INTERMACS Profiles
Risk stratification system for patients with advanced heart failure being considered for mechanical circulatory support (MCS) devices.
INTERMACS Profile Selection
NYHA Functional Class
Hemodynamic Parameters
Laboratory Values
Clinical Parameters
Comorbidities
History of diabetes mellitus
History of chronic obstructive pulmonary disease
History of renal dysfunction or dialysis
History of previous cardiac surgery
History of ventricular arrhythmias
INTERMACS Profile Information
Patients with critical cardiogenic shock despite escalating inotropic support, with evidence of end-organ dysfunction.
Patients with declining function despite inotropic support, with repeated hospitalizations or inability to be weaned from inotropes.
Patients with stable blood pressure and organ function while on continuous inotropic support, but unable to be weaned.
Patients with recurrent episodes of advanced heart failure despite attempts to optimize medical therapy.
Patients who are comfortable at rest but have symptoms with any physical activity, essentially housebound.
Patients who are comfortable at rest and with activities of daily living but have symptoms with mild exertion.
Patients with advanced NYHA Class III symptoms who are not inotrope dependent.
INTERMACS Profiles
The INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) Profiles is a standardized classification system used to stratify risk in patients with advanced heart failure who are being considered for mechanical circulatory support (MCS) devices such as left ventricular assist devices (LVADs). This system helps clinicians assess patient severity, guide treatment decisions, and predict outcomes.
Profile Classification System
The INTERMACS system divides patients into seven profiles based on their clinical status and hemodynamic stability:
| Profile | Description | Mnemonic | Clinical Status |
|---|---|---|---|
| Profile 1 | Critical Cardiogenic Shock | "Crash and burn" | Critical cardiogenic shock despite escalating inotropic support |
| Profile 2 | Progressive Decline | "Sliding on inotropes" | Declining function despite inotropic support |
| Profile 3 | Stable but Inotrope Dependent | "Dependent stability" | Stable on inotropes but unable to be weaned |
| Profile 4 | Recurrent Advanced Heart Failure | "Frequent flyer" | Recurrent episodes of advanced heart failure |
| Profile 5 | Exertion Intolerant | "Housebound" | Comfortable at rest but symptoms with any activity |
| Profile 6 | Exertion Limited | "Walking wounded" | Comfortable at rest and with ADLs but symptoms with mild exertion |
| Profile 7 | Advanced NYHA Class III | "Placeholder" | Advanced NYHA Class III symptoms, not inotrope dependent |
Clinical Implications by Profile
Profile 1: Critical Cardiogenic Shock
- Mortality Risk: 30-50% at 1 year without intervention
- Clinical Features:
- Critical cardiogenic shock despite escalating inotropic support
- Evidence of end-organ dysfunction
- Hemodynamic instability
- Requires immediate intervention
- Management:
- Emergency MCS consideration
- Bridge to decision or destination therapy
- High mortality risk without intervention
- Consider temporary mechanical support
Profile 2: Progressive Decline
- Mortality Risk: 20-30% at 1 year
- Clinical Features:
- Declining function despite inotropic support
- Repeated hospitalizations
- Inability to be weaned from inotropes
- Progressive end-organ dysfunction
- Management:
- Urgent MCS evaluation
- Bridge to transplant or destination therapy
- Rapid clinical deterioration expected
- Consider early intervention
Profile 3: Stable but Inotrope Dependent
- Mortality Risk: 15-25% at 1 year
- Clinical Features:
- Stable blood pressure and organ function
- Continuous inotropic support required
- Unable to be weaned from inotropes
- Stable but high long-term risk
- Management:
- Elective MCS evaluation
- Bridge to transplant preferred
- Stable on inotropes but high long-term risk
- Consider timing of intervention
Profile 4: Recurrent Advanced Heart Failure
- Mortality Risk: 10-20% at 1 year
- Clinical Features:
- Recurrent episodes of advanced heart failure
- Multiple hospitalizations
- Failed attempts to optimize medical therapy
- Unpredictable clinical course
- Management:
- Consider MCS evaluation
- Bridge to transplant or destination therapy
- Recurrent decompensations
- Consider preventive intervention
Profile 5: Exertion Intolerant
- Mortality Risk: 5-15% at 1 year
- Clinical Features:
- Comfortable at rest
- Symptoms with any physical activity
- Essentially housebound
- Limited functional capacity
- Management:
- Consider MCS evaluation
- Bridge to transplant preferred
- Limited functional capacity
- Quality of life considerations
Profile 6: Exertion Limited
- Mortality Risk: 5-10% at 1 year
- Clinical Features:
- Comfortable at rest and with activities of daily living
- Symptoms with mild exertion
- Some functional capacity preserved
- Moderate limitation
- Management:
- Consider MCS evaluation
- Bridge to transplant preferred
- Some functional capacity preserved
- Timing of intervention important
Profile 7: Advanced NYHA Class III
- Mortality Risk: 3-8% at 1 year
- Clinical Features:
- Advanced NYHA Class III symptoms
- Not inotrope dependent
- Limited symptoms but advanced disease
- Stable but progressive
- Management:
- Consider MCS evaluation
- Bridge to transplant preferred
- Limited symptoms but advanced disease
- Preventive intervention consideration
Clinical Applications
The INTERMACS Profiles are used for:
- Risk stratification: Identifying patients at high risk of mortality
- Timing of intervention: Determining optimal timing for MCS
- Device selection: Guiding choice of MCS device
- Outcome prediction: Estimating survival and complications
- Resource allocation: Prioritizing patients for transplantation
- Clinical trials: Patient stratification and inclusion criteria
Integration with Hemodynamic Assessment
The INTERMACS Profiles should be used in conjunction with hemodynamic assessment:
- Cardiac Index: < 2.0 L/min/m² indicates severe impairment
- Pulmonary Capillary Wedge Pressure: > 20 mmHg indicates elevated filling pressures
- Right Atrial Pressure: > 15 mmHg indicates right heart dysfunction
- Pulmonary Vascular Resistance: > 3 Wood units indicates pulmonary hypertension
Laboratory Assessment
Key laboratory parameters for MCS evaluation:
- Renal Function: Creatinine, eGFR
- Hepatic Function: Bilirubin, ALT, INR
- Hematologic: Platelet count, hemoglobin
- Nutritional: Albumin, prealbumin
Comorbidity Assessment
Important comorbidities that affect MCS candidacy:
- Diabetes: Affects wound healing and infection risk
- COPD: May limit functional improvement
- Renal Dysfunction: May require combined heart-kidney transplant
- Previous Cardiac Surgery: Increases surgical complexity
- Ventricular Arrhythmias: May require additional device therapy
Validation and Performance
The INTERMACS Profiles have been extensively validated:
- Discrimination: Excellent ability to distinguish between patients with different outcomes
- Calibration: Well-calibrated across different populations
- External validation: Validated in multiple international registries
- Clinical utility: Shown to improve clinical decision-making
Advantages of the INTERMACS System
- Standardized: Provides consistent classification across centers
- Comprehensive: Incorporates multiple clinical parameters
- Prognostic: Predicts outcomes and complications
- Clinical utility: Guides treatment decisions
- Registry-based: Continuously updated with real-world data
Limitations and Considerations
The INTERMACS system has several limitations:
- Dynamic nature: Profiles can change over time
- Subjective assessment: Relies on clinical judgment
- Population-specific: May need adjustment for different populations
- Not a treatment guide alone: Should be used with clinical judgment
- Evolving therapies: May not reflect benefits of newer treatments
Integration with Clinical Practice
The INTERMACS Profiles should be used as part of a comprehensive clinical assessment:
- Combine with hemodynamic assessment
- Consider patient preferences and values
- Regular reassessment as clinical status changes
- Use in shared decision-making with patients and families
- Follow institutional protocols and guidelines
- Consider local population characteristics
Comparison with Other Risk Models
The INTERMACS Profiles offer several advantages:
- MCS-specific: Designed specifically for mechanical circulatory support
- Registry-based: Developed from large, real-world registries
- Comprehensive: Incorporates multiple clinical domains
- Prognostic: Predicts both survival and complications
- Clinical utility: Guides timing and type of intervention
The INTERMACS Profiles continue to be a fundamental tool in the evaluation and management of patients with advanced heart failure being considered for mechanical circulatory support, providing clinicians with objective risk stratification to guide treatment decisions and improve outcomes.
References
- Stevenson LW, Pagani FD, Young JB, et al. INTERMACS profiles of advanced heart failure: the current picture. J Heart Lung Transplant. 2009;28(6):535-541.
- Kirklin JK, Naftel DC, Pagani FD, et al. Seventh INTERMACS annual report: 15,000 patients and counting. J Heart Lung Transplant. 2015;34(12):1495-1504.
- Kirklin JK, Naftel DC, Kormos RL, et al. The Fourth INTERMACS Annual Report: 4,000 implants and counting. J Heart Lung Transplant. 2012;31(2):117-126.
- Kirklin JK, Naftel DC, Stevenson LW, et al. INTERMACS database for durable devices for circulatory support: first annual report. J Heart Lung Transplant. 2008;27(10):1065-1072.
- Feldman D, Pamboukian SV, Teuteberg JJ, et al. The 2013 International Society for Heart and Lung Transplantation Guidelines for mechanical circulatory support: executive summary. J Heart Lung Transplant. 2013;32(2):157-187.
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