Circulating Biomarkers in Pulmonary Arterial Hypertension: An Update

Pulmonary arterial hypertension (PAH) is a rare subtype of group 1 pulmonary hypertension (PH) diseases, characterized by high pulmonary artery pressure leading to right ventricular dysfunction and potential life-threatening consequences. PAH involves complex mechanisms: vasoconstriction, vascular remodeling, endothelial dysfunction, inflammation, oxidative stress, fibrosis, RV remodeling, cellular hypoxia, metabolic imbalance, and thrombosis. These mechanisms are mediated by several pathways, involving molecules like nitric oxide and prostacyclin. PAH diagnosis requires clinical evaluation and right heart catheterization, confirming a value of mPAP ≥ 20 mmHg at rest and often elevated pulmonary vascular resistance (PVR). Even if an early and accurate diagnosis is crucial, PAH still lacks effective biomarkers to assist in its diagnosis and prognosis. Biomarkers could contribute to arousing clinical suspicion and serve for prognosis prediction, risk stratification, and dynamic monitoring in patients with PAH. The aim of the present review is to report the main novelties on new possible biomarkers for the diagnosis, prognosis, and treatment monitoring of PAH.

Long-Term Functional Limitations on Cardiopulmonary Exercise Testing in Emotion-Triggered Takotsubo Syndrome

Background: In patients with prior Takotsubo syndrome (TTS), long-lasting functional cardiac limitations were described as compared with normal subjects. Emotion-triggered Takotsubo syndrome (E-TTS) has more favorable outcomes than TTS preceded by a physical trigger or by no identifiable factors. The aim of the present study was to assess long-term cardiac functional limitations in a cohort of asymptomatic E-TTS patients. Methods: We enrolled n = 40 asymptomatic patients with a diagnosis of E-TTS. Cardiopulmonary exercise tests (CPET) were performed at 30 (12-40) months median follow-up from the acute event. A cohort of n = 40 individuals matched for age, sex, body mass index and comorbidities served as control. Results: Despite recovery of left ventricular ejection fraction, patients with prior E-TTS had lower peak VO2 and percentage of predicted peak VO2 (17.8 ± 3.6 vs. 22.1 ± 6.5; p < 0.001 and 75.2 ± 14.1% vs. 100.6 ± 17.1%, p < 0.001), VO2 at anaerobic threshold (AT) (11.5 [10.1-12.9] vs. 14.4 [12.5-18.7]; p < 0.001), peak O2 pulse (9.8 ± 2.5 vs. 12.9 ± 3.5; p < 0.001) and higher VE/VCO2 slope (30.5 ± 3.7 vs. 27.3 ± 3.5; p < 0.001) compared with matched controls. We found no statistically significant differences in heart rate reserve (HRR), respiratory equivalent ratio (RER), mean blood pressure and peak PetCO2 between patients and controls. Conclusions: Despite its favorable outcome, patients with E-TTS in our population were found to have subclinical long-term functional cardiac limitations as compared with a control cohort.

What about chronotropic incompetence in heart failure with mildly reduced ejection fraction? Clinical and prognostic implications from the Metabolic Exercise combined with Cardiac and Kidney Indexes score dataset

AIMS

Chronotropic incompetence (CI) is a strong predictor of outcome in heart failure with reduced ejection fraction, however no data on its clinical and prognostic impacts in heart failure with mildly reduced ejection fraction (HFmrEF) are available. Therefore, the study aims to investigate, in a large multicentre HFmrEF cohort, the prevalence of CI as well as its relationship with exercise capacity and its prognostic role over the cardiopulmonary exercise testing (CPET) parameters.

METHODS AND RESULTS

Within the Metabolic Exercise combined with Cardiac and Kidney Indexes (MECKI) database, we analysed data of 864 HFmrEF out of 1164 stable outpatients who performed a maximal CPET at the cycle ergometer and who had no significant rhythm disorders or comorbidities. The primary study endpoint was cardiovascular (CV) death. All-cause death was also explored. Chronotropic incompetence prevalence differed depending on the method (peak heart rate, pHR% vs. pHR reserve, pHRR%) and the cut-off adopted (pHR% from ≤75% to ≤60% and pHRR% ≤ 65% to ≤50%), ranging from 11% to 62%. A total of 84 (9.7%) CV deaths were collected, with 39 (4.5%) occurring within 5 years. At multivariate analysis, both pHR% [hazard ratio 0.97 (0.95-0.99), P < 0.05] and pHRR% [hazard ratio 0.977 (0.961-0.993), P < 0.01] were associated with the primary endpoint. A pHR% ≤ 75% and a pHRR% ≤ 50% represented the most accurate cut-off values in predicting the outcome.

CONCLUSION

The study suggests an association between blunted exercise-HR response, functional capacity, and CV death risk among patients with HFmrEF. Whether the CI presence might be adopted in daily HFmrEF management needs to be addressed in larger prospective studies.

Atrial Fibrillation in Patients with Hypertrophic Cardiomyopathy and Cardiac Amyloidosis: From Clinical Management to Catheter Ablation Indication

Atrial fibrillation (AF) is the most common arrhythmia in patients affected by cardiomyopathies. Reports estimate a prevalence of 27% in patients with hypertrophic cardiomyopathy (HCM) and 40% in patients with cardiac amyloidosis (CA). The presence of AF typically results in progressive functional decline, an increased frequency of hospitalizations for heart failure, and a higher thromboembolic risk. Medical management using mainly beta-blockers or amiodarone has produced variable outcomes and a high rate of recurrence. Catheter ablation reduces symptom burden and complications despite a moderate rate of recurrence. Recent evidence suggests that an early rhythm control strategy may lead to more favorable short- and long-term outcomes. In this review, we summarize contemporary data on the management of AF in patients with cardiomyopathy (HCM and CA) with particular reference to the timing and outcomes of ablation procedures.

Exploring the Prognostic Performance of MECKI Score in Heart Failure Patients with Non-Valvular Atrial Fibrillation Treated with Edoxaban

INTRODUCTION

Risk stratification in heart failure (HF) is essential for clinical and therapeutic management. The Metabolic Exercise test data combined with Cardiac and Kidney Indexes (MECKI) score is a validated prognostic model for assessing cardiovascular risk in HF patients with reduced ejection fraction (HFrEF). From the validation of the score, the prevalence of HF patients treated with direct oral anticoagulants (DOACs), such as edoxaban, for non-valvular atrial fibrillation (NVAF) has been increasing in recent years. This study aims to evaluate the reliability of the MECKI score in HFrEF patients treated with edoxaban for NVAF.

MATERIALS AND METHODS

This study included consecutive outpatients with HF and NVAF treated with edoxaban (n = 83) who underwent a cardiopulmonary exercise test (CPET). They were matched by propensity score with a retrospective group of HFrEF patients with NVAF treated with vitamin K antagonists (VKAs) from the MECKI score registry (n = 844). The study endpoint was the risk of cardiovascular mortality, urgent heart transplantation, or Left Ventricle Assist Device (LVAD) implantation.

RESULTS

Edoxaban patients were treated with a more optimized HF therapy and had different clinical characteristics, with a similar MECKI score. After propensity score, 77 patients treated with edoxaban were successfully matched with the MECKI-VKA control cohort. In both groups, MECKI accurately predicted the composite endpoint with similar area under the curves (AUC = 0.757 vs. 0.829 in the MECKI-VKA vs. edoxaban-treated group, respectively, p = 0.452). The two populations' survival appeared non-significantly different at the 2-year follow-up.

CONCLUSIONS

this study confirms the prognostic accuracy of the MECKI score in HFrEF patients with NVAF treated with edoxaban, showing improved predictive power compared to VKA-treated patients.

Heart failure patients with improved ejection fraction: Insights from the MECKI score database

AIMS

Improvement of left ventricular ejection fraction is a major goal of heart failure (HF) treatment. However, data on clinical characteristics, exercise performance and prognosis in HF patients who improved ejection fraction (HFimpEF) are scarce. The study aimed to determine whether HFimpEF patients have a distinct clinical phenotype, biology and prognosis than HF patients with persistently reduced ejection fraction (pHFrEF).

METHODS AND RESULTS

A total of 7948 patients enrolled in the Metabolic Exercise Cardiac Kidney Indexes (MECKI) score database were evaluated (median follow-up of 1490 days). We analysed clinical, laboratory, electrocardiographic, echocardiographic, exercise, and survival data from HFimpEF (n = 1504) and pHFrEF (n = 6017) patients. The primary endpoint of the study was the composite of cardiovascular death, left ventricular assist device implantation, and urgent heart transplantation. HFimpEF patients had lower HF severity: left ventricular ejection fraction 44.0 [41.0-47.0] versus 29.7 [24.1-34.5]%, B-type natriuretic peptide 122 [65-296] versus 373 [152-888] pg/ml, haemoglobin 13.5 [12.2-14.6] versus 13.7 [12.5-14.7] g/dl, renal function by the Modification of Diet in Renal Disease equation 72.0 [56.7-89.3] versus 70.4 [54.5-85.3] ml/min, peak oxygen uptake 62.2 [50.7-74.1] versus 52.6 [41.8-64.3]% predicted, minute ventilation-to-carbon dioxide output slope 30.0 [26.9-34.4] versus 32.1 [28.0-38.0] in HFimpEF and pHFrEF, respectively (p < 0.001 for all). Cardiovascular mortality rates were 26.6 and 46.9 per 1000 person-years for HFimpEF and pHFrEF, respectively (p < 0.001). Kaplan-Meier analysis showed that HFimpEF had better a long-term prognosis compared with pHFrEF patients. After adjustment for variables differentiating HFimpEF from pHFrEF, except echocardiographic parameters, the Kaplan-Meier curves showed the same prognosis.

CONCLUSIONS

Heart failure with improved ejection fraction represents a peculiar group of HF patients whose clinical, laboratory, electrocardiographic, echocardiographic, and exercise characteristics parallel the recovery of systolic function. Nonetheless, these patients remain at risk for adverse outcome.

