RU2697986C1 - Method for assessment of diffuse atherosclerotic lesion of coronary arteries before revascularization of myocardium - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine and can be used in cardiology and cardiosurgery. Cardioangiography is performed. Method includes determining and evaluating in points 3 parameters: prevalence of atherosclerotic changes in coronary artery wall, distal to hemodynamically significant stenosis, diameter of shunted artery, significance of examined artery in blood supply of myocardium. Obtained points are summed up to determine diffuse damage index (DDI). If the DDI value is less than 4 points, the coronary artery involvement is considered to be non-diffuse. DDI value of 4–6 points is considered as boundary value. If the DDI value is 7–9 points, the injury is considered to be diffuse.

EFFECT: method provides evaluating diffuse atherosclerotic lesions of coronary arteries before revascularization of myocardium, as well as reducing intraoperative and postoperative complications in patients with diffuse involvement of coronary arteries by evaluating complex of most significant parameters.

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Description

The invention relates to medicine and can be used in cardiology and cardiac surgery.

A known method for assessing the degree of atherosclerotic lesions of arteries by measuring the parameters of the main arteries of the heart and atherosclerotic plaques using the procedure of selective radiopaque angiography. On the obtained polyprojection angiograms in the longitudinal anatomical plane of the arterial branches with a mouth clearance of at least 1 mm, 5 linear values are measured: the radius of the lumen and the length of the arteries, the maximum and minimum radii of the lumen of the arteries in the area of atherosclerotic plaques and the length of the atherosclerotic plaques, calculate the total volume of the channel of the main arteries of the heart and the total volume of atherosclerotic plaques, then calculate the relative volume of atherosclerotic plaques. The obtained value of this indicator assesses the degree of systemic morphological severity of atherosclerosis, with values of the relative volume of atherosclerotic plaques 0.12 or more, the degree of morphological severity of atherosclerosis is estimated as significant, with values from 0.05 to 0.11 as average, with values of 0.04 and less - as insignificant. The method allows for a quantitative assessment of the systemic morphological severity of atherosclerosis in the arterial bed of the heart and to use it when conducting multidirectional studies of the pathogenetic and clinical patterns of the disease. This method really allows you to give a morphological characteristic of atherosclerosis of the coronary arteries, however, it has no clinical application and is not informative in assessing coronary atherosclerosis of the coronary arteries before performing myocardial revascularization.

(RF patent No. 2634621, IPC АВВ 6/00, publ. 02.11.2017, Bull. No. 31).

The most common angiographic scale in clinical practice is the Syntax Score, developed by specialists in endovascular methods of treatment and diagnosis. According to it, damage to the coronary artery (CA) is considered diffuse with its small diameter (less than 2 mm) over 75% of the segment of the artery located distal to stenosis, regardless of the presence of atherosclerotic lesions.

(Sianos G., Morel M.A., Kappetein A.R. et. Al. The SYNTAX score: an angiographic tool grading the complexity of coronary artery disease. // EuroIntervention1: 219-227, 2005.).

The disadvantage is that Syntax Score does not allow to evaluate the distal bed from a surgical position and does not clearly determine the diffuse lesion.

Currently, the most effective ways to assess the distal bed are calculators proposed by Graham and Cubero-Gallego. In the first case (Graham scale), taking into account the type of blood supply (right, left), the anatomical options of the coronary bed and the size of the arteries, the contribution to the myocardial blood supply of each artery is estimated in 0.5 steps (minimum - 0, maximum - 2); thus, the sum is always 8. The second step is to assess the severity of the narrowing of the spacecraft: the narrowing of the trunk of the left coronary artery (LCA) is considered more critical than 50%, other arteries - more than 70%. Arteries narrowed below a critical level are not taken into account in the calculation. Affected arteries receive a score from 0 (intact artery) to 5 points (diameter <0.5 mm; very severe atherosclerosis, occlusion or “non-shunting” condition) depending on their caliber and degree of involvement in the process. For each artery with hemodynamically significant stenosis, the severity of the lesion is calculated by evaluating the contribution and scores depending on the caliber. The final step is the summation of the works. The minimum possible score is 8, the maximum is 40. A defeat is considered diffuse, which scores 18 points or more. Based on the results of a clinical study, it is concluded that diffuse CA lesion is associated with worse coronary artery bypass grafting (CABG) results.

