Assessing Catecholamine Treatment Initiation Options: Norepinephrine vs Dopamine for Cardiogenic Shock

Cardiogenic shock is a severe form of acute circulatory failure characterized by inadequate cardiac output, tissue hypoperfusion, and high short-term mortality. Despite advances in revascularization, mechanical circulatory support, and critical care management, early hemodynamic stabilization remains a major determinant of clinical outcomes. Vasoactive drugs are essential components of initial therapy, yet the optimal first-line agent for cardiogenic shock has not been definitively established.

Norepinephrine and dopamine are widely used vasoactive agents, but they may exert their effects through different physiological mechanisms. Their relative impact on vascular tone, cardiac output, and heart rate can vary depending on dose, patient characteristics, and the underlying pathophysiology of shock. Prior studies, including observational analyses and a landmark randomized trial, have suggested potential differences in safety profiles-particularly regarding arrhythmias-but these findings have not been confirmed in a contemporary population with standardized shock definitions and modern management strategies.

This multicenter, open-label, randomized clinical trial is designed to compare norepinephrine and dopamine as the initial vasoactive drug in adults with cardiogenic shock. The study uses a protocol-defined dosing algorithm to ensure consistent titration and incorporates current guideline-based management across participating centers. The primary endpoint evaluates both early hemodynamic deterioration and 28-day mortality, reflecting clinically meaningful outcomes during the most vulnerable phase of shock.

By enrolling a large, diverse population across multiple centers, this trial aims to provide definitive evidence regarding the comparative effectiveness and safety of norepinephrine versus dopamine as first-line therapy. The results are expected to inform clinical guidelines and support standardized treatment strategies for patients with cardiogenic shock.

Inclusion criteria

1&2

• Age ≥ 19
• Cardiogenic shocka in the stage of Society for cardiovascular angiography and intervention (SCAI) C or D

• Cardiogenic shock was defined as follows, and should fulfill both 1) and 2)

• systolic blood pressure <90 mm Hg for ≥30 min or need of inotropes or vasopressors to maintain systolic blood pressure >90 mm Hg And
• Impaired cardiac function confirmed by cardiac catheterization or echocardiography
• Patients will be further classified based on the SCAI shock classification system as follows:

• SCAI B: no signs of hypoperfusion
• SCAI C: any signs of hypoperfusion, cardiogenic shock will be classified as SCAI C, and these include mental status change, cool and clammy skin, mottled skin appearance, decreased urine output (30ml/hour) or lactate over 2.0mmol/L
• SCAI D: requirement of second-line vasoactive drug or mechanical circulatory support based on the predefined treatment protocol

Exclusion criteria

any of these,

• Administration of vasoactive drug more than 6 hours before enrollment
• Patients already on temporary mechanical circulatory supportb before enrollment
• Glasgow Coma Scale lower than 8 or other evidence of irreversible brain injury
• Shock etiologies other than cardiogenic which include postcardiotomy shock or mixed shock
• Pregnancy or lactation