RU2850119C1 - Method for selecting diameter of coronary stent based on optical coherence tomography data - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to endovascular diagnosis and treatment and can be used to select the diameter of a coronary stent based on optical coherence tomography (OCT) data. Selective angiography and OCT of the target lesion of the coronary artery are performed. The stent diameter is selected based on the maximum lumen diameter of the distal reference segment of the target coronary artery lesion, as measured by OCT. The maximum lumen diameter of the distal reference segment of the coronary artery is rounded up to the nearest available stent size.

EFFECT: reduction of perioperative and long-term risks associated with stenting of coronary artery (CA) stenoses by optimising the selection of the diameter of the implanted coronary stent based on OCT data, taking into account the maximum lumen diameter of the CA distal reference segment.

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Description

The invention relates to medicine, namely to X-ray endovascular diagnostics and treatment. It is used in patients with coronary artery disease (CAD). Myocardial revascularization is an effective pathogenetic method for the treatment of CAD. Currently, the number of percutaneous coronary interventions (PCI) in Russia is approximately 6 times higher than the number of coronary artery bypass grafting (CABG) surgeries [1]. However, PCI has shown lower long-term effectiveness than CABG surgeries and requires improvement. Given the number of PCIs performed, any increase in their effectiveness can ensure a reduction in mortality. The introduction of intravascular imaging (IVI) has made it possible to identify defects in coronary stent implantation that are not visible during angiography and to establish a high correlation between stent thrombosis and their insufficient deployment [2]. The use of optical coherence tomography (OCT) or intravascular ultrasound (IVUS) leads to the optimization of PCI in approximately 86% of cases due to the clarification of the morphology and geometry of stenoses, more accurate measurement of reference diameters and assessment of the landing zones of the stent edges [3]. With the introduction of IVUS technologies into practice, a large array of data has been accumulated on the significance of various morphological "phenomena" and measured geometric parameters, which raises the question: when and how to apply and how to interpret the obtained information? To select the required size and assess stent implantation defects using OCT, the MLD MAX algorithm [4] was proposed. The MLD part (M - morphology, L - length, D - diameter) is an assessment of the anatomy and morphology of the lesion to optimize the stent implantation process - determining the landing zones, length and diameter of the stent. The MAX (M - Medial dissection, A - Apposition, X - eXpansion) section evaluates stenting defects and determines strategies for their optimization. This algorithm is proposed as a way to simplify the use of OCT in PCI, as a limited understanding of how to use the information provided by intravascular images is the main reason for the infrequent use of OCT in clinical practice.

There is a known method for selecting the stent diameter based on coronary angiography data so that the stent diameter exceeds the angiographic diameter of the coronary artery by 10%. [5] The same recommendations are given by stent manufacturers in their product instructions.

The disadvantages of this method are the well-known limitations of the X-ray contrast angiography method: 1) low resolution; 2) the planar, two-dimensional nature of the image, which greatly affects the accuracy of measuring the vessel diameter.

A method for selecting the stent diameter proposed by the European Association of PCI (EAPCI) is known, using the calculated average value of the distal diameter of the coronary artery (based on two orthogonal measurements), measured along the external elastic membrane (EEM), with the obtained value rounded down to the nearest existing stent size (for example, the obtained value of 3.73 mm is rounded down to 3.50 mm).

The disadvantage of this method is the impossibility of visualizing NEM in a large number of cases due to the diffuse nature of coronary atherosclerosis (in the ILUMIEN III study, it was not possible to visualize NEM in 23% of cases).

A method for selecting the stent diameter, proposed by EAPCI in the case of impossibility of visualizing the NEM, is known, using the calculated average value of the lumen diameter of the distal reference segment of the coronary artery (based on two orthogonal measurements) with rounding the obtained value up in increments of 0 - 0.25 mm to the nearest existing stent size (for example, the obtained value of 3.76 mm is rounded up to 4.00 mm). [6]

This method is the closest to the declared one in terms of technical essence and the achieved result and was chosen as a prototype.

A drawback of the prototype method is the use of the average lumen diameter of the distal reference segment of the coronary artery for stent diameter selection. Since the stent landing zone is not always completely free of atherosclerosis, the presence of a small, "stable" atherosclerotic plaque in the landing zone is permissible. However, plaque growth into the coronary artery always leads to a decrease in lumen diameter in the direction of this growth. This means that the minimum lumen diameter of the coronary artery in the atherosclerotic plaque zone reflects the stenosis effect. Consequently, the average lumen diameter underestimates the estimate proportionally to the difference between the minimum and maximum lumen diameters of the coronary artery. As a result, the selection of the stent diameter based on the average value of the lumen diameter of the distal reference segment of the coronary artery leads to an underestimation of the required stent diameter, which, as is known, can cause acute stent thrombosis or stent restenosis in the long term.

