RU2513194C1 - Method for detecting developing neointimal hyperplasia and carotid restenosis following angioplasty in patients with progressive cerebral atherosclerosis - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: blood serum lipoprotein-associated phospholipase A2 (Lp-PLA2) biomarker is measured in a patient with progressive cerebral atherosclerosis after carotid angioplasties no more than 6 months later using immunoenzyme method; if the derived value is 360 ng/ml and more, developing neointimal hyperplasia and carotid restenosis are stated.

EFFECT: method provides high-accuracy detection of developing neointimal hyperplasia and carotid restenosis in the patients suffering progressive cerebral atherosclerosis following carotid angioplasties.

Description

The invention relates to medicine, in particular to neurology, and can be used to detect the development of neointima hyperplasia and carotid artery restenosis after angioreconstructive operations on them in patients with progressive cerebral atherosclerosis.

Every year, 60 million people die in the world, 18 million of them from cerebrovascular diseases (CEH), and these rates in Russia are among the highest in the world [Conrado J. Estol. Atherosclerosis: The XXIst Century Epidemic. Stroke 2011; 42: 3338-39].

Atherosclerosis of the vessels of the aortic arch, especially bifurcation of the common carotid artery, is the cause of more than a third of ischemic strokes [Stroke: diagnosis, treatment, prevention. Ed. Z.A.Suslina, M.A.Piradova. - 2nd ed. M., 2009. - 288 p.]. Modern examination methods have greatly facilitated the diagnosis and increased the detection of atherosclerotic lesions of the main arteries of the head, which, along with a low level of prevention of atherosclerosis, has led to an increase in carotid artery operations. Occlusive carotid artery diseases that have not been surgically treated give 5 to 12% of new strokes [Inzitari D., Eliasziw M., Gates P. et al. The causes and risk of stroke in patients with asymptomatic internal-carotid-artery stenosis, North. American Symptomatic Carotid Endarterectomy Trial Collaborators, N. Eng. J. Med., 2000; 342: 1693-1700]. The effectiveness of carotid endarterectomy (CEAE) in the prevention of strokes in patients with atherosclerosis of the carotid bifurcation has been reliably established [Barnett H.J., Taylor D.W., Eliasziw M. et al. Benefit of carotid endarterectomy in patients with symptomatic moderate or severe stenosis, NEJM, 1998; 339: 1415-1425]. CEAE is currently the standard in brain revascularization, while comparable with CEAE, the efficacy and safety of carotid angioplasty with stenting (CAS) cannot be considered absolutely proven. The number of surgical interventions on the arteries supplying the brain is steadily increasing. The total number of operations for stenosis of the carotid arteries in 2011 increased by 15%. The most frequent operation was CEAE (according to the annual report on the work of the vascular departments in the Russian Federation for 2011, published on the website).

With an increase in the number of operated patients, the problem of the timely detection of the development of neointimal hyperplasia and restenosis after angioreconstructive operations on the carotid arteries arose.

A known method for detecting the development of neointima hyperplasia and restenosis after angioreconstructive operations of arteries, including carotid ones, in patients with progressive cerebral atherosclerosis by clinical monitoring of patients and performing color duplex scanning in the peri- and distant postoperative periods to monitor structural and hemodynamic changes in areas of intervention. Moreover, the dynamics of changes in stented arteries must be performed at intervals: for vertebral arteries within 1-3 days after endovascular intervention, after 3, 6, 12 months and then annually; for the carotid and subclavian arteries - in the first 1-3 days after surgery, 6, 12 months and then every year (Chechetkin A.O. Comprehensive assessment of atherosclerotic lesions of the branches of the aortic arch at the stages of endovascular interventions, Abstract of dissertation for the degree of Doctor of Medical Sciences Moscow, 2012, 48 p.).

However, this method of ultrasound dynamic examination of a patient after angioreconstructive operations is associated with the presence of expensive equipment in outpatient conditions and the inability to identify the risk of dangerous development of wall-occlusive lesions. This source of information is considered as the closest analogue.

The objective of the present invention is to identify a new predictor of the development of neointimal hyperplasia and restenosis, available for widespread use. This problem was solved by determining a biochemical indicator - lipoprotein associated phospholipase A2 (Lp-PLA2), an analysis of the changes of which in comparison with clinical parameters characterizes the activity of the inflammatory reaction of the vascular wall, the development of neointima hyperplasia and restenosis after angioreconstructive operations. This is due to the fact that Lp-PLA2 is synthesized mainly by macrophages of the carotid arteries and, penetrating into the general bloodstream, binds to atherogenic particles of LDL circulating in the plasma and hydrolyzes phosphatidylcholine with the formation of lysophosphatidylcholine and oxidized free fatty acids, which are involved in the development of inflammatory infiltration in the region and potentiate the synthesis of cytokines, which allows us to consider it an important indicator of the risk of neointima hyperplasia and carotid restenosis.

