Recommendations of the Experts of the Polish Cardiac Society (PCS) and the Polish Lipid Association (PoLA) on the diagnosis and management of elevated lipoprotein(a) levels.

Lipoprotein(a) [Lp(a)] is made up of a low-density lipoprotein (LDL) particle and a specific apolipoprotein(a). The blood concentration of Lp(a) is approximately 90% genetically determined, and the main genetic factor determining Lp(a) levels is the size of the apo(a) isoform, which is determined by the number of KIV2 domain repeats. The size of the apo(a) isoform is inversely proportional to the blood concentration of Lp(a). Lp(a) is a strong and independent cardiovascular risk factor. Elevated Lp(a) levels ≥ 50 mg/dl (≥ 125 nmol/l) are estimated to occur in more than 1.5 billion people worldwide. However, determination of Lp(a) levels is performed far too rarely, including Poland, where, in fact, it is only since the 2021 guidelines of the Polish Lipid Association (PoLA) and five other scientific societies that Lp(a) measurements have begun to be performed. Determination of Lp(a) concentrations is not easy due to, among other things, the different sizes of the apo(a) isoforms; however, the currently available certified tests make it possible to distinguish between people with low and high cardiovascular risk with a high degree of precision. In 2022, the first guidelines for the management of patients with elevated lipoprotein(a) levels were published by the European Atherosclerosis Society (EAS) and the American Heart Association (AHA). The first Polish guidelines are the result of the work of experts from the two scientific societies and their aim is to provide clear, practical recommendations for the determination and management of elevated Lp(a) levels.

Concordance/discordance between serum apolipoprotein B, low density lipoprotein cholesterol and non-high density lipoprotein cholesterol in NATPOL 2011 participants - An epidemiological perspective.

BACKGROUND: The study compared the distribution of serum LDL-C, non-HDL-C, and apolipoprotein B (apoB) among participants of the NATPOL 2011 survey and analysed concordance/discordance of results in the context of the risk for atherosclerotic cardiovascular disease (ASCVD). METHODS: Serum levels of apoB, LDL-C, non-HDL-C and small dense LDL-C were measured/calculated in 2067-2098 survey participants. The results were compared between women and men, age groups and in relation to body mass index (BMI), fasting glucose and TG levels, and the presence of CVD. Percentile distribution of lipid levels and concordance/discordance analysis were based on medians and ESC/EAS 2019 target thresholds for ASCVD risk and on comparison of measured apoB levels and levels calculated from linear regression equations with serum LDL- C and non-HDL-C as independent variables. RESULTS: Serum apoB, LDL-C and non-HDL-C were similarly related to sex, age, BMI, visceral obesity, cardiovascular disease, and fasting glucose and triglyceride levels. Serum apoB, LDL-C and non-HDL-C very high- and moderate- target thresholds were exceeded in 83%, 99% and 96.9% and in 41%, 75% and 63.7% of subjects, respectively. The incidence of the discordances between the results depended on the dividing values used and ranged from 0.2% to 45.2% of the respondents. Subjects with high apoB / low LDL-C/non-HDL-C discordance had features of metabolic syndrome. CONCLUSIONS: Diagnostic discordances between apoB and LDL-C/non-HDL-C indicate limitations of serum LDL-C/non-HDL-C in ASCVD risk management. Due to the high apoB/low LDL-C/non-HDL-C discordance, obese/metabolic syndrome patients may benefit from replacing LDL-C/non-HDL-C by apoB in ASCVD risk assessment and lipid-lowering therapy.

Effectiveness and safety of PCSK9 inhibitor therapy in patients with familial hypercholesterolemia within a therapeutic program in Poland: Preliminary multicenter data.

