Frailty Among Non-Elderly Patients Undergoing Cardiac Surgery

Abstract

Background:

Usually viewed as a characteristic of old age, frailty may also occur in non-elderly people, primarily in those suffering from chronic disease. Frailty may increase operative risk.

Objectives:

To determine the prevalence of frailty patients undergoing coronary artery bypass (CABG) and/or heart valve replacement or reconstruction and/or heart valve surgery, as well as the influence of frailty on postoperative outcomes.

Methods:

Our study comprised 100 adults who underwent consecutive elective cardiac operations. Frailty was assessed using the Fried scale. Patients also performed a 6-minute walk test, and we measured maximal inspiratory and expiratory pressures. A p value <0.05 was considered significant.

Results:

Of a cohort of 100 patients, based on the Fried frailty criteria, 17 patients (17%) were considered frail, 70 (70%) pre-frail and only 13 (13%) were non-frail. Among patients with valvular heart disease, 11 (18.6%) were considered frail and 43 (73%) pre-frail. Fifty three percent of the patients considered frail were less than 60 years old (median=48 years old). The differences in frailty phenotype between patients with valvular heart disease and coronary artery disease were not statistically significant (p=0.305). A comparison between non-frail, pre-frail, and frail patients showed no significant difference in the distribution of comorbidities and cardiac functional status, regardless of their cardiac disease. However, hospital mortality was significantly higher in frail patients (29.4%, p=0.026) than in pre-frail patients (8.6%) and non-frail patients (0%).

Conclusions:

Frailty is prevalent even among non-elderly patients undergoing CABG or valvular heart surgery and is associated with higher postoperative hospital mortality.

Keywords:
Frailty; Myocardial Revascularization/surgery; Heart Valves/surgery; Postoperative Care/mortality

Resumo

Fundamento:

Geralmente vista como uma característica da velhice, a fragilidade também pode ocorrer em pessoas não idosas, principalmente naquelas que sofrem de doenças crônicas. A fragilidade pode aumentar o risco operatório.

Objetivos:

Determinar a prevalência de fragilidade em pacientes submetidos à cirurgia de revascularização do miocárdio (CRM) e/ou troca ou reconstrução valvar e/ou cirurgia valvar, bem como a influência da fragilidade nos desfechos pós-operatórios.

Métodos:

Nosso estudo incluiu 100 adultos que foram submetidos a operações cardíacas eletivas consecutivas. A fragilidade foi avaliada por meio da escala de Fried. Os pacientes também realizaram um teste de caminhada de 6 minutos, e medimos as pressões inspiratória e expiratória máximas. Um valor de p < 0,05 foi considerado significativo.

Resultados:

De uma coorte de 100 pacientes, com base nos critérios de fragilidade de Fried, 17 pacientes (17%) foram considerados frágeis, 70 (70%) pré-frágeis e apenas 13 (13%) não frágeis. Entre os portadores de valvopatia, 11 (18,6%) foram considerados frágeis e 43 (73%) pré-frágeis. Cinquenta e três por cento dos pacientes considerados frágeis tinham menos de 60 anos (mediana=48 anos). As diferenças no fenótipo de fragilidade entre os pacientes com valvopatia e doença arterial coronariana não foram estatisticamente significativas (p=0,305). A comparação entre pacientes não frágeis, pré-frágeis e frágeis não mostrou diferença significativa na distribuição das comorbidades e do estado funcional cardíaco, independentemente da doença cardíaca. No entanto, a mortalidade hospitalar mostrou-se significativamente maior em pacientes frágeis (29,4%, p=0,026) que em pacientes pré-frágeis (8,6%) e não frágeis (0%).

Conclusões:

A fragilidade é prevalente mesmo entre pacientes não idosos submetidos a CRM ou cirurgia cardíaca valvar e está associada a maior mortalidade hospitalar pós-operatória.

