what information was obtained with routine CAG and how it differed from the OCT data.

ANSWER

We appreciate the reviewer’s request for clarification. Conventional coronary angiography was used for standard procedural guidance, including lesion identification, visual estimation of vessel diameter, lesion preparation, stent positioning, and angiographic optimization.

In contrast, OCT provided quantitative and high-resolution intravascular information not available by angiography, including precise lumen dimensions, plaque morphology, calcium characteristics, stent expansion index, minimum stent area, strut apposition, edge dissections, and tissue protrusion. These OCT-derived parameters directly informed post-PCI optimization decisions and accounted for the discrepancies between angiographic appearance and true stent performance.

 

5. In Section 2.1. Study Population, the authors note that "we evaluated exclusively the non-culprit lesions after appropriate treatment of the culprit lesion during the acute phase" (lines 66-68).
   In this regard, I have the following questions:
   - Does this mean that all patients with STEMI had more than one vessel affected? And does this mean that multivessel stenting was routinely used in such cases? - 26% of patients had a single vessel lesion. If that vessel had a culprit lesion, how could there also be a vessel with non-culprit lesions?

- How did the authors identify culprit lesion and non-culprit lesions in cases of NSTEMI, unstable angina, and stable angina? This is often a challenging clinical task.

ANSWER

We thank the reviewer for bringing this important issue to our attention. Patient baseline characteristics were described before stenting.

In patients presenting with STEMI, NSTEMI and UA treatment of non-culprit lesions after initial treatment of the culprit lesion was included in this analysis according to the ATHEROSCLEROSYS study inclusion criteria. The interventional physician evaluated the acute angiographic appearance and decided on the treatment of the culprit lesion. Other cases were also included in this study. Other cases (chronic coronary syndromes or medically stabilized ACS) classified as having single-vessel disease could still contribute to lesions in the study population.

6. 
   The reference list contains references primarily to publications older than 5 years (9) and older than 10 years (7). Only 4 references to recent publications (less than 5 years). Perhaps the research topic is no longer relevant if it is of no interest to other scientists? Otherwise, one should primarily consider publications from recent years that are widely represented (including in meta-analyses) (e.g., refs. 1-2, see below).
   References:
   1. Lin TY, Chen YY, Huang SS, Wu CH, Chen LW, Cheng YL, Hau WK, Hsueh CH, Chuang MJ, Huang WC, Lu TM. Comparison of angiography-guided vs. intravascular imaging-guided percutaneous coronary intervention of acute myocardial infarction: a real-world clinical practice. Front Cardiovasc Med. 2024 Aug 29;11:1421025. doi: 10.3389/fcvm.2024.1421025.
   2. Khan SU, Agarwal S, Arshad HB, Akbar UA, Mamas MA, Arora S, Baber U, Goel SS, Kleiman NS, Shah AR. Intravascular imaging guided versus coronary angiography guided percutaneous coronary intervention: systematic review and meta-analysis. BMJ. 2023 Nov 16;383:e077848. doi: 10.1136/bmj-2023-077848.

ANSWER

We agree with this observation and have updated the reference list to include additional recent studies and meta-analyses, including publications after 2020. These additions better reflect the current relevance of the topic and strengthen the scientific context of the manuscript.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Even though the revision clarified the study workflow, and how they performed the OCT-guided stent optimization protocol, there are still many confusing parts, and the reviewer is not convinced by data presented in the manuscript, especially the data in Tables 4 and 5. Specific comments are:  

(1) In the manuscript, the authors stated multiple times that Stent underexpansion was defned if SEI ≤ 80% or MSA ≤ 4,5mm. In Table 4, it says that Post-PCI OCT shows that 31 vessels had SEI ≤ 80%, and 13 vessels had MSA ≤ 4,5mm. So the total Stent underexpansion cases should be at least 31 cases (assuming 13 cases with MSA ≤ 4,5mm is a subset of 31 cases with SEI ≤ 80%). How did the authors get the number 13 for Stent underexpansion cases in Table 5?

Did the authors mean that Stent underexpansion is defined as SEI ≤ 80% AND MSA ≤ 4,5mm?

(2) Table 5, the Stent underexpansion cases for post-optimization OCT is 2. I do doubt the correctness of this number, given 27 vessels had SEI ≤ 80%, and 9 vessels had MSA ≤ 4,5mm.

