https://orcid.org/0000-0002-7656-5812
This invited commentary refers to ‘Preinterventional frailty assessment in patients scheduled for cardiac surgery or transcatheter aortic valve implantation: a consensus statement of the European Association for Cardio-Thoracic Surgery (EACTS) and the European Association of Preventive Cardiology (EAPC) of the European Society of Cardiology (ESC)’ by S.H. Sündermann et al., https://doi.org/10.1093/ejcts/ezad181
The assessment of frailty continuously gains importance in everyday clinical practice due to the ageing of the population and thanks to technical improvements, which allow the treatment of patients with decreased physiologic reserve. Frailty refers to a progressive functional status worsening of individuals leading to susceptibility for organic disease, loss of physical reserves and increased dependency on external assistance [1]. Comorbid conditions are frequently related to frailty but the 2 states do not necessarily depend on each other and are not interchangeable. Although frailty and comorbidities are commonly presenting together, there are multimorbid patients without obvious signs of frailty and vice versa.
Patients requiring surgical and interventional cardiac procedures are symptomatic and are exposed to the long-term effects of cardiovascular disease-associated risk factors. Nevertheless, there are cardiac conditions mostly related to structural heart disease, which develop and progress at higher age independent from the presence or absence of risk factors or ongoing symptoms. The assessment of frailty in all the above categories of patients aims to assess the risk of a procedure and the margin of benefit for the specific patient after initiation of a structured management plan. Therefore, the need to discriminate between the predictive value of frailty assessment for the development of specific complications and the limitations according to the perception of the patient is indispensable.
In the current issue of the Journal, the European Association of Cardiothoracic Surgery and the European Association of Preventive Cardiology provide a comprehensive review of frailty assessment for patients prior to cardiac surgery or transcatheter aortic valve procedures [2]. The authors elaborate on different frailty assessment methods and suggest to start with a simple and reproducible gait speed test, which represents the basis of any further evaluation. Further steps include physical condition assessment and muscle mass quantification as signs of physical activity. The document establishes a clear connection between frailty and clinical outcomes such as mortality, prolonged hospitalizations, delirium and readmissions.
More importantly, frailty assessment is a key parameter for the estimation of patient-reported outcome measures after cardiac interventions [3]. This specific area gains substantial relevance in cardiac surgery for the following reasons: first, surgical interventions—when performed through sternotomy under cardiopulmonary bypass and cardioplegic arrest—represent procedures with high functional efficiency combined with maximal invasiveness for the patient. This leads to common discrepancies between the outcome reported by clinical measures and the benefit of a surgical procedure as perceived by the patient. Second, improvements in techniques and technologies have decreased the invasiveness of cardiac surgical procedures without affecting efficacy. This translates to an approximation between medical and patient-oriented outcomes but brings up the question of availability. However, minimally invasive techniques may be unavailable either due to inaccessibility to new technologies or limited centre experience. As a result, possible discrepancies between patient’s expectations and outcomes become again more evident. The introduction of patient-reported outcome measures in cardiac surgery should therefore aim to minimize such discrepancies and optimize the margin of treatment quality and expectations between patients and treating physicians.
Since the degree of frailty clearly relates to outcomes of cardiac interventions, approaches to decrease it before scheduled intervention should receive our full attention. In this regard, improving functional capacity prior to a scheduled intervention, also called prehabilitation, is a logical next step. Prehabilitation is a preparation of the patient for a better functional, nutritional and general condition before any surgical or percutaneous intervention and, importantly, should be continued and complemented by cardiac rehabilitation after the intervention. Prehabilitation is a multimodal approach including exercise training to improve cardiovascular, respiratory and muscular conditioning, but also nutritional optimization and psychological support, for both the adherence and the response to the exercise training.
