Pocket hematoma is a known complication of pacemaker (PM) implantation. Pocket hematoma is accompanied by a local discomfort associated with the infiltration of subcutaneous tissue. In some cases, this complication requires repeated surgical revisions, which increases the risk of infection, and increases the duration of a hospital stay. The search for ways to prevent bleeding from the PM pocket is of great practical interest. This question is especially acute in relation to patients who are constantly on anticoagulation and/or antiplatelet therapy. A number of authors propose to carry out complete or partial cancellation of these drugs for the period before surgery and in the early postoperative period. In our opinion, this approach in most cases carries a potential risk to the health of patients, especially in the case of patients who have previously undergone surgical correction of valve insufficiency and/or who have undergone percutaneous endovascular interventions.

The use of local hemostatic drugs is one of the promising directions for increasing the efficiency of intraoperative hemostasis. The haemostatic solution "Haemoblock" has shown its hemostatic potential in general surgical practice. The possibilities of "Haemoblock" in the prevention of pocket hematoma have not been studied. The hemostatic effect of "Haemoblock" is achieved within 1-2 minutes due to the formation of a clot with blood plasma proteins, first of all with albumin. As a result of the action of the "Haemoblock", a strong polymethacrylate membrane is formed on the surface of the wound, which, among other things, has a bactericidal effect.

А multicenter research trial will be conducted at 6 medical centers:

• Ryazan State Medical University (Ryazan);
• Federal State Budgetary Institution "Federal Center for Cardiovascular Surgery" of the Ministry of Health of the Russian Federation (Astrakhan);
• Federal State Budgetary Institution "Federal Center for Cardiovascular Surgery" of the Ministry of Health of the Russian Federation (Penza);
• Federal State Budgetary Institution "Federal Center for Cardiovascular Surgery" of the Ministry of Health of the Russian Federation (Chelyabinsk);
• Federal State Budgetary Institution "Federal Center for Cardiovascular Surgery" of the Ministry of Health of the Russian Federation (Kaliningrad);
• Federal State Budgetary Institution "Federal Center for Cardiovascular Surgery" of the Ministry of Health of the Russian Federation (Khabarovsk).

Haemostatic solution "Haemoblock" provided by Autonomous non-profit organization "MOSCOW REGIONAL SCIENTIFIC RESEARCH INSTITUTE OF BLOOD".

The study will include 200 patients with indications for pacemaker implantation (atrioventricular block, sick sinus syndrome, atrial fibrillation with impaired atrioventricular conduction or other).

Before starting the study, the patient must give written consent to participate in this study after familiarizing him with the purpose and rules of the clinical study.

All patients during randomisation will be divided into 2 groups:

Group A "Haemoblock" - 100 patients. Haemostatic solution "Haemoblock" will be used after pocket formation during pacemaker implantation (sterile gauze swabs are soaked in 15 ml of "Haemoblock" solution and applied in pacemaker pocket, then pacemaker pocket will be irrigated with 5 ml of "Haemoblock" solution without rinsing).

Group B "Control" - 100 patients. Same procedure will be performed with saline solution in this group.

Before surgery blood sampling, echocardiography will be performed in all patients.

3-5 days after surgery ultrasound of pacemaker pocket will be performed in all patients.

The observation period for patients will be 30 days.

Inclusion Criteria:

• availability of informed consent of the patient to participate in the study;
• men and women aged 40-85 years with indications for pacemaker implantation, taking oral anticoagulants before surgery for at least 7 days;

Exclusion Criteria:

• hypoalbuminemia;
• known contraindications for the study haemostatic solution "Haemoblock";
• severe arterial hypertension: Systolic blood pressure ≥ 200 mmHg and/or Diastolic blood pressure ≥ 110 mmHg;
• unstable forms of ischemic heart disease;
• hemostasis disorders in the number of platelets, prothrombin, fibrinogen levels, or International Normalised Ratio above 3.0
• LVEF according to Simpson <35%;
• the period of pregnancy and lactation;
• chronic renal failure: creatinine clearance less than 40 ml/min;
• hemoglobin level <90 g/l;
• participation in another study.

200 patients with indications for pacemaker implantation (atrioventricular block, sick sinus syndrome, atrial fibrillation with impaired atrioventricular conduction or other).

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