Table 2. INTERMACS stages for classifying patients with advanced heart failure (3).
| INTERMACS level | Description | Time frame for intervention |
|---|---|---|
| 1. Critical cardiogenic shock “Crash and burn” | Hemodynamic instability in spite of increasing doses of catecholamines and/or mechanical circulatory support with critical organ hypoperfusion | Definitive intervention needed within hours |
| 2. Progressive decline despite inotropic support “Sliding on inotropes” | Intravenous inotropic support with acceptable blood pressure but rapid deterioration of renal function, nutritional state, or signs of congestion. Also describes declining status in patients unable to tolerate inotropic therapy | Definitive intervention needed within a few days |
| 3. Stable but inotrope dependent “Dependent stability” | Hemodynamic stability with low or intermediate doses of inotropes, but necessary due to hypotension, worsening of symptoms, or progressive renal failure | Definitive intervention elective over a period of weeks to few months |
| 4. Resting symptoms “Frequent flyer” | Temporary cessation of inotropic treatment is possible but patient presents with frequent symptom recurrences and typically with fluid overload. Doses of diuretics generally fluctuate at very high levels | Definitive intervention elective over a period of weeks to few months |
| 5. Exertion intolerant “Housebound” | Complete cessation of physical activity, stable at rest, but frequently with moderate fluid retention and some level of renal dysfunction | Variable urgency, depends upon maintenance of nutrition, organ function, and activity |
| 6. Exertion limited “Walking wounded” | Minor limitation on physical activity and absence of congestion while at rest. Easily fatigued by light activity | Variable urgency, depends upon maintenance of nutrition, organ function, and activity |
| 7. Advanced NYHA III “Placeholder” | Patient in NYHA Class II with no current or recent unstable fluid balance | Transplantation or circulatory support may not currently be indicated |
Table adapted from Stevenson LW, Pagani FD, Young JB, et al. INTERMACS profiles of advanced heart failure: the current picture. J Heart Lung Transplant 2009;28:535-41, with permission from Elsevier. INTERMACS, Interagency Registry for Mechanically Assisted Circulatory Support.