Patient selection - Clinical Tree

Introduction

The following prerequisites are essential before patient selection in transcatheter aortic valve intervention (TAVI):

1.
An accurate diagnosis of severe aortic stenosis (AS)
2.
An indication for aortic valve intervention (i.e., severe symptomatic AS)
3.
A constellation of clinical, anatomic, or other patient factors likely to favor the transcatheter approach (see Chapter 1 )

This chapter outlines an approach to comprehensive risk stratification and patient selection to enable informed heart team discussion as to whether TAVI could, and should, be performed. Reflecting the frequently complex decision making over the timing and nature of intervention in patients with AS, the importance of involving an appropriate breadth of experts via the multidisciplinary heart team has been exemplified in the pivotal TAVI trials and emphasized in contemporary practice guidelines (Class I recommendation from both American and European societies, Level of Evidence: C).

Incorporating the necessary expertise to permit this approach and involving patients and their relatives through shared decision making are intuitive gold standards for contemporary TAVI centers (see Chapter 2 ).

Key Points

1.
Comprehensive clinical assessment, including appraisal of important cardiovascular and noncardiovascular comorbidities, is essential to inform individualized risk/benefit analyses.
2.
Frailty is a crucial determinant of outcome and should be assessed in an objective, reproducible manner.
3.
Individual patient goals for treatment should be established with options tailored accordingly. Emphasis on improving quantity and quality of life is essential for the majority.
4.
Currently available TAVI risk scores, although additive, lack the requisite discriminatory power for routine clinic decision making in isolation.
5.
Integrated individual assessment discussed in a multidisciplinary heart team setting with full consideration of patient preferences remains the cornerstone of appropriate patient selection.

Comprehensive clinical assessment

The key components of comprehensive assessment to guide patient selection in TAVI are summarized in Table 3.1 . As patient priorities may be varied and fluid, establishing individualized goals of care a priori is vital to inform heart team discussion and recommendations. For example, a patient relatively unimpeded by symptoms at baseline (e.g., New York Heart Association [NYHA] Functional Class II) may prioritize a reduction in mortality risk with the maintenance of an acceptable quality of life whereas, as previously characterized in elderly heart failure populations, patients chiefly limited by symptoms may place greatest value on functional improvement.

TABLE 3.1

Checklist for Pre-TAVI Patient Selection and Evaluation

Adapted from Otto CM, Kumbhani DJ, Alexander KP, et al. ACC expert consensus decision pathway for transcatheter aortic valve replacement in the management of adults with aortic stenosis: a report of the American College of Cardiology Task Force on Clinical Expert Consensus Documents. J Am Coll Cardiol. 2017;69:1313-1436.