Fluid balance in heart failure

Fluid retention is a major determinant of symptoms in patients with heart failure (HF), and it is closely associated with prognosis. Hence, congestion represents a critical therapeutic target in this clinical setting. The first therapeutic strategy in HF patients with fluid overload is optimization of diuretic intervention to maximize water and sodium excretion. When diuretic therapy fails to relieve congestion, renal replacement therapy represents the only alternative option for fluid removal, as well as a way to restore diuretic responsiveness. On this background, the pathophysiology of fluid balance in HF is complex, with heart, kidney, and lung being deeply involved in volume regulation and management. Therefore, the interplay between these organs should be appreciated and considered when fluid overload in HF patients is targeted.

The cardiopulmonary exercise test in the prognostic evaluation of patients with heart failure and cardiomyopathies: the long history of making a one-size-fits-all suit

Cardiopulmonary exercise test (CPET) has become pivotal in the functional evaluation of patients with chronic heart failure (HF), supplying a holistic evaluation both in terms of exercise impairment degree and possible underlying mechanisms. Conversely, there is growing interest in investigating possible multiparametric approaches in order to improve the overall HF risk stratification. In such a context, in 2013, a group of 13 Italian centres skilled in HF management and CPET analysis built the Metabolic Exercise test data combined with Cardiac and Kidney Indexes (MECKI) score, based on the dynamic assessment of HF patients and on some other instrumental and laboratory parameters. Subsequently, the MECKI score, initially developed on a cohort of 2716 HF patients, has been extensively validated as well as challenged with the other multiparametric scores, achieving optimal results. Meanwhile, the MECKI score research group has grown over time, involving up to now a total of 27 centres with an available database accounting for nearly 8000 HF patients. This exciting joint effort from multiple HF Italian centres allowed to investigate different HF research field in order to deepen the mechanisms underlying HF, to improve the ability to identify patients at the highest risk as well as to analyse particular HF categories. Most recently, some of the participants of the MECKI score group started to join the forces in investigating a possible additive role of CPET assessment in the cardiomyopathy setting too. The present study tells the ten-year history of the MECKI score presenting the most important results achieved as well as those projects in the pipeline, this exciting journey being far to be concluded.

"Under the Bridge": Looking for Ischemia in a Patient with Intramyocardial Coronary Artery Course-The Role of the Cardiopulmonary Exercise Test

Many variables obtained during cardiopulmonary exercise test (CPET), including O2 uptake (VO2) versus heart rate (HR, O2-pulse) and work rate (VO2/Watt), provide quantitative patterns of responses to exercise when left ventricular dysfunction is an effect of myocardial ischemia (MI). Therefore, CPET offers a unique approach to evaluate exercise-induced MI in the presence of fixed or dynamic coronary arteries stenosis. In this paper, we examined the case of a 74-year-old patient presenting with an ischemic CPET and a normal stress cardiac magnetic resonance (CMR) with dipyridamole. A coronary angiography demonstrated the presence of myocardial bridging (MB), a well-known congenital coronary anomaly that is able to generate MI during exercise (but not in provocative testing using coronary artery vasodilators, such as dipyridamole). Despite the good diagnostic accuracy of the imaging methods (i.e., stress CMR) in MI detection, this case shows that exercise should be the method of choice in elicit ischemia in specific cases, like MB.

Effects of sacubitril/valsartan on exercise capacity: a prognostic improvement that starts during uptitration

PURPOSE

Sacubitril/valsartan is a mainstay of the treatment of heart failure with reduced ejection fraction (HFrEF); however, its effects on exercise performance yielded conflicting results. Aim of our study was to evaluate the impact of sacubitril/valsartan on exercise parameters and echocardiographic and biomarker changes at different drug doses.

METHODS

We prospectively enrolled consecutive HFrEF outpatients eligible to start sacubitril/valsartan. Patients underwent clinical assessment, cardiopulmonary exercise test (CPET), blood sampling, echocardiography, and completed the Kansas City Cardiomyopathy Questionnaire (KCCQ-12). Sacubitril/valsartan was introduced at 24/26 mg b.i.d. dose and progressively uptitrated in a standard monthly-based fashion to 97/103 mg b.i.d. or maximum tolerated dose. Study procedures were repeated at each titration visit and 6 months after reaching the maximum tolerated dose.

RESULTS

Ninety-six patients completed the study, 73 (75%) reached maximum sacubitril/valsartan dose. We observed a significant improvement in functional capacity across all study steps: oxygen intake increased, at peak exercise (from 15.6 ± 4.5 to 16.5 ± 4.9 mL/min/kg; p trend = 0.001), while minute ventilation/carbon dioxide production relationship reduced in patients with an abnormal value at baseline. Sacubitril/valsartan induced positive left ventricle reverse remodeling (EF from 31 ± 5 to 37 ± 8%; p trend < 0.001), while NT-proBNP reduced from 1179 [610-2757] to 780 [372-1344] pg/ml (p trend < 0.0001). NYHA functional class and the subjective perception of limitation in daily life at KCCQ-12 significantly improved. The Metabolic Exercise Cardiac Kidney Index (MECKI) score progressively improved from 4.35 [2.42-7.71] to 2.35% [1.24-4.96], p = 0.003.

CONCLUSIONS

A holistic and progressive HF improvement was observed with sacubitril/valsartan in parallel with quality of life. Likewise, a prognostic enhancement was observed.

Sex Differences in Repolarization Markers: Telemonitoring for Chronic Heart Failure Patients

Aging and chronic heart failure (CHF) are responsible for the temporal inhomogeneity of the electrocardiogram (ECG) repolarization phase. Recently, some short period repolarization-dispersion parameters have been proposed as markers of acute decompensation and of mortality risk in CHF patients. Some important differences in repolarization between sexes are known, but their impact on ECG markers remains unstudied. The aim of this study was to evaluate possible differences between men and women in ECG repolarization markers for the telemonitoring of CHF patients.

METHOD

5 min ECG recordings were collected to assess the mean and standard deviation (SD) of the following variables: QT end (QTe), QT peak (QTp), and T peak to T end (Te) in 215 decompensated CHF (age range: from 49 to 103 years). Thirty-day mortality and high levels of NT-pro BNP (<75 percentile) were considered markers of decompensated CHF.

RESULTS

A total of 34 patients (16%) died during the 30-day follow-up, without differences between sexes. Women showed a more preserved ejection fraction and higher LDL and total cholesterol levels. Among female patients, implantable cardioverter devices, statins, and antiplatelet agents were less used. Data for Te mean showed increased values among deceased men and women compared to survival, but Te_SD was shown to be the most reliable marker for CHF reacutization in both sexes.

CONCLUSION

Te_SD could be considered a risk factor for CHF worsening and complications for female and male patients, but different cut offs should be taken into account. (ClinicalTrials.gov number, NCT04127162.).

Effect of Head-Up/-Down Tilt on ECG Segments and Myocardial Temporal Dispersion in Healthy Subjects

The head-up/-down tilt test acutely modifies the autonomic nervous system balance throughout a deactivation of the cardiopulmonary reflexes. The present study examines the influence of head-up/-down tilt on a number of ECG segments. A total of 20 healthy subjects underwent a 5 min ECG and noninvasive hemodynamic bio-impedance recording, during free and controlled breathing, lying at (a) 0°; (b) -45°, tilting up at 45°, and tilting up at 90°. Heart rate variability power spectral analysis was obtained throughout some ECG intervals: P-P (P), P-Q (PQ), P_eQ (from the end of P to Q wave), Q-R peak (QR intervals), Q-R-S (QRS), Q-T peak (QT_p), Q-T end (QT_e), ST_p, ST_e, T peak-T end (T_e), and, eventually, the T_eP segments (from the end of T to the next P waves). Results: In all study conditions, the Low Frequency/High Frequency_PP and LF_{PP normalized units (nu)} were significantly lower than the LF/HF_RR and LF_RRnu, respectively. Conversely, the HF_PP and HF_PPnu were significantly higher in all study conditions. ST_e, QT_p, and QT_e were significantly related to the PP and RR intervals, whereas the T wave amplitude was inversely related to the standard deviations of all the myocardial repolarization variables and to the left ventricular end-systolic volume (LVEDV). The T wave amplitude diminished during head-up tilt and significantly correlated with the LVEDV.

Influence of exertional oscillatory breathing and its temporal behavior in patients with heart failure and reduced ejection fraction

BACKGROUND

Exertional oscillatory breathing (EOV) represents an emerging prognostic marker in heart failure (HF) patients, however little is known about EOV meaning with respect to its disappearance/persistence during cardiopulmonary exercise test (CPET). The present single-center study evaluated EOV clinical and prognostic impact in a large cohort of reduced ejection fraction HF patients (HFrEF) and, contextually, if a specific EOV temporal behavior might be an addictive risk predictor.

METHODS AND RESULTS

Data from 1.866 HFrEF patients on optimized medical therapy were analysed. The primary cardiovascular (CV) study end-point was cardiovascular death, heart transplantation or LV assistance device (LVAD) implantation at 5-years. For completeness a secondary end-point of total mortality at 5- years was also explored. EOV presence was identified in 251 patients (13%): 142 characterized by EOV early cessation (Group A) and 109 by EOV persistence during the whole CPET (Group B). The entire EOV Group showed worse clinical and functional status than NoEOV Group (n = 1.615) and, within the EOV Group, Group B was characterized by a more severe HF. At CV survival analysis, EOV patients showed a poorer outcome than the NoEOV Group (events 27.1% versus 13.1%, p < 0.001) both unpolished and after matching for main confounders. Instead, no significant differences were found between EOV Group A and B with respect to CV outcome. Conversely the analysis for total mortality failed to be significant.

