Comparing the Diagnostic Performance of HFA-PEFF and H2FPEF Scoring Systems in Heart Failure with Preserved Ejection Fraction Patients: Insights from the APOLLON Registry.

BACKGROUND: Heart failure with preserved ejection fraction is a complex and heterogeneous clinical syndrome, poses significant diagnostic challenges. The HFA-PEFF [Heart Failure Association of ESC diagnostic algorithm, P (Pretest Assessment), E  (Echocardiographic and Natriuretic Peptide score), F1 (Functional testing in Case of Uncertainty), F2 (Final Aetiology)] and H2FPEF [Heavy (BMI>30 kg/m2), Hypertensive (use of ≥2 antihypertensive medications), atrial Fibrillation (paroxysmal or persistent), Pulmonary hypertension (Doppler Echocardiographic estimated Pulmonary Artery Systolic Pressure >35 mm Hg), Elderly (age >60 years), Filling pressure (Doppler Echocardiographic E/e' >9)] scoring systems were developed to aid in diagnosing heart failure with preserved ejection fraction. This study aimed to assess the concordance and clinical accuracy of these scoring systems in the 'A comPrehensive, ObservationaL registry of heart faiLure with mildly reduced and preserved ejection fractiON' cohort. METHODS: A comPrehensive, ObservationaL registry of heart faiLure with mildly reduced and preserved ejection fractiON study was conducted as a multicenter, cross-sectional, and observational study; to evaluate a group of Heart failure with mildly reduced ejection fraction and heart failure with preserved ejection fraction patients who were seen by cardiologists in 13 participating centers across 12 cities in Türkiye. RESULTS: The study enrolled 819 patients with heart failure with preserved ejection fraction, with high probability heart failure with preserved ejection fraction rates of 40% and 26% for HFA-PEFF and H2FPEF scorings, respectively. The concordance between the 2 scoring systems was found to be low (Kendall's taub correlation coefficient of 0.242, P < .001). The diagnostic performance of both scoring systems was evaluated, revealing differences in their approach and ability to accurately identify heart failure with preserved ejection fraction patients. CONCLUSION: The low concordance between the HFA-PEFF and H2FPEF scoring systems underscores the ongoing challenge of accurately diagnosing and managing patients with heart failure with preserved ejection fraction. Clinicians should be aware of the strengths and limitations of each scoring system and use them in conjunction with other clinical and laboratory findings to arrive at an accurate diagnosis. Future research should focus on identifying additional diagnostic factors, developing more accurate and comprehensive diagnostic algorithms, and investigating alternative methods of diagnosis or stratification of patients based on different clinical characteristics.

Influence of cardiac biomarkers on predicting significant coronary artery disease in hypertrophic cardiomyopathy patients.

BACKGROUND: In this study, our aim was to investigate the role of cardiac biomarkers in predicting the presence of significant coronary artery disease in hypertrophic cardiomyopathy (HCM) patients. METHODS: The study population was composed of hypertrophic cardiomyopathy patients who underwent coronary angiography at a single center between June 2021 and March 2023, and whose cardiac biomarkers were evaluated before the procedure. HCM patients were screened retrospectively. Significant CAD was defined as > 50% stenosis of the left main coronary artery or > 70% stenosis in a major coronary vessel. Demographic, echocardiographic and cardiac biomarker values were compared between the two groups. RESULTS: A total of 123 patients were evaluated. Significant CAD was detected in 39 (31.7%) patients. Patients with significant CAD had higher CK-MB values than those without CAD [2.8 (2.1-4.0) vs. 3.4 (2.8-4.6), p = 0.036], and a higher level of high-sensitivity troponin T (hs-TnT) than those without CAD (24 vs. 17.8, p = 0.022). the NT-proBNP/hs-TnT ratio was found to be significantly lower in patients with CAD than in those with CAD (31.4 vs. 21.4, p = 0.019). In multivariate anaylsis, NT-proBNP/hs-TnT was determined as an independent predictor for significant CAD. In ROC analysis, NT-proBNP/hs-TnT ratio lower than the cut-off value of 30.7 could detect the presence of significant CAD with 76.9% sensitivity and 53.6% specificity (AUC: 0.632, 95% CI: 0.528-0.736, p = 0.019). CONCLUSION: To sum up, we suggest that cardiac biomarkers were valuable and simple parameters in terms of significant CAD in HCM patients.