The technical result of our proposed method for detecting the development of neointimal hyperplasia and carotid artery restenosis after angioreconstructive operations in patients with progressive cerebral atherosclerosis is that laboratory monitoring of the inflammatory response of the vascular wall and atherosclerosis of lipoprotein-associated phospholipase A2 (Lp-PLA2) allows high accuracy to identify the development of neointima and restenosis hyperplasia as a result of increasing its values in individuals with progressive stenosing process in the internal carotid artery.

The technical result is achieved by the fact that after carrying out angioreconstructive surgery on the carotid artery no more than 6 months later, the content of the patient’s blood serum biomarker lipoprotein-associated phospholipase A2 is determined in the patient’s blood serum and at a level of 360 ng / ml or more they reveal the development of neointima and restenosis hyperplasia in the operated carotid artery.

The method is as follows.

A patient with progressive cerebral atherosclerosis after angioreconstructive surgery (in particular, CEAE or CAS) does not take more than 6 months for blood sampling for examination from the cubital vein in the morning on an empty stomach in the morning after 12-hour fasting. Blood samples are centrifuged and determined by the method of enzyme immunoassay on a reader Perkin Elmer Victor2 (USA) the concentration of Lp-PLA2. Results are expressed in ng / ml.

The determination is carried out by a solid-phase non-competitive method based on a direct "sandwich" technology. Moreover, in the streptovidin-coated microplate cells, standard and patient samples are incubated together with biotinylated monoclonal antibodies to Lp-PLA2 and antibodies to the Lp-PLA2 antigen conjugated with horseradish peroxidase. After washing the cells with a buffer solution, a chromogenic substrate (3.3.5.5-tetramethylbenzidine) is added to each cell for an enzymatic reaction. During the reaction, a blue color develops, the intensity of which is directly proportional to the amount of Lp-PLA2. The color intensity is measured on a microplate reader with the addition of a stop solution at a wavelength of 450 nm.

With the value of this biomarker 360 ng / ml or more, which is 180% higher than the threshold value (a group of experts, the threshold value of Lp-PLA2 is considered to be 200 ng / ml) [Colley KJ, Wolfert RL, Cobble ME. Lipoprotein associated phospholipase A (2): role in atherosclerosis and utility as a biomarker for cardiovascular risk. EPMA J. 2011 Mar; 2 (l): 27-38. Epub 2011 Mar 10] reveal the development of neointimal hyperplasia and restenosis in the operated artery.

56 patients with progressive cerebral atherosclerosis (38 men, 18 women) who underwent angioreconstructive surgery for ICA stenosis and were hospitalized in the vascular department of the NCH RAMS were examined, the average age was 65 (47; 80) years. Patients were divided into 2 groups. Group I (n = 23) included patients who underwent CEAE, and group II (n = 35) included CAS. The survey was carried out in 2 stages. At both the 1st and 2nd stages, all patients underwent a general clinical examination, a duplex scan of the main arteries of the head (MAG) on the Philips iu2 apparatus to determine the degree of progression of atherosclerosis. To study the content of the marker of the inflammatory reaction of the vascular wall (Lp-PLA2) in these patients, blood was taken from the ulnar vein on an empty stomach 5-6 months after CEAE and CAS. Also, the content of Lp-PLA2 was determined in ten individuals without progressive cerebral atherosclerosis (group 3) and in 10 individuals with progressive cerebral atherosclerosis, without stenocclosing atherosclerotic lesion of the ICA (group 4), comparable in gender and age. Statistical analysis of the results was carried out using the software package Statistica 6.0 (StatSoft, 2003). The results were considered statistically significant at p <0.05.

In the first and second groups, patients with progression of the stenotic process after CEAE and CAS were allocated. In the first group of patients, neointima hyperplasia and the development of restenosis were observed in 13.04% of cases (n = 3), while in the second group - 17.14% (n = 6). When evaluating the results of Lp-PLA2, it was found that the level was higher than the threshold value (200 ng / ml) in patients in both the first and second groups with the development of neointimal hyperplasia and restenosis (367.83 ± 53.8 and 369 ± 53 , 1 ng / ml, respectively, p = 0.008). Moreover, in the group of patients after CAS, the content of Lp-PLA2 was slightly higher than in the group after CEAE with neointima hyperplasia and restenosis. In the third control group, the Lp-PLA2 content was 210 ± 45.07 ng / ml. The content of Lp-PLA2 in patients after CEAE and CAS with neointima hyperplasia and the development of restenosis (first and second groups) was 141% higher than the content of Lp-PLA2 in the control group. In the fourth group, the content of Lp-PLA2 was 291 ± 52.7 ng / ml. This corresponded to the content of the biomarker of lipoprotein-associated phospholipase A2 in the first and second groups by 105% more relative to the values of Lp-PLA2 of the fourth group. Thus, in patients with the development of neointimal hyperplasia and restenosis in the reconstructed artery, the content of Lp-PLA2 was 360 ng / ml or more, which was higher relative to both the threshold value and the values of the control group and the values of the group with progressive cerebral atherosclerosis. This suggests that the development of neointima and restenosis hyperplasia occurs on the basis of deeper inflammatory processes in the endothelium and with a corresponding increase in Lp-PLA2 production. Developing restenosis after CEAE and CAS leads to the need for repeated surgical intervention and increases the risk of cerebrovascular events.

