Systemic endothelin receptor blockade in ST-segment elevation acute coronary syndrome protects the microvasculature: a randomised pilot study.

Aims: ST-elevation acute coronary syndrome (STE-ACS) is characterised by compromised blood flow at the epicardial and microvascular levels. Endothelin-1 (ET-1) is a mediator of microvascular dysfunction and adverse cardiac remodelling. We hypothesised that administration of an endothelin type A (ETA) receptor antagonist (BQ-123; Clinalfa, Läufelfingen, Switzerland) may protect microvascular function.