BACKGROUND: In Poland, treatment with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors has become available free of charge in a therapeutic program. Assessed herein, is the efficacy and safety of alirocumab and evolocumab in patients with heterozygous familial hypercholesterolemia (FH). METHODS: Data of 55 adult FH patients who participated in the program were analyzed upon meeting the criteria established by the Ministry of Health (low density lipoprotein cholesterol [LDL-C] above 160 mg/dL on max. tolerated statin dose and ezetimib). The efficacy of PCSK9 inhibitors in reducing LDL-C with drug administration every 2 weeks was assessed after 3 months and 1 year of therapy. A safety profile evaluation was performed at each visit. 48 patients completed the 3-month and 21 for the 1-year observation periods (34 patients treated with alirokumab and 14 with evolocumab). RESULTS: The mean concentration of direct-measured LDL-C decreased from the initial level of 215.1 ± 74.5 mg/dL to 75.3 ± 64.1 mg/dL, i.e., by 65 ± 14% following 3 months of treatment. This effect was stable in 1-year observation (77.7 ± 72.8 mg/dL). Adverse effects were flu-like symptoms (13.0%), injection site reactions (11.1%), fatigue (5.6%) and musculoskeletal symptoms (5.6%). Seven patients failed to complete the 3-month treatment period due to side effects or non-compliance, and 1 patient failed to complete the 1-year treatment due to myalgia. CONCLUSIONS: This study confirmed high effectiveness of PCSK9 inhibitors in reducing LDL-C levels in patients with FH. Due to restrictive inclusion criteria with LDL-C threshold level > 160 mg/dL (> 4.1 mmol/L) required for participation in the therapeutic program, a relatively small number of FH patients were eligible for treatment.

Assessment of microvascular function and pharmacological regulation in genetically confirmed familial hypercholesterolemia.

BACKGROUND: Familial hypercholesterolemia (FH) is a genetic lipid disorder leading to accelerated atherosclerosis, premature cardiovascular disease and death. Microvascular endothelial dysfunction is one of the earliest vascular pathology manifestations and may precede symptomatic atherosclerosis. METHODS: In this paper, microvascular endothelial function was assessed in FH patients and healthy controls using flow mediated skin fluorescence (FMSF), based on measurements of nicotinamide adenine dinucleotide fluorescence intensity during brachial artery occlusion (ischemic response, IR) and immediately after occlusion (hyperemic response, HR). Low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) were used to assess its relation with microvascular parameters evaluated in vivo. RESULTS: LDL-C levels were significantly correlated to both HRmax (r = -0.548, p = 0.001) and HRindex (r = -0.514, p = 0.003). Similarly, there was a significant inverse correlation of TC levels and both HRmax (r = -0.538, p = 0.002) and HRindex (r = -0.512, p = 0.003). All FMSF parameters were found lower in FH patients compared to age- and sex-matched healthy controls. Hyperemic response (HRmax) was significantly higher in FH patients examined on statins compared to those without any lipid-lowering treatment (19.9 ± 3.1 vs. 16.4 ± 4.2 respectively, p = 0.022). CONCLUSIONS: This study shows that, in patients with FH, microvascular endothelial-dependent hyperemic response is impaired and inversely correlated to plasma cholesterol levels. Microvascular function was found better in FH patients receiving statins.

Carotid intima-media thickness (IMT) in patients with severe familial and non-familial hypercholesterolemia: The effect of measurement site on the IMT correlation with traditional cardiovascular risk factors and calcium scores.

BACKGROUND: The carotid intima-media thickness (IMT) measurement may be carried out proximally (pIMT) or distally (dIMT) in relation to the bulb of the common carotid artery which has significant implications on the results and correlation with risk factors. The aim of the study was to compare the pIMT and dIMT in patients with familial hypercholesterolemia confirmed by genetic testing (FH group) and patients with severe non-familial hypercholesterolemia, with negative results of genetic testing (NFH group) and to determine the correlation of results with traditional atherosclerotic risk factors and calcium scores. METHODS: A total of 86 FH and 50 NFH patients underwent pIMT and dIMT measurements of both carotid arteries as well as computed tomography (CT) with coronary and thoracic aorta calcium scoring. RESULTS: The meanpIMT of both right and left common carotid artery were significantly higher in patients with FH compared to the NFH group (meanpRIMT 0.721 ± 0.152 vs. 0.644 ± 0.156, p < 0.01, meanpLIMT 0.758 ± 0.173 vs. 0.670 ± 0.110, p < 0.01). Patient age, pre-treatment lowdensity lipoprotein (LDL) cholesterol levels (LDLmax) at baseline and systolic blood pressure were independent predictors of pIMT increases in both carotid arteries. Smoking history, age and LDLmax were independent predictors of dIMT increase. There was a significant correlation between the calcium scores of the ascending aorta, coronary artery and aortic valve and all IMT parameters. CONCLUSIONS: The IMT measured proximally better between patients with familial and non-familial hypercholesterolemia. The association between IMT and traditional cardiovascular risk factors varies between measurement sites. IMT values correlate CT calcium scores in all patients with hypercholesterolaemia regardless of genetic etiology.

Observed and relative survival and 5-year outcomes of patients discharged after acute myocardial infarction: the nationwide AMI-PL database.

