Structural and functional changes of the heart in patients with chronic ischemic heart failure, associated with renal dysfunction

Abstract

Kidney disease is a frequent complication of congestive heart failure (CHF) and may contribute to the progression of ventricular dysfunction. Regardless of the degree of heart failure, chronic kidney disease (CKD) increases the risk of death and cardiac decompensation. Left ventricular hypertrophy (LVH) is a known parameter of cardiac remodelling and has a higher prevalence and incidence among people with impaired kidney function. LVH is an early subclinical marker of cardiovascular disease and heart failure risk, and is probably an intermediary step in the pathway leading from kidney dysfunction to heart failure and its complications. The effects of CKD on other left ventricular and myocardial parameters, however, have been less characterized.

         The aim of the study was to examine the structural and functional changes, geometric remodeling of the heart in patients with ischemic chronic heart failure, being hospitalized, according to the presence of renal dysfunction.

Materials and methods. The study involved 333 patients with ischemic CHF (277 men and 56 women, mean age 59,3±9,4 years). The functional class of heart failure was assessed on the recommendations of the New York Heart Association (NYHA). The etiology of heart failure in 288 (86.5%) patients had a combination of coronary artery disease and essential hypertension, in 45 (13.5%) – only CAD. 1 FC of heart failure was diagnosed in 9 (2.7%) patients, 2 FC - in 106 (31.8%), 3 FC - in 199 (59.8%) and 4 FC - 19 (5.7%) patients. Diabetes was in 61 (18.3%), myocardial infarction history was in 240 (72.1%) patients. Depending on the glomerular filtration rate, patients were divided into 3 groups: 72 with normal GFR (>90 ml/min/1.73m²), 218 with a slight decrease in GFR (60-90 ml/min/1.73m²) and 43 with moderate reduced GFR (<60 ml/min/1.73m²). Echocardiography was performed using the General Electric VIVID 3 system (General Electric Healthcare, USA) with the 2.5–3.5 MHz transducer and Doppler technique. Descriptive statistics are presented as mean±standard deviation for continuous variables and as percentages for categorical variables. Depending on the distribution of the analyzed parameters used unpaired Student's t-test or U-Mann-Whitney test. Comparisons among all groups for baseline clinical variables were performed with the Pearson χ² or Fisher exact test for categorical variables. Differences considered reliable for values of p<0,05.

Results. In patients with ischemic CHF as far as reduction of GFR, an increase in left atrial diameter (p=0.006), end-diastolic size (p=0.03), end-systolic size (p=0.003) end-diastolic (p=0.03) and end-systolic volumes (p=0.02). Analysis of ejection fraction showed a significant reduction in the progression of renal dysfunction: from 55,1±14,5% in GFR over 90 ml/min/1,73m² to 46,3±14,6% with a GFR less than 60 ml/min/1.73 m². LV hypertrophy was registered in 63 (87.5%) with normal renal function, in 202 (92.7%) with mild dysfunction and in 42 (97.7%) patients with moderate renal dysfunction. In the analysis of LV remodeling in patients with heart failure and normal renal function revealed the prevalence of concentric hypertrophy - in 45.8%. In mild decrease GFR stored value for concentric hypertrophy in 50% of cases. However, at lower eGFR less than 60 ml/min/1,73m² dominated eccentric hypertrophy - in 55.8%, concentric hypertrophy in 41.9% and no patient with normal geometry. After analyzing the distribution of patients by type of violation diastolic function in patients with ischemic CHF, depending on the level of GFR, we can conclude that in normal renal function in 48.6% reported pseudonormal type, 36.1% - a abnormal of relaxation, 4.2% - restrictive type. In patients with mild to moderate decrease in GFR revealed a gradual deterioration in diastolic function as increase the proportion of more serious disorders: pseudonormal (56.9% and 60.5%, respectively) and restrictive type (3.7% and 9.3%, respectively).

Conclusion. In patients with ischemic CHF decrease in GFR accompanied by structural adjustment in the form of an increase in the diameter of the left atrium, left ventricle, both in diastole and systole. The presence of renal dysfunction is associated with increased left ventricular myocardium index, the development of maladaptive remodeling of the left ventricle, as increase in patients with eccentric hypertrophy and diastolic function deterioration dominated pseudonormal and restrictive type. Thus, the progressive decrease GFR in patients with ischemic chronic heart failure accompanied geometric and hemodynamic transformation that leads to severe diastolic dysfunction.