Key Steps	Essential Elements	Additional Details
Approach to Care
Shared decision making	❑ Heart valve team ❑ Referring physician ❑ Patient involvement ❑ Family involvement	❑ General cardiologist ❑ Interventional cardiologist ❑ Imaging cardiologist/radiologist ❑ Cardiothoracic surgeon ❑ Cardiac anesthesiologist ❑ Elder care physician ❑ Specialist nurses ❑ Valve clinic care coordinators
Establishing the Goals of Care
Live longer, feel better	❑ Life expectancy ❑ Patient preferences and values ❑ Goals and expectations ❑ End-of-life wishes	❑ Life table estimates ❑ Symptom relief and/or survival ❑ What complications to avoid? ❑ Ideas about end of life?
Initial Assessment
AS symptoms and severity	❑ Symptoms ❑ AS severity	❑ Intensity, acuity ❑ Echocardiography and other imaging
Baseline clinical data	❑ Cardiac history ❑ Physical examination and laboratory tests ❑ Prior chest irradiation ❑ Dental evaluation ❑ Allergies ❑ Social support network	❑ Prior cardiac investigations/interventions ❑ Routine blood tests, pulmonary function tests ❑ Access issues, other cardiac effects ❑ Aim to treat dental issues before TAVI ❑ Contrast, latex, drugs ❑ Recovery, transportation, discharge planning
Major CV comorbidity	❑ Coronary artery disease ❑ LV systolic dysfunction ❑ Concurrent valve disease ❑ Pulmonary hypertension ❑ Aortic disease ❑ Peripheral arterial disease	❑ Coronary angiography ❑ LV ejection fraction ❑ Severe MS/MR ❑ Pulmonary pressure assessment ❑ Porcelain aorta, aortic root dilation ❑ Prohibitive reentry after previous cardiac surgery ❑ Hostile chest ❑ Imaging of peripheral arterial access
Major non-CV comorbidity	❑ Malignancy ❑ Digestive system and liver disease; prior bleeding ❑ Kidney disease ❑ Chronic lung disease ❑ Neurologic disorders	❑ Active or remote, life expectancy implication ❑ IBD, cirrhosis, varices, tolerance/contraindication to antithrombotic agents ❑ eGFR <30 mL/min/1.73 m ² or dialysis ❑ Oxygen dependency, FEV ₁ <50% predicted or DLCO <50% predicted ❑ Movement disorders, dementia
Functional Assessment
Frailty and disability	❑ Frailty assessment ❑ Nutritional risk/status	❑ Gait speed (<0.5 ms ⁻¹ or <0.83 ms ⁻¹ with disability or cognitive impairment) ❑ Frailty (frail or not by assessment) ❑ Nutritional risk status (BMI <21 kg ⁻² , albumin <40 mmol/L, >5 kg weight loss in the past year, or score ≤11 on MNA)
Physical function	❑ Physical function and endurance ❑ Functional independence	❑ 6-minute walk distance <50 m or unable to walk ❑ Dependence for ≥1 activity
Cognitive function	❑ Cognitive impairment ❑ Depression ❑ Prior disabling stroke	❑ MMSE <24 or dementia ❑ Depression history or positive screen
Futility	❑ Life expectancy ❑ Lag time to benefit	❑ <1 year life expectancy ❑ Survival with benefit of <25% at 2 years
Overall Procedural Risk
Risk categories	❑ Low risk	❑ STS-PROM <4% and ❑ No frailty and ❑ No comorbidity and ❑ No procedure-specific impediments
	❑ Intermediate risk	❑ STS-PROM 4%–8% or ❑ Mild frailty or ❑ ≥1 major organ system compromise not to be improved postoperatively or ❑ A possible procedure-specific impediment
	❑ High risk	❑ STS-PROM >8% or ❑ Moderate-severe frailty or ❑ >2 major organ system compromises not to be improved postoperatively or ❑ A possible procedure-specific impediment
	❑ Prohibitive risk	❑ PROMM >50% or ❑ Severe frailty or ❑ ≥3 major organ system compromise not to be improved postoperatively, or ❑ Severe procedure-specific impediment
Integrated Benefit Versus Risk of TAVI and Shared Decision Making
No current indication for AVR	❑ AS not severe or ❑ Minimal or equivocal symptoms or ❑ No other indication for AVR	❑ Periodic monitoring of AS severity and symptoms ❑ Reevaluate when AS severe or symptoms occur
TAVI candidate with expected benefit > risk	❑ Symptom relief or improved survival ❑ Possible complications and expected recovery ❑ Review of goals and expectations	❑ Discussion with patient and family ❑ Proceed with TAVI planning and procedure
Severe symptomatic AS but benefit < risk (futility)	❑ Life expectancy <1 year ❑ Chance of survival with benefit at 2 years <25%	❑ Discussion with patient and family ❑ Palliative care inputs ❑ Palliative balloon aortic valvuloplasty in selected patients

AS, Aortic stenosis; AVR, aortic valve replacement; BMI, body mass index; CV, cardiovascular; eGFR, estimated glomerular filtration rate; FEV1 , forced expiratory volume in 1 second; DLCO, diffusing capacity of the lungs for carbon monoxide; IBD, inflammatory bowel disease; MMSE, Mini-Mental State Examination; MNA, multinutritional assessment; MR, mitral regurgitation; MS, mitral stenosis; STS-PROM, Society of Thoracic Surgeons Predicted Operative Mortality; TAVI, transcatheter aortic valve implantation.

Drawing from best practice first described in oncology settings, discussions around treatment should ideally take place with all options on the table, affording patients the opportunity to define their wishes in the event of an adverse outcome or for the end of life. In the minority of cases where TAVI may be considered futile and not recommended, it is important that appropriate care plans are enacted to avoid a feeling of abandonment in the patient, family, or caregivers.