BACKGROUND: Long­term follow­up data from a large Polish acute myocardial infarction (AMI­PL) database are still unavailable. AIMS: This study aimed to assess the 5­year outcomes of patients discharged after hospitalization for AMI in Poland in relation to age. METHODS: The studywas based on the nationwide AMI­PL registry including data on the management and long­term outcomes of all patients admitted to hospitals with AMI (codes I21-I22 according to the International Classification of Diseases and Related Health Problems, 10th Revision [ICD ­10]), derived from the database of the obligatory healthcare payer in Poland.The current analysis included all patients after AMI who were discharged alive between the years 2009 and 2010 (n = 134 602). RESULTS: The median age of the study patients was 66.8 years, 62.8% of them were male, and 57.1% had ST­segment elevation myocardial infarction. Older patients, especially those at age ≥80 years, were less likely to receive invasive treatment during the index hospitalization and follow­up. There were 37 437 deaths during the follow­up, and the observed 5­year survival ranged from 0.921 in women at the age below 55 years to 0.383 in men older than 80 years. Relative survival, however, ranged from 0.94 to 0.68 in these age­sex groups. The mortality risk increased with age, was higher in men, in patients treated noninvasively, hospitalized for non-ST­segment elevation myocardial infarction, and discharged from non­cardiology wards. Patients were rehospitalized due to cardiovascular reasons in 63% of cases, heart failure in 17.9%, and AMI in 12.8%. CONCLUSIONS: More than 1 in 4 patients discharged after hospitalization for AMI died within 5 years. Age strongly affects the treatment and long­term outcomes of AMI patients. Our findings indicate the need for improvement in secondary prevention after AMI.

Cardiovascular risk factor profiles in familial hypercholesterolemia patients with and without genetic mutation compared to a nationally representative sample of adults in a high-risk European country.

BACKGROUND: There is a paucity of data on the distribution of cardiovascular risk factors in patients with familial hypercholesterolemia (FH) as compared to the general population. The aim of the study was to compare cardiovascular risk factors in a cohort of FH patients to the representative sample of adults in Poland who represent a high-cardiovascular risk European region. METHODS: We compared the distribution of risk factors in 1,382 individuals with FH phenotype referred for genetic testing between 2006 and 2014 to the National Centre of Familial Hypercholesterolemia in Gdansk, Poland. The cohort was comprised of 637 positive FH(+) and 745 negative FH(-) patients who were compared to a nationally representative sample of 2,413 adults age 18-79, standardized by age and sex, from the NATPOL 2011 study (NATPOL). We analyzed patients' distribution of history of atherosclerotic cardiovascular disease (ASCVD) and standard risk factors including total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, triglycerides, systolic and diastolic blood pressure (SBP, DBP), body mass index, smoking, and diabetes. RESULTS: FH(+) patients (mean age 45.6 years) had the highest LDL-C of 241.7 mg/dL (95% CI 234.8-248.5) compared to 206.1 mg/dL (200.5-211.7) in FH(-) patients (mean age 48.2) and 126.2 mg/dL (124.8-127.6) in NATPOL. Mean SBP was the lowest in FH(+) patients at 128.7 mm Hg (126.7-130.7) compared to 133.4 mm Hg (132.6-134.3) in NATPOL and 134.4 mm Hg (132.3-136.5) in FH(-). No differences were found in the prevalence of diabetes and body mass index. Smoking was less common in FH(+) at 12.4% (9.4-15.4) compared to both FH(-) and NATPOL: 20.4% (16.6-24.1) and 28.4% (26.6-30.2), respectively. The prevalence of individuals with a history of ASCVD in both FH(+) and FH(-) was nearly 3-fold higher compared to NATPOL: 26% (21.8-30.1) and 26.6% (22.2-30.9) versus 9.5% (8.3-10.7), respectively. CONCLUSIONS: The FH(+) patients had significantly higher mean LDL-C, but the levels of nonlipid factors were lower or similar compared to the other groups. Both FH(+) and FH(-) were characterized by a heavy burden of ASCVD. This suggests that cholesterol, and no other risk factors, is a key contributor to cardiovascular risk in patients with FH, especially those with genetic mutation.

Aortic valve calcium score in hypercholesterolemic patients with and without low-density lipoprotein receptor gene mutation.

