Diagnosis of Chronic Heart Failure in Patients with Chronic Kidney Disease

The dissertation is devoted to improving the diagnosis of chronic heart failure (CHF) in patients with chronic kidney disease (CKD). The work substantiates the necessity of a comprehensive clinical and instrumental examination of such patients using echocardiography and Doppler echocardiography, since the early symptoms of CHF (dyspnea, fatigue, edema) may be manifestations of CKD itself and complicate the diagnostic process. Particular attention is paid to the differentiation between systolic and diastolic left ventricular dysfunction, as well as to the assessment of the quality of life and anxiety in this category of patients.

The study analyzes the structural and functional changes of the heart in CKD patients with CHF, examines the prevalence and types of left ventricular hypertrophy, and describes the variants of diastolic dysfunction, including impaired relaxation and the pseudonormal transmitral flow pattern. Based on the results obtained, an algorithm is proposed for examining CKD patients with possible CHF, relying on the clarification of diastolic function through the measurement of the propagation velocity of the early diastolic filling flow of the left ventricle by color M-mode Doppler, which helps to avoid the overdiagnosis of CHF.

Relevance of the Problem

In Russia, chronic heart failure (CHF) is the leading cause of death among patients receiving renal replacement therapy (Russian Registry of Chronic Renal Failure, 2004). Every second patient beginning dialysis has CHF (Young E.W., 1995), and among those without it the annual incidence of de novo chronic heart failure is 7.6% (Harnett J.D. et al., 1995). Cardiac pathology in the majority of patients develops long before the start of renal replacement therapy (K/DOQI Clinical Practice Guidelines for Cardiovascular Disease in Dialysis Patients, 2005; Tomilina N.A. et al., 2003; Volgina G.V. et al., 2000). The multicenter CREAT study established that left ventricular hypertrophy (LVH) is observed in half of the patients with a creatinine clearance of 15–35 ml/min (Eckardt K-U. et al., 2002). According to A.M. Shutov and co-authors (2001), the prevalence of LVH among pre-dialysis patients in Russia is even higher, which is probably related to insufficient control of arterial hypertension and, in particular, anemia due to the infrequent use of erythropoietin at the pre-dialysis stage of treatment.

The diagnosis of CHF presents certain difficulties associated with the low specificity of clinical manifestations (Russian National Guidelines for the Diagnosis and Treatment of CHF, 2003), as well as with the absence of unified approaches to the interpretation of CHF (Zile M.R. et al., 2002).

There are disagreements in the assessment of left ventricular systolic function. It suffices to note that the European Guidelines for the Diagnosis and Treatment of CHF (2005) and the Russian National Guidelines for the Diagnosis and Treatment of CHF (2003) diagnose systolic dysfunction at LVEF <45%, while the analogous recommendations of the American College of Cardiology and the American Heart Association (ACC/AHA) of 2005 use LVEF <40%.

The interpretation of the state of cardiac diastolic function is even more controversial. Most often, the assessment of cardiac diastolic function follows the Recommendations of the Working Group on the Diagnosis of Diastolic Heart Failure of the European Society of Cardiology of 1998. At the same time, there is an opinion that diastolic CHF can be diagnosed without studying diastolic function, since it is sufficient to have clinical manifestations of chronic heart failure and to identify preserved or only mildly reduced left ventricular systolic function (Dauterman K.W. et al., 1998; Caruana L., 2000; Gibson D.G. et al., 2003; Sanderson J.E. et al., 2003).

There is no clear understanding of the relationship between systolic and diastolic dysfunction as causes of chronic heart failure in patients with chronic kidney disease. The scarce data on the state of diastolic function in patients with chronic kidney disease are based on the study of transmitral flow, which is insufficient for establishing the type of dysfunction (Petrie M.C. et al., 2004; Shutov A.M. et al., 2001).

It can be assumed that in a number of patients, for example, those with chronic kidney disease, the presence of anemia and edema not related to heart failure will complicate the interpretation of such clinical manifestations as dyspnea, palpitations, and weakness, which are the earliest and most frequent signs of CHF. It is also unclear how realistic it is to diagnose diastolic CHF in patients with CKD solely by excluding systolic dysfunction.

Aim of the Study

To improve the effectiveness of diagnosing chronic heart failure in patients with chronic kidney disease by clarifying the diagnostic significance of symptoms of chronic heart failure and by optimizing the use of clinical, echocardiographic, and Doppler echocardiographic methods of investigation.