CONCLUSIONS

Our analysis, albeit retrospective, supports the inclusion of EOV into a CPET-centered clinical and prognostic evaluation of the HFrEF patients. EOV characterizes per se a more advanced HFrEF stage with an unfavorable CV outcome. However, the EOV persistence, albeit suggestive of a more severe HF, does not emerge as a further prognostic marker.

Cardiopulmonary exercise testing and heart failure: a tale born from oxygen uptake

Since 50 years, cardiopulmonary exercise testing (CPET) plays a central role in heart failure (HF) assessment. Oxygen uptake (VO₂) is one of the main HF prognostic indicators, then paralleled by ventilation to carbon dioxide (VE/VCO₂) relationship slope. Also anaerobic threshold retains a strong prognostic power in severe HF, especially if expressed as a percent of maximal VO₂ predicted value. Moving beyond its absolute value, a modern approach is to consider the percentage of predicted value for peak VO₂ and VE/VCO₂ slope, thus allowing a better comparison between genders, ages, and races. Several VO₂ equations have been adopted to predict peak VO₂, built considering different populations. A step forward was made possible by the introduction of reliable non-invasive methods able to calculate cardiac output during exercise: the inert gas rebreathing method and the thoracic electrical bioimpedance. These techniques made possible to calculate the artero-venous oxygen content differences (ΔC(a-v)O₂), a value related to haemoglobin concentration, pO₂, muscle perfusion, and oxygen extraction. The role of haemoglobin, frequently neglected, is however essential being anaemia a frequent HF comorbidity. Finally, peak VO₂ is traditionally obtained in a laboratory setting while performing a standardized physical effort. Recently, different wearable ergo-spirometers have been developed to allow an accurate metabolic data collection during different activities that better reproduce HF patients' everyday life. The evaluation of exercise performance is now part of the holistic approach to the HF syndrome, with the inclusion of CPET data into multiparametric prognostic scores, such as the MECKI score.

Atrial natriuretic peptide stimulates autophagy/mitophagy and improves mitochondrial function in chronic heart failure

Mitochondrial dysfunction, causing increased reactive oxygen species (ROS) production, is a molecular feature of heart failure (HF). A defective antioxidant response and mitophagic flux were reported in circulating leucocytes of patients with chronic HF and reduced ejection fraction (HFrEF). Atrial natriuretic peptide (ANP) exerts many cardiac beneficial effects, including the ability to protect cardiomyocytes by promoting autophagy. We tested the impact of ANP on autophagy/mitophagy, altered mitochondrial structure and function and increased oxidative stress in HFrEF patients by both ex vivo and in vivo approaches. The ex vivo study included thirteen HFrEF patients whose peripheral blood mononuclear cells (PBMCs) were isolated and treated with αANP (10^-11 M) for 4 h. The in vivo study included six HFrEF patients who received sacubitril/valsartan for two months. PBMCs were characterized before and after treatment. Both approaches analyzed mitochondrial structure and functionality. We found that levels of αANP increased upon sacubitril/valsartan, whereas levels of NT-proBNP decreased. Both the ex vivo direct exposure to αANP and the higher αANP level upon in vivo treatment with sacubitril/valsartan caused: (i) improvement of mitochondrial membrane potential; (ii) stimulation of the autophagic process; (iii) significant reduction of mitochondrial mass-index of mitophagy stimulation-and upregulation of mitophagy-related genes; (iv) reduction of mitochondrial damage with increased inner mitochondrial membrane (IMM)/outer mitochondrial membrane (OMM) index and reduced ROS generation. Herein we demonstrate that αANP stimulates both autophagy and mitophagy responses, counteracts mitochondrial dysfunction, and damages ultimately reducing mitochondrial oxidative stress generation in PBMCs from chronic HF patients. These properties were confirmed upon sacubitril/valsartan administration, a pivotal drug in HFrEF treatment.

Electrocardiographic and other Noninvasive Hemodynamic Markers in Decompensated CHF Patients

Acutely decompensated chronic heart failure (adCHF) is among the most important causes of in-hospital mortality. R-wave peak time (RpT) or delayed intrinsicoid deflection was proposed as a risk marker of sudden cardiac death and heart failure decompensation. Authors want to verify if QR interval or RpT, obtained from 12-lead standard ECG and during 5-min ECG recordings (II lead), could be useful to identify adCHF. At hospital admission, patients underwent 5-min ECG recordings, obtaining mean and standard deviation (SD) of the following ECG intervals: QR, QRS, QT, JT, and T peak-T end (Te). The RpT from a standard ECG was calculated. Patients were grouped by the age-stratified Januzzi NT-proBNP cut-off. A total of 140 patients with suspected adCHF were enrolled: 87 (mean age 83 ± 10, M/F 38/49) with and 53 (mean age: 83 ± 9, M/F: 23/30) without adCHF. V5-, V6- (p < 0.05) RpT, and QRSD, QRSSD, QTSD, JTSD, and TeSDp < 0.001 were significantly higher in the adCHF group. Multivariable logistic regression analysis demonstrated that the mean of QT (p < 0.05) and Te (p < 0.05) were the most reliable markers of in-hospital mortality. V6 RpT was directly related to NT-proBNP (r: 0.26, p < 0.001) and inversely related to a left ventricular ejection fraction (r: 0.38, p < 0.001). The intrinsicoid deflection time (obtained from V5-6 and QRSD) could be used as a possible marker of adCHF.

Time and Frequency Repolarization Domains in Elderly Candidates to Transcatheter Aortic Valve Replacement

Background and aim

Aortic valve stenosis (AVS) is a well-known risk factor for sudden cardiac death. Therefore, some non-invasive, electrocardiographic markers are capable to stratify the risk of sudden death at rest and during light mental challenge [mini-mental state examination (MMSE) administration].

Method

We compared short period RR, QT and Te intervals variability in 42 candidates to and 12 age-matched hypertensive control patients at rest and during mental challenge.

Results

At rest, AVS patients showed a higher QT standard deviation (sd), QT low frequency power (LF), QT High Frequency (HF), Tpeak-Tend intervals sd (Te sd) and Te HF than the control group. During mental challenge AVS group showed a decrease of RR mean and RR HF, expressed in normalized units (NU), and an increase of RR total power (TP), RR LF, RR LF NU, RR LF, HF ratio (LF/HF). During this same mental test, QT sd, QT LF, QT HF, Te sd, Te LF, Te HF, QT variability index (VI), TeVI, QT normalized variance (VN) were higher in AVS patients than the control group. During mental challenge Te LF (r:0.825, p<0.05) was significantly associated to: serum albumin (β:-0.473, p<0.001), MMSE (β:-0.267, p:0.038), diastolic blood pressure (β:-0.443, p:0.03) and cardiac index (β:-0.303, p:0.029).

Conclusion

AVS patients showed temporal dispersion of ventricular repolarization phase, useful maker to individuate high risk patients. MMSE administration induced a sympathetic sinus activation and vagal deactivation in AVS subjects. Frailty and mental function influenced Te HF and Te LF.

Does moderate hyperkalemia influence survival in HF? Insights from the MECKI score data base

BACKGROUND

The prognostic role of moderate hyperkalemia in reduced ejection fraction (HFrEF) patients is still controversial. Despite this, it affects the use of renin-angiotensin-aldosterone system inhibitors (RAASi) with therapy down-titration or discontinuation.

OBJECTIVES

Aim of the study was to assess the prognostic impact of moderate hyperkalemia in chronic HFrEF optimally treated patients.

METHODS AND RESULTS

We retrospectively analyzed MECKI (Metabolic Exercise test data combined with Cardiac and Kidney Indexes) database, with median follow-up of 4.2 [IQR 1.9-7.5] years. Data on K⁺ levels were available in 7087 cases. Patients with K⁺ plasma level ≥ 5.6 mEq/L and < 4 mEq/L were excluded. Remaining patients were categorized into normal >4 and < 5 mEq/L (n = 4826, 68%) and moderately high ≥5.0 and ≤ 5.5 mEq/L (n = 496, 7%) K⁺. Then patients were matched by propensity score in 484 couplets of patients. MECKI score value was 7% [IQR 3.1-14.1%] and 7.3% [IQR 3.4-15%] (p = 0.678) in patients with normal and moderately high K⁺ values while cardiovascular mortality events at two years follow-up were 41 (4.2%) and 33 (3.4%) (p = 0.333) in each group respectively.

CONCLUSIONS

Moderate hyperkalemia does not influence patients' outcome in a large cohort of ambulatory HFrEF patients.

348 PROGNOSTIC EVALUATION OF HEART FAILURE IN WOMEN: INSIGHT FROM THE MECKI SCORE DATABASE

Background

Heart failure (HF) in women often assumes extremely peculiar characteristics. The risk stratification and prognostic evaluation of HF in women is a challenge for clinicians. The actual prognostic scores are, in fact, lacking a specific sex-oriented assessment. In HF women show better survival despite a comparatively low peak oxygen consumption (VO2) at cardiopulmonary exercise testing: this raises doubt about the accuracy of risk assessment in women. Previous studies on MECKI score database have demonstrated that female prognostic advantage is lost when sex-specific differences are correctly considered. The present analysis has the aim to identify parameters which could be differently associated to prognosis in men and women and to re-calibrate the MECKI score according to these differences.

Methods

The new weights of the MECKI score variables according to gender, were calculated using the means of the 200 repetitions obtained to cross-validation procedure. The primary outcome of the study was the composite of all-cause mortality, urgent heart transplant and LVAD implant. The difference in predictive ability between the native and gender re-calibrated MECKI was calculated with the ROC curve at 2 years follow-up and calibration plot.

Results

We retrospectively analyzed 7900 HF patients with reduced ejection fraction included in the MECKI score registry (61±13 years, 6456 M/ 1444 F, LVEF 33±10%, VO2 /kg 14.9±4.9 mL/min Kg). Patients follow up was: 4.05 years [1.72-7.47]. Table 1 presents the weights of the individual MECKI variables for males and females. The main differences have been detected for the intercept value, hemoglobin and Na+. We used these variables to recalibrate the algorithm of MECKI score. We obtained higher AUC for MECKI re-calibrated by gender than for Native MECKI (0.7893 vs. 0.7799, p=0.0194, Fig. 1 left panel). Moreover, the gender MECKI was better calibrated (Fig. 1, right panels).