The aim of this study was a comparison of aortic valve calcium score (AVCS) between patients with hypercholesterolemia and genetic diagnosis of familial hypercholesterolemia with low-density lipoprotein receptor gene mutation (LDLR-M group), versus patients with hypercholesterolemia without LDLR gene mutation (LDLR-WT group). A total of 72 LDLR-M patients and 50 LDLR-WT patients were enrolled in the study and underwent CT as a part of an assessment of coronary calcium scoring. AVCS was determined and compared between the two patient groups. AVCS was significantly higher in the LDLR-M group in comparison to the LDLR-WT group (13.8 ± 37.9 vs. 0.94 ± 3.1, p = 0.03). The Yates' chi-squared test for independence revealed that LDLR mutation and AVCS were significantly dependable (Chi^2 = 6.106, p = 0.013). The LDLR mutation was a strong predictor of a high AVCS (OR 7.83, 95% CI 2.08-29.50, p = 0.002) on multivariate regression analysis. Among the traditional risk factors, age (odds ratio 1.12, 95% CI 1.05-1.18, p<0.001) and SBP (OR 1.04, 95% CI 1.00-1.07, p = 0.045) were also significant for high result of AVCS. An assessment of computed tomography calcium scores showed that LDLR-M patients have increased AVCS in comparison to those with LDLR-WT. In addition, LDLR mutation can be considered as an independent risk factor of having high AVSC even after adjustment for risk factors including cholesterol levels. This may result from the associated process connected with the regulatory role of LDLR in evolution of aortic valve calcifications.

Overview of the current status of familial hypercholesterolaemia care in over 60 countries - The EAS Familial Hypercholesterolaemia Studies Collaboration (FHSC).

BACKGROUND AND AIMS: Management of familial hypercholesterolaemia (FH) may vary across different settings due to factors related to population characteristics, practice, resources and/or policies. We conducted a survey among the worldwide network of EAS FHSC Lead Investigators to provide an overview of FH status in different countries. METHODS: Lead Investigators from countries formally involved in the EAS FHSC by mid-May 2018 were invited to provide a brief report on FH status in their countries, including available information, programmes, initiatives, and management. RESULTS: 63 countries provided reports. Data on FH prevalence are lacking in most countries. Where available, data tend to align with recent estimates, suggesting a higher frequency than that traditionally considered. Low rates of FH detection are reported across all regions. National registries and education programmes to improve FH awareness/knowledge are a recognised priority, but funding is often lacking. In most countries, diagnosis primarily relies on the Dutch Lipid Clinics Network criteria. Although available in many countries, genetic testing is not widely implemented (frequent cost issues). There are only a few national official government programmes for FH. Under-treatment is an issue. FH therapy is not universally reimbursed. PCSK9-inhibitors are available in ∼2/3 countries. Lipoprotein-apheresis is offered in ∼60% countries, although access is limited. CONCLUSIONS: FH is a recognised public health concern. Management varies widely across countries, with overall suboptimal identification and under-treatment. Efforts and initiatives to improve FH knowledge and management are underway, including development of national registries, but support, particularly from health authorities, and better funding are greatly needed.

Temporal trends in secondary prevention in myocardial infarction patients discharged with left ventricular systolic dysfunction in Poland.

Background The proportion of patients discharged after myocardial infarction with left ventricular systolic dysfunction remains high and the prognosis is unfavourable. The aim of this study was to analyse the temporal trends in the treatment and outcomes of a nationwide cohort of patients. Methods and results Data from the Polish Registry of Acute Coronary Syndromes and Acute Myocardial Infarction in Poland Registry were combined to achieve complete information on inhospital course, treatment and outcomes. An all-comer population of patients discharged with left ventricular ejection fraction of 40% or less formed the sample population ( n = 28,080). The patients were analysed for the incidence of significant temporal trends and their possible consequences. The implementation of guideline-based treatment at discharge was high. In the post-discharge course a trend towards a higher frequency of percutaneous coronary intervention and a lower prevalence of planned coronary artery bypass grafting procedures was observed. The number of implantable cardioverter defibrillator/cardiac resynchronisation therapy defibrillator implantations was increasing. Cardiac rehabilitation was performed in 19-23% cases. The post-discharge outpatient care was based on general practitioner visits, with only 47.9-48.1% of patients attending an ambulatory cardiology specialist visit. In 12 months of observation the frequency of heart failure rehospitalisations was 17.5-19.1%, while the prevalence of rehospitalisations due to myocardial infarction decreased (8.3% in 2009 to 6.7% in 2013, P < 0.001). A trend towards lower all-cause mortality was observed. Assessment of composite outcomes (death, myocardial infarction, stroke or heart failure rehospitalisation) adjusted for sex and age at 12 months revealed a significant decreasing trend. Conclusion The overall prognosis in this population is improving slowly. This may be due to the increasing prevalence of guideline-based forms of secondary prevention. Efforts aimed at maintaining these trends are essential, as overall compliance with these guideline remains suboptimal.