The aim of the invention is to reduce perioperative and long-term risks associated with stenting of coronary artery stenoses by optimizing the selection of the diameter of the implanted coronary stent based on OCT data.

The stated goal is achieved in the X-ray operating room using: 1) an angiograph; 2) an apparatus for performing OCT; 3) coronary stents; 4) other types of instrumentation for performing endovascular interventions on coronary arteries.

A novel feature of this method is that when a coronary artery stenosis requiring stent implantation is detected, OCT of the stenosis is performed, the lesion length is determined, and the distal and proximal landing zones are selected. The stent diameter is then selected based on the maximum lumen diameter of the distal reference segment of the coronary artery. To achieve this, the coronary artery lumen is automatically outlined at the level of the distal reference segment on the OCT cross-sectional image of the coronary artery, with manual adjustments being made if necessary. The OCT device's built-in algorithm determines the maximum and minimum lumen diameters of the coronary artery. The stent diameter is selected based on the maximum lumen diameter of the coronary artery by rounding the obtained maximum lumen diameter up to the nearest existing stent diameter.

The new features have demonstrated in the claimed set new properties that do not clearly follow from the level of technology in this area and are not obvious to a specialist.

The invention will be clear from the following description and the accompanying figure.

Fig. 1 shows an OCT image of a cross-section of the coronary artery:

1 - lumen of the KA;

2 - contour of the lumen of the coronary artery;

3 - maximum diameter of the lumen of the spacecraft;

4 - minimum diameter of the lumen of the spacecraft;

5 - the arc indicates an atherosclerotic plaque narrowing the lumen of the coronary artery.

The method is performed as follows (Fig. 1). Selective coronary angiography is performed using the standard technique, and the target coronary lesion is determined. OCT of the target coronary lesion is performed, and distal and proximal reference segments are selected, and the stent length is selected accordingly. If the atherosclerotic plaque (5) occupies more than 180 degrees of the circumferential arc of the coronary artery cross-section on the OCT image of the distal landing zone, the stent diameter is selected based on the maximum diameter of the coronary lumen. For this purpose, the coronary lumen contour (2) is outlined, the device draws the maximum (3) and minimum (4) diameters of the coronary lumen, and displays their numerical values. The stent diameter is selected by rounding the maximum (4) obtained value of the coronary lumen diameter up to the nearest existing stent size.

An identical set of features was not found in the patent and scientific medical literature.

The proposed method can be used in practical healthcare.

Based on the above, the method proposed as an invention should be considered to meet the patentability conditions of “Novelty”, “Inventive step”, “Industrial applicability”.

Clinical example.

Patient V., male, 50 years old, Complaints of episodes of rapid, irregular heartbeat, accompanied by pressing chest pain without radiating, increased blood pressure to 180 mmHg, and inspiratory dyspnea with moderate physical activity, relieved by rest. Blood pressure has been elevated for the past 4 years. He had had arrhythmia for about two years; in the last few months, his arrhythmia attacks have been accompanied by shortness of breath and pressing chest pain. He was not taking antiarrhythmic therapy. After consulting a cardiologist, he was prescribed Eliquis 10 mg/day, Betaloc Zok 25 mg/day, and losartan 50 mg/day. Hospitalization at the Research Institute of Cardiology was recommended. He was admitted to the Research Institute of Cardiology on a planned basis for examination and a decision on restoring sinus rhythm.

The ECG showed an episode of atrial flutter with a heart rate of 136 bpm. The EOS was normal. Downsloping ST depression of up to 2 mm was observed in leads V4-V6, I, and AVL. At the end of the recording, sinus rhythm was restored with a heart rate of 70 bpm. The EOS was normal. Downsloping ST depression of up to 2 mm was observed in leads V4-V6, I, and AVL.

According to echocardiography data, the LV ejection fraction is normal, slight hypokinesis of the anterior apical segment was detected, and myocardial ischemia along the anterior wall of the LV was suspected.

