Cardiogenic Shock in Older Adults: The Intersection of Geriatric Medicine and Critical Care Cardiology

Cardiogenic shock is a heterogeneous clinical syndrome characterized by systemic hypoperfusion and end-organ dysfunction due to cardiac failure.^1,2 While outcomes for cardiovascular processes such as acute myocardial infarction (AMI) and chronic heart failure have dramatically improved with the advent of percutaneous coronary intervention and drug therapies, similar progress has not been made in cardiogenic shock.^3,4 Short-term mortality remains >40% despite advances in temporary mechanical circulatory support (t-MCS), valvular interventions, and heart transplantation.⁵ While cardiogenic shock describes the final common pathway of diminished cardiac output, hypoperfusion, and maladaptation leading to end-organ failure, there are multiple pathophysiologic mechanisms, including AMI, decompensated heart failure, valvular heart disease, and arrhythmias, that can initiate this hemodynamic spiral. The heterogeneity in underlying cardiac pathology, physiologic adaptation, and patient-level comorbidities contributes to the limited success of therapeutic trials that aim to address cardiogenic shock.

Older adults represent a complex patient subgroup, even in areas of cardiovascular disease with more established evidence than cardiogenic shock.⁶ While chronological age is often used as a surrogate marker for comorbidity burden, cognitive status, physical function, and life expectancy, it fails to capture the biologic complexity of older adults.⁷. Multimorbidity - the coexistence of multiple chronic medical conditions - polypharmacy, geriatric syndrome, and frailty increase with biologic, rather than chronologic, age and more accurately reflect morbidity and mortality outcomes.^7–9 These comorbid conditions can complicate the care of older adults and predispose them to higher risk of bleeding, vascular injury, and organ failure, particularly in the setting of cardiogenic shock.^10–13

Accurate risk assessment is therefore paramount to determine the appropriate treatment strategy but represents a unique challenge in older adults. For patients with cardiogenic shock, this involves assessing baseline frailty, sarcopenia, polypharmacy, cognitive impairment, and functional status.^6,13 However, no such tool has been validated in this critically ill and heterogeneous population. Additionally, most established risk scores were not designed with older adults in mind.¹⁴ Many clinical trials utilize age cut offs to minimize confounders and maximize the likelihood of finding clinical efficacy.¹⁵ Predictive power in this setting is lost and older adults are often labeled as "high-risk" by age alone due to disproportionate weighting of chronologic age.⁶

Outside of early revascularization for AMI cardiogenic shock, little strong randomized clinical data is available to guide individualized therapy selection among patients with cardiogenic shock.^1,5,16 Since older adults are less often included in trials, they are underrepresented in these few studies. With this background, it is unsurprising, that little is known about the efficacy of available therapies in patients aged 65 years and older. Even when the evidence for medical and invasive therapies supports improved survival and functional status, older adults are less likely to be offered those interventions and are more likely to prioritize symptom relief and quality of life than younger patients.^17,18 With limited randomized data to guide decision making, care of cardiogenic shock has thus largely been driven by expert opinion and observational data. The current statement provides much needed guidance to drive care in this high-risk patient population of older adults and focuses on several key themes:

1. Cardiogenic shock carries significant morbidity and mortality at any age, but especially in older adults. Early recognition, even when typical trial or guideline definitions are not met, is essential to initiate timely care.
2. Numerical age fails to capture the complexity of the older patient population, and may limit resource allocation to patients who, aside from their chronological age, are biologically young. Instead, clinicians can utilize objective measures of multimorbidity, polypharmacy, cognitive decline, delirium, and frailty to determine appropriateness of invasive therapies.
3. Objective risk scores unique to older adults need to be developed to assess short and long-term mortality.
4. In the absence of evidence-based therapies, shared decision-making and early palliative care involvement facilitate alignment of patient values and preferences with treatment choices.
5. Future work should focus on understanding risk, improving representation of older adults in trials, and inclusion of meaningful endpoints to older adults, including health related quality of life.

While the scientific statement reviews data for the range of available medical, invasive, and palliative therapeutic strategies that could be employed when facing an older patient with cardiogenic shock, the authors emphasize the importance of only considering these in patients with potential benefit and whose wishes are in line with such a treatment plan. It is essential to discuss the patient's goals and wishes at first encounter and incorporate them with their clinical markers to inform the appropriateness of therapeutic options. Acknowledgement of the significant trade-offs associated with therapeutic approaches is essential. This is one of the most important considerations when caring for older adults and reflects our own clinical practice. The potential benefit of each therapeutic step must be weighed against the possible risks, and then individualized to the clinical scenario and goals of the patient to form a treatment plan through shared decision making. This process is typically repeated several times each day and the clinical course is adjusted accordingly while maintaining a constant line of communication with the patient and family.

The first step in management is prompt initiation of diuretic therapy and inotropes to halt further hemodynamic collapse. In patients willing to undergoing a minor procedure, a pulmonary artery catheter (PAC)- or hemodynamic-guided strategy is preferred to inform titration of diuretics, inotropes, afterload reduction, and the need for t- MCS. A PAC-guided approach provides the best opportunity for hemodynamic profiling, prognostication, and survival.¹⁹ It is important, however, to select patients carefully as PAC use may contribute to delirium and confine to bedrest a patient in whom prolonged immobility can accelerate sarcopenia, frailty, and loss of muscle mass.^13,20 As part of an admission, it's also important to also assess for muscle wasting, discuss baseline cognition and functional status with the patient and family, and evaluate strength to understand baseline frailty, sarcopenia, and disability. While objective risk scores, such as the Hospital Frailty Risk Score and SARC-F (Strength, Assistance Walking, Rise From a Chair, Climb Stairs, and Falls), can be utilized, this is frequently not feasible in the critical care setting.²⁰

Decisions regarding t-MCS, left ventricular assist devices (LVAD), and heart transplantations depend not only on patient factors, but also on local expertise and experience, and so there is no one-size-fits-all approach. A Shock Team with multidisciplinary involvement is imperative in all cardiogenic shock but is especially important in older adults. Involvement of both physician and non-physician expertise, including physical and occupational therapy, nutrition, spiritual services, palliative care and geriatrics, among others, is often helpful to identify pre-hospital functional limitations, clarify ongoing goals of care, and mitigate intensive care unit complications such as delirium and muscle wasting. When caring for older adults with cardiogenic shock, the health care team strives to be proactive and take an all-hands-on-deck approach, knowing that a reactive approach may precipitate decompensation in a patient who is not an optimal candidate for invasive bailout strategies.

Cardiogenic shock remains a growing frontier with an evidence base still in its infancy despite a growing number of therapies to treat the heterogeneous etiologies. This statement casts an important lens on older adults, highlighting the complexity of this vulnerable patient population that is poorly studied and frequently overlooked. Statements such as that by Blumer et al lay the groundwork for the clinical care of these patients, but future work should advance risk stratification and provide a framework to tailor therapies for older adults.