Systemic Immune-Inflammatory Index Is Associated with Residual SYNTAX Score in Patients with ST-Segment Elevation Myocardial Infarction.

BACKGROUND: Systemic immune-inflammatory index (platelet count × neutrophil-lymphocyte ratio) is a new marker that predicts adverse clinical outcomes in coronary artery diseases. Our aim was to investigate the relationship between the systemic immune-inflammatory index and residual SYNTAX score in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention. METHODS: In this retrospective study, 518 consecutive patients who underwent primary percutaneous coronary intervention (PCI) with the diagnosis of ST-segment elevation myocardial infarction were analyzed. The severity of coronary artery diseases was determined by residual SYNTAX score. In the receiver operating characteristic curve analysis, systemic immune-inflammatory index with an optimal threshold value of 1025.1 could detect the presence of a high residual SYNTAX score; the patients were divided into 2 groups as low (326) and high (192) according to the threshold value. In addition, binary multiple logistic regression analysis methods were used to evaluate independent predictors of high residual SYNTAX score. RESULTS: In binary multiple logistic regression analysis, systemic immune-inflammatory index [odds ratio = 6.910; 95% CI = 4.203-11.360; P <.001] was an independent predictor of high residual SYNTAX score. In addition, there was a positive correlation between the systemic immune-inflammatory index and residual SYNTAX score (r = 0.350, P <.001). In the receiver operating characteristic curve analysis, the systemic immune-inflammatory index with an optimal threshold value of 1025.1 could detect the presence of a high residual SYNTAX score with 73.8% sensitivity and 72.3% specificity. CONCLUSION: Systemic immune-inflammatory index, an inexpensive and easily measurable laboratory variable, was an independent predictor of the increased residual SYNTAX score in patients with ST-segment elevation myocardial infarction.

Cardiac hemangioma in a difficult anatomical location presented with ventricular tachycardia. A rare case report.

Cardiac hemangioma is a benign and rare primary tumor of the heart. Though it has benign histopathological features, its complications can be life-threatening. We report a young adult male without any prior structural heart disease or medical history who presented with ventricular tachyarrhythmia. Echocardiography revealed an echogenic mass located intramurally in the left lateral ventricle and its distinctive characteristics were revealed with further imaging modalities. Though simple complete removal of the mass is the preferred treatment, its firm texture and thinned encircling myocardium prevented the total excision. In this case report, we discussed cardiac hemangioma, its potential complications and treatment options.

Malnutrition provides important long-term prognostic information in patients undergoing endovascular abdominal aortic aneurysm repair.

OBJECTIVES: Malnutrition has been shown to be associated with survival in a variety of diseases. Our aim is to evaluate the prognostic value of objective nutritional indexes indicating malnutrition, in patients underwent endovascular aortic replacement. METHODS: We retrospectively evaluated 149 consecutive patients who underwent technically successful endovascular aortic replacement operation between October 2010 and August 2019. Objective nutritional indexes, prognostic nutritional index, geriatric nutritional risk index and controlling nutritional status, scores were calculated using the preoperative data. Optimal cut-off values were obtained by receiver operating characteristic analysis. According to the cut-off values, we investigated the relationship between indexes and the long-term all-cause mortality. RESULTS: During mean 48.0 ± 30.3 months follow-up duration, in 47 of patients (31.5%), all-cause mortality were documented. In mortality group, prognostic nutritional index (42.8 ± 7.1 vs 51.3 ± 5.2, p < 0.001) and geriatric nutritional risk index (100.7 ± 10.1 vs 107.6 ± 9.2, p < 0.001) were significantly lower, controlling nutritional status score (2.0 (1.0-4.0) vs 1.0 (0.0-2.0), p < 0.001) was higher when compared to survivor group. Kaplan-Meier curves presented higher mortality incidence in malnutrition patients evaluated with objective nutritional indexes (Log-rang test, for all three indexes p < 0.001). Besides Cox-proportional hazard analysis showed all three nutritional indexes may be a predictive marker for all-cause mortality, prognostic nutritional index introduced more valuable data than other two indexes. CONCLUSIONS: Malnutrition is associated with significant increase in postoperative long-term mortality in endovascular aortic replacement patients. Preoperatively calculated objective nutritional indexes especially prognostic nutritional index can be used as an important prognostic tool.