Coronary angiography was performed and stenosing atherosclerosis of the coronary arteries was revealed: stenosis of the proximal segment of the LAD 80%; stenosis of the middle segment of the LAD 70%,

Atherosclerotic lesion: proximal RCA segment - 30% stenosis; middle RCA segment - 30% stenosis; distal RCA segment - 30% stenosis; first diagonal branch - 30% stenosis. OCT of the middle and proximal LAD segments was performed. Diffuse LAD lesion with cascading stenosis along the proximal and middle segments was revealed, distal and proximal landing zones were determined, and the stent length was selected accordingly. Due to the diffuse lesion (the presence of fibrous atherosclerotic plaque), visualization of NEM in the distal reference segment was possible over less than 180 degrees of the circumference of the OCT image of the coronary artery cross-section. A decision was made to select the stent diameter based on the lumen diameter of the OCT image of the coronary artery cross-section. With automatic lumen contouring and manual correction of the obtained image, the following values were obtained: minimum lumen diameter 2.61 mm; maximum lumen diameter 3.45 mm; average lumen diameter 2.96 mm. The stent size was selected in accordance with the maximum obtained diameter value of 3.45 mm, rounded up to the nearest existing stent size, that is, 3.5 mm. Balloon angioplasty with stenting of the proximal and middle segments of the LAD with a 3.5 x 48 mm antiproliferative-coated stent was performed. OCT monitoring yielded a stent expansion rate of 84%, which corresponds to the recommended values (>80%). There were no marginal dissections or malpositions. The postoperative period was uneventful. The ECG showed sinus rhythm with a heart rate of 72 bpm. The electrical axis was normal, with downsloping ST depression of up to 2 mm in leads V4-V6.1 and AVL. The patient was discharged on the second postoperative day with a recommendation to be followed up by a local cardiologist. A Holter ECG should be performed after 6 months, followed by a consultation with an arrhythmologist.

The proposed method has been tested on 22 patients and demonstrated its efficacy and safety. Efficacy is assessed by the degree of stent expansion relative to the area of the distal reference segment, and safety is assessed by the number of adverse events during stent implantation. This method allows for optimal selection of coronary stent diameter in the presence of diffuse atherosclerotic lesions and is safe and easy to use.

Bibliography:

1. Alekyan B.G., Grigoryan A.M., Staferov A.V., Karapetyan N.G. X-ray endovascular diagnostics and treatment of heart and vascular diseases in the Russian Federation - 2021. Endovascular surgery. 2022; 9 (Special issue): 5-254. DOI: 10.24183/2409-4080.

2. Moreno R, Fernández C, Hernández R, Alfonso F, Angiolillo DJ, Sabaté M, Escaned J, Bañuelos C, Fernández-Ortiz A, Macaya C. Drug-eluting stent thrombosis: results from a pooled analysis including 10 randomized studies. J Am Coll Cardiol. 2005 Mar 15;45(6):954-9. doi: 10.1016/j.jacc.2004.11.065. PMID: 15766835.

3. Bergmark B, Dallan LAP, Pereira GTR, KuderJF, Murphy SA, Buccola J, Wollmuth J, Lopez J, Spinelli J, Meinen J, West NEJ, Croce K; LightLab Initiative Investigators. Decision-Making During Percutaneous Coronary Intervention Guided by Optical Coherence Tomography: Insights From the LightLab Initiative. CircCardiovascInterv. 2022 Nov;15(11):872-881. doi: 10.1161/ CIRCINTERVENTIONS. 122. 011851. Epub 2022 Nov 15. PMID: 36378739; PMCID: PMC9648988

4. Shlofmitz E, Croce K, Bezerra H, Sheth T, Chehab B, West NEJ, Shlofmitz R, Ali ZA. The MLD MAX OCT algorithm: An imaging-based workflow for percutaneous coronary intervention. Catheter CardiovascInterv. 2022 Nov;100Suppl 1:S7-S13. doi: 10.1002/ccd.30395. PMID: 36661367

5. Coronary stenting and stents / D.G. Ioseliani, D.A. Asadov, A.M. Babunashvili. - Moscow: GEOTAR-Media, 2022.256 pp.: ill. - 256 pp. - INSBN 978-5-9704-6513-4.

6. Raber, L. et al. Clinical use of intracoronary imaging. Part 1: guidance and optimization of coronary interventions. An expert consensus document of the European Association of Percutaneous Cardiovascular Interventions. Eur. Heart J. 39 , 3281-3300 (2018).

Claims (1)

A method for selecting the diameter of a coronary stent based on optical coherence tomography (OCT) data, including performing selective angiography, selecting a target lesion of a coronary artery, and performing OCT of the target lesion of the coronary artery, characterized in that the stent diameter is selected based on the value of the maximum lumen diameter of the distal reference segment of the target lesion of the coronary artery, measured using OCT, for which the obtained maximum lumen diameter value of the distal reference segment of the coronary artery is rounded up to the nearest existing stent size.