(Graham M., Chambers J., Davies R. et. Al. Angiographic quantification of diffuse coronary artery disease: Reliability and prognostic value for bypass operations // J. Thor. Cardiovasc. Surg. - 1999.- V. 118 (4 ). - P. 618-627).

This method of calculating the diffusion of the lesion does not give a quantitative characteristic of the atherosclerotic lesions of the distal bed. The gradations used are very conditional and do not give an idea due to which there was a narrowing of the distal lumen (atherosclerotic thickening of the walls or a truly small caliber of the vessel). The second scale (Cubero-Gallego) evaluates each artery separately according to 3 criteria. The total score for a single, target, or shunted artery (0 to 9 points) is calculated, i.e. the total score for all target arteries divided by their number. 7.6 was proposed as a quantitative value: this value predicts the development of cardiovascular events (myocardial infarction, unstable angina, cardiac death) with a specificity of 59% and a sensitivity of 64%. This method of assessing the distal bed includes insufficiently clear gradations of the “visibility” of the vessel, and when assessing the diameter, only the minimum diameter of 1.5 mm was studied, smaller gradations of the caliber of the arteries were not considered. Accordingly, its use is impossible when bypassing arteries of smaller diameter. In addition, unlike most generally accepted methods for assessing atherosclerosis of coronary arteries, in this method, more affected coronary arteries have less digital value than intact ones.

The objective of the invention is to provide an effective method for assessing diffuse atherosclerotic lesions of the coronary arteries before myocardial revascularization, allowing at the preoperative preparation stage to give an objective assessment of the severity of coronary artery atherosclerosis and select the most optimal strategy for myocardial revascularization, evaluate the need for specialized surgical techniques (endarterectomy from coronary arteries with anastomosis through atherosclerotic plaque, shun ation of small diameter arteries (<1.5 mm), multiple distal bypass surgery), as well as to predict the possible complications and the postoperative prognosis.

The technical result is to reduce intraoperative and postoperative complications in patients with diffuse lesions of the coronary arteries.

The technical result is achieved by the fact that in the claimed method for evaluating diffuse atherosclerotic lesions of the coronary arteries before revascularization of the myocardium by conducting a cardioangiographic study to determine artery parameters and evaluate the results in points, according to the invention, 3 parameters are determined and evaluated in points, namely, the prevalence of atherosclerotic changes in the wall coronary artery distal to hemodynamically significant stenosis: intact wall of the coronary vessel - 0 points, and eroskleroz less than 10% of the affected segment of the artery - 1 point, atherosclerosis more than 10% but less than 50% of the affected segment of the artery - 2 points, atherosclerosis over 50% or calcification phenomena in the neovascularization zone - 3 points; diameter of the shunt artery, more than 2 mm - 0 points, 1.5-2 mm - 1 point, 1 - less than 1.5 mm - 2 points, less than 1 mm - 3 points; the significance of the studied artery in the blood supply to the myocardium: high significance, that is, the dominant vessel - 0 points, average significance, that is, balanced blood supply - 1 point, unknown significance, that is, collateral blood flow - 2 points, low significance, that is, a reduced vessel or zone of cardiosclerosis - 3 points. In this case, the points of three parameters are summarized to determine the diffuse lesion index (IDI), and if the IDI is less than 4 points, the coronary artery lesion is considered not diffuse and the standard anastomosis formation technique is used, the IDP value of 4-6 points is considered borderline and specialized surgical methods can be used ( CXM). If the IDP value is 7–9 points, the lesion is considered diffuse, in which it is necessary to use SCM, and there is a high probability of the need for endarterectomy from the coronary artery.

The implementation of the method.

For all patients, as part of a preoperative examination, they perform coronary angiography (CAG), based on which IDPs are calculated to determine the type, degree and prevalence of atherosclerotic lesions of the coronary channel. For this, three parameters are determined for each coronary artery (main trunks and branches of the first order).

