Clinical and Diagnostic Characteristics and Features of Interventional Treatment of Patients with Dysplasia-Associated Pathology of the Coronary Arteries

The dissertation is devoted to the study of the clinical and diagnostic characteristics and the features of interventional treatment of patients with pathology of the coronary arteries associated with hereditary connective tissue insufficiency. The work addresses the prevalence, clinical manifestations, diagnostic criteria, and therapeutic tactics for myocardial bridges of the coronary arteries (MB of CA) in patients with coronary artery disease. The author analysed the dysplasia-dependent phenotypical signs in patients with MB of CA, developed a diagnostic and treatment algorithm for the management of such patients, and evaluated the immediate and long-term results of interventional procedures, including stenting, myotomy, and aortocoronary bypass grafting.

The practical significance of the work is related to the refinement of indications for coronarography in patients with suspected MB of CA, the justification of the choice of interventional treatment methods, and the implementation of the obtained data into the clinical practice of departments of cardiovascular surgery and roentgen-surgical methods of diagnosis and treatment.

Relevance of the problem

Cardiovascular diseases are the leading cause of mortality and disability in the population. At the same time, a significant proportion of cases are accounted for by acute and chronic disorders of the coronary circulation. The introduction of highly accurate and widely available angiographic techniques has made it possible, alongside atherosclerotic lesions of the coronary arteries, to identify other causes of impaired coronary blood flow. Among such conditions are myocardial bridges of the coronary arteries, the presence of which a number of authors associate with systemic connective tissue insufficiency [1, 4, 20, 23, 31, 35, 104, 105, 121, 133, 155, 175].

At present, there are no in-depth clinical studies devoted to the clinical features, distinctive characteristics of the functional state of the myocardium, and biochemical profile in patients with myocardial bridges of the coronary arteries. Likewise, there are no studies concerning treatment tactics or the rationale for choosing between conservative and interventional therapy [3, 12, 20, 104, 109, 121, 133, 155].

The literature contains only isolated reports on surgical and roentgen-surgical treatment of patients with myocardial bridges of the coronary arteries [3, 20, 52, 104, 121, 165].

In view of the above, further investigation of this problem is of considerable scientific and practical interest.

Aim of the study

To analyse the clinical and diagnostic features and the results of interventional treatment of patients with pathology of the coronary bed associated with hereditary connective tissue insufficiency.

Objectives of the study:

1. To evaluate the frequency and features of the clinical course of myocardial bridges of the coronary arteries in patients with coronary artery disease.

2. To investigate the features of the clinical course of CAD with account taken of the presence of MB of CA.

3. To study the dysplasia-dependent shifts in the phenotype of patients with myocardial bridges of the coronary arteries.

4. To develop a diagnostic and treatment algorithm for the management of patients suspected of having myocardial bridges of the coronary arteries.

5. To analyse the results of interventional treatment of patients with myocardial bridges of the coronary arteries.

Scientific novelty of the work

For the first time, the frequency and features of the clinical course of myocardial bridges of the coronary arteries have been analysed with account taken of other somatic manifestations of connective tissue dysplasia.

For the first time, a comprehensive analysis of the results of interventional treatment of patients with myocardial bridges of the coronary arteries has been presented in relation to biological factors, the clinical picture of the disease, and the baseline data of instrumental investigations.

For the first time, a diagnostic algorithm has been developed for the identification of patients with suspected dysplasia-associated pathology of the coronary arteries, and therapeutic and tactical recommendations have been presented with account taken of the clinical and diagnostic features of the disease in these patients.

Main propositions of the dissertation submitted for defence

1. MB of CA constitute an independent cause of CAD in persons of working capacity, detectable by means of coronarography performed with the use of appropriate projections.

2. MB of CA represent a particular manifestation of the syndrome of undifferentiated connective tissue dysplasia.

3. The presence of MB of CA can be preliminarily predicted with account taken of defined diagnostic criteria.

4. The pathological influence of haemodynamically significant MB of CA can be successfully corrected by means of interventional methods, such as stenting of the causative segment of the coronary artery, myotomy of the myocardial bridge, and aortocoronary bypass grafting with the shunt placed beyond the myocardial bridge.

Scientific and practical significance of the work

The completed study has made it possible to clarify the clinical features inherent to myocardial bridges of the coronary arteries.

An association has been revealed between myocardial bridges of the coronary arteries and age, sex, constitutional type, the presence of concomitant pathology in patients, and minor cardiac anomalies.

The indications for coronarography in patients suspected of having myocardial bridges of the coronary arteries have been refined.

An algorithm has been developed for the detection of myocardial bridges in patients with CAD.

The dynamics of quality of life in patients with myocardial bridges who underwent an interventional procedure has been studied, and the indications for interventional treatment of myocardial bridges of the coronary arteries have been refined.

Implementation of the results into practice.

The results of the investigation have been implemented in the clinical work of the departments of cardiovascular surgery and roentgen-surgical methods of diagnosis and treatment of the State Healthcare Institution "SKKTs SVMP".

The obtained data are used in lectures and practical classes of the departments of cardiovascular surgery and high surgical technologies of the Faculty of Postgraduate Education, and of internal diseases No. 2 of the medical faculty of the Stavropol State Medical Academy.

Approbation and publications. The materials of the dissertation were presented at the V Congress of Cardiologists of the Southern Federal District "Clinical Examination, Quality Diagnosis, Treatment, and Rehabilitation — the Key to Success of the Cardiology Service" — Kislovodsk, 2006, and at the XIV Final (Interregional) Scientific Conference of Students and Young Scientists — Stavropol, 2006. Fourteen scientific works have been published on the topic of the dissertation.