Проценка на левокоморна дијастолна дисфункција и капацитет на физичко оптоварување кај пациенти со висок кардиоваскуларен ризик скор и сочувана систолна левокоморна функција

Abstract

Background. Heart failure with preserved left ventricular function (HF-PEF) is defined as a condition with symptoms typical for heart failure, eventually with signs of its existence and normal or just mildly reduced left ventricular ejection fraction (LVEF), but with (presence of) relevant structural heart disease (left ventricular hypertrophy or dilatation of the left atrium) and/or diastolic dysfunction (DD). Around 50% of patients with symptoms or signs of heart failure have normal LVEF and most of them show signs of DD, which is crucial for defining this specific and complex condition. A number of studies have reported that morbidity and mortality of HF-PEF is high, but efficient treatment has still not been found. Aim. It was our aim to determine clinical and demographic characteristics and risk factors in patients with HF-PEF and their correlations with markers of DD, defined by echocardiography as well as with functional characteristics and exercise capacity. In addition, it was our aim to recognize markers of DD as independent predictors of severity of the symptoms, DD, subclinical systolic dysfunction and exercise capacity. Material and methods. Our research included 183 patients at the age over 45 of both genders. This was a cross-sectional study. Patients were analyzed by using: anamnesis/medical history, risk stratification for coronary artery disease (CAD), physical examination, electrocardiography, biochemistry analyses of the blood, spirometry, echocardiography and exercise test. Statistical analyses of the data were done using the SPSS program. Results. A total of 183 patients with HF-PEF were at the average/mean age of 62.31 10.0; females predominated (60.7%); they were overweight and with abdominal adiposity over the normal; diabetes was present in 50.8% of patients, and hypertension and dyslipidemia were present in almost all of them (96.7% and 95.1%, respectively). Thirty-one patients (16.9%) had CAD. SCORE (Systematic COronary Risk Evaluation) risk score showed that patients were at a moderate 10-year risk of cardiovascular death. All of the patients had normal inner dimensions of the left ventricle (LV), LV end-systolic and end-diastolic volumes, normalized by calculating body-surface area (BSA), preserved LVEF with average/mean value of 66.1% and volume of ejection and cardiac index normalized by BSA in the normal ranges. Patients with higher filling pressure (Е/Е’15 measured at any level) had also signs of subclinical systolic dysfunction, manifested as statistically significant reduction of mitral annular plane systolic excursion, evaluated by M-mode (MAPSE), mitral annular plane of systolic velocity (MAPSV) evaluated by tissue Doppler (TD) and of global longitudinal deformation evaluated by speckle tracking echocardiography (GLS). Regression analyses showed that severe DD was an independent marker for the presence of subclinical stage of systolic dysfunction. Analyzing DD we found markers that proved higher filling pressures to be independent predictors of its existence. Patients with HF-PEF had LV hypertrophy of concentric type, and of all 183 examined patients with HF-PEF, 91.3% had increased LV mass normalized with BSA. Statistically significant higher LV mass was found in patients with higher filling pressures of LV, which was proven by correlation and regression analyses, but LV mass measurements were also connected with reduction of GLS. Left atrial (LA) dimensions and volumes were also increased in patients with HF-PEF and they positively correlated with age, presence of risk factors for atherosclerosis and severity of DD. Thus, they present themselves to be markers for duration and staging of DD, but impaired LA function showed a significant correlation with subclinical LV systolic dysfunction (SD). All the measurements of the velocities of transmitral flow evaluated by pulse or/and continuous Doppler showed values that proved existence of moderate DD typed as pseudonormalisation. Analyzing sensitivity and specificity of the markers of DD and SD in determination of the symptoms described by NYHA classification, IVRT/E-e’-tau index, increased E/E`>15 measured as average of both walls of the ventricle and GLS taken as average of all three sections were found to be independent predictors of severity of the symptoms. Optimal sensitivity of E/E` of ≥15 as average of both measurements that can predict existence of symptoms (breathless/dyspnea) was 57%, and specificity was 70%; IVRT/E-e’-tau index had a sensitivity of 30% and specificity of 80%; GLS index had a sensitivity of 50% and specificity of 65%. Results obtained about the exercise capacity confirmed that signs of severe DD and subclinical SD in patients with HF-PEF were responsible for reduced exercise capacity expressed by the lower number of MET-s achieved. Chronotropic incompetence (CI) was found in 43.3% of the examined patients, and when defined as a heart rate reserve (%HRR) where %HRR≤80% was calculated to be indicative for CI was found in 67.8% of patients. CI presented by %MaxPHR and/or %HRR in patients with HF-PEF showed a significant correlation with more severe DD or subclinical SD. Regarding the reserve of recovery of the heart rate (RRHR), patients with abnormal RRHR had a significantly higher SCORE risk score and regarding echocardiography parameters we found E/E` measured on the level of interventricular septum as expression of DD to be an independent predictor of impaired RRHR. Conclusion. (We can conclude that) HF-PEF can be a fundamental disease of the cardiovascular reserve function - diastolic, systolic, chronotropic and vascular. Signs for severe DD and subclinical SD are the main reason for reduced exercise capacity in these patients.