The first indicator was the prevalence of the atherosclerotic process in the affected segment of the artery. Depending on the prevalence of atherosclerotic changes in the SC wall, distal to hemodynamically significant stenosis, from 0 to 3 points are assigned. If the coronary vessel has an intact wall, then 0 points are assigned, with atherosclerosis less than 10% of the segment of the affected artery - 1 point, with atherosclerosis more than 10%, but less than 50% of the segment of the affected artery, 2 points are assigned, with atherosclerosis more than 50% or in the presence of phenomena calcification in the revascularization zone - 3 points.

The next of the three measured parameters is the assessment of the diameter of the shunt artery of the distal segment and, depending on the size of the vessel, is also assigned from 0 to 3 points. If the diameter of the shunt artery is> 2 mm, then 0 points are assigned, with a diameter of 1.5-2 mm - 1 point, with a diameter of 1-1.5 mm - 2 points, if the diameter of the shunt artery is <1 m, then 3 points are assigned. This ranking, depending on the caliber of the artery, is based on the results of studies and international practice, demonstrating that the patency of shunts correlates precisely with such sizes of the distal segments of the spacecraft.

The third parameter evaluated is the significance of the shunt artery in the blood supply to the myocardium. Estimation of the volume of blood supply to the myocardium is based on the principle of balanced (equal) distribution of branches, the dominance of a vessel (blood supply to a larger area with the capture of an adjacent artery) or reduction of the vascular bed (an adjacent branch extends into the blood supply to the vessel under study). Points are assigned according to the following principle: high significance (dominant vessel) - 0 points, average significance (balanced blood supply) - 1 point, unknown significance (collateral blood flow) - 2 points, low significance (reduced vessel or cardiosclerosis zone) - 3 points.

The total value of all assessed characteristics (the prevalence of coronary atherosclerosis, caliber and significance in the blood supply to the shunt artery) is the value of the Diffuse Damage Index (IDP). If the IDP value is <4 points, the coronary artery lesion is considered non-diffuse and the standard technique for the formation of an anastomosis is used, the IDP value of 4-6 points is considered borderline, and it is possible to use SCM. If the IDP value is 7–9 points, the lesion is considered diffuse, in which SCM is necessary, and endarterectomy from the coronary artery is also highly likely.

The presence of diffuse lesion may be important for the operating surgeon in terms of resolving the need for the use of SCM. It is worth noting that with an IDP value of 7-9 points, adequate myocardial revascularization with the formation of a standard distal anastomosis is not possible, the use of SCM using optical zoom is required. Surgery, accompanied by the use of SCM, in some cases, may be associated with a longer cardiopulmonary bypass time, myocardial ischemia compared to standard coronary artery bypass grafting. Nevertheless, the use of SCM for diffuse lesions of the coronary arteries allows us to obtain acceptable results of surgical treatment, comparable with the results of surgical intervention with the proximal type of lesion of the coronary arteries with the formation of standard anastomoses.

Examples of the method.

Example 1. Patient S., 60 years old. Received with a clinic of rest angina pectoris (4 FC), severe atherosclerosis of the coronary arteries. History: angina pectoris with gradual progression over 8 years. Previously consulted by cardiac surgeons of other medical institutions, CABG was refused due to the severity of coronary artery damage. A survey was performed according to the CAG: multivascular damage to the coronary arteries, the IDP for the target arteries was calculated, the results were 9 points for the anterior descending artery (PNA), intermediate artery (IMA), 8 points for the artery envelope (OA), 6 points for the right coronary artery (PKA). All of these arteries had hemodynamically significant stenoses with a length of atherosclerotic changes of more than 50% of the distal segment (3 points), with a diameter of less than 1 mm (3 points). PNA is regarded as reduced, other arteries of the left coronary artery system had low (IMA) and unknown significance (OA) in the blood supply to the myocardium (3, 3 and 2 points, respectively). PKA is regarded as a dominant vessel (0 points). Given the severity of coronary artery damage (IDP - 6–9 points), a decision was made on the need for SCM for adequate myocardial revascularization. 8 distal anastomoses were performed (Mammaro-coronary artery bypass grafting (anastomosis in pr / 3, d = 1 mm, before the septal perforator leaves) [sequentially] + anterior descending artery (anastomosis in dist / 3, d <1 mm); Aorto - coronary artery bypass grafting of the diagonal artery (d <1 m) + intermediate artery (d <1 mm, anastomosis through atherosclerotic plaque (ASB) [artificial Y-construction], envelope of the artery (d <1 mm, anastomosis through ASB) + blunt edge arteries (d = 1 mm, anastomosis via ASB) [artificial Y-construction], posterior descending arteries (d <1 mm) + sharp-edge arteries (d <1 mm, anastomosis via ASB) [natural plug] using an operating microscope. In the postoperative period, anginal pains did not recur, according to control coronary bypassography: all shunts are passable. The patient was discharged in satisfactory condition.