Surgical and transcatheter risk scoring in the modern era

Our ability to contrast predicted benefit with expected risk is central to informing treatment decisions in patients under consideration for TAVI. Clinical risk prediction models have the potential to inform the latter in an objective, reproducible manner. The ideal risk model should be well calibrated (predicted risk equates to observed risk); accurately distinguish patients with the outcome of interest ( discrimination, of which the concordance statistic [c-statistic] is an important measure); be externally validated; and, most crucially, be easily interpretable and suitable for integration into daily clinical practice.

Surgical risk scores

Because TAVI was developed to offer a therapeutic option to patients with severe symptomatic AS of prohibitive or high operative risk, objective consideration of surgical risk has been a fundamental aspect of patient selection since its inception; it is used to guide pivotal clinical trial design and heart team discussions.

The most well-established surgical risk scores are detailed in Table 3.2 .

TABLE 3.2

Surgical AVR Risk Scores

Data from the following sources:

Risk Score	First Author, Year	n	Validation Population	Included Predictors	Predicted Outcomes	C-Statistic	Limitations/Comments
Additive EuroSCORE	Nashef, 1999	13,302	EuroSCORE database Cardiac surgical patients in Europe	Age, gender, COPD, extracardiac arteriopathy, neurologic dysfunction, previous cardiac surgery, serum creatinine, active endocarditis, critical preoperative state, unstable angina on IV nitrates, reduced LVEF, recent myocardial infarction, pulmonary hypertension, emergency operation, other than isolated coronary surgery, thoracic aorta surgery, surgery for postinfarct septal rupture	Early or operative mortality	0.79	Majority CABG cohort, minority had isolated AVR Now out of date
Logistic EuroSCORE I	Roques, 2003	19,000	EuroSCORE database	Logistic regression of the same risk factors included in the additive EuroSCORE	Early or operative mortality	0.78	Systematically overestimates mortality at lower scores (≤6) and underestimates mortality at higher scores (>13) Replaced by EuroSCORE II
Logistic EuroSCORE II	Nashef, 2012	22,381		Updates included: use of creatinine clearance in addition to serum creatinine	Early or operative mortality	0.81	Omits several key risk factors, including porcelain aorta, chest radiation, frailty Developed primarily in patients undergoing coronary procedures
STS-PROM (part 2—isolated valve surgery)	O’Brien, 2009	109,759	STS National Adult Cardiac Surgery Database (NCD)	Continually updated; 28 variables in latest version	Early mortality and postoperative complications *	0.78	Continually updated; latest version (2.81) includes frailty, previous radiation exposure, and liver disease

Nashef SAM, Roques F, Michel P, et al. European system for cardiac operative risk evaluation (EuroSCORE). Eur J Cardiothorac Surg. 1999;16:9-13.

Roques F. The logistic EuroSCORE. Eur Heart J. 2003;24:882.

Nashef SAM, Roques F, Sharples LD, et al. Euroscore II. Eur J Cardiothorac Surg. 2012;41:734-745.

O’Brien SM, Shahian DM, Filardo G, et al. The Society of Thoracic Surgeons 2008 cardiac surgery risk models: part 2—isolated valve surgery. Ann Thorac Surg. 2009;88(1 Suppl):S23-S42.

* Predicted outcomes: operative mortality, permanent stroke, renal failure, prolonged ventilation (>24 hours), deep sternal wound infection, reoperation for any reason, a major morbidity or mortality composite endpoint, prolonged postoperative length of stay, and short postoperative length of stay. AVR, Aortic valve replacement; CABG, coronary artery bypass grafting; COPD, chronic obstructive pulmonary disease; EuroSCORE, European System for Cardiac Operative Risk Evaluation; LVEF, left ventricular ejection fraction; STS-PROM, Society of Thoracic Surgeons’ Predicted Risk of Mortality score.

The Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) score and European System for Cardiac Operative Risk Evaluation (EuroSCORE) II accurately distinguish between high and low short-term mortality in patients undergoing surgical aortic valve replacement ([SAVR], c-statistic 0.78–0.81; where 1.0 is a perfect model and 0.5 no better than a coin toss) and are recommended to aid surgical risk assessment and heart team discussion in practice guidelines across Europe and North America.
However, although extensively validated in surgical cohorts, STS-PROM and EuroSCORE were neither developed nor intended for use in older populations undergoing TAVI. Consequently, discriminative performance in this setting is limited, with a tendency to systematically overestimate procedural mortality (c-statistic 0.60–0.65).
The omission of key anatomic information (e.g., hostile chest, suitability for transfemoral access) and functional factors (e.g., frailty, cognitive function) and the inclusion of predictive variables for outcomes that are less relevant (e.g., sternal wound infection) are further key limitations in their use to inform TAVI risk.

