Sodium loading in ambulatory patients with heart failure with reduced ejection fraction: Mechanistic insights into sodium handling.

AIMS: Sodium restriction was not associated with improved outcomes in heart failure patients in recent trials. The skin might act as a sodium buffer, potentially explaining tolerance to fluctuations in sodium intake without volume overload, but this is insufficiently understood. Therefore, we studied the handling of an increased sodium load in patients with heart failure with reduced ejection fraction (HFrEF). METHODS AND RESULTS: Twenty-one ambulatory, stable HFrEF patients and 10 healthy controls underwent a 2-week run-in phase, followed by a 4-week period of daily 1.2 g (51 mmol) sodium intake increment. Clinical, echocardiographic, 24-h urine collection, and bioelectrical impedance data were collected every 2 weeks. Blood volume, skin sodium content, and skin glycosaminoglycan content were assessed before and after sodium loading. Sodium loading did not significantly affect weight, blood pressure, congestion score, N-terminal pro-brain natriuretic peptide, echocardiographic indices of congestion, or total body water in HFrEF (all p > 0.09). There was no change in total blood volume (4748 ml vs. 4885 ml; p = 0.327). Natriuresis increased from 150 mmol/24 h to 173 mmol/24 h (p = 0.024), while plasma renin decreased from 286 to 88 µU/L (p = 0.002). There were no significant changes in skin sodium content, total glycosaminoglycan content, or sulfated glycosaminoglycan content (all p > 0.265). Healthy controls had no change in volume status, but a higher increase in natriuresis without any change in renin. CONCLUSIONS: Selected HFrEF patients can tolerate sodium loading, with increased renal sodium excretion and decreased neurohormonal activation.

Mitral regurgitation in heart failure with preserved ejection fraction: The interplay of valve, ventricle, and atrium.

Mitral regurgitation (MR) is highly prevalent among patients with heart failure and preserved ejection fraction (HFpEF). Despite this combination being closely associated with unfavourable outcomes, it remains relatively understudied. This is partly due to the inherent heterogeneity of patients with HFpEF. To address this gap, dissecting HFpEF into mechanism-based phenotypes may offer a promising avenue for advancing our comprehension of these complex intertwined conditions. This review employs the validated CircAdapt model to explore the haemodynamic implications of moderate to severe MR across a well-defined spectrum of myocardial disease, characterized by impaired relaxation and reduced myocardial compliance. Both heart failure and mitral valve disease share overlapping symptomatology, primarily attributed to elevated pulmonary pressures. The intricate mechanisms contributing to these elevated pressures are multifaceted, potentially influenced by diastolic dysfunction, left atrial myopathy, and MR. Accurate evaluation of the haemodynamic and clinical impact of MR necessitates a comprehensive approach, taking into account the characteristics of both the left atrium and left ventricle, as well as their intricate interactions, which may currently be underemphasized in diagnostic practice. This holistic assessment is imperative for enhancing our understanding and refining therapeutic strategies within this patient cohort.