Perceived stress level is associated with coronary artery disease severity in patients with ST-segment elevation myocardial infarction.

OBJECTIVE: Stress is known to be a significant risk factor for coronary atherosclerosis and adverse cardiovascular events; however, the stress-related coronary atherosclerotic burden has not yet been investigated. The aim of this study was to investigate the relationship between the Perceived Stress Scale (PSS) and the SYNTAX scores in patients with ST-segment elevation myocardial infarction (STEMI). METHODS: A total of 440 patients with STEMI were prospectively enrolled and divided into 2 groups according to the PSS score with a ROC curve analysis cut-off value of 17.5. In all, 361 patients with a low PSS score were categorized as Group 1 and 79 patients with a high PSS score were categorized as Group 2. RESULTS: The SYNTAX score [Group 1, 16.0 (10.0-22.5); Group 2, 22.5 (15.0-25.5); p<0.001] and the SYNTAX score II were significantly higher in Group 2 [Group 1, 24.8 (19.0-32.6); Group 2, 30.9 (22.3-38.9); p<0.001]. Spearman analysis demonstrated that the PSS score was associated with the SYNTAX score (r=0.153; p=0.001) and the SYNTAX score II (r=0.216; p<0.001). Additionally, the PSS (odds ratio: 2.434, confidence interval: 1.446-4.096; p=0.001) was determined to be an independent predictor of a moderate-to-high SYNTAX score. The PSS score of patients with in-hospital mortality was also higher than those who survived [15 (10-20); 9 (4-16), respectively; p=0.007]. CONCLUSION: Stress appears to accelerate the coronary atherosclerotic process and the associated burden. An increased stress level was found to be an independent predictor of a high SYNTAX score.

Comparison of clinical characteristics of patients with heart failure and preserved ejection fraction with atrial fibrillation versus sinus rhythm: Insights from the APOLLON registry.

OBJECTIVE: The aim of this study was to assess the clinical characteristics of patients with heart failure and preserved ejection fraction (HFpEF) and atrial fibrillation (AF) and compare them with those of HFpEF patients without AF. METHODS: This study was a sub-group analysis of a multicenter, observational, and cross-sectional registry conducted in Turkey (ClinicalTrials.gov identifier: NCT03026114). Patients with HFpEF were divided into 2 groups: HFpEF with AF and HFpEF with sinus rhythm (SR), and the clinical characteristics of the groups were compared. RESULTS: In a total of 819 HFpEF patients (median age: 67 years; 58% women), 313 (38.2%) had AF. Compared to the patients with SR, those with AF were older (70 years vs 66 years; p<0.001) and more symptomatic, with a higher rate of classification as New York Heart Association functional class III-IV, paroxysmal nocturnal dyspnea, orthopnea, palpitations, fatigue, pulmonary crepitations, and peripheral edema. The hospitalization rate for heart failure was higher (28.4% vs 12.6%; p<0.001) in patients with AF, and participants with AF had higher level of N-terminal pro-B-type natriuretic peptide (887 pg/mL vs 394.8 pg/mL; p<0.001) and higher left atrial volume index level. Patients without AF had a higher burden of diabetes mellitus, obstructive sleep apnea, and coronary artery disease. The prescription rate of nondihydropyridine calcium blockers, digoxin, loop diuretics, and anticoagulant drugs was higher in the AF group. CONCLUSION: The results of this study revealed that in a large Turkish cohort with HFpEF, significant clinical differences were present between those with and without AF and. Further prospective studies are needed to clarify the prognostic implications of AF in this growing heart failure population in our country.

Evaluation of serum endocan levels in relation to epicardial fat tissue thickness in metabolic syndrome patients.