Transcatheter risk scores

The suboptimal performance of surgical scores in TAVI cohorts has stimulated a large body of work in the attempt to develop a risk model more suited for use in these patients. The most prominent examples are summarized in Table 3.3 .

TABLE 3.3

TAVI Risk Scores

First Author, Year	n	Population	Predictors	Outcome(s)	C-Statistic	Limitations/Comments
Arnold, 2014 [CR]	2137	PARTNER study cohort (USA)	Arrhythmia, serum creatinine, oxygen-dependent lung disease, diabetes, mean aortic valve gradient, Mini-Mental Status Examination, baseline KCCQ score	6-month death or poor outcome (as per KCCQ)	0.66	High STS-risk study population Not validated in lower-risk populations
Edwards, 2016 [CR]	13,718	STS/ACC TVT Registry	Age, eGFR, hemodialysis, NYHA Class IV, severe chronic lung disease, nontransfemoral access, procedural acuity	In-hospital mortality	0.67	No inclusion of frailty or quality-of-life measures No longer-term prediction outcomes
Martin, 2018 [CR]	6339	UK-TAVI registry	Age, gender, BMI, eGFR, lung disease, extracardiac arteriopathy, arrhythmia, prior BAV, critical preoperative status, poor mobility, Katz score, pulmonary artery pressure, nonelective procedure, nontransfemoral access	30-day mortality	0.70	Includes frailty variable (Katz score)
Iung, 2014 [CR]	3833	France 2 Registry	Age ≥90 years, BMI <30 kg/m ² , NYHA Class IV, pulmonary hypertension, critical hemodynamic state, ≥2 pulmonary edema presentations/year, respiratory insufficiency, dialysis, and nontransfemoral access	30-day or in-hospital mortality	0.67	No inclusion of frailty or functional assessment
Seiffert, 2014 [CR]	845	Hamburg, Bonn, Germany	BMI, eGFR, hemoglobin, pulmonary hypertension, low mean baseline transaortic gradient, LVEF < 45%	1-year mortality	0.66	No functional or quality-of-life measures Relatively small sample size, low event rate (50 deaths)
Capodanno, 2014 [CR]	1871	Italian OBSERVANT study cohort	eGFR, critical preoperative state, NYHA IV, pulmonary hypertension, diabetes, previous BAV, LVEF <40%	30-day mortality	0.73	Performance attenuated in external validation cohorts: c-statistic 0.60 [CR] [CR]
Schiller, 2017 [CR]	18,054	German Aortic Valve Registry–II *	Gender, BMI, NYHA Class IV, CCS Class III or IV angina, cardiogenic shock, CPR within 48 h, pulmonary hypertension, absence of sinus rhythm, ASA grade, LVEF <30%, coronary artery disease, endocarditis or sepsis, diabetes, peripheral arterial disease, high serum creatinine or hemodialysis, mechanical circulatory support, redo surgery	In-hospital mortality	0.74	Performance attenuated in external validation cohort: c-statistic 0.63 [CR]

ASA, American Society of Anesthesiologists; BAV, balloon aortic valvuloplasty; BMI, body mass index; CCS, Canadian Cardiovascular Society; CPR, cardiopulmonary resuscitation; eGFR, estimated glomerular filtration rate; GAVS, German Aortic Valve Score; KCCQ, Kansas City Cardiomyopathy Questionnaire; NYHA, New York Heart Association; OBSERVANT, Observational Study of Appropriateness, Efficacy and Effectiveness of AVR-TAVR Procedures for the Treatment of Severe Symptomatic Aortic Stenosis (OBSERVANT) study; PARTNER, Placement of Aortic Transcatheter Valve Trial; STS/ACC TAVR , Society of Thoracic Surgeons/American College of Cardiology TAVR in-hospital mortality risk score; STS/ACC TVT, Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy; UK TAVI CPM, UK-TAVI Clinical Prediction Model.