Conclusions

The calibration of MECKI Score according to gender specific differences improves the prognostic power and accuracy of mortality prediction at two years follow up.

755 ATRIAL NATRIURETIC PEPTIDE STIMULATES AUTOPHAGY/MITOPHAGY AND IMPROVES MITOCHONDRIAL DISFUNCTION IN CHRONIC HEART FAILURE

Background

Mitochondrial dysfunction, causing increased reactive oxygen species production, is a molecular feature of heart failure (HF) and it has been reported in circulating leucocytes of patients with HF with reduced ejection fraction (HFrEF). Atrial natriuretic peptide (ANP) exerts many cardiac beneficial effects, including the ability to protect cardiomyocytes by promoting autophagy.

Objective

To test the impact of ANP on autophagy/mitophagy responses, altered mitochondrial structure and function and increased oxidative stress in chronic HFrEF patients.

Experimental design. The present study used both ex-vivo and in-vivo approaches. We examined sixteen consecutive chronic HFrEF patients referring to the outpatient clinic of the Cardiology unit of Sant’Andrea Hospital in Rome. Out of them, for the ex-vivo study we enrolled 10 patients matching the following inclusion criteria: age under 75 years and left ventricle ejection fraction &lt;40%. For the in-vivo study we recruited six patients and evaluated them before and after 2-month treatment with the Angiotensin Receptor Neprilysin inhibitor (ARNi) sacubitril/valsartan started at the dosage of 49/51 mg twice daily, rapidly uptitrated at the dosage of 97/103 mg twice daily, while maintaining unchanged the remaining therapy. Patients with recent hospitalizations for acute HF or other acute conditions within the last 3 months before the enrollment, with malignancy, inflammatory or infectious diseases, diabetes mellitus, history of cigarette smoking and alcohol abuse were excluded.

Results

The ex-vivo direct exposure to αANP caused an improvement of mitochondrial membrane potential with a restoration of the mitochondrial protonmotive force (p&lt;0.05) and promoted the recovery of the IMM extension with a significant improvement in the IMM/OMM index (p&lt;0.05). The production of ROS was significantly decreased after the exposure to αANP (p&lt;0.05). Analyzing the mitochondrial stress, we observed that the treatment with αANP induced a down-modulation of p66shc mRNA (p&lt;0.01). The αANP treatment induced a rapid and significant autophagic response. The cytofluorimetric analysis showed a significant increase of LysoTracker levels highlighting a rise of intracellular acidic compartments (p&lt;0.05), with the up modulation of the LC3 and Beclin mRNA levels (p&lt;0.01 and p&lt;0.05 respectively). The significant reduction in mitochondrial mass observed in treated PBMCs evoked an increase of the mitophagic process related to αANP (p&lt;0.01). In vivo, the efficacy of the treatment with sacubitril/valsartan was proved by the increase in αANP levels (p&lt;0.01) whereas levels of NT-proBNP decreased (p&lt;0.05). PBMCs collected after treatment were characterized by lower mitochondrial oxidative stress levels and were provided of structurally more intact mitochondria characterized by better functional performances (p&lt;0.05). PBMCs of the treated patients showed an increased level of acid compartments associated with an up-modulation of LC3 and Beclin mRNA levels and a reduction of mitochondrial mass (p&lt;0.05). Also in this experimental context, the activation of autophagy was confirmed by ultrastructural morphometric evaluation (p&lt;0.05).

Conclusions

αANP stimulates both autophagy and mitophagy responses, counteracts mitochondrial dysfunction and damage ultimately reducing mitochondrial oxidative stress generation in PBMCs from chronic HF patients. These properties were confirmed upon sacubitril/valsartan administration, a therapeutic approach indicated for HFrEF treatment.

728 GALECTINE-3 AND SST2 IN SYSTEMIC SCLEROSIS: AN EARLY DETECTION OF PULMONARY VASCULAR INVOLVEMENT IS REALLY POSSIBLE?

Introduction

Pulmonary arterial hypertension (PAH) is a rare form of pulmonary hypertension (PH) that may also be associated with connective tissue diseases (CTD). In particular, PAH may affect from 5 to 19% of patients with systemic sclerosis (SSc), leading to a significant prognostic worsening. The current challenge is an early detection of PAH in such patients, in order to provide an early referral to PH centers to supply specific therapies as soon as possible. In the latest ESC guidelines for PH, cardiopulmonary exercise testing (CPET) has been included in the diagnostic algorithm for patients with unexplained exertional dyspnoea and/or suspected PH. Patients with PAH show a typical pattern, with a low end-tidal partial pressure of carbon dioxide (PETCO2), high ventilatory equivalent for carbon dioxide (VE/VCO2), low oxygen pulse (VO2/ HR) and low peak oxygen uptake (VO2). CPET may identify patients with SSc at low risk of PAH, to avoid unnecessary right heart catheterization (RHC). However, CPET is not available in all centers. So, we designed a preliminary study to identify new biomarkers that correlate with CPET's parameters.

Material and Methods

We enrolled 62 SSc patients [53 females, median age 52 years] with no other comorbidities and asymptomatic for dyspnea or other symptoms. 56% and 44% of them presented limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc), respectively.

For all patients we performed serum analysis for sST2, Galectine-3, pro-ANP, BNP and IL6, diagnostic imaging with echocardiography and cardiac MRI, CPET and pulmonary functionality test (PFT).

Results

All patients presented normal echocardiographic and RMI imaging findings.

Galectin-3, sST2, pro-ANP, BNP and IL6 presented respectively the following median value: 13.45 ng/mL [11.78; 18.70], 23.25 ng/mL [13.04; 43.35], 1897 fmol/ml [1487; 2445], 12.18 pg/mL [9.34; 15.01]. Both Galectin-3 and sST2 showed a linear correlation with VE/VCO2 slope with R 0.339 (P-value 0.018) and 0.355 (P-value 0.013) respectively. After linear regression analysis, Galectin-3 and sST2 were overall statistically significant with R2 of 0.115 and 0.126, F of 5.97 and 6.62 and P-value of 0.018 and 0.013, respectively. It was found that Galectin-3 and SST2 significantly predicted VE/VCO2 slope with β = 0.364 [0,064; 0,665] for Galectin-3 and 0.137 [0,030; 0,244] for SST2.

All other CPET parameters did not show correlation with the biomarkers.

Conclusion

Our preliminary results suggest that Galectine-3 and sST2 may be useful biomarkers for predicting increasing VE/VCO2 slope. Future analysis may confirm the role of these new biomarkers for early detection of pulmonary vascular involvement in SSc patients to allow an early referral and treatment and, conversely, to avoid unnecessary RHC.

848 SACUBITRIL/VALSARTAN IMPROVES EXERCISE PERFORMANCE IN PATIENTS WITH REDUCED EJECTION FRACTION: A DOSE AND TIME DEPENDENT EFFECT

Background

Sacubitril/Valsartan therapy has become a cornerstone of heart failure with reduced ejection fraction (HFrEF) pharmacological therapy due to its positive prognostic impact. However, conflicting results have emerged on the effects of sacubitril/valsartan on exercise performance assessed by cardiopulmonary exercise test (CPET).

Aim of the study

The aim of this study was to prospectively evaluate the effects of sacubitril/valsartan on prognostically significant CPET parameters in a larger population of HFrEF patients at different drug doses.

Methods

We prospectively enrolled HFrEF outpatients eligible to start sacubitril/valsartan according to 2016 ESC Guidelines in 3 Heart Failure Units. Patients underwent CPET at baseline (before sacubitril/valsartan treatment), after 1, 2, 3 months (respectively after a month taking the 24/26–49/51–97/103mg doses), and 6 months after the maximum tolerated dose was reached (end-study). The subjective impression of disease-related limitation was assessed using the 12-item Kansas City Cardiomyopathy Questionnaire (KCCQ).

Results

113 patients were enrolled (age 64.5±9.7, 81% males). Peak oxygen intake (peakVO2) improved at each step from 15.0±4.5 mL/min/kg at baseline to 16.5±4.9 mL/min/kg at end study visit, corresponding to 61.5±16.0 and 67.9±17.4% of predicted, respectively (p&lt;0.05). Minute ventilation/carbon dioxide production relationship (VE/VCO2 slope) reduced from 39.6±5.5 to 35.9±7.1 (p = 0.005) in the 39 patients (42%) with pathological VE/VCO2≥34 at baseline. KCCQ improved significantly since the first visit with an overall summary score increase from 47.9±11.1 to 52.6±9.8 (p&lt;0.001).

Conclusions

These findings suggest that sacubitril/valsartan benefits on exercise capacity are immediately evident at the lowest dose and progressively improve as the dose increases.

QT and Tpeak-Tend interval variability: Predictive electrical markers of hospital stay length and mortality in acute decompensated heart failure. Preliminary data

BACKGROUND

As previously reported, an increased repolarization temporal imbalance induces a higher risk of total/cardiovascular mortality.

HYPOTHESIS

The aim of this study was to assess if the electrocardiographic short period markers of repolarization temporal dispersion could be predictive of the hospital stay length and mortality in patients with acutely decompensated chronic heart failure (CHF).

METHOD

Mean, standard deviation (SD), and normalized variance (VN) of QT (QT) and Tpeak-Tend (Te) were obtained on 5-min ECG recording in 139 patients hospitalized for acutely decompensated CHF, subgrouping the patients for hospital length of stay (LoS): less or equal 1 week (≤1 W) and those with more than 1 week (>1 W).

