Levosimendan 

1. Introduction

Levosimendan is a calcium sensitizer + inodilator used in acute decompensated heart failure (ADHF) and selected cardiogenic shock states.

  • Unlike catecholamines, it improves contractility without increasing intracellular Ca²⁺
  • Produces inotropy + vasodilation (inodilator)
  • Has prolonged action due to active metabolites

2. Mechanism of Action

A. Calcium Sensitization

  • Binds to troponin C
  • Enhances actin–myosin interaction
  • No increase in intracellular Ca²⁺ no increase in myocardial oxygen consumption

 Key exam point:
Improves contractility without tachycardia or increased O₂ demand


B. KATP Channel Opening

  • Opens ATP-sensitive K⁺ channels
    • Vascular smooth muscle vasodilation
    • Mitochondria cardioprotection

C. Net Hemodynamic Effects

Effect

Mechanism

Cardiac output

Positive inotropy

SVR

Vasodilation

Preload

Venodilation

Pulmonary pressures

Pulmonary vasodilation

3. Pharmacokinetics 

Parameter

Value

Route

IV infusion

Onset

Within minutes

Half-life (parent drug)

~1 hour

Active metabolite (OR-1896)

Half-life ~70–80 hours

Duration of action

Up to 7–10 days

Effects persist even after stopping infusion


4. Indications in ICU 

A. Acute Decompensated Heart Failure (ADHF)

  • Especially:
    • Low cardiac output
    • Beta-blocker use (catecholamine-resistant)

B. Cardiogenic Shock (Selected cases)

  • Not first-line
  • Consider when:
    • Poor response to noradrenaline/dobutamine
    • Need to avoid tachyarrhythmia

C. Right Ventricular Failure

  • Pulmonary vasodilation + RV contractility improvement

D. Weaning from VA-ECMO

  • Improves myocardial recovery

5. Dose & Administration

Standard Regimen

  • Loading dose: 6–12 µg/kg over 10 min (often avoided in ICU)
  • Infusion: 0.05–0.2 µg/kg/min for 24 hours

 ICU practice:

  • Avoid bolus prevents hypotension
  • Start low dose (0.05–0.1 µg/kg/min)

6. Hemodynamic Profile vs Other Inotropes

Drug

Inotropy

Vasodilation

HR effect

O₂ demand

Dobutamine

↑↑

↑↑

Milrinone

↑↑

↑↑

Levosimendan

↑↑

↑↑

Minimal

Unique advantage:
No significant increase in myocardial oxygen consumption


7. Advantages 

  • Works independent of β-receptors
  • Effective in patients on beta-blockers
  • No tachyphylaxis
  • Prolonged action
  • Improves:
    • Cardiac output
    • Renal perfusion
    • Pulmonary pressures

8. Adverse Effects

Common

  • Hypotension (most important)
  • Headache
  • Nausea

Serious

  • Arrhythmias (less than catecholamines)
  • Hypokalemia

 Key point:
Hypotension limits use in shock


9. Contraindications

  • Severe hypotension
  • Severe hypovolemia
  • Significant arrhythmias
  • Severe renal/hepatic failure (caution due to metabolite accumulation)

10. Evidence & Trials 

A. SURVIVE Trial

  • Compared levosimendan vs dobutamine
  • No mortality benefit
  • Better hemodynamics

B. REVIVE Trials

  • Symptom improvement
  • More hypotension and arrhythmias

C. CHEETAH Trial (Cardiac surgery)

  • No mortality benefit

11. Guideline Recommendations

European Society of Cardiology (ESC HF Guidelines)

  • May be considered in:
    • ADHF with low output
    • Especially on β-blockers
  • Not first-line in cardiogenic shock

American Heart Association / American College of Cardiology

  • Limited recommendation
  • Not routine first-line
  • Consider as adjunct in refractory cases

12. Comparison with Milrinone 

Feature

Levosimendan

Milrinone

Mechanism

Ca sensitizer

PDE-3 inhibitor

β-receptor dependence

No

No

Hypotension

Moderate

Significant

Duration

Very long

Short

Arrhythmia risk

Less

More

13. Special ICU Situations

A. Septic Cardiomyopathy

  • Mixed evidence
  • Not routine

B. Cardiorenal Syndrome

  • Improves renal perfusion via:
    • Increased CO
    • Renal vasodilation

C. Pulmonary Hypertension

  • Useful due to pulmonary vasodilation