Palavras-chave:
Fragilidade; Revascularização Miocárdica/cirurgia; Valvas Cardíacas/cirurgia; Cuidados Pós-Operatórios/mortalidade

Introduction

Frailty is a syndrome of increased vulnerability to stressors including hospitalization and is associated with a reduced physiological reserve secondary to a decline in the optimal function of multiple physiological systems, which predisposes individuals to high risk of adverse events.¹ It is a multidimensional syndrome comprising physical, psychological and social dimensions,² usually viewed primarily as a geriatric syndrome³ characterized by low physical activity, muscle weakness, slowed performance, fatigue or poor endurance and unintentional weight loss. In this context, the Fried criteria are widely used for the physical domains of frailty, which can be easily interpreted by non-geriatricians and may have prognostic value.^{4, 5} Association of frailty with chronic comorbidities has been shown.^2,6 Therefore, even non-elderly patients may present with this condition.

We have observed, in the course of our clinical practice, that several non-elderly patients undergoing open heart surgery demonstrate clinical features compatible with frailty, usually experiencing less favorable postoperative hospital outcomes.

Therefore, the objective of the present study was to determine the prevalence of frailty in non-elderly patients undergoing coronary artery bypass (CABG) and/or heart valve surgery, as well as to assess the influence of frailty on postoperative hospital outcomes.

Patients and Methods

Study Design and Participants

We studied a prospective cohort of adults regardless of gender and race, who underwent CABG or heart valve replacement or reconstruction. These patients were consecutively and electively operated between January 2016 and December 2017. Exclusion criteria were: patients with restricted mobility secondary to orthopedic or neurological conditions, those with unstable angina, those classified as class IV as per the New York Heart Association Functional Classification (NYHA) at the time of the operation, and patients diagnosed with acute myocardial infarction <30 days preoperatively.

Median sternotomy and cardiopulmonary bypass (CPB) were performed on all patients. The CPB circuit was primed using Ringer's solution, and the pump flow was adjusted to 2.4 L/min/m². No patient received corticosteroids. Inotropes, vasopressors, nitrates and sodium nitroprusside were administered intra- or postoperatively at the discretion of the anesthesiologist or the intensive care unit staff.

This study was approved by the institutional review board of Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto-USP (registry 15363/2014) and informed consent was obtained from each patient included in the study.

Assessment of Frailty

Frailty was assessed using the Fried frailty index, which includes 5 criteria (5-m gait speed test, handgrip strength, weight loss, exhaustion and inactivity). Those who met 3 of these 5 criteria were diagnosed with frailty. Patients who met 2 of the 5 criteria were considered as being in the pre-frail stage (a subset at high risk of progressing to frailty).⁷ Physical activity was assessed using the International Physical Activity Questionnaire.⁸

For the 5-m gait speed test, the patient was positioned behind the 5-m start line and instructed to walk at a comfortable pace until a few steps past the 5-m mark. The timer was started with the first footfall after the 0-m line and stopped with the first footfall after the 5-m line. Handgrip strength was assessed by measuring the degree of isometric strength developed using a mechanical hand dynamometer (MN 70142-North Coast®).

Sarcopenia is known to affect respiratory muscle strength; thus, we evaluated maximal inspiratory and expiratory pressure using a portable digital manovacuometer (Mvd 300®, Globalmed, Porto Alegre, Brazil). Measurements were performed over a minimum of 3 trials with a 1-min interval between each repetition using a nasal clip. Any value showing >10% variation was disregarded, and measurements with the highest value were used.

Functional Capacity Assessment

A 6-minute walk test was performed based on the recommendations of the American Thoracic Society, 2002 statement, to assess the functional capacity of patients.⁹

Outcomes

Death from any cause until 1 month after hospital discharge was considered postoperative hospital mortality, which was the primary outcome measure of this study. Our secondary outcomes were the incidence of postoperative infection(s), and respiratory, renal or cardiovascular dysfunction.