Examples of the method.

Example 1

Patient G., 59 years old. For a long time, he suffers from diabetes mellitus, arterial hypertension and progressive cerebral atherosclerosis. Duplex scanning of the main arteries of the head (DS MAG) revealed the presence of asymptomatic heterogeneous atherosclerotic plaque (ASB) in the right internal carotid artery (ICA), stenosing the lumen of the vessel by 75-80%, in the left ICA - 45%. 01/24/2011 conducted by CEAE on the right. In order to determine the inflammatory reaction of the vascular wall after CEAE, after 6 months, the content of the Lp-PLA2 biomarker in the blood serum was studied, the concentration of which was 410 ng / ml, which corresponds to the presence of the development of neointima hyperplasia and restenosis in the operated carotid artery. After 8 months in the neurological status of the patient, the appearance of neurological symptoms in the form of vestibulo-atactic syndrome was noted. To confirm the adequacy of the conclusion of the development of the pathological process in the operated carotid artery on the basis of the Lp-PLA2 biomarker, its study was conducted after 8 months using MAG DS. Neointima hyperplasia was detected with stenosis of the lumen of the right internal carotid artery by 45%. In a second study of MAG DS after 1 year and 2 months, the development of neointimal hyperplasia with stenosis in the specified artery was observed up to 55%. Thus, this diagnostic indicator makes it possible to timely detect the presence of neointima and restenosis hyperplasia in the operated artery even without MAG DS and to determine the further medical and surgical management tactics of the patient.

Example 2

Patient B., 71 years old. Against the background of progressive cerebral atherosclerosis, long-term arterial hypertension, diabetes mellitus, the clinical symptom complex was represented by cephalgic, vestibulo-atactic syndrome. When conducting MAG DS, stenosis of the right ICA was detected 75%, magnetic resonance imaging (MRI) of the brain determined the focus in the deep parts of the right hemisphere, in connection with which 04.04.2010 was performed CEAE of the right ICA. In order to determine the inflammatory reaction of the vascular wall after CEAE, after 5 months, the content of the Lp-PLA2 biomarker in the blood serum was studied, the concentration of which was 388 ng / ml, which corresponds to the presence of neointima and restenosis in the operated carotid artery. To confirm the conclusion of the development of the pathological process in the operated carotid artery on the basis of the Lp-PLA2 biomarker, a study of the carotid artery was performed using MAG DS. Neointima hyperplasia was detected with stenosis of the lumen of the right internal carotid artery by 45%. At the visit after 1.5 years there was an increase in vestibulo-atactic syndrome, the appearance of intellectual and mnestic disorders, and on MAG DS (after 1.5 years) the presence of restenosis due to heterogeneous masses in the bifurcation of the OSA up to 75%, as well as neointimal hyperplasia during ICA up to 30%. Therefore, the determination of the Lp-PLA2 biomarker (after CEAE after 5 months) ensures the timely detection of the development of restenosis and allows further adjusting the tactics of drug and surgical management of the patient.

Thus, in patients with cerebral atherosclerosis, after angioreconstructive operations, the inflammatory reaction of the vascular wall is often progressive and intensified in response to damage during CEAE or by installing a stent, stimulating the proliferation of smooth muscle cells with the development of neointima hyperplasia and the formation of restenosis in the reconstructed artery. Potentially, a new opportunity for diagnostic examination of patients opens up - by the level of Lp-PLA2, which ensures the determination of the activity of the inflammatory process in the endothelium of the vessel and the identification of the dangerous development of stenocclusive lesions after angioreconstructive operations.

Our proposed method provides high accuracy of timely detection of the development of neointimal hyperplasia and restenosis in the operated artery without instrumental angio-visualization and is of great prognostic value in determining the further medical and surgical management of patients.

Claims (1)

A method for detecting the development of neointima hyperplasia and restenosis after angioreconstructive operations on the carotid arteries in patients with progressive cerebral atherosclerosis, characterized in that after angioreconstructive surgery, the serum content of the lipoprotein-associated L-phospholipase A2 biomarker is determined after no more than 6 months after immuno-reconstructive surgery ( PLA2) and with a value of 360 ng / ml or more, the development of neointima and restenosis hyperplasia in the operated carotid artery is detected.