Table References:

1.
Arnold SV, Reynolds MR, Lei Y, et al. Predictors of poor outcomes after transcatheter aortic valve replacement results from the PARTNER (Placement of Aortic Transcatheter Valve) trial. Circulation. 2014;129:2682-2690. https://pubmed.ncbi.nlm.nih.gov/24958751/
2.
Edwards FH, Cohen DJ, O’Brien SM, et al. Development and validation of a risk prediction model for in-hospital mortality after transcatheter aortic valve replacement. JAMA Cardiol. 2016;1:46-52. https://pubmed.ncbi.nlm.nih.gov/27437653/
3.
Martin GP, Sperrin M, Ludman PF, et al. Novel United Kingdom prognostic model for 30-day mortality following transcatheter aortic valve implantation. Heart. 2018;104:1109-1116. https://pubmed.ncbi.nlm.nih.gov/29217636/
4.
Iung B, Laouénan C, Himbert D, et al. Predictive factors of early mortality after transcatheter aortic valve implantation: individual risk assessment using a simple score. Heart. 2014;100:1016-1023. https://pubmed.ncbi.nlm.nih.gov/24740804/
5.
Seiffert M, Sinning JM, Meyer A, et al. Development of a risk score for outcome after transcatheter aortic valve implantation. Clin Res Cardiol. 2014;103: 631-640. https://pubmed.ncbi.nlm.nih.gov/24643728/
6.
Capodanno D, Barbanti M, Tamburino C, et al. A simple risk tool (the OBSERVANT score) for prediction of 30-day mortality after transcatheter aortic valve replacement. Am J Cardiol. 2014;113:1851-1858. http://dx.doi.org/10.1016/j.amjcard.2014.03.014
7.
Martin GP, Sperrin M, Ludman PF, et al. Inadequacy of existing clinical prediction models for predicting mortality after transcatheter aortic valve implantation. Am Heart J. 2017;184:97-105.
8.
Wolff G, Shamekhi J, Al-Kassou B, et al. Risk modeling in transcatheter aortic valve replacement remains unsolved: an external validation study in 2946 German patients. Clin Res Cardiol. 2021;110:368-376. https://doi.org/10.1007/s00392-020-01731-9
9.
Schiller W, Barnewold L, Kazmaier T, et al. The German aortic valve score II. Eur J Cardiothoracic Surg. 2017;52:881-887. https://pubmed.ncbi.nlm.nih.gov/28950361/

* Mixed surgical (isolated surgical aortic valve replacement) and TAVI registry. GAVS I was remodeled in 2017 to reflect the increasing proportion of TAVI.

The presence of background comorbid conditions (age, renal impairment, chronic lung disease) and features of cardiovascular disease severity (NYHA Class IV symptoms, impaired left ventricle [LV] function, pulmonary hypertension) is strikingly consistent.
Yet overall discriminatory performance is modest to date, with no score emerging into routine clinical use.
In particular, many of the models have not been widely tested or externally validated. Further, where undertaken, it is notable that performance (particularly discrimination, i.e., c-statistic) is frequently inferior in the validation cohort.
It is also notable that—with some exceptions—the majority do not incorporate measures of cognition (e.g., Mini-Mental State Examination [MMSE]) or functional ability/frailty, perhaps reflecting the incomplete collection or reporting of these variables in the data sets from which they were developed.
Τhe overwhelming focus on procedural mortality, as opposed to outcomes encompassing both clinical events and quality of life and function, is a further critical limitation of the present scores to inform discussions with the TAVI patient population (see later in this chapter).

Frailty assessment in TAVI: Why and how?

An essential component to the evaluation of patients under consideration for TAVI is an assessment of frailty status. Although the subject of some ongoing debate, a practical definition of frailty is a multisystem syndrome that results in (1) reduced physiologic reserve and (2) increased vulnerability to stressors. Its importance to the recovery of patients undergoing TAVI is thus both intuitive and pivotal. Related to yet distinct from comorbidity, its presence demonstrably increases risk of poor outcomes and futility, and accordingly augments risk prediction in adjusted analyses. ^,

Practice guidelines emphasize frailty evaluation as central to risk stratification and patient selection. However, routine assessment in the cardiovascular “real world” has perhaps been hampered by the lack of a universally accepted tool for diagnosis, and concerns, either founded or unfounded, over availability of appropriate expertise and the potential interruption to clinical workflow.
The subjective “eyeball test” is perhaps superficially attractive but is insufficient, with poor consistency between observers. An ideal objective assessment should encompass an appraisal of three key domains: (1) cognition, (2) mobility/physical function, and (3) nutritional status, yet be balanced with sufficient brevity for routine clinical use.