Statistical Analysis

Data distribution was verified by analysis of distribution histograms, Q-Q graphs and the Shapiro-Wilk test. Since our data had non-normal distributions, we chose to use non-parametric statistical methods. Results were presented as median and interquartile range for continuous variables and percentages for categorical variables. Fisher's Exact Test was used to compare categorical variables. Mann-Whitney or Kruskal-Wallis test followed by a Dunn-Bonferroni post hoc test were used to compare continuous data. A p value <0.05 was considered statistically significant. Statistical analysis was performed using the software Statistical Package for the Social Sciences (IBM-SPSS) version 22.0.

Results

Our study included 100 patients: 59 underwent heart valve surgery and 41 underwent CABG. Table 1 shows the clinical characteristics of patients.

Table 1
Clinical characteristics according to the heart disease

	VHD n=59	CAD n=41	p
Age (y)	54 (45–61)	62 (55–69)	0.002
Female	60%	29%	0.013
Weight	75 (64–87)	79 (72–86)	0.104
Height (cm)	164 (154–173)	165 (158–170)	0.501
Body mass index	29 (24–32)	29 (25–32)	0.342
Arterial hypertension	55.0%	82.4%	0.062
Diabetes mellitus	15.0%	64.7%	<0,001
Stroke	8%	2%	0.211
Previous MI	34%	4%	<0.001
Chronic atrial fibrillation	25.0%	0.0%	<0.001
Smoke	15.0%	35.3%	0.272
Pulmonary hypertension	17.5%	0.0%	0.005
Kidney failure	5.0%	0.0%	0.211
Previous operation	35.0%	5.9%	<0.001
NYHA class
I	0.0%	5.9%
II	62.5%	52.9%	0.230
III	37.5%	41.2%
IV	0.0%	0.0%
Ejection fraction	60 (48–66)	51 (44–63)	0.028
Serum creatinine (dg/l)	1.1 (0.9–1.4)	1.2 (1.1–1.3)	0.484
Hemoglobin	13 (12–14)	13 (12–14)	0.793

• CAD: coronary artery disease; VHD: valvular heart disease; MI: myocardial infarction. Fisher's Exact Test (categorical variables) and Mann-Whitney (continuous data)

CPB time for valvular surgery and CABG was 122 min (100–165 min) and 110 (77–130 min), respectively (p=0.002), and the aortic cross-clamp time was 93 min (76–117 min) and 72 (49–95 min), respectively (p<0.001).

The median age for the whole cohort was 57 years (49-66 years) and 57% of the patients were younger than 60. Overall, based on the Fried frailty criteria, 17 patients (17%) were considered frail, 70 (70%) were considered pre-frail and only 13 (13%) were non-frail.

Among patients with valvular heart disease, 11 (18.6%) were considered frail and 43 (73%) were considered pre-frail. The percentage of patients showing frailty and pre-frailty among those who underwent CABG was 6 (14.6%) and 27 (66%), respectively. The difference in the percentage of frailty between patients with valvular and coronary artery disease was not significant (p=0.788).

CPB time was 110 min (85–135 min), 120 (95–147 min) and 107 min (75–145 min), respectively, in non-frail, pre-frail and frail patients (p=0.656), whereas aortic cross-clamp time was 76 min (67–100 min), 90 (71–113 min) and 86 min (46–114 min), respectively (p=0.361).

Distribution of Fried criteria between patients with valvular heart disease (VHD) and coronary artery disease (CAD) is shown in Table 2. The heart valvular disease group had significantly higher proportion of patients with change of body weight and transition time (5 min) was significantly longer in the CAD group.

Table 2
Fried's criteria distribution to according the heart disease

	All (%)	VHD n=59	CAD n=41	p (VHDxCAD)
Change in body weight	14%	20%	5%	0.028
Exhaustion	63%	68%	56%	0.223
Low physical activity	62%	68%	54%	0.152
Transition time (sec.)	4.7 (4.0–5.7)	4.5 (4.0–5.3)	5.1 (4.4–6.0)	0.019
Handgrip strength (kgf)	28 (20–35)	28 (20–35)	29 (20–36)	0.615

• CAD: coronary artery disease; VHD: valvular heart disease; HVD: heart valve disease. Fisher's exact Test (categorical variables) and Mann-Whitney (continuous data)