INTRODUCTION: Metabolic syndrome has been recognized as a predictor of cardiovascular diseases. Epicardial fat tissue (EFT) thickness has recently been shown to be a predictor of cardiovascular diseases in metabolic syndrome patients. Endocan is a novel molecule which is considered to be an early marker of endothelial dysfunction. Our aim was to evaluate endocan serum levels for the first time in metabolic syndrome patients, in relation to EFT thickness. MATERIAL AND METHODS: The study included 44 patients with metabolic syndrome who had neither chronic kidney disease nor chronic inflammation and 26 healthy controls. Fasting blood samples were obtained from the groups. The serum levels of endocan were measured with a Sunred ELISA kit. EFT thickness of patients was measured by echocardiography. RESULTS: The serum endocan levels were significantly lower in the metabolic syndrome patients compared to the healthy controls (120.71 ±90.17 pg/ml vs. 414.59 ±277.57, p < 0.001). Metabolic syndrome patients demonstrated significantly higher EFT (p = 0.042). EFT thickness had a positive correlation with age (r = 0.397, p = 0.008) and weight (r = 0.010). However, there was no correlation with serum endocan (r = -0.021, p = 0.893) or other parameters. Regression analysis revealed that waist circumference is the parameter among metabolic syndrome criteria having the strongest relationship with serum endocan levels (ß = -0.499, p = 0.21). CONCLUSIONS: EFT thickness was high in metabolic syndrome patients and can be a useful marker for cardiovascular risk assessment. However, serum endocan levels were found to be low and there was no correlation with EFT thickness. Large sample sized prospective studies are needed to clarify the relation of endocan levels with the other clinical indicators of cardiovascular risk in metabolic syndrome.

The relationship between myocardial fibrosis detected by cardiac magnetic resonance and Tp-e interval, 5-year sudden cardiac death risk score in hypertrophic cardiomyopathy patients.

BACKGROUND: The aim of this study was to investigate the relationship between QT (QTc) interval, Tp-e interval, Tp-e/QTc ratio, 5-year sudden cardiac death (SCD) risk score, and late gadolinium enhancement (LGE) detected by CMR in hypertrophic cardiomyopathy (HCM) patients. METHOD: A total of 74 consecutive patients who underwent CMR with HCM diagnosis were included in the study. These patients were divided into two groups according to the presence of LGE on CMR. All patients underwent detailed echocardiography and QTc interval, Tp-e interval, and Tp-e/QTc ratios and 5-year SCD risk scores were calculated. These parameters were compared for two groups. RESULTS: CMR revealed LGE in 32 (43.2%) of 74 HCM patients. In the group with LGE, significantly higher QTc interval (p = 0.002), Tp-e interval (p < 0.001), Tp-e/QTc ratio (p = 0.004), and 5-year SCD risk score were detected. In addition, QTc interval, Tp-e interval, Tp-e/QTc ratio, maximum wall thickness, left ventricular mass index, 5-year SCD risk score, and cardiac fibrosis index were found to be correlated with various degrees in correlation analysis. Also, Tp-e interval is found to be an independent predictor of LGE detected by CMR in HCM patients (p = 0.017, OR [%95 CI] = 1.017 [1.001-1.034]). In addition, the Tp-e interval can detect the LGE with a sensitivity of 64.3% and a specificity of 84.2% at 99.4 ms. (p < 0.001, AUC [95% CI] = 0.790 [0.676-0.905]). CONCLUSION: The Tp-e interval can be used to optimize SCD risk stratification in HCM patients and determine which patients will benefit from implantable cardioverter-defibrillator (ICD) treatment.

Gender disparities in heart failure with mid-range and preserved ejection fraction: Results from APOLLON study.

OBJECTIVE: This study aimed to examine gender-based differences in epidemiology, clinical characteristics, and management of consecutive patients with heart failure with mid-range ejection fraction (HFmrEF) and heart failure with preserved ejection fraction (HFpEF). METHODS: The APOLLON trial (A comPrehensive, ObservationaL registry of heart faiLure with mid-range and preserved ejection fractiON) is a multicenter, cross-sectional, and observational study. Consecutive patients with HFmrEF or HFpEF who were admitted to the cardiology clinics were included (NCT03026114). Herein, we performed a post-hoc analysis of data from the APOLLON trial. RESULTS: The study population included 1065 (mean age of 67.1+-10.6 years, 54% women) patients from 11 sites in Turkey. Compared with men, women were older (68 years vs. 67 years, p<0.001), had higher body mass index (29 kg/m2 vs. 27 kg/m2, p<0.001), and had higher heart rate (80 bpm vs. 77.5 bpm, p<0.001). Women were more likely to have HFpEF (82% vs. 70.9%, p<0.001), and they differ from men having a higher prevalence of hypertension (78.7% vs. 73.2%, p=0.035) and atrial fibrillation (40.7% vs. 29.9%, p<0.001) but lower prevalence of coronary artery disease (29.5% vs. 54.9%, p<0.001). Women had higher N-terminal pro-B-type natriuretic peptide (691 pg/mL vs. 541 pg/mL, p=0.004), lower hemoglobin (12.7 g/dL vs. 13.8 g/dL, p<0.001), and serum ferritin (51 ng/mL vs. 64 ng/mL, p=0.001) levels, and they had worse diastolic function (E/e'=10 vs. 9, p<0.001). The main cause of heart failure (HF) in women was atrial fibrillation, while it was ischemic heart disease in men. CONCLUSION: Clinical characteristics, laboratory findings, and etiological factors are significantly different in female and male patients with HFmrEF and HFpEF. This study offers a broad perspective for increased awareness about this patient profile in Turkey.

