Structural heart disease (SHD) intervention is the fastest-growing area in cardiology and cardiac surgery. The number of transcatheter procedures has increased from approximately 5000 procedures in 2012 to over 60,000 cases in 2018 in the United States alone ( Fig. 1.1 ). These numbers are set to increase even further as the market expands into lower-risk patients and procedures become more refined. If TAVR is routinely performed in low risk patients, annual case volume may exceed 150,000 patients per year. ,
Training in SHD is evolving, with novel procedures and devices introduced every year.
This handbook of SHD training is a “how-to” practical handbook structure covering clinical pearls of wisdom, pitfalls, and tips and tricks from the experts. We will use the “building-blocks” approach, which breaks down each procedure into component blocks, enabling practitioners to more easily train in new procedures and gain competency.
Structured procedural training
The American College of Cardiology (ACC) framework for established cardiovascular training uses outcomes-based evaluations. Milestones are used to describe progression from early learner status through advanced learning until unsupervised practice is achieved. Minimal recommended procedural volumes in percutaneous coronary intervention (PCI) for both training and maintenance of competency were developed by the ACC due to the relationship between high procedural volumes and low complication rates. Although less evidence exists for a procedure volume–outcome relationship in structural intervention, selected procedures do show a similar relationship. ,
For SHD, the number of mitral interventions, left atrial appendage procedures, and paravalvular leak closures, even in high-volume sites, are small compared with coronary intervention. However, if each procedure is considered a series of steps, many of which are common between structural cases, development of a competency-based framework and maintenance of procedural numbers during training and ongoing practice becomes achievable.
Modular training using the building-blocks approach
In the modular approach, a structural intervention is considered the sum of a series of building blocks. By combining different building blocks, a complete structural procedure is assembled ( Figs. 1.2–1.4 ). Procedural competency can therefore be taught and assessed by component blocks, which remain constant, rather than by procedures, which change over time. These building blocks also provide the foundation for new procedures.
We describe 10 key SHD building blocks. When combined with the cognitive skills of structural intervention and device-specific training, use of these blocks aids training and assessment of competency in SHD intervention.
Cognitive training in structural intervention
In addition to procedural training in each specific building block, parallel training in the complex decision-making essential for structural intervention is required. For structural interventions, preprocedural planning may be as long as the case itself and is equally as important. The access route, potential complications, and bailout plan in the event of a severe complication should be predetermined. This requires understanding of preprocedural anatomic imaging, particularly transthoracic echocardiogram/transesophageal echocardiogram (TTE/TEE) and computed tomography (CT).
Case review with imaging specialists before the intervention are often helpful, particularly for less common procedures and in the early stages of independent practice. This preplanning often avoids complications and ensures that backup equipment and personnel are available if required, for example, for surgical cutdown in the event of unfavorable vascular access.
Three key elements to cognitive training will develop during structural interventional training: cognizant observation (early learning phase), dynamic intraprocedural decision-making (advanced learner), and innovation ( Fig. 1.5 ). In addition to case-by-case examination and discussion, case-based conferences are a good way to increase exposure to complex disease and develop these decision-making skills. Self-directed learning and online education tools also allow case-based review and consultation of evidence-based practice guideline recommendations.
Much of the equipment used in structural intervention is not custom made and was originally designed for other purposes, usually coronary intervention. Catheters and wires therefore need to be measured to ensure they will reach the target, and preplanning will ensure that an appropriate-sized sheath is selected for delivery of the equipment needed. Particularly for vascular occlusion devices, the likely size of the defect will guide the choice of sheath. Although sizes on the manufacturer packaging are a guide, they are not always intuitive. For example, a 6F shuttle sheath (Cook Medical) will fit through an 8.5F Agilis sheath (St. Jude Medical), but a 7F will not. We recommend the use of compatibility tables for advanced planning. These are included in the appendix.
Interdisciplinary learning
Many of the structural intervention techniques were developed in conjunction with other disciplines. Training therefore requires learning from other disciplines, both within cardiology and beyond. For interventional imaging, training in TTE and TEE is required for an understanding of 3D relational anatomy, while training in transseptal puncture may be performed in parallel with electrophysiology trainees. Exposure to pediatric and congenital cardiology allows development of techniques for navigation of peripheral vessels and anomalous connections, while training with cardiothoracic and vascular colleagues allows better understanding of vessel entry and exit options and planning for the prevention and management of complications.
TAVR practice in the United States requires a comprehensive, multidisciplinary approach, and this approach holds true for many structural heart disease procedures. Detailed preoperative assessment, including estimation of patient- and procedure-specific risk, allows choice of appropriate access routes, informed discussion of risk and benefit with patients, and formulation of emergency management plans in the event of serious complications. Training in the cognitive skill set required for these decisions will have begun during core cardiology training, and structural trainees will become familiar with specific considerations for access routes, choice of device, and potential for complications.
Structured training schemes using the building-blocks approach
Training schemes may approach the building blocks in different orders, depending on available opportunities. Each block may be learned in parallel with other blocks. Vascular access (entry and exit) is a common cause of complications, and training in this usually begins during coronary training. Familiarity with closure devices before starting structural training is desirable, but will depend on local opportunity and expertise. Many companies have models that enable practice in deployment of closure devices before using them in the catheter laboratory.
Most structural programs begin after completion of coronary intervention training, and therefore trainees will have gained skills in PCI decision-making, including choice of catheter and catheter manipulation. Training for transseptal puncture may be performed in parallel with trainees in electrophysiology. However, it is important to note that the position of the transseptal puncture is more important during structural procedures, as this will either aid or hinder catheter and device manipulation if it is too high or low, or posterior or anterior.
3D relational anatomy is a more complex skill that is gained with time and experience. Structural interventionalists need to learn to “think in 3D” to guide catheter and wire manipulation. Trainees benefit from cross-discipline training with imaging fellows to develop skills in interpretation of CT of both the heart and peripheral vasculature and TTE and TEE echocardiography. Although the structural interventionalist does not need to learn how to perform a TEE, he or she does need a comprehensive understanding of the images used, particularly during mitral procedures, and how these relate to what is seen on fluoroscopy.
We describe the core building blocks here in brief. Dedicated chapters later in the book will describe specific blocks common to many structural procedures.
