Real-world experience with hypertonic saline and loop diuretics in acute heart failure: descriptive results from an elderly cohort treated with the SMAC-HF protocol
G Ropero Luis, M E Carmona-Moreno, M Melgar-Velasco, J M Gonzalez-Miret, F Guerrero-MarquezAbstract
Background
Hypertonic saline combined with loop diuretics has been proposed to improve decongestion and correct electrolyte disturbances in acute heart failure (AHF), but real-world evidence in very elderly patients with preserved ejection fraction remains limited.
Purpose
To characterise a real-world cohort treated with the SMAC-HF protocol and evaluate electrolyte response, prognostic analytical changes, safety, and reasons for treatment discontinuation.
Methods
Retrospective observational study including 191 AHF episodes treated with the SMAC-HF protocol between 2021 and 2024, corresponding to 140 patients. Correction of hyponatraemia and hypochloraemia was assessed in episodes with baseline abnormalities. Prognostic renal change was defined by relative estimated glomerular filtration rate (eGFR) variation (favourable ≤10% reduction; unfavourable ≥20% deterioration). Additional analyses included NT-proBNP reduction >30%, hypotension during treatment (mean arterial pressure <70 mmHg), hypokalaemia at treatment end, and reasons for protocol discontinuation.
Results
Mean age was 82.2 ± 9.1 years, with 50% male. The most frequent HF aetiology was hypertensive (28.6%), followed by ischaemic (22.9%) and valvular (13.6%), while no specific cause was identified in 15.7%. HF with preserved ejection fraction predominated (left ventricular ejection fraction >50% in 74.8%), and 87.2% of episodes were NYHA III–IV at admission. Combined pulmonary and peripheral congestion was present in 72.8%. Mean baseline serum sodium was 133.7 ± 7.0 mmol/L, with hyponatraemia in 47.3%; mean creatinine was 1.91 ± 1.13 mg/dL and mean eGFR 39.9 ± 23.6 mL/min. Median baseline NT-proBNP was 9,344 pg/mL. The SMAC-HF protocol was predominantly administered using 2.1% and 3.4% hypertonic saline solutions, with a median treatment duration of 4 days (interquartile range 2). Among episodes with baseline electrolyte abnormalities, hyponatraemia corrected in 65.3% and hypochloraemia in 56.3%. A favourable eGFR change occurred in 37.7%, no relevant change in 39.6%, and prognostic worsening in 22.6%. NT-proBNP reduction >30% was observed in 64.3% of episodes with available measurements. Combined diuretic therapy was frequently used, including SGLT2 inhibitors (46.6%), acetazolamide (28.8%), thiazides (19.4%), and mineralocorticoid receptor antagonists at diuretic doses (16.2%). Hypotension occurred in 26.2% and hypokalaemia in 35.1%. Clinical improvement was the most frequent reason for treatment discontinuation (65.4%).
Conclusions
In a real-world cohort of very elderly patients with predominant HF with preserved ejection fraction, severe congestion, and baseline renal impairment, the SMAC-HF protocol was associated with high rates of electrolyte correction and favourable prognostic analytical changes in a substantial proportion of episodes, supporting its applicability in selected patients with complex AHF.