Table 3 shows anthropometric characteristics, distribution of associated comorbidities, Fried frailty criteria, respiratory pressures and functional status (NYHA class, left ventricular ejection fraction, 6MWT distance) among non-frail, pre-frail and frail patients, regardless of the cardiac disease. Among frail patients, 53% were less than 60 years old (median=48 years, 44–54 years). The proportion of patients who experienced previous myocardial infarction among non-frail, pre-frail and frail patients with CAD was 50%, 37% and 50%, respectively. Etiologies of valve disease were rheumatic fever in 44%, degenerative in 37%, endocarditis in 5% and annular dilation due to ventricular enlargement in 13%. Table 4 shows the etiology and mechanism of valve dysfunction according the Fried phenotype.

Table 3
Clinical characteristics to according the Fried's phenotype

	Non-Frail n=13	Pre-frail n=70	Frail n=17	p
Age	58 (51–60)	57 (49–66)	57 (48–69)	0.830
Female	38%	44%	76%	0.042
Body mass index	28 (25–30)	29 (25–32)	30 (24–34)	0.617
Arterial hypertension	92%	70%	71%	0.243
Diabetes mellitus	37%	30%	35%	0.793
Previous MI	31%	16%	23%	0.389
Previous stroke	8%	7%	0%	0.519
Kidney failure	0%	8%	0%	0.255
SAPH	8%	11%	6%	0.757
Atrial fibrillation	8%	18%	17%	0.629
Previous cardiac operation	8%	20%	29%	0.338
NYHA class
I	8%	0%	6%
II	61%	67%	47%	0.163
III	31%	33%	47%
IV	0%	0%	0%
Ejection fraction	56 (46–60)	58 (47–65)	60 (45–68)	0.605
Serum creatinine (dg/l)	1.1 (1.0–1.1)	1.2 (0.9–1.4)	1.1 (1.0–1.2)	0.565
6MWT distance (m)	417 (384–482)	423 (360–493)	307 (275–364)	0.005**
MIP (cm H2O)	65 (52–106)	70 (49–96)	44 (40–66)	0.015*
MEP (cm H2O)	77 (58–123)	90 (73–118)	64 (56–108)	0.160
Change in body weight	0%	9%	47%	<0.001**
Exhaustion	0%	66%	94%	<0.001*
Low physical activity	0%	69%	88%	<0.001*
5-m gait speed test (sec)	4.6 (3.5–4.7)	4.7 (4.0–5.6)	6.7 (5.3–8.4)	<0.001**
Handgrip strength (kgf)	34 (23–45)	30 (21–37)	20 (15–27)	0.018**

• ^*
  significant for frail vs. non-frail;
• ^**
  significant for frail vs. non-frail and pre-frail. Fisher's exact test (categorical variables) and Kruskal-Wallis test followed by a Dunn-Bonferroni post hoc test (continuous data). IQR: interquartile range. Fisher's exact test (categorical variables). MI: myocardial infarction; SAPH: systolic arterial pulmonary hypertension; MIP: maximal inspiratory pressures; MEP: maximal expiratory pressures.

Table 4
Etiology and dysfunction of valve diseases

		FRIED
Valve dysfunction		Non-frail		Pre-frail		Frail
		n	%	n	%	n	%
	Mitral stenosis	0	0.0%	1	2.3%	0	0.0%
	Mitral regurgitation	1	20.0%	8	18.6%	3	27.2%
	Aortic regurgitation	1	20.0%	1	2.3%	0	0.0%
	Aortic stenosis	0	0.0%	3	7.0%	4	36.4%
	Double mitral lesion	0	0.0%	5	11.6%	0	0.0%
Etiology	Double aortic lesion	1	20.0%	4	9.3%	0	0.0%
	Mitro-aortic dysfunction	2	40.0%	21	48.8%	4	36.4%
	Degenerative	2	40.0%	13	30.2%	5	45.5%
	Rheumatic	1	20.0%	19	44.2%	3	27.3%
	Endocarditis	0	0.0%	2	4.7%	1	9.1%
	Secondary MR	1	20.0%	6	14.0%	1	9.1%
	Other

Table 5 shows the valve disease characteristics according to the Fried phenotype.