[Coordinated heart failure care in Poland: towards optimal organisation of the health care system]. / Coordinated heart failure care in Poland: towards optimal organisation of the health care system.

Heart failure has becoming an increasing medical, economic, and social problem globally. The prevalence of this syndrome is rising, and despite unequivocal positive effects of modern therapy, reduction of mortality has been achieved at the cost of more frequent hospitalisations. Unlike in many European countries, in Poland heart failure is usually recognised later, at a more advanced stage of the disease, leaving less time for ambulatory treatment and resulting in a high number of hospitalisations. The current paper presents the most important data regarding morbidity and mortality due to heart failure in Poland. The experts in the field focus on the key source of high costs of therapy and highlight several critical organisational deficits present in the Polish health care system. This background information builds a basis for a concept of coordinated care for patients with heart failure. The paper discusses the fundamental elements of the system of coordinated care for patients with heart failure necessary to enhance the diagnosis, improve therapeutic effects, and reduce medical, economic, and social costs.

Prevalence, diagnosis, and treatment of familial hypercholesterolaemia in outpatient practices in Poland.

BACKGROUND: Familial hypercholesterolaemia (FH) is the most common genetic disease leading to premature atherosclerosis. AIM: The aim of the study was to evaluate the prevalence, diagnosis, and treatment of FH in outpatient practices in Poland. METHODS: The study included a representative sample of 147 primary care physicians, cardiologists, and diabetologists caring for 2812 adult patients with hypercholesterolaemia and low-density lipoprotein cholesterol (LDL-C) level > 1.8 mmol/L, who were treated with statins or did not receive statins due to intolerance or contraindications. The physicians declared whether they diagnosed FH in the study group. In addition, we evaluated the Dutch Lipid Clinic Network (DLCN) diagnostic criteria for FH in all patients. The results were weighted and extrapolated to the general outpatient population in Poland. Treatment and its effectiveness were also evaluated. RESULTS: FH6+ score by the DLCN criteria was found in 3.6% of the study group, which translates by extrapolation to 136,300 adult patients with FH in Poland. Among patients with FH6+, this diagnosis was correctly made by physicians in 25% of cases and was not established in 75% of cases. Only 32.8% of patients received high statin doses. High LDL-C levels were found in a large proportion of patients, including levels ≥ 5.0 mmol/L in 42.7% of patients and ≥ 4.1 mmol/L in 59.7% of patients. CONCLUSIONS: Familial hypercholesterolaemia is inadequately diagnosed and treated in Poland, which calls for a radical im-provement of pre- and postgraduate education in this regard.

Efficacy of clinical diagnostic criteria for familial hypercholesterolemia genetic testing in Poland.

BACKGROUND AND AIMS: Familial hypercholesterolemia (FH), which leads to premature cardiovascular events, still remains underrecognized and undertreated in most countries. Untreated FH individuals aged 20-39 years are at 100-fold higher risk of mortality from coronary heart disease compared to those of a general population. Therefore, special efforts should be implemented to diagnose FH patients at early stages of life. The aim of this study was to evaluate the efficacy of the revised Dutch Lipid Clinic Network (DLCN) criteria proposed by the Polish Lipid Experts Forum to select index FH patients for DNA mutational analysis in Poland. METHODS: The study included 193 unrelated adult patients (mean age 48 ± 13 years) with clinical diagnosis of FH based on the revised DLCN score, tested sequentially for mutations in LDLR and APOB genes using bidirectional Sanger sequencing and MLPA techniques. The cut-off points of the clinical FH criteria score were assessed by ROC statistics to identify patients with the highest probability of carrying an FH-causing mutation. RESULTS: The causal heterozygous LDLR or APOB mutation was identified in 41% (80/193) of probands. Adults aged <40 years were more likely to carry an FH-causing mutation compared to subjects aged ≥40 years (65% vs. 33%; p < 0.001). LDL-C thresholds for the molecular diagnosis of FH were 5.79 mmol/l for individuals aged<40 and 6.7 mmol/l for subjects ≥40 years old. The threshold values of the clinical diagnostic score for efficient selection of patients for genetic testing were 5 and 7 points for individuals aged <40 and ≥40 years, respectively. CONCLUSIONS: The study validated the efficacy of proposed clinical FH criteria for the disease diagnosis in Poland. The clinical criteria score thresholds for positive FH molecular diagnosis differ depending on age (<40 and ≥40 years). We propose that in the healthcare systems with limited genetic testing resources individuals younger than 40 years, who fulfill the clinical criteria for possible, probable or definite FH should qualify for the FH mutation testing. The index patients aged ≥40 years with clinical diagnosis of probable or definite FH should also qualify for the genetic testing.

