Evaluation of the Effectiveness of Antianginal Therapy in Patients with Stable Angina

The dissertation is devoted to a comprehensive evaluation of the effectiveness of antianginal therapy in patients with stable angina from the standpoint of clinical and economic analysis and quality-of-life assessment. The relevance of the study is determined by the high prevalence of ischemic heart disease, the considerable expenditures of the healthcare system on the treatment of such patients, and the need for the rational use of limited resources. The work compares different regimens of organic nitrate use and analyzes quality-of-life parameters in patients during therapy. The author carried out a retrospective and prospective analysis of quality of life, a pharmacoeconomic analysis using the "cost of illness," "cost minimization," and "cost-effectiveness" methods, as well as an assessment of the economic losses associated with the typical practice of inpatient and outpatient treatment. The data obtained supplement the existing understanding of the relationship between the clinical and economic effectiveness of antianginal therapy and may be used to optimize treatment programs for stable angina.

Relevance of the Problem

Cardiovascular diseases (CVD) remain the most pressing healthcare problem in the majority of countries of the world in the twenty-first century, despite the continuous improvement of methods for the diagnosis and treatment of cardiac patients. According to the forecast of WHO experts, by 2020 ischemic heart disease (IHD) will become the leading, most frequent cause of loss of working capacity and death of people. Among patients with IHD, stable angina is the most prevalent form. The presence of unmitigated attacks of exertional angina increases the risk of mortality from IHD by a factor of 2.2 in men and by a factor of 1.7 in women [86, 91]. Studies carried out in the United States and a number of European countries have shown that the hopes placed on high-technology types of medical care as first-line means of combating CVD have not been justified. Despite the enormous number of balloon angioplasties and aortocoronary bypass (ACB) operations performed in economically developed countries (1.6 million procedures annually in the United States alone), it has not yet been possible to halt the CVD epidemic and to alter the leading contribution of these diseases to the mortality structure [177]. All of the foregoing requires the study of new approaches to optimizing the therapy of such patients and the search for informative criteria for the evaluation of the treatment administered.

The rising cost of medical care and the emergence of alternative methods of treatment generate interest in the problems of the pharmacoeconomic evaluation of the effectiveness of IHD treatment. The relevance of the search for a pharmacoeconomic strategy for IHD treatment at the outpatient and inpatient stages is determined not only by the prevalence of this pathology but also by the high cost of treatment. The current trend in Russian healthcare is associated with the strengthening of mechanisms of state regulation aimed primarily at a more rational use of limited resources and cost containment. In this situation it is necessary to employ indicators of economic evaluation of treatment effectiveness, which will make it possible to select, in a specific clinical situation, the most optimal type of treatment, taking into account its effectiveness and cost [10].

The problem of studying and improving the quality of life (QoL) of patients with IHD remains one of the most important at present, because in the majority of cases patient satisfaction with the treatment administered and their adherence to therapy are not taken into account in the course of therapy. The study of QoL in patients suffering from stable exertional angina makes it possible to assess the degree of the impact of this pathology on the patient's life and to identify those of its spheres that are most affected by the disease. It is necessary to evaluate the patient's perception of his or her health, his or her point of view regarding his or her functional capabilities, and his or her opinion on the degree of well-being associated with health. In patients with stable angina (St A), the QoL is greatly affected by the frequency and duration of anginal attacks; therefore, interest arises in studying this indicator during the administration of various antianginal agents. On the other hand, in the light of new requirements imposed by society on medical science, QoL acts as one of the principal criteria for the effectiveness of treatment of chronic diseases [147].

In this connection, it is of interest to determine the pharmacoeconomic effectiveness of the treatment administered, including a study of the effectiveness of St A therapy taking into account the QoL of such patients.

Objective of the study:

On the basis of the use of methods of clinical and economic analysis and a comprehensive study of quality-of-life parameters, to evaluate the effectiveness of different variants of antianginal therapy in patients with stable angina.

