A contemporary training concept in critical care cardiology

Critical care cardiology (CCC) in the modern era is shaped by a multitude of innovative treatment options and an increasingly complex, ageing patient population. Generating high-quality evidence for novel interventions and devices in an intensive care setting is exceptionally challenging. As a result, formulating the best possible therapeutic approach continues to rely predominantly on expert opinion and local standard operating procedures. Fostering the full potential of CCC and the maturation of the next generation of decision-makers in this field calls for an updated training concept, that encompasses the extensive knowledge and skills required to care for critically ill cardiac patients while remaining adaptable to the trainee’s individual career planning and existing educational programs. In the present manuscript, we suggest a standardized training phase in preparation of the first ICU rotation, propose a modular CCC core curriculum, and outline how training components could be conceptualized within three sub-specialization tracks for aspiring cardiac intensivists.


Introduction
Critical care cardiology (CCC) in the modern era is shaped by a multitude of innovative treatment options and an increasingly complex, ageing patient population (Figure 1) (1)(2)(3).Generating high-quality evidence for novel interventions and devices in an intensive care setting is exceptionally challenging.As a result, formulating the best possible therapeutic approach continues to rely predominantly on expert opinion and local standard operating procedures.Fostering the full potential of CCC and the maturation of the next generation of decision-makers in this field calls for an updated training concept, that encompasses the extensive knowledge and skills required to care for critically ill cardiac patients while remaining adaptable to the trainee's individual career planning and existing educational programs (4-7).In the present manuscript, we suggest a standardized training phase in preparation of the first intensive care unit (ICU) rotation, propose a modular CCC core curriculum, and outline how training components could be conceptualized within three subspecialization tracks for aspiring cardiac intensivists.Trainees entering the internal medicine department usually spend 2-3 years primarily working in elective and emergency non-intensive care scenarios on a normal ward, outpatient clinic, or emergency department.Multimorbidity and clinical deterioration, however, may be encountered early on and offer learning opportunities in organ-specific disease management, patient selection for various procedures, ICU admission criteria,

An updated core curriculum for training in critical care cardiology
The 2015 COCATS 4 statement on Critical Care Cardiology Training (8) listed basic competences that should be acquired during a 3-year cardiovascular fellowship program (Level I training).In theory, fellows with a specific interest in CCC could satisfy optional training elements by extending their ICU exposure by 3-6 months during the standard fellowship period (Level II training).However, the definition of these elements remains vague owing to the limited experience with the suggested educational pathway.Advanced training modules for CCC sub-specialization are conceptualized within an additional 1-year fellowship program (Level III training).On behalf of the European Society of Cardiology (ESC), the 2014 Association for Acute CardioVascular Care (ACVC) Core Curriculum (9) also defined main objectives, knowledge, skills, and behaviours/ attitudes across 20 key categories pertaining to acute cardiovascular diseases and other central didactic topics for CCC sub-specialization.To meet these training requirements, the ACVC stipulates at least month-long rotations in anaesthesia, respiratory medicine, and nephrology, in addition to a total of 18 months in a specialized cardiac ICU (6 months during cardiovascular fellowship and 12 months thereafter), as well as 3 months in a general medical ICU.While the curricula proposed by the ACVC, the international Competency Based Training programme in Intensive Care Medicine for Europe (CoBaTrICE) (10), and other committees, provide detailed prerequisites for independently managing (cardiac) ICU patients, there are no widely accepted, comprehensive standard curricula specifying how CCC training elements can be tailored to the various stages of a fellow's career.
In this chapter, we propose three sets of core training components (Tables 1-3), that have been compiled based on the abovementioned guideline recommendations, local training curricula at the authors respective institutions, and the collective opinion of CCC program directors, consultant critical care cardiologists, and cardiovascular fellows currently pursuing CCC training.While there is undoubtedly some overlap between the suggested categories, Tables 1-3 attempt to distinguish core elements of patient care, medical knowledge, practical skillset, competences in systems of care, and professionalism within basic level CCC training (Table 1), contrasting them with core competences in general intensive care medicine (Table 2), and advanced-level CCC training (Table 3).
Table 1 outlines competences that are needed for the trainee's first integration into a cardiac ICU team, representing the initial point of contact with critically ill cardiac patients.Irrespective of their chosen sub-specialty, these core CCC training elements are relevant to all cardiovascular fellows for gaining a full understanding of cardiac emergency care.Table 2 depicts a broader set of core competences in intensive care medicine, focussing on the management of a greater spectrum of acute medical illnesses, trauma, and post-operative care as well as a broader practical skillset and leadership qualities essential for assuming responsibility for patients in a general (surgical or medical) intensive care setting.Lastly, specific training elements for specialization in CCC are presented in Table 3.This set of core training components is incomplete by nature, and the allocation of individual elements warrants further discussion.Nevertheless, the suggested framework may function as a handrail for the development of CCC sub-specialization programs and for cardiovascular and intensive care medicine fellows aspiring to advance in this direction.
Structured assessment of the trainee's clinical performance is essential to boost compliance with educational benchmarks and ensure the highest standards of training and professional development.Personal evaluation should also consider scientific achievements and continued assessment of quality of care after specialization.Beyond that, the need for quality assessment extends to the specialization program itself.Intensive care societies and program supervisors should strive for establishing key performance indicators, such as the number of training positions per year, the number of graduates per year, dropout rate, and measures of flexibility, as well as indicators of institutional conditions, that help identify the need for structural optimization, and improve comparability and measurability of training outcomes on a national/international level.

