Author: Michael A. Evans, MD – Ann & Robert H. Lurie Children’s Hospital of Chicago, Northwestern Feinberg School of Medicine
A 17-year-old adolescent male with a history of Shone’s complex, depressed ejection fraction of 20% and severe mitral regurgitation is awaiting heart transplantation as an inpatient due to vasoactive dependence and worsening end-organ dysfunction. Over the last two days, he has had increased abdominal pain with emesis and escalation to high flow nasal cannula but remains hemodynamically stable on unchanging doses of epinephrine and milrinone. Which of the following is the MOST appropriate Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) classification for this patient?
Correct!
Wrong!
Question of the Week 335
This patient has shown the “progressive decline” that is characteristic of the Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) 2 classification, as evidenced by worsening end-organ dysfunction (abdominal pain) and by increased respiratory support (high flow nasal cannula) while remaining on two vasoactive agents.
The Pedimacs patient profiles provide a general description of patients that require mechanical circulatory support (MCS) with Ventricular Assist Device(s) (VADs). The patient profile classification is recorded into a registry at the time of VAD implantation as a means of tracking outcomes. Pedimacs classification categories are analogous to Intermacs (Interagency Registry for Mechanically Assisted Circulatory Support) categories in the adult population. The numeric classes correlate between the classification systems. In both instances, patient scoring at time of initiation of MCS is useful to predict prognosis.
Patients classified into the Pedimacs 1 category are in “critical cardiogenic shock” by definition with rapid clinical deterioration. These patients may have life-threatening hypotension or arrhythmias and require escalating doses of vasoactive agents. This patient population often suffers from worsening lactic acidosis. Pedimacs 1 patients require emergent intervention.
Patients classified into the Pedimacs 2 category, such as the patient above, demonstrate a progressive clinical decline in the setting of vasoactive dependence. The decline may be manifested by any type of end-organ dysfunction - such as renal, hepatic, respiratory, cardiac (new arrhythmias), or gastrointestinal dysfunction.
Patients classified into the Pedimacs 3 category are “stable but inotrope dependent” by definition. Patients with temporary MCS devices in place but with failure to wean from these devices are also classified as Pedimacs 3.
Patients classified into the Pedimacs 4 category have “resting symptoms.” Often, a patient may be at home on an oral heart failure regimen and still experience heart failure symptoms at rest, including orthopnea, shortness of breath while performing activities of daily living, gastrointestinal symptoms, or severe edema or ascites.
Patients classified into the Pedimacs 5 category are “exertion intolerant” but comfortable at rest while Pedimacs 6 patients are “exertion limited.” Finally, patients classified into the Pedimacs 7 category are considered to be in the “Advanced NYHA Class 3” classification. They have reasonable comfort with activity at baseline but have experienced prior episodes of decompensated heart failure.
A “current device strategy at time of implant” is also recorded in the registry in order to illustrate reasoning and medical decision-making at the time of VAD implantation. VADs may be placed as a “Bridge to Recovery” when recovery of cardiac function is anticipated. They may also be used as a “Rescue Therapy” when an acute event has occurred in a patient without prior cardiac dysfunction. VADs are also used as a “Bridge to Transplant” when a patient whom has previously been listed for heart transplantation requires mechanical support. Additionally, VADs are used as a “Bridge to Decision” when a potentially-transplant-eligible patient requires MCS but has not been evaluated for transplant eligibility or as a “Destination Therapy” when a patient is not eligible for transplant. A wealth of additional information is recorded in the Pedimacs registry at the time of implantation and can be found in the Society of Thoracic Surgeons Pedimacs Users’ Guide.
Based on the most recent Pedimacs data published in 2020, the most common diagnosis leading to MCS was cardiomyopathy in 58.1% of patients (93.8% had dilated cardiomyopathy). At the time of implantation, 30% of patients were Pedimacs profile 1, 55% were profile 2, 13% were profile 3, and 2% were profiles 4 to 7. Device strategy at time of VAD implantation was a bridge to transplantation in 49.3% of patients, bridge to decision in 38%, bridge to recovery in 7.6%, and destination therapy in 1.3%. Survival of patients on VAD support at 6 months was 74%.