Several studies on general surgery (e.g. liver transplantation, lung cancer resection, bariatric surgery) demonstrated that patients enrolled in prehabilitation programmes prior to surgery have reduced postoperative complications and have better functional, psycho-social, and surgery-related outcomes [4]. Specifically for cardiac surgery, data on prehabilitation remain scarce. In a small study of fifteen patients scheduled for coronary artery bypass graft surgery, Sawatzky et al. [5] showed that patients in the prehabilitation group increased walking distance and gait speed compared to the control group. Remarkably, adherence to cardiac rehabilitation postoperatively, was 100% in the prehabilitation group and only 43% in the control group. Although not performed explicitly in the frail, Herdy et al. [6] demonstrated that 5 days of in-hospital prehabilitation in patients who await CABG is superior to standard care and led to reduced rates of postoperative complications and shorter hospital stay. In the same line, prehabilitation has a proven value for preventing physical deconditioning for frail patients on the heart transplant waiting list [7]. In a recent meta-analysis, studying patients scheduled for elective cardiac surgery, the participation in exercise-based prehabilitation significantly improves postintervention and post-surgery 6-min walking distance and length of hospital stay and decreases the risk of postoperative atrial fibrillation in patients below the age of 65 [8]. Last but not least, exercise training plays a pivotal role in prehabilitation; nevertheless, frailty assessment should always include cognitive and social aspects as well [9].
For future clinical guidance, a practical scheme [i.e. when (best timing for prehabilitation programme initiation), how (main tools, individualized programmes or activities)] could improve clinical care. While Sündermann et al. [2] briefly mention these aspects in the current consensus statement, the modalities of prehabilitation are not discussed in detail, mainly given the paucity of data and heterogeneity of study interventions. However, there are some principles, which should be considered for planning. On the question of prehabilitation timing, the odds are with us. We may assume that aortic valve stenosis patients are followed for many months and even years before an intervention is planned. This means that there is ample time and opportunity to plan the prehabilitation programme. Also, the earlier it starts, the better are the achievable results, especially in frail patients. Second, the type of exercise training should be defined. Resistance training is important to maintain the musculature and prevent sarcopenia and should be offered in addition to aerobic exercise training. Whether continuous or even interval training makes sense depends on the condition of the patient. Therefore, it is mandatory to assess the exercise capacity and severity of the aortic stenosis prior to engage in exercise training. Then, the programme can be tailored to the patients' individual needs. Third, concerning the schedule, it is important to look what is feasible for the specific patient. A home-based training programme could remove logistic barriers and should be considered a valuable alternative for patients unable to attend in-hospital training. Fourth, in the unfortunate circumstance of a frail patient scheduled for TAVI on a short notice, we can offer them short-term pre-training anything, such as handgrip exercises, or bedside cycle ergometer. Any kind of exercise will be better than just lying in bed. The authors rightfully stress that maximum effort should go into the optimization and further development of such therapeutic approaches to optimize the outcome of the increasing number of frail patients undergoing cardiovascular interventions.
A common aspect of both risk assessment and risk optimization through prehabilitation is to distinguish between patients whose frailty status is related to a short and activity-limiting medical condition and those with longstanding idleness and limited functional reserve (Fig. 1). The first category of patients has very good chances to reach the status quo ante and return to a high level of quality of life. The second category encompasses multifactorial conditions, the majority of which are irreversible. In this case, even if the structural problem of the heart is solved, the general condition remains unchanged because of the irreversibility of concomitant diseases. The first refers to patients with a cardiac disease and the latter to those with life-limiting conditions and cardiac disease. It is obvious that the benefit/risk ratio in the second group may be very low to justify an intervention, even if the latter is technically possible. There is another parameter, which may play a decisive role in this context, which relates to the duration of physical limitations. Obviously, the shorter the sickness interval the higher the possibility or recovery, whereas in long-term conditions the vicious circle of the disease cannot be easily stopped.
Decision-making for cardiac interventions based on the symptoms/frailty ratio and the duration of physical activity limitations.
Undoubtedly, there is not always easy to distinguish between the 2 conditions, as most cases are somewhere in between. Therefore, it is extremely important before we delve into technical surgical details for the operation to assess those 2 aspects of potential candidates. This process is for the physician time-consuming and requires probably repetitive visits to acquire as many jigsaw pieces as possible. On the other hand, it is probably one of the few activities in medicine, which cannot be replaced by AI algorithms. Two vectors synthesize clinical evaluation: objective diagnostic and therapeutic assessment, which can be perfectly performed per software and classification of patient’s symptoms in relation to needs, expectations and emotional condition. The latter will remain a clinical responsibility for the next generation of surgeons at least.
ACKNOWLEDGEMENT
The figure was created by BioRender (www.biorender.com).
REFERENCES
Author notes
Nikolaos Bonaros and Emeline Van Craenenbroeck contributed equally to this work.