Sub-specialization pathways and institutional preconditions
The challenge of defining training targets is not the only issue at hand.Educational guideline committees and program supervisors must also navigate the delicate balance between incorporating the evolving skillset and knowledge in CCC and minimizing specialization durations.Inspired by training pathways at the Ludwig-Maximilians-University (LMU) hospital and other international accreditation tracks, we propose three adaptable models for sub-specialization in CCC (Figure 3) in the following section (6,(11)(12)(13).
Models 1 and 2 are based on completion of a fellowship in general cardiovascular medicine including at least 6 months of ICU training, which reflects the application requirements for CCC sub-specialization set forth by the ACVC.In conjunction with the knowledge acquired during rotations in cardiac imaging, electrophysiology, and to the catheterization laboratory, the content of Table 1 represents key milestones for the cardiovascular fellow's integration into the cardiac ICU roster as a junior team member.For example, trainees must gain a common understanding of cardiac interventions that enables them to systematically screen for and manage complications on a basic level (5,14).Also, the hemodynamic principles of cardiogenic shock along with treatment concepts and underlying diseases, as well as general handling of mechanical circulatory support (MCS) devices are nowadays core elements of training in cardiovascular medicine (14).By contrast, the in-depth knowledge on indications and risks of interventional cardiac procedures, such as emergent coronary interventions, transcatheter aortic valve replacement (TAVR), interventional mitral valve repair, mechanical thrombectomy, implantation of transcatheter closure devices, and ablation of ventricular tachycardias, that are required for decision-making in high-risk patients with hemodynamic instability go beyond what can be expected from early career fellows (15)(16)(17)(18)(19)(20).Similarly, comprehensive management of cardiogenic shock patients including advanced understanding of hemodynamics and device-based treatment options requires a profound familiarity with current evidence on MCS and an advanced skillset for emergent troubleshooting in case of deterioration or device-associated complications (21)(22)(23).Models 1 and 2 envision the highest level of qualification (Table 3) to be acquired during an additional 12-month (Model 1) or 6-month (Model 2) cardiac ICU rotation as part of the CCC sub-specialization program.

