Tolvaptan in Hyponatraemic HF — EECC MCQ

Correct answer: D — Tolvaptan (a vasopressin V2 receptor antagonist) may be considered to increase free water clearance and correct hyponatraemia, but has no mortality benefit

Tolvaptan is a selective vasopressin V2 receptor antagonist that promotes aquaresis (free water excretion without electrolyte loss). In the EVEREST trial, tolvaptan improved short-term symptoms (dyspnoea, oedema, body weight) and corrected hyponatraemia in acute HF, but showed no reduction in long-term mortality or HF hospitalisations. The ESC HF Guidelines include tolvaptan as a Class IIb recommendation specifically for treatment of resistant hypervolaemic hyponatraemia in HF (Na⁺ <130 mmol/L) when fluid restriction and diuretics are insufficient. It does not replace loop diuretics and should be initiated in hospital with close sodium monitoring to avoid overly rapid correction (risk of osmotic demyelination).

Reference: ESC (2023): Focused Update on Heart Failure; EVEREST Trial