RESULTS

We observed an increase of short-period repolarization variables (TeSD and TeVN, p < .05), a decrease of blood pressure (p < .05), lower ejection fraction (p < .05), and higher plasma level of biomarkers (NT-proBNP, p < .001; Troponin, p < .05) in >1 W LoS subjects. 30-day deceased subjects reported significantly higher levels of QTSD (p < .05), Te mean (p < .001), TeSD (p < .05), QTVN (p < .05) in comparison to the survivors. Multivariable Cox regression analysis reported that TeVN was a risk factor for longer hospital stay (hazard ratio: 1.04, 95% confidence limit: 1.01-1.08, p < .05); whereas, a longer Te mean was associated with higher mortality risk (hazard ratio: 1.02, 95% confidence limit: 1.01-1.03, p < .05).

CONCLUSION

A longer hospital stay is considered a clinical surrogate of CHF severity, we confirmed this finding. Therefore, these electrical and simple parameters could be used as noninvasive, transmissible, inexpensive markers of CHF severity and mortality.

Noninvasive Hemodynamic Monitoring in Advanced Heart Failure Patients: New Approach for Target Treatments

Using bio-impedance to deduce some hemodynamic parameters combined with some short-term ECG temporal dispersion intervals, and measuring myocardial depolarization, intraventricular conduction, and repolarization. A total of 65 in-hospital patients (M/F:35/30) were enrolled, 39 with HFrEF and 26 HFpEF, in New York Heart Association (NYHA) class IV. Stroke volume (SVI), cardiac indexes (CI), left ventricular ejection fraction (LVEFBIO), end diastolic volume (LV-EDV), and other systolic and diastolic parameters were noninvasively obtained at enrollment and at hospital discharge. At the same time, QR, QRS, QT, ST, Tpeak-Tend (Te) interval mean, and standard deviation (SD) from 5 min ECG recordings were obtained. At baseline, HFrEF patients reported significantly lower SVI (p < 0.05), CI (p < 0.05), and LVEF (p < 0.001) than HFpEF patients; moreover, HFrEF patients also showed increased LV-EDV (p < 0.05), QR, QRS, QT, ST, and Te means (p < 0.05) and standard deviations (p < 0.05) in comparison to HFpEF subjects. Multivariable logistic regression analysis reported a significant correlation between hospital mortality and Te mean (odds ratio: 1.03, 95% confidence limit: 1.01−1.06, p: 0.01). Fifty-seven percent of patients were considered responders to optimal medical therapy and, at discharge, they had significantly reduced NT-proBNP, (p < 0.001), heart rate (p < 0.05), and TeSD (p < 0.001). LVEF, obtained by transthoracic echocardiography, and LVEFBIO were significantly related (r: 0.781, p < 0.001), but these two parameters showed a low agreement limit. Noninvasive hemodynamic and ECG-derived parameters were useful to highlight the difference between HFrEF and HFpEF and between responders and nonresponders to the optimal medical therapy. Short-period bioimpedance and electrocardiographic data should be deeply evaluated to determine possible advantages in the therapeutic and prognostic approach in severe CHF.

Old and new equations for maximal heart rate prediction in patients with heart failure and reduced ejection fraction on beta-blockers treatment: results from the MECKI score data set

AIMS

Predicting maximal heart rate (MHR) in heart failure with reduced ejection fraction (HFrEF) still remains a major concern. In such a context, the Keteyian equation is the only one derived in a HFrEF cohort on optimized β-blockers treatment. Therefore, using the Metabolic Exercise combined with Cardiac and Kidney Indexes (MECKI) data set, we looked for a possible MHR equation, for an external validation of Keteyien formula and, contextually, for accuracy of the historical MHR formulas and their relationship with the HR measured at the anaerobic threshold (AT).

METHODS AND RESULTS

Data from 3487 HFrEF outpatients on optimized β-blockers treatment from the MECKI data set were analyzed. Besides excluding all possible confounders, the new equation was derived by using HR data coming from maximal cardiopulmonary exercise test. The simplified derived equation was [109-(0.5*age) + (0.5*HR rest) + (0.2*LVEF)-(5 if haemoglobin <11 g/dL)]. The R2 and the standard error of the estimate were 0.24 and 17.5 beats min-1 with a mean absolute percentage error (MAPE) = 11.9%. The Keteyian equation had a slightly higher MAPE = 12.3%. Conversely, the Fox and Tanaka equations showed extremely higher MAPE values. The range 75-80% of MHR according to the new and the Keteyian equations was the most accurate in identifying the HR at the AT (MAPEs = 11.3-11.6%).

CONCLUSION

The derived equation to estimate the MHR in HFrEF patients, by accounting also for the systolic dysfunction degree and anaemia, improved slightly the Keteyian formula. Both formulas might be helpful in identifying the true maximal effort during an exercise test and the intensity domain during a rehabilitation programme.

Short-Period Temporal Dispersion Repolarization Markers in Elderly Patients with Decompensated Heart Failure

OBJECTIVES

Aging and chronic heart failure (CHF) are responsible for the temporal inhomogeneity of electrocardiogram (ECG) repolarization phase. In the past, short period repolarization-dispersion parameters were used as makers of mortality risk in different heart diseases, yet. Aim of this work was to evaluate risk of mortality or worsening condition in CHF elderly subjects by mean of these repo-larization variables.

METHOD

An observational, prospective cohort study was performed, collecting 5 minutes ECG recordings to assess the mean and standard deviation (SD) of the following variables: QT end (QTe), QT peak (QTp) and T peak to T end (Te) in 117 decompensated CHF (age range: from 49 to 103 years). 30-day mortality and high levels of NT-pro BNP (<75 percentile) were considered markers of decompensated CHF.

RESULTS

A total of 27 patients (23%) died during the 30-day follow-up (overall mortality rate 23%). Te mean (odd ratio (OR): 1.04, 95% confidence limit (Cl 7u): 1.02-1.09, p<0.01), NT-pro BNP (OR: 1.00, 95% cl: 1.00-1.00, p<0.01) and LVMI (OR : 0.98, 95% cl: 0.96-0.10, p<0.05) were associated to risk of mortality at the multivariable logistic analysis. On the contrary, the same statistical analysis selected TeSD (OR: 1.36, 95% cl: 1.16-1.59, p<0.001) and LVEF (OR: 0.91, 95% cl: 0.87-0.95, p<0.001) as marker of decompensated CHF.

CONCLUSION

In decompensated CHF elderly subjects, Te mean seem be associated to mortality and TeSD could be considered a risk factor for CHF worsening and complications. These evidences could provide useful tools for telemonitoring CHF elderly patients, amelio-rating treatments and outcomes.

P295 EXERCISE OXYGEN KINETIC IN HYPERTROPHIC CARDIOMYOPATHY: RESULTS FROM A MULTICENTER CARDIOPULMONARY EXERCISE TESTING STUDY

Aims

Reduced cardiac output (CO) has been considered crucial in symptoms’ genesis in hypertrophic cardiomyopathy (HCM). We evaluated the cardiopulmonary exercise testing (CPET) response in HCM focusing on parameters strongly associated with stroke volume (SV) and cardiac output (CO), such as oxygen uptake (VO2) and O2–pulse, considering both their absolute values and temporal behavior during physical exercise.

Methods and Results

We enrolled 312 non–end stage HCM patients, divided according to left ventricle outflow tract obstruction (LVOTO) at rest or during Valsalva maneuver (72% with LVOTO&lt;30; 10% between 30 and 49 and 18% ≥ 50mmHg). Peak VO2 (percent of predicted), O2–pulse and ventilation to carbon dioxide production (VE/VCO2) slope did not change across LVOTO groups. Ninety–six (31%) HCM patients presented an abnormal O2–pulse temporal behavior, irrespective of LVOTO values. These patients showed lower peak systolic pressure, workload (106±45 vs. 130±49W), VO2 (74±17 vs. 80±20%) and O2–pulse (12 [9–14] vs. 14 [11–17]ml/beat), with higher VE/VCO2 slope (28 [25–31] vs. 27 [24–31]) (p &lt; 0.005 for all). Only 2 patients had an abnormal VO2/work slope.

Conclusion

None of CPET parameters, either as absolute values or dynamic relationships, were associated with LVOTO. Differently, an abnormal O2–pulse exercise behavior, which is strongly related to inadequate SV during exercise, correlates with reduced functional capacity (peak and anaerobic threshold VO2 and workload) and increased VE/VCO2 slope, helping identifying more advanced disease irrespectively of LVOTO. Adding O2–pulse kinetics evaluation to standard CPET could lead to a potential incremental benefit in terms of HCM prognostic stratification and, then, therapeutic management.

Exercise oxygen pulse kinetics in patients with hypertrophic cardiomyopathy

OBJECTIVES

Reduced cardiac output (CO) has been considered crucial in symptoms' genesis in hypertrophic cardiomyopathy (HCM). Absolute value and temporal behaviour of O₂-pulse (oxygen uptake/heart rate (VO₂/HR)), and the VO₂/work relationship during exercise reflect closely stroke volume (SV) and CO changes, respectively. We hypothesise that adding O₂-pulse absolute value and kinetics, and VO₂/work relationship to standard cardiopulmonary exercise testing (CPET) could help identify more exercise-limited patients with HCM.

METHODS

CPETs were performed in 3 HCM dedicated clinical units. We retrospectively enrolled non-end-stage consecutive patients with HCM, grouped according to left ventricle outflow tract obstruction (LVOTO) at rest or during Valsalva manoeuvre (72% of patients with LVOTO <30; 10% between 30 and 49 and 18% ≥50 mm Hg). We evaluated the CPET response in HCM focusing on parameters strongly associated with SV and CO, such as O₂-pulse and VO₂, respectively, considering their absolute values and temporal behaviour during exercise.