This number is not likely to happen even in the case that the definition of Stent underexpansion is SEI ≤ 80% AND MSA ≤ 4,5mm? Please attach all your data as supplementary file to convince others.

(3) Some text in Results subsection is redundant. For example, the 2^nd paragraph in Section 3.4, the authors just re-state the data in the Table 4, should be deleted.

(4) I do believe that OCT-guided stent optimization procedure would result better OCT finding. But the additional surgery in optimization procedure, like additional stent implantation, might also cause additional surgical complication. The authors should discuss this in the limitation section.

Author Response

Even though the revision clarified the study workflow, and how they performed the OCT-guided stent optimization protocol, there are still many confusing parts, and the reviewer is not convinced by data presented in the manuscript, especially the data in Tables 4 and 5. Specific comments are:  

(1) In the manuscript, the authors stated multiple times that Stent underexpansion was defned if SEI ≤ 80% or MSA ≤ 4,5mm. In Table 4, it says that Post-PCI OCT shows that 31 vessels had SEI ≤ 80%, and 13 vessels had MSA ≤ 4,5mm. So the total Stent underexpansion cases should be at least 31 cases (assuming 13 cases with MSA ≤ 4,5mm is a subset of 31 cases with SEI ≤ 80%). How did the authors get the number 13 for Stent underexpansion cases in Table 5?

Did the authors mean that Stent underexpansion is defined as SEI ≤ 80% AND MSA ≤ 4,5mm?

ANSWER

Thank you very much for your observations. It is correct (it is with "AND" not "or"). Based on this, we have rearranged the information, modified the data in the table and modified the text. I apologize that it took longer.

(2) Table 5, the Stent underexpansion cases for post-optimization OCT is 2. I do doubt the correctness of this number, given 27 vessels had SEI ≤ 80%, and 9 vessels had MSA ≤ 4,5mm.

This number is not likely to happen even in the case that the definition of Stent underexpansion is SEI ≤ 80% AND MSA ≤ 4,5mm? Please attach all your data as supplementary file to convince others.

ANSWER

Thank you very much for your observations. We made the changes.

(3) Some text in Results subsection is redundant. For example, the 2^nd paragraph in Section 3.4, the authors just re-state the data in the Table 4, should be deleted.

ANSWER

Thank you very much for your observations. We made the changes.

(4) I do believe that OCT-guided stent optimization procedure would result better OCT finding. But the additional surgery in optimization procedure, like additional stent implantation, might also cause additional surgical complication. The authors should discuss this in the limitation section.

ANSWER

Thank you very much for your observations. We made the changes.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have made corrections to the text and responded to my comments. As far as I understand the responses to my comments 3 and 5, this material is part of the ATHEROSCLEROSYS study. If so, this should be indicated in the text of the manuscript.

Author Response

The authors have made corrections to the text and responded to my comments. As far as I understand the responses to my comments 3 and 5, this material is part of the ATHEROSCLEROSYS study. If so, this should be indicated in the text of the manuscript.

ANSWER

Thank you very much. We made the changes.

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

(1) The manuscript is NOT consistent. for the definition of Stent underexpansion, some text says "SEI ≤ 80% AND MSA ≤ 4,5mm", some says " underexpansion as a combination of SEI <80% and MSA <4.,5 mm²".  

Also, I cannot found this definition of  Stent underexpansion in the reference [7] as the authors provided. 

(2) I recommended (last time) to provide all the original data as a supplementary file to convince all the readers, which I did not see this time.  

Author Response

(1) The manuscript is NOT consistent. for the definition of Stent underexpansion, some text says "SEI ≤ 80% AND MSA ≤ 4,5mm", some says " underexpansion as a combination of SEI <80% and MSA <4.,5 mm²".  Also, I cannot found this definition of  Stent underexpansion in the reference [7] as the authors provided. 

ANSWER

Thank you again for your comments. We have corrected it.

Reference (7) refers to a protocol of an artificial intelligence-based study, from which we used the patient inclusion criteria/data for the analysis, but we further refined the analysis (including the definition of stent underexpansion).

 

(2) I recommended (last time) to provide all the original data as a supplementary file to convince all the readers, which I did not see this time. 

ANSWER

We have attached the requested table.

Author Response File: Author Response.pdf