Energy and Momentum in the Diagnosis and Management of Cardiogenic Shock

As I write this, I am recovering from a red eye flight after four days in San Diego at the 2018 Society for Cardiovascular Angiography and Interventions (SCAI) Scientific Sessions. By all indications the meeting was an astounding success, with the highest attendance of physicians, industry colleagues and fellows-in-training, and a jam-packed yet clearly organized flow of educational sessions for everyone.

From my standpoint, one of my major clinical interests is the diagnosis and management of cardiogenic shock. Having written one of the earliest reviews on percutaneous ventricular assist devices (PVAD) in Circulation in 2011, and co-chaired with Dr. Charanjit Rihal the multi-society consensus document on the use of these technologies in 2015, the field of cardiogenic shock may finally be poised to see significant growth and real clinical application and impact. Indeed, 2017 saw the publication of an update statement by the American Heart Association, chaired by Dr. Sean van Diepen, and the launch of the National CSI Initiative, a prospective registry of one proposed clinical algorithm of cardiogenic shock management, driven by chief architect Dr. William O’Neill.

There are three specific areas where we need better understanding and clinical care in cardiogenic shock. All were addressed to some extent at the meeting, with a palpable buzz around cardiogenic shock and next steps seemingly in sight. First, we need to better define cardiogenic shock and recognize its earliest stages as well as when the physiology has advanced to later, more extreme stages. Second, we need to better determine how to treat the condition, both in in terms of supportive care such as drips and devices, and in terms of primary interventions (such as revascularization in the case of acute myocardial infarction, for example). And, finally, we need to determine the ideal processes, including systems of care, members of a team-based approach, and clinical algorithms for both initial management and escalation.

From a definition standpoint, SCAI formally announced progress on a SCAI and Heart Failure Society of America (HFSA) consensus document on Defining the Spectrum of Cardiogenic Shock. This document, which I am honored to chair with Drs. David Baran and Cindy Grines, has already convened multiple times including a face-to-face two hour session at the SCAI meeting. Goals are to define the spectrum of cardiogenic shock and provide a consensus definition to guide clinical care, provide entry points for clinical algorithms, and to be used for both future research protocols and retrospectively to re-evaluate existing data and registries. The writing group includes representation from prominent interventional cardiologists, cardiothoracic surgeons, heart failure specialists, critical care physicians, hemodynamicists, emergency room physicians, and nursing coordinators, to allow for all viewpoints, the various entry points for cardiogenic shock in the hospital and community, and to aid in multi-societal endorsements prior to publication.

From a treatment standpoint, more data came out regarding primary revascularization in acute myocardial infarction with cardiogenic shock. A late-breaking-clinical-trial authored by Dr. Andrew McNiece from Canada evaluated multi-vessel versus culprit-vessel only percutaneous coronary intervention (PCI) in cardiogenic shock. IABP was used in a subset of patients, but PVADs were not utilized. Overall mortality was in the 30% range, indicating perhaps a slightly less morbid or earlier stage of cardiogenic shock than previous studies in this space. The authors found that culprit vessel PCI was favored with a significant reduction in mortality, driven primarily by multi-vessel PCI revascularization risk in patients with non-culprit proximal left anterior descending (LAD) PCI. Although the authors felt this lends further support to a culprit only PCI strategy, it remains unclear whether a higher risk population (at later stages of shock) and/or a higher use of PVADs would have changed the outcome. This highlights the need for the aforementioned consensus document, such that trials of cardiogenic shock can be compared to one another, improving understanding and generalizability.

Finally, in terms of real-world treatment strategies, team-based approach and systems of care, the National CSI Initiative continues to enroll centers and patients, based on a strategy that is showing excellent survival over 70% in the Detroit area. It was reported at SCAI scientific sessions that roughly 30 centers have now become part of the initiative. The protocol prioritizes prompt PVAD support pre-PCI, early use of right heart catheterization, and the use of hemodynamics and support devices to rapidly de-escalate vasopressors and inotropes, all areas that have shown in observational retrospective evidence to potentially improve outcomes. While this makes sense, there remains much controversy in this area based on the lack of randomized controlled data.

To address this, SCAI is holding a formal program in Boston on Friday evening and all day Saturday, October 12–13, 2018, chaired by Drs. Emmanouil Brilakis and myself and bringing together a world-renowned faculty. At dinner the evening before, several hospital-based clinical algorithms will be revealed and deliberated, to help build consensus on the best real-world approach in the current evidentiary landscape. The Saturday program will start with a pharmacotherapy session over breakfast, followed by rapid didactic sessions with group discussions. Break-out sessions for nurses, techs and physicians who work in the emergency room, cardiac catheterization laboratory and critical care units will allow a deeper dive into the management of shock and PVADs in these settings. A one-hour round-robin simulator station hands-on experience will allow better understanding of the various devices used in cardiogenic shock, including tips and tricks and advanced troubleshooting. More didactic sessions end the day, with plenty of time for consensus-building. As the only society-sponsored course on cardiogenic shock, with multi-industry grant support and full CME offering, this course should help both in terms of the optimal team-based approach and clinical algorithms to approach the patient regardless of where they present, and at what stage they present in.

Taken together, the excitement, focus and offerings within the field of cardiogenic shock that occurred at SCAI scientific sessions was quite nice to see, and a palpable buzz was noted throughout the four days as the above developments unfolded. These new data, educational offerings, and consensus documents should address each of the three areas of deficiency in the diagnosis and management of cardiogenic shock and hopefully move the needle on mortality in this population of patients. I’m sure the best is yet to come, but at least for now it is good to know we are working hard to get there.

Dr. Srihari S. Naidu is the director of the Cardiac Catheterization Laboratories and Hypertrophic Cardiomyopathy Center at Westchester Medical Center. He is an associate professor of medicine at New York Medical College.

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