RESULTS

We included 312 patients (70% males, age 49±18 years). Peak VO₂ (percentage of predicted), O₂-pulse and ventilation to carbon dioxide production (VE/VCO₂) slope did not change across LVOTO groups. Ninety-six (31%) patients with HCM presented an abnormal O₂-pulse temporal behaviour, irrespective of LVOTO values. These patients showed lower peak systolic pressure, workload (106±45 vs 130±49 W), VO₂ (21.3±6.6 vs 24.1±7.7 mL/min/kg; 74%±17% vs 80%±20%) and O₂-pulse (12 (9-14) vs 14 (11-17) mL/beat), with higher VE/VCO₂ slope (28 (25-31) vs 27 (24-31)) (p<0.005 for all). Only 2 patients had an abnormal VO₂/work slope.

CONCLUSION

None of the frequently used CPET parameters, either as absolute values or dynamic relationships, were associated with LVOTO. Differently, an abnormal temporal behaviour of O₂-pulse during exercise, which is strongly related to inadequate SV increase, correlates with reduced functional capacity (peak and anaerobic threshold VO₂ and workload) and increased VE/VCO₂ slope, identifying more advanced disease irrespectively of LVOTO.

53 Exercise oxygen kinetic in hypertrophic cardiomyopathy: results from a multicentre cardiopulmonary exercise testing study

Aims

Reduced cardiac output (CO) has been considered crucial in symptoms’ genesis in hypertrophic cardiomyopathy (HCM). We evaluated the cardiopulmonary exercise testing (CPET) response in HCM focusing on parameters strongly associated with stroke volume (SV) and cardiac output (CO), such as oxygen uptake (VO2) and O2-pulse, considering both their absolute values and temporal behaviour during physical exercise.

Methods and results

We enrolled 312 non-end stage HCM patients, divided according to left ventricle outflow tract obstruction (LVOTO) at rest or during Valsalva manoeuver (72% with LVOTO &lt; 30; 10% between 30 and 49; and 18% ≥50 mmHg). Peak VO2 (percent of predicted), O2-pulse, and ventilation to carbon dioxide production (VE/VCO2) slope did not change across LVOTO groups. Ninety-six (31%) HCM patients presented an abnormal O2-pulse temporal behaviour, irrespective of LVOTO values. These patients showed lower peak systolic pressure, workload (106 ± 45 vs. 130 ± 49 W), VO2 (74 ± 17% vs. 80 ± 20%) and O2-pulse (12 [9–14] vs. 14 [11–17]ml/beat), with higher VE/VCO2 slope (28 [25–31] vs. 27 [24–31]) (P &lt; 0.005 for all). Only two patients had an abnormal VO2/work slope.

Conclusions

None of CPET parameters, either as absolute values or dynamic relationships, were associated with LVOTO. Differently, an abnormal O2-pulse exercise behaviour, which is strongly related to inadequate SV during exercise, correlates with reduced functional capacity (peak and anaerobic threshold VO2 and workload) and increased VE/VCO2 slope, helping identifying more advanced disease irrespectively of LVOTO. Adding O2-pulse kinetics evaluation to standard CPET could lead to a potential incremental benefit in terms of HCM prognostic stratification and, then, therapeutic management.

Minute ventilation/carbon dioxide production in chronic heart failure

In chronic heart failure, minute ventilation (V'_E) for a given carbon dioxide production (V'_CO2 ) might be abnormally high during exercise due to increased dead space ventilation, lung stiffness, chemo- and metaboreflex sensitivity, early metabolic acidosis and abnormal pulmonary haemodynamics. The V'_E versus V'_CO2 relationship, analysed either as ratio or as slope, enables us to evaluate the causes and entity of the V'_E/perfusion mismatch. Moreover, the V'_E axis intercept, i.e. when V'_CO2 is extrapolated to 0, embeds information on exercise-induced dead space changes, while the analysis of end-tidal and arterial CO₂ pressures provides knowledge about reflex activities. The V'_E versus V'_CO2 relationship has a relevant prognostic power either alone or, better, when included within prognostic scores. The V'_E versus V'_CO2 slope is reported as an absolute number with a recognised cut-off prognostic value of 35, except for specific diseases such as hypertrophic cardiomyopathy and idiopathic cardiomyopathy, where a lower cut-off has been suggested. However, nowadays, it is more appropriate to report V'_E versus V'_CO2 slope as percentage of the predicted value, due to age and gender interferences. Relevant attention is needed in V'_E versus V'_CO2 analysis in the presence of heart failure comorbidities. Finally, V'_E versus V'_CO2 abnormalities are relevant targets for treatment in heart failure.

Insights from Cardiopulmonary Exercise Testing in Pediatric Patients with Hypertrophic Cardiomyopathy

The usefulness of cardiopulmonary exercise test (CPET) in adult hypertrophic cardiomyopathy (HCM) patients is well-known, whereas its role in pediatric HCM patients has not yet been explored. The present study investigates possible insights from a CPET assessment in a cohort of pediatric HCM outpatients in terms of functional and prognostic assessment. Sixty consecutive pediatric HCM outpatients aged <18 years old were enrolled, each of them undergoing a full clinical assessment including a CPET; a group of 60 healthy subjects served as controls. A unique composite end-point of heart failure (HF) related and sudden cardiac death (SCD) or SCD-equivalent events was also explored. During a median follow-up of 53 months (25th–75th: 13–84 months), a total of 13 HF- and 7 SCD-related first events were collected. Compared to controls, HCM patients showed an impaired functional capacity with most of them showing peak oxygen uptake (pVO₂) values of <80% of the predicted, clearly discrepant with functional New York Heart Association class assessment. The composite end-point occurred more frequently in patients with the worst CPETs’ profiles. At the univariate analysis, pVO₂% was the variable with the strongest association with adverse events at follow-up (C-index = 0.72, p = 0.025) and a cut-off value equal to 60% was the most accurate in identifying those patients at the highest risk. In a pediatric HCM subset, the CPET assessment allows a true functional capacity estimation and it might be helpful in identifying early those patients at high risk of events.

Short-period temporal repolarization dispersion in subjects with atrial fibrillation and decompensated heart failure

BACKGROUND/OBJECTIVES

The association between chronic heart failure (CHF) and permanent atrial fibrillation is very frequent. The repolarization duration was already found predictive for atrial fibrillation. Aim of this study was to evaluate the influence of atrial fibrillation on short period repolarization variables in decompensated CHF patients.

METHOD

We used 5 min ECG recordings to assess the mean, standard deviation (SD), and normalized variance (NV) of the following variables: QT end (QTe), QT peak (QTp), and T peak to T end (Te) in 121 decompensated CHF, of whom 40 had permanent atrial fibrillation, too. We reported also the 30-day mortality.

RESULTS

QTp_SD (p < .01), Te_SD (p < .01), QTpVN (p < .01), and TeVN (p < .01) were higher in the atrial fibrillation than among sinus rhythm CHF subjects. Multivariable logistic analysis selected only Te_SD (odd ratio, o.r.: 1.32, 95% confidence interval, c.i.: 1.06-1.65, p: .015) associated with atrial fibrillation. A total of 27 patients died during the 30-days follow-up (overall mortality rate 22%), 7 (18%), and 20 (25%) respectively in the atrial fibrillation and sinus rhythm patients. Furthermore, the following variables were associated to the morality risk: NT-pro Brain Natriuretic Peptide (o.r.: 1.00, 95% c.i.: 1.00-1.00, p: .041), left ventricular end diastolic diameter (o.r.: 0.81, 95% c.i.: 0.67-0.96, p: .010), and Te mean (o.r.: 1.04, 95% c.i.: 1.02-1.09, p: .012).

CONCLUSION

In decompensated CHF subjects, Te mean seems be associated to mortality and Te_SD to the permanent atrial fibrillation. We could hypothesize that, during severe CHF, the multi-level ionic CHF channel derangement could be critical in influencing these non-invasive markers. (ClinicalTrials.gov number, NCT04127162).

Risk stratification in heart failure with mild reduced ejection fraction

Heart failure with mid-range ejection fraction represents a heterogeneous and relatively young heart failure category accounting for nearly 20-30% of the overall heart failure population. Due to its complex phenotype, a reliable clinical picture of heart failure with mid-range ejection fraction patients as well as a definite risk stratification are still relevant unsolved issues. In such a context, there is growing interest in a comprehensive functional assessment by means of a cardiopulmonary exercise test, yet considered a cornerstone in the clinical management of patients with heart failure and reduced ejection fraction. Indeed, the cardiopulmonary exercise test has also been found to be particularly useful in the heart failure with mid-range ejection fraction category, several cardiopulmonary exercise test-derived parameters being associated with a poor outcome. In particular, a recent contribution by the metabolic exercise combined with cardiac and kidney indexes research group showed an independent association between the peak oxygen uptake and pure cardiovascular mortality in a large cohort of recovered heart failure with mid-range ejection fraction patients. Contextually, the same study supplied an easy approach to identify a high-risk heart failure with mid-range ejection fraction subset by using a combination of peak oxygen uptake and ventilatory efficiency cut-off values, namely 55% of the maximum predicted and 31, respectively. Thus, looking at the above-mentioned promising results and waiting for specific trials, it is reasonable to consider cardiopulmonary exercise test assessment as part of the heart failure with mid-range ejection fraction work-up in order to identify those patients with an unfavourable functional profile who probably deserve a close clinical follow-up and, probably, more aggressive therapeutic strategies.

Time- and frequency-domain analysis of repolarization phase during recovery from exercise in healthy subjects

BACKGROUND/AIM

Recently, data from temporal dispersion of myocardial repolarization analysis have gained a capital role in the sudden cardiac death risk stratification. Aim of this study was to evaluate the influence of heart rate, autonomic nervous system, and controlled breathing on different myocardial repolarization markers in healthy subjects.

METHOD

Myocardial repolarization dispersion markers from short-period (5 minutes) electrocardiogram (ECG) analysis (time and frequency domain) have been obtained in 21 healthy volunteers during the following conditions: free breathing (rest); controlled breathing (resp); the first 5 minutes of postexercise recovery phases (exercise_Peak ), maximum sympathetic activation; and during the second 5 minutes of postexercise recovery phases (exercise_Recovery ), intermediate sympathetic activation. Finally, we analyzed the whole repolarization (QTe), the QT peak (QTp), and T peak - T end intervals (Te).