Objectives of the Study

1. To study the clinical features of chronic heart failure in patients with chronic kidney disease.

2. To study the structural state of the heart in patients with chronic kidney disease.

3. To identify echocardiographic and Doppler echocardiographic changes associated with the syndrome of chronic heart failure in patients with chronic kidney disease and to develop optimal approaches to the diagnosis and assessment of chronic heart failure in patients with chronic kidney disease.

4. To investigate the role of chronic heart failure in changes in the quality of life, as well as in reactive and personal anxiety of patients with chronic kidney disease.

Main Statements Defended

1. The early and most frequent symptoms of chronic heart failure (dyspnea, fatigue, edema) may be manifestations of chronic kidney disease, which substantially complicates the diagnosis of chronic heart failure.

2. The majority of patients with stage I–IV chronic kidney disease present with left ventricular hypertrophy, the predominant type of which is concentric hypertrophy.

3. In patients with chronic kidney disease, diastolic heart failure occurs considerably more often than chronic heart failure with systolic dysfunction.

4. The quality of life of patients with chronic kidney disease is determined to a greater extent by the presence of chronic heart failure than by chronic kidney disease itself.

Scientific Novelty of the Work

It has been established that systolic dysfunction as a cause of CHF in patients with stage IV chronic kidney disease is uncommon. The main cause of chronic heart failure is diastolic dysfunction, the predominant type of which in patients with chronic kidney disease is the impaired relaxation pattern. For the first time, the high frequency of the pseudonormal transmitral flow pattern in patients with chronic kidney disease has been demonstrated, including in patients with NYHA functional class I and II CHF.

It has been established that in patients with chronic kidney disease, the diagnosis of diastolic chronic heart failure based solely on the exclusion of systolic dysfunction without clarifying the state of diastolic function leads to the overdiagnosis of chronic heart failure.

For the first time, the author has shown that the quality of life of patients with chronic kidney disease is determined to a greater extent by the presence of chronic heart failure than by chronic kidney disease itself.

Practical Significance of the Work

The data obtained in the work confirm the necessity of investigating left ventricular diastolic function in all patients with CKD who have clinical signs that may indicate the presence of CHF. In view of the high frequency of pseudonormalization of the transmitral flow pattern, the author has substantiated the determination of the propagation velocity of the early diastolic filling flow of the left ventricle using color M-mode Doppler (Vp) to clarify the state of diastolic function.

Based on the results of the conducted study, the author has developed an algorithm for the examination of a patient with chronic kidney disease who presents with clinical manifestations that may indicate the presence of CHF. The early detection of chronic heart failure and the clarification of the functional state of the heart in this category of patients are of great importance for clinical practice, as they allow optimization of patient treatment.

Approval of the Work

The main statements of the dissertation were reported and discussed at the Seventh All-Russian Medical and Biological Conference of Young Researchers "Human and His Health" (2004, Saint Petersburg), at the First All-Russian Congress and the Fifth Annual Conference of the Society of Specialists in Heart Failure (2004, Moscow), at the Sixth Congress of the Scientific Society of Nephrologists of Russia (2005, Moscow), at the Second All-Russian Scientific Conference "Current Issues of Health and the Living Environment of the Modern Person" (2005, Ulyanovsk), and at the interdepartmental conference of the staff of the therapeutic departments of Ulyanovsk State University (2006, Ulyanovsk). Twenty scientific works have been published on the topic of the dissertation, including 2 articles in journals recommended by the Higher Attestation Commission for the publication of dissertation research materials (Nephrologiya, 2005; Nephrologiya i Dializ, 2005).

Implementation of the Results of the Work

The results of the work have been implemented in the practice of the Nephrology Department of the Ulyanovsk Regional Clinical Hospital and the Nephrology Department of the Penza Regional Clinical Hospital. A number of the statements and conclusions of the work are used in the educational process at the Department of Therapy and Occupational Diseases of the Medical Faculty of the Institute of Medicine, Ecology and Physical Culture of Ulyanovsk State University.

Scope and Structure of the Dissertation

The dissertation is presented on 138 pages of typewritten text and consists of an introduction, a review of the literature, a description of the materials and methods of the study, methods of statistical analysis of the results, 4 chapters of the author's research with their discussion, a conclusion, findings, recommendations for practical public health, and a list of references. The materials of the dissertation are illustrated with 21 figures and 28 tables. The bibliography contains 209 references, of which 26 are domestic and 183 are foreign authors.