Table 3.4 summarizes selected key frailty assessment tools employed in TAVI populations and their association with important outcomes. Among them, the Essential Frailty Toolset (EFT, Fig. 3.1 ) may be particularly promising.

TABLE 3.4

Frailty Scores

Risk Score	First Author, Year	Included Components	Predicted Outcomes After TAVI	Limitations/Comments
Katz ADL [CR]	Katz, 1970	Dependence (0 points) or independence (1 point) in the following ADLs: bathing, dressing, toileting, transferring, continence, feeding (>6 = independent)	Katz index <6 predicts long term all-cause mortality	Simple to perform Widely used Assesses basic ADLs but does not assess more advanced ADLs
CSHA/Rockwood CFS	Rockwood, 2005	7-point descriptive incremental scale measure of frailty, with scoring based on clinical judgment; ranges from 1 (robust health) to 7 (complete functional dependence on others)	30-day and 1 year mortality ^,	Includes functional abilities only
Essential Frailty Toolset (EFT)		Four components: physical function through chair raises, cognition using MMSE, hemoglobin, and serum albumin	30-day and 1-year mortality	Compared with six other frailty scores, the EFT showed the strongest association with 1-year mortality
Erasmus Frailty Score	Goudzwaard, 2019	A composite including MMSE score, MUST score, grip strength, Katz index, and Lawton and Brody index	Delirium and 1-year mortality	Relatively small sample, wide confidence intervals ^a
Fried [CR]	Fried, 2001	5 items, with at least 3 required to diagnose frailty: 5-m gait speed, grip strength, weight loss, exhaustion, and inactivity	30-day and 1-year mortality
Fried +		Same items as Fried, plus cognition, assessed (MMSE) and mood (short-form geriatric depression scale)	30-day and 1-year mortality
SPPB	Guralnik, 1994	3 physical tests: gait speed, time to stand 5 times from a seated position without using arms, and ability to stand 10 s with the feet in tandem or side-by-side positions	30-day and 1-year mortality	Only assesses lower-extremity muscle function
Bern	Stortecky, 2012	6 components: gait speed, mobility, cognition, nutrition, ADL and IADL disability (Katz)	Functional decline at 6 months, 30-day and 1-year mortality
Columbia	Green, 2015	4 components: gait speed, grip strength, serum albumin, and Katz score	One-year mortality or poor outcome ^b ^, [CR]

ADLs, Activities of daily living; CFS, Clinical Frailty Scale; CSHA, Canadian Study Health Association; IADLs, instrumental activities of daily living; SPPB, Short Physical Performance Battery.

Table References:

1.
Katz S, Downs TD, Cash HR, Grotz RC. Progress in development of the index of ADL. Gerontologist. 1970;10(1 Part 1):20-30.
2.
Puls M, Sobisiak B, Bleckmann A, et al. Impact of frailty on short- and long-term morbidity and mortality after transcatheter aortic valve implantation: risk assessment by Katz Index of activities of daily living. EuroIntervention. 2014;10(5):609-619.
3.
Rockwood K, Song X, MacKnight C, et al. A global clinical measure of fitness and frailty in elderly people. CMAJ. 2005;173(5):489-495.
4.
Shimura T, Yamamoto M, Kano S, et al. Impact of the Clinical Frailty Scale on outcomes after transcatheter aortic valve replacement. Circulation. 2017;135(21):2013-2024.
5.
Afilalo J, Lauck S, Kim DH, et al. Frailty in older adults undergoing aortic valve replacement: the FRAILTY-AVR study. J Am Coll Cardiol. 2017;70(6):689-700.
6.
Goudzwaard JA, de Ronde-Tillmans MJAG, El Faquir N, et al. The Erasmus Frailty Score is associated with delirium and 1-year mortality after transcatheter aortic valve implantation in older patients. The TAVI Care & Cure program. Int J Cardiol. 2019;276:48-52.
7.
Fried LP, Tangen CM, Walston J, et al. Frailty in older adults: evidence for a phenotype. J Gerontol A Biol Sci Med Sci. 2001; 56(3):M146-156.
8.
Guralnik JM, Simonsick EM, Ferrucci L, et al. A short physical performance battery assessing lower extremity function: association with self-reported disability and prediction of mortality and nursing home admission. J Gerontol. 1994; 49(2):M85-M94.
9.
Stortecky S, Schoenenberger AW, Moser A, et al. Evaluation of multidimensional geriatric assessment as a predictor of mortality and cardiovascular events after transcatheter aortic valve implantation. JACC Cardiovasc Interv. 2012;5(5):489-496.
10.
Schoenenberger AW, Stortecky S, Neumann S, et al. Predictors of functional decline in elderly patients undergoing transcatheter aortic valve implantation (TAVI). Eur Heart J. 2013;34(9):684-692.
11.
Green P, Arnold SV, Cohen DJ, et al. Relation of frailty to outcomes after transcatheter aortic valve replacement (from the PARTNER trial). Am J Cardiol. 2015;116(2):264-269.