RESULTS

During the exercise_Peak , major part of repolarization variables changed in comparison to the rest and resp conditions. Particularly, QTe, QTp, and Te standard deviations (QTe_SD , QTp_SD , and Te_SD ); variability indexes (QTeVI and QTpVI), normalized variances (QTeVN, QTpVN, and TeVN); and the ratio between short-term QTe, QTp, and Te variability RR (STV_QTe/RR , STV_QTp/RR, and STV_Te/RR ) increased. During exercise_Recovery , QTp_SD (P < .05), QTpVI (P < .05), QTeVN (P < .05), QTpVN (P < .001), TeVN (P < .05), STV_QTe/RR (P < .05), STV_QTp/RR (P < .001), and STV_Te/RR (P < .001) were significantly higher in comparison to the rest. The slope between QTe (0.24 ± 0.06) or QTp (0.17 ± 0.06) and RR were significantly higher than Te (0.07 ± 0.06, P < .001).

CONCLUSION

Heart rate and sympathetic activity, obtained during exercise, seem able to influence the time domain markers of myocardial repolarization dispersion in healthy subjects, whereas they do not alter any spectral components.

Hospital mortality in decompensated heart failure. A pilot study

BACKGROUND/AIM

Heart failure is a leading cause of morbidity and mortality worldwide and it is a major cause of emergency department access for cardiovascular disease patients. Aim of this study was to identify the electrocardiographic (ECG) markers, based on short-term temporal repolarization dispersion, capable to individuate decompensated chronic heart failure (CHF) patients at high mortality risk.

METHODS

We obtained the following variables from an ECG recording, monitored via mobile phone, during 5-minute recordings in decompensated CHF patients: RR, QT end (QTe), QT peak (QTp) and T peak to T end (Te) and we calculated mean, standard deviation (_SD) and normalized index (N).

RESULTS

In-hospital mortality occurred for 25 subjects on 101 studied (25%). Deceased patients showed higher QTe_SD (p < 0.01), Te mean (p < 0.01), Te_SD (p < 0.05), QTeVN (p < 0.05) than the surviving group. Logistic multivariable analysis evidenced that Te mean was a significant predictor of in-hospital mortality (odd ratio: 0.09, 95% confidence limit: 0.02-0.35, p: 0.001). At multiple regression analysis, Te_SD was significantly and positively related only to the NT-pro BNP levels (r: 0.540; p < 0.001). The Te mean (AUC: 0.677 p < 0.01) and Te_SD (AUC: 0.647, p: 0.05) showed significant sensitivity/specificity for the event.

CONCLUSIONS

The Te mean and Te_SD seem to be a promising noninvasive clinical marker able to identify patients with decompensated CHF at high risk of in-hospital mortality.

Short-Period Temporal Dispersion Repolarization Markers Predict 30-Days Mortality in Decompensated Heart Failure

BACKGROUND AND OBJECTIVES

Electrocardiographic (ECG) markers of the temporal dispersion of the myocardial repolarization phase have been shown able to identify chronic heart failure (CHF) patients at high mortality risk. The present prospective single-center study sought to investigate in a well-characterized cohort of decompensated heart failure (HF) patients the ability of short-term myocardial temporal dispersion ECG variables in predicting the 30-day mortality, as well as their relationship with N-terminal Pro Brain Natriuretic Peptide (NT-proBNP) plasmatic values.

METHOD

One hundred and thirteen subjects (male: 59, 67.8%) with decompensated CHF underwent 5 min of ECG recording, via a mobile phone. We obtained QT end (QTe), QT peak (QTp) and T peak to T end (Te) and calculated the mean, standard deviation (SD), and normalized index (VN).

RESULTS

Death occurred for 27 subjects (24%) within 30 days after admission. Most of the repolarization indexes (QTe mean (p < 0.05), QTe_SD (p < 0.01), QTp_SD (p < 0.05), mean Te (p < 0.05), Te_SD (p < 0.001) QTeVN (p < 0.05) and TeVN (p < 0.01)) were significantly higher in those CHF patients with the highest NT-proBNP (>75th percentile). In all the ECG data, only Te_SD was significantly and positively related to the NT-proBNP levels (r: 0.471; p < 0.001). In the receiver operating characteristic (ROC) analysis, the highest accuracy for 30-day mortality was found for QTe_SD (area under curve, AUC: 0.705, p < 0.01) and mean Te (AUC: 0.680, p < 0.01), whereas for the NT-proBNP values higher than the 75th percentile, the highest accuracy was found for Te_SD (AUC: 0.736, p < 0.001) and QTe_SD (AUC: 0.696, p < 0.01).

CONCLUSION

Both mean Te and Te_SD could be considered as reliable markers of worsening HF and of 30-day mortality. Although larger and possibly interventional studies are needed to confirm our preliminary finding, these non-invasive and transmissible ECG parameters could be helpful in the remote monitoring of advanced HF patients and, possibly, in their clinical management. (ClinicalTrials.gov number, NCT04127162).

SARS-CoV-2 spread in Northern Italy: what about the pollution role?

The recent epidemic of the new SARS-CoV-2 in the northern regions of Italy is putting the organization of the Italian health system under serious attack. The current emergency requires all possible efforts to stem the spread of the virus. In this context, it is clear that we have the urgent need to rely upon etiopathogenetic data, in order to do all possible efforts to block the epidemic. However, observing the trend of the infections in China and the geographic areas of the main outbreaks, it could be hypothesized that air pollution plays a role. In particular, it has been previously demonstrated, in specific populations, a role of particulate matter in worsening clinical presentation of virus infection in airways. Without prejudice to the ascertained virus spread by air droplets or contaminated surfaces, the factors that could have favored its spread remain to be investigated. Moreover, if these observations were to be confirmed, when the health emergency is resolved, it will be mandatory to redesign an economic-productive model in balance with the environment.

Choosing among β-blockers in heart failure patients according to β-receptors' location and functions in the cardiopulmonary system

Several large clinical trials showed a favorable effect of β-blocker treatment in patients with chronic heart failure (HF) as regards overall mortality, cardiovascular mortality, and hospitalizations. Indeed, the use of β-blockers is strongly recommended by current international guidelines, and it remains a cornerstone in the pharmacological treatment of HF. Although different types of β-blockers are currently approved for HF therapy, possible criteria to choose the best β-blocking agent according to HF patients' characteristics and to β-receptors' location and functions in the cardiopulmonary system are still lacking. In such a context, a growing body of literature shows remarkable differences between β-blocker types (β1-selective blockers versus β1-β2 blockers) with respect to alveolar-capillary gas diffusion and chemoreceptor response in HF patients, both factors able to impact on quality of life and, most likely, on prognosis. This review suggests an original algorithm for choosing among the currently available β-blocking agents based on the knowledge of cardiopulmonary pathophysiology. Particularly, starting from lung physiology and from some experimental models, it focuses on the mechanisms underlying lung mechanics, chemoreceptors, and alveolar-capillary unit impairment in HF. This paper also remarks the significant benefit deriving from the correct use of the different β-blockers in HF patients through a brief overview of the most important clinical trials.

Comorbidities in chronic heart failure: An update from Italian Society of Cardiology (SIC) Working Group on Heart Failure

The increasing number of patients with heart failure HF and comorbidities is due to aging population and increase of life expectancy of patients with cardiovascular disease. Encouraging results derived by recent trials may suggest some comorbidities as new targets for new drugs, highlighting the need for a better understanding of the comorbidities' effects in HF patients and the need of a multidisciplinary approach for the management of chronic HF with comorbidities. We report a brief review about main cardiovascular and non-cardiovascular comorbidities in HF patients in order to update physicians and researchers engaged in the HF research or in "fight against heart failure."

Gender and age normalization and ventilation efficiency during exercise in heart failure with reduced ejection fraction

Aims

Ventilation vs. carbon dioxide production (VE/VCO₂) is among the strongest cardiopulmonary exercise testing prognostic parameters in heart failure (HF). It is usually reported as an absolute value. The current definition of normal VE/VCO₂ slope values is inadequate, since it was built from small groups of subjects with a particularly limited number of women and elderly. We aimed to define VE/VCO₂ slope prediction formulas in a sizable population and to test whether the prognostic power of VE/VCO₂ slope in HF was different if expressed as a percentage of the predicted value or as an absolute value.

Methods and results

We calculated the linear regressions between age and VE/VCO₂ slope in 1136 healthy subjects (68% male, age 44.9 ± 14.5, range 13–83 years). We then applied age‐adjusted and sex‐adjusted formulas to predict VE/VCO₂ slope to HF patients included in the metabolic exercise test data combined with cardiac and kidney indexes score database, which counts 6112 patients (82% male, age 61.4 ± 12.8, left ventricular ejection fraction 33.2 ± 10.5%, peakVO₂ 14.8 ± 4.9, mL/min/kg, VE/VCO₂ slope 32.7 ± 7.7) from 24 HF centres. Finally, we evaluated whether the use of absolute values vs. percentages of predicted VE/VCO₂ affected HF prognosis prediction (composite of cardiovascular mortality + urgent transplant or left ventricular assist device). We did so in the entire cardiac and kidney indexes score population and separately in HF patients with severe (peakVO₂ < 14 mL/min/kg, n = 2919, 61.1 events/1000 pts/year) or moderate (peakVO₂ ≥ 14 mL/min/kg, n = 3183, 19.9 events/1000 pts/year) HF. In the healthy population, we obtained the following equations: female, VE/VCO₂ = 0.052 × Age + 23.808 (r = 0.192); male, VE/VCO₂ = 0.095 × Age + 20.227 (r = 0.371) (P = 0.007). We applied these formulas to calculate the percentages of predicted VE/VCO₂ values. The 2‐year survival prognostic power of VE/VCO₂ slope was strong, and it was similar if expressed as absolute value or as a percentage of predicted value (AUCs 0.686 and 0.690, respectively). In contrast, in severe HF patients, AUCs significantly differed between absolute values (0.637) and percentages of predicted values (0.650, P = 0.0026). Moreover, VE/VCO₂ slope expressed as a percentage of predicted value allowed to reclassify 6.6% of peakVO₂ < 14 mL/min/kg patients (net reclassification improvement = 0.066, P = 0.0015).