Medical knowledge and skillset
Pathophysiology, diagnostic criteria, and basic treatment options of cardiogenic shock and associated syndromes depending on different underlying aetiologies: - The concept of Model 1 further allows for a 6-month rotation in a surgical and neurologic ICU, respectively, to extend the trainee's general intensive care knowledge and skillset (Table 2).By contrast, formal training time in a general ICU according to Model 2 would be an 18-month period followed by 6 months of time dedicated to the cardiac ICU.When the 24-month sub-specialization program is completed successfully, trainees should have gained the knowledge and experience needed to act independently as a consultant cardiac intensivist and assume a leadership role within the multidisciplinary cardiac ICU team.In theory, programs adopting Models 1 or 2 could integrate advanced CCC training content (Table 3) with other advanced fellowship programs, e.g., interventional cardiology or heart failure (24).Compared to CCC, heart failure sub-specialization training typically covers additional aspects of long-term patient management, such as evaluation for heart transplantation or ventricular assist devices, and long-term follow-up.Combining training in CCC and heart failure could leverage the significant overlap in theoretical knowledge and practical skillset between these sub-specialities while strengthening the candidate's abilities to develop individual treatment concepts for the acute, intermediate, and chronic phase.
The structure of Model 3 differs from Models 1 and 2 regarding the basic clinical training that precedes sub-specialization in CCC.This pathway features a fellowship in general intensive care medicine, which is often designed in conjunction with training in anaesthesiology and pulmonary medicine, followed by 24 months of time dedicated to sub-specialization in CCC.For example, the current stage 1 postgraduate program in intensive care medicine in the United Kingdom spans a total of 4 years subdivided into training blocks in anaesthesiology, internal medicine, and emergency care (25).While this type of initial clinical exposure strengthens core qualifications in intensive care such as endotracheal intubation and ventilation management (Table 2, elements of Table 1), integrating the content of general cardiology training, which is indispensable for managing cardiac ICU patients, is more challenging.Within their internal medical rotations, trainees should focus on acquiring basic knowledge on the management of patients with structural heart disease and arrhythmias.Working in emergency care and in cardiac anaesthesiology provides learning opportunities about acute cardiovascular illnesses and treatment algorithms and could further improve the fellow's ability to assess arrhythmias and perform

Procedural skills
Insertion of arterial and central venous lines including large-bore catheters for renal replacement therapy transthoracic and transoesophageal echocardiography.Program directors should encourage fellows interested in CCC to seek mentorship from within the cardiovascular department and engage in extra-curricular interdisciplinary seminars.Nonetheless, sub-specialization programs designed for candidates holding board certification in intensive care medicine must be adaptable to accommodate the trainee's individual level of experience in the field of cardiovascular medicine.Model 3 suggests a minimum of 24 months spent in the cardiac ICU, which may be complemented by rotations to the catheterization laboratory or heart failure unit.This approach could allow for a personalized roadmap leading to the acquisition of core competences in basic and advanced CCC (Table 3, elements of Table 1).
All three models provide a framework for integrating the extensive training content into personalized sub-specialization tracks, which potentially allow for interruption of training, rotations/transitions to non-tertiary institutions, and hybridization with other sub-specialization programs.Generally, many crucial aspects of training are contingent on team composition and organization of the CCC program  established by the teaching institution.To ensure patient safety and efficacy of training, CCC sub-specialization programs should be situated in accredited tertiary hospitals and overseen by an experienced cardiac intensivist with the requisite national teaching qualification.Integrating specialists in interventional cardiology, cardiac surgery, electrophysiology, cardiac imaging, microbiology, and pharmacology into recurrent meetings and cardiac ICU rounds presents trainees with opportunities to gain a more comprehensive understanding of multidisciplinary treatment concepts and liaise with experts to enhance their skillset.By promoting scientific endeavours, institutions will contribute to academic progress and foster evidence-based medicine as well as lifelong learning.