a Risk of delirium [OR 3.3 (95% CI 1.55–7.10), p = 0.002]. Risk of 1-year mortality [HR 2.1 (95% CI 1.01–4.52), p = 0.047].

b Poor outcome was defined as (1) death, (2) KCCQ <60, or (3) decrease of ≥10 points in the KCCQ score from baseline to 1 year.

Fig. 3.1, The Essential Frailty Toolset (EFT).

Developed in a population of 1020 older adults undergoing aortic valve intervention (about two-thirds TAVI) the EFT proved the strongest discriminator of mortality (odds ratio [OR]: 3.72; 95% confidence interval [CI]: 2.54 to 5.45), and a composite of mortality/worsening disability (OR: 2.13; 95% CI: 1.57–2.87) compared with six other frailty indices.
The intuitive 5-point ordinal score is reached through assessment of cognition (MMSE), functional activity (chair raises within 15 seconds), anemia, and hypoalbuminemia.
A full MMSE or similar focused cognitive assessment may take 8 to 10 minutes to perform, although the shorter Mini-Cog is an accepted screening simplification. Here, patients are asked to recall three words after a distractive task, such as drawing a clock face. If all three words are recalled clinically significant cognitive impairment (i.e., MMSE <24 points) is exceedingly unlikely, similarly if only one or two are recalled but the drawn clock face is normal.
In addition to poorer long-term outcomes, impaired cognitive function is an established risk factor for postprocedure delirium, which is itself linked to prolonged length of stay, readmission, diminished likelihood of independent discharge, and increased mortality. Its presence should therefore prompt an awareness of these considerations and, where appropriate, the involvement of specialist expertise (e.g., an elder-care physician with an interest in perioperative care) to implement preemptive strategies for mitigation.

Ambulatory physical assessments provide further useful quantitative information on baseline function and, in the case of the 6-minute walk test, are independently associated with long-term mortality. Appropriate attention must be paid to the conditions in which the test is performed (e.g., avoiding inadvertent coaching) to avoid introducing bias. The outpatient setting is generally recommended for similar reasons. Whether techniques that examine function in free-living conditions (e.g., wearable sensors) can enhance the fidelity and accuracy of these assessments remains the subject of active ongoing research.

Of course, the emergence of a true consensus frailty metric among the broad range available will likely require further comparative studies. Consistency within an institution and adherence to the guiding principles of objective multisystem assessment, with recourse to appropriate specialist input in the case of concern or ambiguity, should therefore govern present practice.

Optimizing patient assessment to avoid futility

The pivotal trials of the last decade established the transformative mortality, morbidity, and quality of life benefits offered by TAVI to patients with severe symptomatic AS across the surgical risk spectrum. And yet, there remains heterogeneity in individual outcome. Moreover, despite excellent periprocedural success (≈ 95%), failure to realize benefit from TAVI, so-called treatment “futility,” may occur in up to a third of patients, defined as (1) death within 6 to 12 months, despite a successful procedure, or (2) survival without symptomatic benefit (e.g., failure to improve ≥1 NYHA class or ≥1 Canadian Cardiovascular Society [CCS] class).

An appreciation of factors associated with suboptimal clinical outcomes is therefore vital to appraise the likelihood of treatment success, inform patient selection, identify modifiable preprocedure factors, and guide postprocedure management. The best characterized factors are outlined in Fig. 3.2 and discussed in detail later in this chapter.

You're Reading a Preview

Become a Clinical Tree membership for Full access and enjoy Unlimited articles

Become membership

If you are a member. Log in here