Example 2. Patient D. 68 years. He was admitted with a clinic of severe angina pectoris (3 FC). History: previous myocardial infarction of lower localization from 2016, a positive stress test (stress echocardiography), diabetes mellitus. According to the CAG: the type of blood supply is right, the PNA is reduced (3 points for IDP) with the presence of multiple stenoses of the PNA, the prevalence of more than 50% throughout the vessel (3 points for IDP) with the occlusion of the distal segment (3 points for IDP). Also, according to the CAG data, proximal critical stenoses of the diagonal artery (DA), OA, blunt edge arteries (ATC), and PCA are determined. Thus, the IDP for PNA is 9 points; for DA - 3 points (the prevalence of atherosclerosis - 1 point, diameter - 1 point, significance - 1 point); OA - 2 points (the prevalence of atherosclerosis - 1 point, diameter - 0 points, significance - 1 point); ATC - 2 points (the prevalence of atherosclerosis - 1 point, diameter - 0 points, significance - 1 point); PKA - 1 point (the prevalence of atherosclerosis - 1 point, diameter - 0 points, significance - 0 points). Given the severity of PNA damage, the absence of a distal bed (IDP - 9 points), it was decided that endarterectomy from PNA should be performed using an operating microscope. Taking into account the non-diffuse lesion of other coronary arteries (IDP 1-3 points), standard coronary artery bypass grafting was performed. In the postoperative period, anginal pain did not recur, taking into account the performed endarterectomy, warfarin therapy was started. Control MSCT shuntography was performed: all shunts are passable. The patient was discharged in satisfactory condition.

The calculation of the diffuse lesion index (IDP) allows at the stage of preoperative preparation to give an objective assessment of the severity of atherosclerosis of individual coronary artery bypass grafts and choose the most optimal myocardial revascularization strategy, as well as predict possible complications and postoperative prognosis.

Claims (5)

A method for assessing diffuse atherosclerotic lesions of coronary arteries before myocardial revascularization by conducting a cardioangiographic study to determine artery parameters and evaluate the results in points, characterized in that 3 parameters are determined and evaluated in points, namely: the prevalence of atherosclerotic changes in the wall of the coronary artery distal to hemodynamically significant stenosis: intact wall of the coronary vessel - 0 points, atherosclerosis of less than 10% of the segment of the affected artery - 1 point, atherosclerosis of more than 10%, but less than 50% of the segment of the affected artery - 2 points, atherosclerosis over 50% or calcification in the revascularization zone - 3 points; diameter of the shunt artery: more than 2 mm - 0 points, 1.5 - 2 mm - 1 point, 1 - less than 1.5 mm - 2 points, less than 1 mm - 3 points; the significance of the studied artery in the blood supply to the myocardium: high significance, that is, the dominant vessel - 0 points, average significance, that is, balanced blood supply - 1 point, unknown significance, that is, collateral blood flow - 2 points, low significance, that is, a reduced vessel or zone of cardiosclerosis - 3 points; the obtained points of three parameters are summarized to determine the diffuse lesion index (IDI), with an IDI of less than 4 points, the coronary artery lesion is considered not diffuse, an IDP of 4-6 points is considered borderline, with an IDI of 7-9 points, the lesion is considered diffuse.