Medical knowledge and skillset
In-depth knowledge on pathophysiology, diagnostic criteria, differential diagnoses, advanced treatment options, and outcomes of structural heart diseases and cardiomyopathies In-depth knowledge on pathophysiology, diagnostic criteria, differential diagnoses, advanced treatment options, and outcomes of primary arrhythmic disorders In-depth knowledge on pathophysiology, diagnostic criteria, differential diagnoses, advanced treatment options, and outcomes of left-ventricular, right-ventricular, and biventricular cardiogenic shock, associated syndromes, and underlying aetiologies Pathophysiology, diagnostic criteria, treatment options, and outcomes of cardiogenic shock and other critical care scenarios in patients with inherited heart diseases (i.e.hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, Long-QT-syndrome) Pathophysiology, diagnostic criteria, treatment options, and outcomes of cardiogenic shock and other critical care scenarios in special patient populations (i.e.HIV-positive patients, pregnant women, patients after heart transplantation, patients with left ventricular assist device, pulmonary hypertension, Takotsubo-cardiomyopathy, oncologic patients) In-depth knowledge of indications, contraindications, and associated risks of the full spectrum of interventional cardiac treatment options in acute high-risk settings Indications, contraindications, and associated risks of mechanical circulatory support for patients in advanced/refractory cardiogenic shock or cardiac arrest, i.
Cardiovascular fellows must be prepared for their first intensive care training phase in the best possible way during the preceding internal medicine/cardiovascular training program.Our exemplary proposal for a standardized pre-intensive care unit (pre-ICU) training comprises basic cardiovascular training elements with an intermediate period of focused practical skill acquisition and off-patient theoretical ICU preparation, leading up to the first supervised phases of intensive care training (Figure 2).Although many institutions may already have a pre-ICU training concept in place, we advocate for including standard prerequisites for a first ICU rotation into a comprehensive CCC training model.

FIGURE 1
FIGURE 1Challenges of contemporary critical care cardiology.