Conclusions

The percentage of predicted VE/VCO₂ slope value strengthens the prognostic power of VE/VCO₂ in severe HF patients, and it should be preferred over the absolute value for HF prognostication. Furthermore, the widespread use of VE/VCO₂ slope expressed as percentage of predicted value can improve our ability to identify HF patients at high risk, which is a goal of utmost clinical relevance.

Exercise oscillatory ventilation and prognosis in heart failure patients with reduced and mid-range ejection fraction

AIMS

Exercise oscillatory ventilation (EOV) is a pivotal cardiopulmonary exercise test parameter for the prognostic evaluation of patients with chronic heart failure (HF). It has been described in patients with HF with reduced ejection fraction (<40%, HFrEF) and with HF with preserved ejection fraction (>50%, HFpEF), but no data are available for patients with HF with mid-range ejection fraction (40-49%, HFmrEF). The aim of the study was to evaluate the prognostic role of EOV in HFmrEF patients.

METHODS AND RESULTS

We analysed 1239 patients with HFmrEF and 4482 patients with HFrEF, enrolled in the MECKI score database, with a 2-year follow-up. The study endpoint was the composite of cardiovascular death, urgent heart transplant, and ventricular assist device implantation. We identified EOV in 968 cases (16% and 17% of cases in HFmrEF and HFrEF, respectively). HFrEF EOV+ patients were significantly older, and their parameters suggested a more severe HF than HFrEF EOV- patients. A similar behaviour was found in HFmrEF EOV+ vs. EOV- patients. Kaplan-Meier analysis, irrespective of ejection fraction, showed that EOV is associated with a worse survival, and that patients with HFrEF and HFmrEF EOV+ had a significantly worse outcome than the EOV- of the same ejection fraction groups. EOV-associated survival differences in HFmrEF patients started after 18 months of follow-up.

CONCLUSION

Exercise oscillatory ventilation has a similar prevalence and ominous prognostic value in both HFmrEF and HFrEF patients, indicating a group of patients in need of a more intensive follow-up and a more aggressive therapy. In HFmrEF, the survival curves between EOV+ and EOV- patients diverged only after 18 months.

Changes in left ventricular repolarization after short-term testosterone replacement therapy in hypogonadal males

BACKGROUND AND AIM

Evidences suggest that androgen deficiency is associated with sudden cardiac death (SCD). Our purpose was to analyse some electrocardiographic (ECG) markers of repolarization phase in hypogonadal patients either at baseline or after testosterone replacement therapy (TRT).

PATIENTS AND METHODS

Baseline and after 6 months of testosterone replacement therapy, 14 hypogonadal patients and 10 age-matched controls underwent a short-term ECG recordings at rest and immediately after a maximal exercise test. The following ECG parameters have been collected: QTe (the interval between the q wave the end of T wave), QTp (the interval between the q wave and the peak of T wave), and Te (the interval between the peak and the end of T wave).

RESULTS

At baseline, in the hypogonadal patients, corrected QTe and QTp values were longer at rest than in the controls at rest (p < 0.05), whereas, during the recovery phase, only the QTp remained significantly longer (p < 0.05). After TRT, hypogonadal patients showed an improvement only in Te (p < 0.05). Conversely, any difference between hypogonadal patients and control subjects was found with respect to the markers of temporal dispersion of repolarization phases, except for a worse QTp → Te coherence (p = 0.001) obtained during the recovery phase.

CONCLUSIONS

In conclusion, at rest, hypogonadal patients suffer from a stable increase in the myocardial repolarization phase without an increase in its temporal dispersion and, hence, the SCD risk seems to be low.

Arrhythmic Risk in Elderly Patients Candidates to Transcatheter Aortic Valve Replacement: Predictive Role of Repolarization Temporal Dispersion

Background/Aim

Degenerative aortic valve stenosis (AS) is associated to ventricular arrhythmias and sudden cardiac death, as well as mental stress in specific patients. In such a context, substrate, autonomic imbalance as well as repolarization dispersion abnormalities play an undoubted role. Aim of the study was to evaluate the increase of premature ventricular contractions (PVC) and complex ventricular arrhythmias during mental stress in elderly patients candidate to the transcatheter aortic valve replacement (TAVR).

Methods

In eighty-one elderly patients with AS we calculated several short-period RR- and QT-derived variables at rest, during controlled breathing and during mild mental stress, the latter being represented by a mini-mental state evaluation (MMSE).

Results

All the myocardial repolarization dispersion markers worsened during mental stress (p < 0.05). Furthermore, during MMSE, low frequency component of the RR variability increased significantly both as absolute power (LF_RR) and normalized units (LF_{RRN U}) (p < 0.05) as well as the low-high frequency ratio (LF_RR/HF_RR) (p < 0.05). Eventually, twenty-four (30%) and twelve (15%) patients increased significantly PVC and, respectively, complex ventricular arrhythmias during the MMSE administration. At multivariate logistic regression analysis, the standard deviation of QTend (QTe_sd), obtained at rest, was predictive of increased PVC (odd ratio: 1.54, 95% CI 1.14-2.08; p = 0.005) and complex ventricular arrhythmias (odd ratio: 2.31, 95% CI 1.40-3.83; p = 0.001) during MMSE. The QTe_sd showed the widest sensitive-specificity area under the curve for the increase of PVC (AUC: 0.699, 95% CI: 0.576-0.822, p < 0.05) and complex ventricular arrhythmias (AUC: 0.801, 95% CI: 0.648-0.954, p < 0.05).

Conclusion

In elderly with AS ventricular arrhythmias worsened during a simple cognitive assessment, this events being a possible further burden on the outcome of TAVR. QTe_sd might be useful to identify those patients with the highest risk of ventricular arrhythmias. Whether the TAVR could led to a QTe_sd reduction and, hence, to a reduction of the arrhythmic burden in this setting of patients is worthy to be investigated.

Heart failure prognosis over time: how the prognostic role of oxygen consumption and ventilatory efficiency during exercise has changed in the last 20 years

AIMS

Exercise-derived parameters, specifically peak exercise oxygen uptake (peak VO₂ ) and minute ventilation/carbon dioxide relationship slope (VE/VCO₂ slope), have a pivotal prognostic value in heart failure (HF). It is unknown how the prognostic threshold of peak VO₂ and VE/VCO₂ slope has changed over the last 20 years in parallel with HF prognosis improvement.

METHODS AND RESULTS

Data from 6083 HF patients (81% male, age 61 ± 13 years), enrolled in the MECKI score database between 1993 and 2015, were retrospectively analysed. By enrolment year, four groups were generated: group 1 1993-2000 (n = 440), group 2 2001-2005 (n = 1288), group 3 2006-2010 (n = 2368), and group 4 2011-2015 (n = 1987). We compared the 10-year survival of groups and analysed how the overall risk (cardiovascular death, urgent heart transplantation, or left ventricular assist device implantation) changed over time according to peak VO₂ and VE/VCO₂ slope and to major clinical and therapeutic variables. At 10 years, a progressively higher survival from group 1 to group 3 was observed, with no further improvement afterwards. A 20% risk for peak VO₂ 15 mL/min/kg (95% confidence interval 16-13), 9 (11-8), 4 (4-2) and 5 (7-4) was observed in group 1, 2, 3, and 4, respectively, while the VE/VCO₂ slope value for a 20% risk was 32 (37-29), 47 (51-43), 59 (64-55), and 57 (63-52), respectively.

CONCLUSIONS

Heart failure prognosis improved over time up to 2010 in a HF population followed by experienced centres. The peak VO₂ and VE/VCO₂ slope cut-offs identifying a definite risk progressively decreased and increased over time, respectively. The prognostic threshold of peak VO₂ and VE/VCO₂ slope must be updated whenever HF prognosis improves.

Long-Term Left Ventricular Remodeling of Patients With Hypertrophic Cardiomyopathy

In hypertrophic cardiomyopathy (HC), a process of left ventricular (LV) remodeling carrying an adverse prognosis has been described. Conversely, a gradual and benign LV wall thinning has been suggested but never investigated. Therefore, we studied a HC cohort over a long period of time to evaluate the occurrence of a LV remodeling with a benign clinical course. Data of HC patients aged 18 to 65 years and without any condition known to influence LV remodeling were analyzed over a mean follow-up of 7.6 ± 5.7 years. Of 231 HC patients (65% males, mean age 46 ± 12 years), 47 (20%) developed LV remodeling, of whom 23 (10%) had a thinning ≥15% of LV maximal wall thickness from baseline without systolic dysfunction (MWT thinning); 13 (6%) progressed to a LV ejection fraction <50% (end-stage HC) and 11 (5%) developed an apical aneurysm. Follow-up length (odds ratio 1.07, 95% confidence interval 1.00 to 1.15, p = 0.06) and maximal LV wall thickness at baseline (odds ratio 1.14, 95% confidence interval 1.04 to 1.25, p = 0.004) were the main predictors of MWT thinning. Compared with patients with end-stage HC and apical aneurysm, those with MWT thinning showed lower HC-related morbidity (92% and 36% vs 22%, p = 0.003) and mortality (31% and 27% vs 4%, p = 0.02). Furthermore, they showed a combined HC-related morbidity and mortality similar to patients without LV remodeling (incidence 29/1000 vs 26/1000 patient-year, p = 0.77). In conclusion, a process of LV wall thinning with a benign outcome can occur over the long term in patients with HC. The prognostic importance of LV remodeling varies in relation to the different changes in LV morphology and function.