Incidence, treatment, in-hospital mortality and one-year outcomes of acute myocardial infarction in Poland in 2009-2012--nationwide AMI-PL database.

BACKGROUND AND AIM: Nationwide data on acute myocardial infarction (AMI) are available for some Western but not for Central and Eastern European countries. We performed a study on nationwide data of all Polish AMI patients in 2009-2012 to assess incidence, quality of care, and cardiovascular events during 1 year following AMI. METHODS: The database of the only public, obligatory health insurer in Poland (National Health Fund) together with data from the Central Statistical Office were used. AMI cases were selected based on primary diagnosis ICD-10 codes I21-I22. For years 2009-2012, index hospitalisations (n = 311,813) in a given year and death records were analysed. Additionally, data on hospitalisations, procedures and deaths during 1 year follow-up were obtained for 2009. RESULTS: Age-adjusted incidence of AMI in Poland in 2009 was 196 cases per 100,000 population (176 per 100,000 were hospitalised), with a decreasing trend over time. The incidence was 2.5 times higher in men than in women. The median age was 63 years in men and 74 years in women. The proportion of ST elevation myocardial infarction (STEMI) decreased from 59% to 48% in 2012, and the proportion of patients receiving invasive treatment increased from 72% to 81%. Age-adjusted case fatality rate was equal in women and men. In 2009, the number of patients with AMI was 75,054 (61% men, 39% women) and 83% of them were treated in cardiology units. Invasive strategy was used in 77% of patients with STEMI and 66% of those with non-STEMI, thrombolysis in 1% and coronary artery bypass grafting in 1.9% of patients. Invasive treatment was used less frequently in women and the elderly patients. When all hospitals where a patient was treated until the final discharge were taken into account, in-hospital mortality was 10.5%. The lowest in-hospital mortality was noted among patients treated invasively (6.3%). The total number of readmissions within 1 year following AMI was 84,718, of which 61.9% were due to cardiovascular causes. The most common causes were stable coronary artery disease (27%), heart failure (7.9%), recurrent infarction (7.0%), and unstable angina (6.8%). Within 1 year after AMI, only 22% of patients participated in a cardiac rehabilitation programme. Total 1-year mortality was 19.4% (invasive treatment 12.3%, non-invasive treatment 38.0%). CONCLUSIONS: Standards of care and early outcomes in AMI in Poland are similar to Western countries. The major cause of higher mortality due to AMI in the Polish population is a high incidence of AMI, indicating a need for intensification of primary prevention programmes. Secondary prevention is also underused, especially in the field of cardiac rehabilitation.

Comparison of wavelet transform modulus maxima and multifractal detrended fluctuation analysis of heart rate in patients with systolic dysfunction of left ventricle.

BACKGROUND: In recent years the WTMM (wavelet transform modulus maxima) and MDFA (multifractal detrended fluctuation analysis) methods have become widely used techniques for the determination of nonlinear, multifractal heart rate (HR) dynamics. The purpose of our study was to compare multifractal parameters of heart rate calculated using both methods in a group of 90 patients with reduced left ventricular systolic function (rlvs group) and in a group of 39 healthy persons (nsr group). METHODS: For each subject from the rlvs group (LVEF < or =40%) and the nsr group, a 24-hour ECG Holter monitoring was performed. The width of the multifractal spectrum and global Hurst exponent were calculated by means of WTMM and MDFA methods for 5-hour daytime and nighttime subsets. RESULTS: The width of the multifractal spectrum was significantly lower and the Hurst exponent was significantly higher in rlvs group in comparison to nsr group both during diurnal activity and nocturnal rest according to MDFA and only during diurnal activity according to WTMM method. In both groups we observed significant differences of the multifractal spectrum width and the global Hurst exponent between the nighttime and daytime recordings. CONCLUSIONS: MDFA seems to be more sensitive as compared with WTMM method in differentiation between multifractal properties of the heart rate in healthy subjects and patients with left ventricular systolic dysfunction.