References
1. Version 5.0 STS Pedimacs Users’ Guide Version Date 03/26/2018. Accessed 8/9/2021. https://www.sts.org/sites/default/files/Puf%20documents/Pedimacs_Users_Guide_v5_0_2018_03_26.docx
2. Morales DLS, Adachi I, Peng DM, et al. Fourth Annual Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) Report. Ann Thorac Surg. 2020;110(6):1819-1831. doi:10.1016/j.athoracsur.2020.09.003
The Pedimacs patient profiles provide a general description of patients that require mechanical circulatory support (MCS) with Ventricular Assist Device(s) (VADs). The patient profile classification is recorded into a registry at the time of VAD implantation as a means of tracking outcomes. Pedimacs classification categories are analogous to Intermacs (Interagency Registry for Mechanically Assisted Circulatory Support) categories in the adult population. The numeric classes correlate between the classification systems. In both instances, patient scoring at time of initiation of MCS is useful to predict prognosis.
Patients classified into the Pedimacs 1 category are in “critical cardiogenic shock” by definition with rapid clinical deterioration. These patients may have life-threatening hypotension or arrhythmias and require escalating doses of vasoactive agents. This patient population often suffers from worsening lactic acidosis. Pedimacs 1 patients require emergent intervention.
Patients classified into the Pedimacs 2 category, such as the patient above, demonstrate a progressive clinical decline in the setting of vasoactive dependence. The decline may be manifested by any type of end-organ dysfunction - such as renal, hepatic, respiratory, cardiac (new arrhythmias), or gastrointestinal dysfunction.
Patients classified into the Pedimacs 3 category are “stable but inotrope dependent” by definition. Patients with temporary MCS devices in place but with failure to wean from these devices are also classified as Pedimacs 3.
Patients classified into the Pedimacs 4 category have “resting symptoms.” Often, a patient may be at home on an oral heart failure regimen and still experience heart failure symptoms at rest, including orthopnea, shortness of breath while performing activities of daily living, gastrointestinal symptoms, or severe edema or ascites.
Patients classified into the Pedimacs 5 category are “exertion intolerant” but comfortable at rest while Pedimacs 6 patients are “exertion limited.” Finally, patients classified into the Pedimacs 7 category are considered to be in the “Advanced NYHA Class 3” classification. They have reasonable comfort with activity at baseline but have experienced prior episodes of decompensated heart failure.
A “current device strategy at time of implant” is also recorded in the registry in order to illustrate reasoning and medical decision-making at the time of VAD implantation. VADs may be placed as a “Bridge to Recovery” when recovery of cardiac function is anticipated. They may also be used as a “Rescue Therapy” when an acute event has occurred in a patient without prior cardiac dysfunction. VADs are also used as a “Bridge to Transplant” when a patient whom has previously been listed for heart transplantation requires mechanical support. Additionally, VADs are used as a “Bridge to Decision” when a potentially-transplant-eligible patient requires MCS but has not been evaluated for transplant eligibility or as a “Destination Therapy” when a patient is not eligible for transplant. A wealth of additional information is recorded in the Pedimacs registry at the time of implantation and can be found in the Society of Thoracic Surgeons Pedimacs Users’ Guide.
Based on the most recent Pedimacs data published in 2020, the most common diagnosis leading to MCS was cardiomyopathy in 58.1% of patients (93.8% had dilated cardiomyopathy). At the time of implantation, 30% of patients were Pedimacs profile 1, 55% were profile 2, 13% were profile 3, and 2% were profiles 4 to 7. Device strategy at time of VAD implantation was a bridge to transplantation in 49.3% of patients, bridge to decision in 38%, bridge to recovery in 7.6%, and destination therapy in 1.3%. Survival of patients on VAD support at 6 months was 74%.
References
1. Version 5.0 STS Pedimacs Users’ Guide Version Date 03/26/2018. Accessed 8/9/2021. https://www.sts.org/sites/default/files/Puf%20documents/Pedimacs_Users_Guide_v5_0_2018_03_26.docx
2. Morales DLS, Adachi I, Peng DM, et al. Fourth Annual Pediatric Interagency Registry for Mechanical Circulatory Support (Pedimacs) Report. Ann Thorac Surg. 2020;110(6):1819-1831. doi:10.1016/j.athoracsur.2020.09.003