Table 5
Postoperative evolution according to the Fried's scale

	Non-frail n=13	Pre-frail n=70	Frail n=17	p
Hospital death	0%	8.6%	29.4%	0.026
Intensive care time (days)	3 (2–3)	3 (2–5)	3 (2–4)	0.946
Hospital time (days)	10 (7–11)	11 (7–16)	9 (6–22)	0.861
IMV time (hour)	15 (5–19)	17 (7–28)	13 (7–12)	0.615
Creatinine	1.2 (0.9–1.2)	1.3 (1.0–1.7)	1.1 (1.0–1.4)	0.231
Hemoglobin	10 (9–11)	10 (9–11)	10 (10–11)	0.994
Non-invasive ventilation	38%	40%	23%	0.448
Cardiogenic pulmonary congestion	46%	41%	47%	0.888
Pneumonia	8%	8%	23%	0.193
Urinary infection	0.0%	13%	23%	0.164
Superficial wound infection	8%	6%	12%	0.667
Mediastinitis	0%	3%	6%	0.640
Acute kidney failure	0.0%	8%	0%	0.255
Stroke	0.0%	3%	12%	0.178

• IQR: interquartile range. Fisher's exact test (categorical variables). IMV: Invasive mechanical ventilation.

Overall hospital mortality was 11%, 12% for valvular heart disease and 10% for CABG (p=0.762). Hospital mortality was significantly higher in frail patients (29.4%, p=0.026) than in pre-frail patients (8.6%) and non-frail patients (0%). No statistically significant differences were observed in the percentage of in-hospital complications (Table 5).

Discussion

Our results have shown that, overall, 17% of patients studied were frail and 70% pre-frail, despite the fact that non-elderly (<60 years) prevailed in the cohort studied (57%). In addition, except for the higher proportion of women among frail patients, frail, pre-frail and non-frail patients were similar regarding the distribution of comorbidities, left ventricle function and NYHA class.

It is well known that frailty is associated with adverse postoperative outcomes in those undergoing cardiac surgery.^10–14 However, most studies have reported frailty in elderly patients.^6,10,13,14 Our findings demonstrate that frailty occurs in a significant percentage of non-elderly patients diagnosed with valvular heart disease or coronary artery disease undergoing open heart surgery. This fact can be attributed to the association of socioeconomic factors with chronic disease, representing the concept of “secondary frailty,” a term used to refer to frailty in the presence of chronic diseases.¹⁵ The frail patients observed in our study did not differ from others in terms of the presence of comorbidities and cardiac functional status. They differed essentially in terms of psychological aspects and also in terms of sarcopenia, evidenced by the reported changes in body weight and low physical activity and mobility.

Although usually viewed as a characteristic of old age, frailty has been described in non-elderly people, primarily among the lower socioeconomic strata in societies.^16,17 Santos-Eggimann et al.¹⁷ analyzed 18,227 randomly selected European communities and observed 4.1% frail and 37.4% pre-frail individuals in a middle-aged population. Moreover, they observed a strong relationship between education and frailty. Brothers et al.¹⁸ observed higher levels of frailty among middle-aged and older European immigrants born in low- and middle-income countries, also suggesting that socioeconomic factors may significantly influence an individual's health throughout his/her life.

Risk assessment in these patients has been a concern among cardiothoracic surgeons. Consequently, different risk scoring systems have been developed to predict mortality and morbidity.^19–21 However, most scoring systems emphasize specific organic dysfunction and aspects of operation, with lesser emphasis on the physical and psychological consequences of chronic diseases and the effects of the socioeconomic dimension. In addition, we speculate that the high mortality found in the fragile group (29.4%), compared to previous information found in the literature, may result from the association between fragility and the preexisting chronic conditions.^22–24

Our findings demonstrate that in addition to comorbidities and specific organ dysfunctions, frailty phenotype should be considered an important factor for operative risk assessment, because it may reflect not only the consequences of a chronic disease, but also the socioeconomic dimension. Therefore, frailty phenotype, even in non-elderly, may contribute toward offering a more holistic view of the patient's health status that can assist the development of intervention actions of the multi-professional team.