Geographical Variations in Patients with Heart Failure and Preserved Ejection Fraction: A Sub-Group Analysis of the APOLLON Registry

Background: Clinical characteristics of patients with heart failure may vary geographically. However, limited data are available regarding the geographical differences of patients with heart failure and preserved ejection fraction. Aims: The present subgroup analysis aims to investigate the geographical differences in clinical characteristics, management, and primary etiology of patients with heart failure and preserved ejection fraction in Turkey. Study Design: A cross-sectional study. Methods: A comPrehensive, ObservationaL registry of heart faiLure with mid-range and preserved ejection fractiON (APOLLON) is a multicenter and observational study conducted in seven regions of Turkey (NCT03026114). The present study is a post-hoc analysis of the APOLLON registry. In this substudy, we compared the clinical characteristics of 819 consecutive patients with heart failure and preserved ejection fraction (mean age, 67 years; 57.8% women) admitted to cardiology outpatient units in different geographical regions. Results: Based on the geographical distribution of the entire Turkish population, the highest number of patients enrolled were from Marmara (271 patients, 33.1%). All demographical characteristics, clinical and laboratory findings, comorbidities, primary etiology, and medications prescribed were significantly different between the regions. Furthermore, inter-regional gender differences were identified. Comparatively, the Aegean and Mediterranean regions had older patients with heart failure and preserved ejection fraction (p<0.001), and the Black Sea, Southeast, and East Anatolia regions had predominantly male patients (51.2, 54.5, and 56.9%, respectively; p=0.002). Notably, the Mediterranean and Southeast Anatolia had more symptomatic patients, and history of hospitalization for heart failure was more prevalent in Southeast Anatolia (33.3%, p<0.001). Prevalence of atrial fibrillation was higher in the Mediterranean and Southeast Anatolia regions (51 and 48.5%, p<0.001), and patients with heart failure and preserved ejection fraction had a higher prevalence of hypertension in the Mediterranean, Southeast Anatolia, and Black Sea regions (p=0.002). Angiotensin-converting enzyme inhibitors were more frequently prescribed in East Anatolia (52.3%, p=0.001), and the prevalence of patients with heart failure and preserved ejection fraction using loop diuretics (48.8%, p=0.003) was higher in the Black Sea region. Conclusion: This study was the first to show geographical differences in clinical characteristics of patients with heart failure and preserved ejection fraction in Turkey. Determination of the clinical characteristics of the heart failure and preserved ejection fraction population based on the geographical region may enables physicians to adopt a region-specific clinical approach toward heart failure and preserved ejection fraction.

Clinical features of heart failure with mid-range and preserved ejection fraction in octogenarians: Results of a multicentre, observational study.

OBJECTIVES: To compare real-world characteristics and management of individuals aged 80 and older with heart failure (HF) and mid-range ejection fraction (HFmrEF) and heart failure with preserved ejection fraction (HFpEF) derived from a large cohort of survey and to compare them with those younger than 80 from the same survey. METHODS: This is an observational, multicentre and cross-sectional study conducted in Turkey (NCT03026114). Consecutive 1065 (mean age of 67.1 ± 10.6 years) patients admitted to the cardiology outpatient units with HFmrEF and HFpEF were included. RESULTS: Participants aged 80 and older (n = 123, 11.5%) were more likely to be female (66.7% vs 52.5%, P = 0.003), had a higher prevalence of atrial fibrillation (49.6% vs 34%, P = 0.001), and anaemia (46.3% vs 33.4%, P = 0.005) than those who were younger than 80. N-terminal pro B-type natriuretic peptide levels were higher in those aged 80 and older than in those younger than 80 (1037 vs 550 pg/ml, P < 0.001). The prescription rates of HF medications (including in ACE-Is/ARBs, ß-blockers, MRAs, digoxin, ivabradine and diuretics) were similar (P > 0.05) in both groups. Octogenarians did not significantly differ from younger patients in the prevalence of HFmrEF (24.4% vs 22.9%) and HFpEF (75.6% vs 77.1%). Coronary artery disease was associated with HFmrEF (P < 0.05), whereas atrial fibrillation was associated with HFpEF (P < 0.05) in octogenarians. CONCLUSIONS: This study revealed that nearly 12% of the individuals with HFmrEF and HFpEF in this real-world sample were aged 80 and older. Participants aged 80 and older are more likely to be female and have more comorbidities than those who were younger than 80. However, HF medication profiles were similar in both groups. This study also showed that associated factors with HFmrEF and HFpEF were differ in octogenarians.

