Table 1.

Interagency Registry for Mechanically Assisted Circulatory Support scale for classifying patients with advanced heart failure

ProfileDescription
INTERMACS 1Hemodynamic instability in spite of increasing doses of catecholamines and/or mechanical circulatory support with critical hypoperfusion of end organs (severe cardiogenic shock)
INTERMACS 2Intravenous inotropic support with acceptable BP but rapid deterioration of kidney function, nutritional status, or signs of congestion
INTERMACS 3Hemodynamic stability with low or intermediate (but necessary due to hypotension) doses of inotropic support, worsening of symptoms, or progressive kidney failure
INTERMACS 4Temporary cessation of inotropic support is possible, but patient presents frequently with symptom recurrence and typically with fluid overload
INTERMACS 5Complete cessation of physical activity; stable at rest but frequently with moderate water retention and some level of kidney dysfunction
INTERMACS 6Minor limitation of physical activity and absence of congestion while at rest; easily fatigued by light activity
INTERMACS 7Patient in NYHA functional class IIa or IIIb with no current or recent unstable water balance
  • Adapted from INTERMACS. INTERMACS, Interagency Registry for Mechanically Assisted Circulatory Support; NYHA, New York Heart Association.

  • a NYHA class II: slight limitation of physical activity; comfortable at rest but ordinary physical activity results in fatigue, palpitation, or dyspnea.

  • b NYHA class III: marked limitation of physical activity; comfortable at rest but less than ordinary physical activity results in fatigue, palpitation, or dyspnea.