FIGURE 2
FIGURE 2Preparation for critical care training.ALS, advanced life support; CICU, cardiac intensive care unit; CT, computed tomography; ICU, intensive care unit.
Acute myocardial infarction and potential mechanical complications -Acute decompensated heart failure -Fulminant myocarditis -Acute decompensated valvular diseases -Pericardial tamponade -High-risk pulmonary embolism -Pulmonary hypertension -Aortic dissection -Acute arrhythmias Pathophysiology, diagnostic criteria, basic treatment options, and outcomes in patients with fulminant infective endocarditis Clinical pharmacology focussing on indications, contraindications, pharmacodynamics, and associated risks of: -Antiarrhythmic medications -Vasoactive/inotropic medications, calcium-sensitizers -Anticoagulant/antiplatelet/fibrinolytic medications -Antihypertensive medications including agents used for pulmonary hypertension -Heart failure medication -Diuretics -Sedatives, analgesics, and neuromuscular blocking agents -Antimicrobial agents Basic understanding of indications, contraindications, and associated risks of interventional and surgical cardiac procedures: -Electrophysiological procedures for supraventricular/ventricular tachycardias -Percutaneous coronary interventions, chronic total occlusion PCI, bypass surgery -Surgical treatment of mechanical complications -Ventricular assist device implantation -Transcatheter aortic valve replacement, surgical valve replacement/reconstruction -Aortic surgery -Transcatheter tricuspid/mitral valve reconstruction/replacement, surgical replacement/reconstruction of atrio-ventricular valves -Transcatheter left atrial appendage occluder implantation -Transcatheter closure device implantation for inter-ventricular/inter-atrial shunts Indication for heart transplantation, basic understanding of immunosuppressive treatment Assessment and general management of post-operative patients Pathophysiology, diagnostic criteria, differential diagnoses, basic treatment options, and outcomes of acute neurologic disorders Pathophysiology, diagnostic criteria, differential diagnoses, basic treatment options, and outcomes of acute renal, acid-base, and electrolyte disorders Pathophysiology, diagnostic criteria, differential diagnoses, basic treatment options, and outcomes of acute gastrointestinal disorders Detection and management of peripheral and abdominal compartment syndromes Patient care Structured assessment of medical history and physical examination in an intensive care setting Basic assessment of hemodynamic instability and respiratory dysfunction Performing advanced cardiac life support according to standard algorithms Basic understanding of post-resuscitation care Understanding of emergency antiarrhythmic treatment options Indication and interpretation of non-invasive and invasive hemodynamic monitoring Indication and interpretation of laboratory testing including blood gas analysis Management of hypertensive emergency/urgency Indication and interpretation of radiographic imaging in liaison with imaging specialists Indication for and basic interpretation of diagnostic left/right heart catheterization Sedation management, analgesia, and neuromonitoring Comprehensive fluid management Management of bleeding or thromboembolic events Management of hyperthermia, infection, and sepsis in liaison with microbiology specialists Management of acid-base disorders Comprehensive management of nutrition Basic understanding of indication, contraindication, and associated risks of pharmacological and mechanical circulatory support options Indication, contraindication, and associated risks of non-invasive and invasive respiratory support, basic weaning algorithms, indication of tracheostomy Diagnostic criteria and management of acute kidney injury, indications, contraindications, and associated risks of renal replacement therapy Prophylaxis and basic management of bleeding and thromboembolic complications Management of multimorbid and elderly patients Understanding principles of palliative care (continued) Performing cardioversion, defibrillation, and ventricular overdrive pacing Transvenous pacemaker insertion, performing transthoracic cardiac pacing Performing point-of-care echocardiography Echocardiographic assessment of ventricular function, valvular function, and pericardial effusion Basic sonographic assessment of vascular access sites, lungs, pleura, abdominal organs, and free abdominal fluid Safe administration of blood products according to standard algorithms Performing endotracheal intubation Performing thoracocentesis and paracentesis Placement of nasogastric tube Obtaining appropriate microbiological samples Performing basic vascular ultrasound Transportation of stable patients outside the cardiac ICU System of care competences Understanding ICU admission criteria Working in a multidisciplinary environment Participation in M&M conferences Participation in quality of care and safety training Participation in institutional infection control and isolation training Professionalism Respectful interaction with all ICU team members Demonstrating commitment to high-quality care Self-reflection regarding the limitations of own knowledge and skill Prioritizing and organizing clinical responsibilities Performing adequate documentation Communicating goals of care to patient and family of different backgrounds Sensitivity to patient's wishes and spiritual/cultural background, particularly in end-of-life decisions Obtaining informed consent Respecting the patient's privacy and autonomy Addressing psychosocial issues of patients and families Understanding ethical/legal implications of withdrawal of care Engaging in continuous self-directed learning through seminars, web-based/simulation-based training programs, and teaching sessions embedded in scientific conferences ICU, intensive care unit; M&M, morbidity and mortality; PCI, percutaneous coronary intervention.