Patients with HFpEF and HFmrEF have different clinical characteristics in Turkey: A multicenter observational study.

BACKGROUND: To determine and compare the demographic characteristics, clinical profile and management of patients with heart failure with mid-range ejection fraction (HFmrEF) and heart failure with preserved ejection fraction (HFpEF) in a Turkish cohort. METHODS: The APOLLON trial (A comPrehensive, ObservationaL registry of heart faiLure with mid-range and preserved ejection fractiON) is an observational and multicenter study conducted in Turkey. Consecutive patients admitted to the cardiology clinics who were at least 18 years of age and had HFmrEF or HFpEF were included (NCT03026114). RESULTS: The study population included 1065 (mean age of 67.1 ±â€¯10.6 years, 54% women) patients from 12 sites in Turkey. Among participants, 246 (23.1%) had HFmrEF and 819 (76.9%) had HFpEF. Compared to patients with HFpEF, those with HFmrEF were more likely to be male (57.7 vs 42.2%; p < 0.001), had higher N-terminal pro-B-type natriuretic peptide levels (853 vs 528 pg/ml, p < 0.001), were more likely to have ECG abnormalities (72.4 vs 53.5%, p < 0.001) and hospitalization history for heart failure (28 vs 18.6%; p = 0.002). HFmrEF patients were more likely to use ß-blockers (69.9 vs 55.2%, p < 0.001), aldosterone receptor antagonists (24 vs 14.7%, p = 0.001), statins (37 vs 23%, p < .001), and loop diuretics (39.8 vs 30.5%, p = 0.006) compared to patients with HFpEF. CONCLUSIONS: The results of APOLLON study support that the basic characteristics and etiology of HFmrEF are significantly different from HFpEF. This registry also showed that the patients with HFmrEF and HFpEF were younger but undertreated in Turkey compared to patients in western countries.

Rationale, Design, and Methodology of the APOLLON trial: A comPrehensive, ObservationaL registry of heart faiLure with midrange and preserved ejectiON fraction.

OBJECTIVE: Although almost half of chronic heart failure (HF) patients have mid-range (HFmrEF) and preserved left-ventricular ejection fraction (HFpEF), no studies have been carried out with these patients in our country. This study aims to determine the demographic characteristics and current status of the clinical background of HFmrEF and HFpEF patients in a multicenter trial. METHODS: A comPrehensive, ObservationaL registry of heart faiLure with mid range and preserved ejectiON fraction (APOLLON) trial will be an observational, multicenter, and noninterventional study conducted in Turkey. The study population will include 1065 patients from 12 sites in Turkey. All data will be collected at one point in time and the current clinical practice will be evaluated (ClinicalTrials.gov number NCT03026114). RESULTS: We will enroll all consecutive patients admitted to the cardiology clinics who were at least 18 years of age and had New York Heart Association class II, III, or IV HF, elevated brain natriuretic peptide levels within the last 30 days, and an left ventricular ejection fraction (LVEF) of at least 40%. Patients fulfilling the exclusion criteria will not be included in the study. Patients will be stratified into two categories according to LVEF: mid-range EF (HFmrEF, LVEF 40%-49%) and preserved EF (HFpEF, LVEF ≥50%). Regional quota sampling will be performed to ensure that the sample was representative of the Turkish population. Demographic, lifestyle, medical, and therapeutic data will be collected by this specific survey. CONCLUSION: The APOLLON trial will be the largest and most comprehensive study in Turkey evaluating HF patients with a LVEF ≥40% and will also be the first study to specifically analyze the recently designated HFmrEF category.