Research tasks:

1. To conduct a retrospective study of quality of life in patients with stable angina receiving organic nitrates in order to identify the most informative criteria of this indicator.

2. To evaluate the effectiveness of the treatment administered, to conduct a prospective study of quality of life in patients with stable angina under different variants of antianginal therapy.

3. On the basis of pharmacoeconomic analysis methods — "cost minimization," "cost/effectiveness," and "cost of illness" — to identify the most effective variants of treatment of stable angina with organic nitrates.

4. To evaluate the economic costs of medical institutions in the inpatient and outpatient treatment of patients with stable angina under different variants of antianginal therapy.

Scientific novelty:

For the first time, in the course of a retrospective and prospective analysis of quality of life, a sharp decrease in its integral indicator has been revealed in patients with stable angina, while the increase in quality-of-life parameters depends on the use in antianginal therapy of different groups of organic nitrates.

For the first time, from the entire spectrum of the studied quality-of-life parameters, the most informative indicators have been identified that reflect the degree of reduction in physical activity and the increase in psychological discomfort, and the possibility of using them to assess the severity of stable angina and the effectiveness of antianginal therapy administered has been demonstrated.

For the first time, a direct relationship has been established between the parameters of clinical and economic effectiveness of antianginal therapy and the quality of life of patients with stable angina. It has been shown that a comprehensive clinical and economic analysis of antianginal therapy makes it possible to determine the economic burden of the irrational use of organic nitrates and to identify the least costly treatment programs, which substantially increases the effectiveness of the therapy administered at the inpatient and outpatient stages.

Practical significance.

The conduct of a clinical and pharmacoeconomic analysis in evaluating the rationality of the use of antianginal agents makes it possible to optimize IHD treatment. The application of economic methods in evaluating the quality of the therapy administered makes it possible to objectively assess state and patient expenditures in order to determine the most rational regimens of antianginal therapy and allows the effectiveness of therapeutic measures to be assessed in three directions: "patients — physicians — healthcare authorities."

On the basis of the results obtained, recommendations have been substantiated for the use of prolonged-release forms of organic nitrates as long-term antianginal therapy in St A patients, which makes it possible to significantly reduce costs at both the inpatient and outpatient stages of treatment.

The study of QoL in St A patients during antianginal therapy makes it possible to determine the effect of the disease on the physical, psychological, and emotional state of the patient, to identify the highest-priority parameters for each patient, which makes it possible to carry out individualized targeted correction of the disorders arising and to increase the effectiveness of treatment of patients with angina from the standpoint of QoL in this group.

Data on changes in QoL may serve as a source of an additional, more objective evaluation of treatment, and its dynamics in the course of treatment may serve as an objective characteristic of the patient's status.

Principal statements defended:

1. On the basis of an analysis of the results of a retrospective and prospective study of QoL in St A patients, it has been demonstrated that the most substantial positive effect on the parameters and integral assessment of QoL is exerted by therapy with prolonged-release forms of isosorbide-5-mononitrate. At the same time, the most informative parameters for predicting the effectiveness of treatment in St A patients are the parameters of activity and psychological discomfort.

2. According to the results of different methods of pharmacoeconomic analysis ("cost of illness," "cost minimization," "cost/effectiveness"), it has been established that antianginal agents differ in effectiveness. It has been demonstrated that, during long-term therapy of St A with prolonged-release nitrates, financial losses can be reduced by more than 20%. The results of the "cost/effectiveness" and "cost minimization" analyses have shown that the use of prolonged-release forms of isosorbide-5-mononitrate in the treatment of St A patients is the most justified from the standpoint of clinical effectiveness and economic expediency.

3. The results of the analysis of the "typical" practice of St A treatment show that the use of prolonged-release nitrates makes it possible to obtain an economic effect at both the inpatient and outpatient stages of treatment (per 1 ruble of expenditures when using prolonged-release nitrates, 1.3 rubles are accounted for by the use of conventional-release nitrates at the inpatient stage and 1.69 rubles at the outpatient stage of treatment).