Advanced assessment and management of post-operative patients Pathophysiology, diagnostic criteria, hemodynamic implications, differential diagnoses, treatment options, and outcomes of anaphylactic, septic, hypovolemic, haemorrhagic, and obstructive shock Pathophysiology, diagnostic criteria, treatment options, and outcomes of multi-organ dysfunction Pathophysiology, diagnostic criteria, differential diagnoses, treatment options, and outcomes of acute respiratory disorders; indications, contraindications, and associated risks of VV-ECMO therapy Pathophysiology, diagnostic criteria, differential diagnoses, treatment options, and outcomes of acute endocrine disorders Pathophysiology, diagnostic criteria, differential diagnoses, treatment options, and outcomes of acute intoxication Pathophysiology, diagnostic criteria, differential diagnoses, treatment options, and outcomes of acute peripartum complications Assessment and general management of trauma patients Patient care Advanced management of resuscitation Advanced circulatory management, optimization of preload and afterload using different medical options, balanced fluid management, diuretics, and renal replacement therapy Interpretation of complex electrocardiography findings Advanced management of respiratory support including different ventilation modalities and (prolonged) weaning algorithms Advanced anti-microbial management, antibiotic stewardship, particularly in patients with intrinsic or acquired immunodeficiencies Integrating multiple imaging modalities into clinical context Management of high-volume fluid and blood transfusions and associated risks Interpretation of brain death diagnostics, assessment of organ donation criteria Participation in multidisciplinary withdrawal-of-care decisions Advanced management and prevention of pain and psychological distress Procedural skills Performing advanced thoracic ultrasound Performing advanced abdominal ultrasound Performing lumbar puncture Performing tracheotomy Performing bedside fiberoptic laryngotracheobronchoscopy System of care competences Engaging in clinical consultation Coordinating referrals and patient triage Management of retrieval and transfer of ICU patients from other units/hospitals Understanding ICU discharge criteria Engaging in teaching activity for junior fellows Critical application of (inter)national and local guidelines and protocols Professionalism Assuming a leadership role and striving for holistic patient care Promoting effective multidisciplinary team-working Communication of complex case summaries to team members and other health care professionals Implementation of new guidelines and scientific papers into clinical practice Identifying potential risks for ICU staff and promoting adequate safety measures Giving structured feedback to ICU team members Establishing a constructive culture of dealing with medical errors Evaluating cost-effectiveness of advanced treatment options Participation in international conferences ICU, intensive care unit; VV-ECMO, veno-venous extracorporeal membrane oxygenation.
implications, contraindications, and associated risks of different LV-venting modalities during VA-ECMO therapy Assessment and management of patients admitted to the cardiac ICU after extracorporeal cardiopulmonary resuscitation Patient care Assuming leadership role during cardiopulmonary resuscitation and integrating emergency diagnostics to formulate management plan Management of patients receiving complex interventional procedures including coronary interventions, valvular interventions, and device implantation Detection and management of multi-organ failure Indication and interpretation of advanced hemodynamic monitoring (i.e.PICCO, thermodilution) Indication for and comprehensive interpretation of diagnostic left-and right heart catheterization as well as various radiographic imaging modalities Advanced management of patients receiving MCS devices including VA-ECMO, Tandem-Heart, IABP, Impella Management of patients in advanced heart failure stages including eligibility criteria for left ventricular assist device implantation and high-urgency listing for heart transplantation Emergency assessment, post-operative care, and complication management of patients with durable left ventricular devices Advanced post-resuscitation care including targeted temperature management Procedural skills Performing advanced point-of-care echocardiography Performing bedside transoesophageal echocardiography Performing advanced vascular ultrasound Performing pericardiocentesis Comprehensive assessment of arrhythmias recorded by implantable cardiac devices, function assessment and adjustment of the settings of bradycardia pacemakers as well as anti-tachycardic function of implantable cardioverter defibrillators Cannulation, setup, maintenance, and decannulation of VA-ECMO and Tandem-Heart devices Insertion, maintenance, and explantation of IABP and Impella devices (excluding surgical implantation and explantation of Impella 5.0 and 5.5) System of care competences Coordinating and leading multidisciplinary daily rounds Coordinating and supervising intra-and interhospital transfers of cardiac ICU patients Initiating and moderating M&M conferences Assessment of mortality and other relevant outcome variables using standard risk prediction models and (inter)national registries Professionalism Gradually assuming responsibility for the full spectrum of CCC patients Promoting efficiency and effectiveness of patient care within the CCC team Shared decision making with patients, families, and other health care professionals Engaging in teaching and continued scholarly activity IABP, intra-aortic balloon pump; ICU, intensive care unit; M&M, morbidity and mortality; PCI, percutaneous coronary intervention; PICCO, pulse index continuous cardiac output; VA-ECMO, veno-arterial extracorporeal membrane oxygenation.Binzenhöfer et al. 10.3389/fcvm.2024.1351633Frontiers in Cardiovascular Medicine 08 frontiersin.orgConclusion To keep pace with the rapidly changing field of CCC, intensive care societies should establish an updated training concept, that encompasses core training elements spanning all career stages, different educational pathways, and formal institutional standards.Harmonizing regional training models into a comprehensive educational framework can provide valuable guidance for program directors and help fulfilling the needs of future critical care cardiologists.Ultimately, the versatility and holistic nature of training will play a pivotal role in shaping the success of the next generation of experts in the field as they work toward enhancing patient safety and achieving favourable outcomes.

TABLE 1
Basic level core competences in critical care cardiology.

TABLE 2
Core competences in general intensive care medicine.

TABLE 3
Advanced level core competences in critical care cardiology.