INTERMACS classification for advanced heart failure

INTERMACS classification for advanced heart failure

INTERMACS classification for advanced heart failure was developed as a sub classification for advanced heart failure, typically for those in advanced NYHA (New York Heart Association) Functional Class III and IV. Interagency Registry for Mechanically Assisted Circulatory Support
(INTERMACS) developed this classification with seven clinical profiles and an arrhythmia modifier [1].  This was to allow optimal selection of patients for medical and pacing therapies, cardiac transplantation and mechanical circulatory support.

They found that 80% of current devices are being used in 2 profiles with the highest level of clinical compromise. Two modifiers were added for those on temporary circulatory support devices in the hospital and for frequent rehospitalization of patients being treated at home. So finally it became 7 profiles and 3 modifiers.

Unlike in the usual types of classifications, in the INTERMACS classification, profile 1 is the most severe. It is critical cardiogenic shock with life threatening hypotension despite escalating inotropic support, with critical organ hypoperfusion. This is associated with worsening acidosis and/or lactate levels. This has been called “Crash and burn”.

Profile 2 is one of progressive decline with declining function despite intravenous inotropic support with worsening renal function, nutritional depletion and inability to restore volume balance. This profile has been nicknamed “Sliding on inotropes”

Profile 3 is stable, but inotrope dependent. They have stable blood pressure, organ function on continuous intravenous inotropic support. Some may be on a temporary mechanical support device. This group demonstrates repeated failure to wean from support due to recurrent symptomatic hypotension or renal dysfunction. This profile is named “Dependent stability”

Profile 4 is with resting symptoms, but can be stabilized close to normal volume status. They experience daily symptoms of congestion at rest or during activities of daily living. Diuretic doses fluctuate at very high levels. They require intensive management and surveillance for compliance to therapy.

Profile 5 is exercise intolerant group. They are comfortable at rest and with activities of daily life, but unable to engage in any other activity and are mostly home bound. They have only marginal changes in nutritional status and organ function.

Profile 6 is exertion limited, without evidence of fluid overload. They are comfortable at rest, with activities of daily living and minor activities outside of home. But they develop fatigue after a few minutes of any meaningful activity.

Profile 7 is advanced NYHA class III. This group does not have current or recurrent episodes of unstable fluid balance. They live comfortably with meaningful activity limited to mild physical exertion.

Modifier profiles as mentioned earlier are TCS with temporary circulatory support in hospital, A with arrhythmia including frequent ICD shocks or external defibrillator shocks, and FF or Frequent Flyer requiring frequent emergency visits, hospitalization for diuretics or temporary intravenous vasoactive therapy.

Various treatment strategies for patients with an INTERMACS I profile has been reviewed in another article [2]. The strategies reviewed were intra-aortic balloon pump (IABP), Impella 2.5 and 5.0, TandemHeart, venoarterial extracorporeal membrane oxygenation (VA ECMO) and CentriMag/BioMedicus Centrifugal Pumps. Selection of device will depend on patient’s clinical status, availability of the device and the time needed to place the device.

Impella 2.5 and TandemHeart can be placed in the cardiac catheterization laboratory. Impella 2.5 may provide only partial unloading of the left ventricle, while TandemHeart needs placement of a transseptal inflow catheter.

References

1. Stevenson LW, Pagani FD, Young JB, Jessup M, Miller L, Kormos RL, Naftel DC, Ulisney K, Desvigne-Nickens P, Kirklin JK. INTERMACS profiles of advanced heart failure: the current picture. J Heart Lung Transplant. 2009 Jun;28(6):535-41. doi: 10.1016/j.healun.2009.02.015. PMID: 19481012.
2. Abu Saleh WK, Jabbari OA, Guha A, Loebe M, Bruckner BA. Treatment strategies for patients with an INTERMACS I profile. Methodist Debakey Cardiovasc J. 2015 Jan-Mar;11(1):4-8. doi: 10.14797/mdcj-11-1-4. PMID: 25793022; PMCID: PMC4362064.