In view of these facts, it is important when treating frail patients (both elderly and non-elderly) to decide if they would benefit from postponing their operation to engage in a preoperative multidisciplinary rehabilitation program. Evidence-based research has shown that several aspects related to frailty such as sarcopenia, physical inactivity and nutritional issues are potentially treatable^25–27 and might decrease operative mortality.^28,29

Waite et al.²⁹ conclusively demonstrated that a home-based preoperative rehabilitation program for frail patients aged ≥65 years undergoing CABG or valvular surgery may improve their functional status and reduce the duration of hospitalization. Additionally, evidence suggests that psychological preparation may help reduce postoperative pain, negative effects, and the length of hospitalization, as well as improve behavioral recovery,¹⁶ and, besides exercise, a preoperative nutritional support program can potentially reduce sarcopenia and improve postoperative outcomes.^27,30

Although evidence-based research suggests the superiority of multicomponent exercise programs over a single component exercise program for the rehabilitation of frail patients,³¹ a more focused program aimed at specific organ dysfunction may prove beneficial. Katsura et al.³² reported that preoperative inspiratory muscle training was associated with reduced postoperative atelectasis, pneumonia and length of hospitalization in adults undergoing cardiac and major abdominal surgery. However, notwithstanding the favorable effects that an exercise program may provide, it is necessary to consider the risks and uncertainty associated with frequency, type, and duration of exercise for frail patients diagnosed with heart disease in whom a cardiac operation is essential.

We believe that our study is one of the first to investigate the prevalence of frailty among non-elderly patients diagnosed with valvular heart disease or coronary artery disease undergoing cardiac surgery and its consequences with regard to hospital outcomes.

The limitations of our study are the small-sized cohort, which might not provide the required statistical power to comment on the significance of findings/results or to analyze confounders. Moreover, a small cohort may not include all postoperative complications that may be associated with frailty. Therefore, future studies are necessary to corroborate our findings and to verify the risk-benefit ratio of using preoperative rehabilitation programs for frail patients.

Conclusion

We observed that frailty is prevalent even among non-elderly patients undergoing CABG or valvular heart surgery and is associated with higher postoperative hospital mortality.

• Sources of Funding
  There were no external funding sources for this study.
• Study Association
  This article is part of the thesis of master submitted by Camila Bottero, from Universidade de São Paulo.

Referências

• ¹
  Afilalo J, Alexander KP, Mack MJ, Maurer MS, Green P, Allen LA, et al. Frailty assessment in the cardiovascular care of older adults. J Am Coll Cardiol.2014;63(8):747-62.
• ²
  Sieber CC. Frailty - From concept to clinical practice. Exp Gerontol. 2017;87(Pt B):160-7.
• ³
  Fried LP, Tangen CM, Walston J, Newman AB, Hirsch C, Gottdiener J, et al. Frailty in older adults: evidence for a phenotype. J Gerontol Biol Sci Med Sci.2001;56(3):M146-56.
• ⁴
  Pereira AA, Borim FSA, Neri AL. Risk of death in elderly persons based on the frailty phenotype and the frailty index: a review study. Rev Bras Geritr Bras Gerontol. 2017;20(2):273-85.
• ⁵
  Rajabali N, Rolfson D,Bagshaw SM. Assessment and Utility of Frailty Measures in Critical Illness, Cardiology, and Cardiac Surgery. Canad J Cardiol. 2016;32(9):1157-65.
• ⁶
  Angulo J, El Assar M, Rodriguez-Manas L. Frailty and sarcopenia as the basis for the phenotypic manifestation of chronic diseases in older adults. Mol Aspects Med. 2016 Aug;50:1-32.
• ⁷
  Xue QL. The frailty syndrome: definition and natural history. Clin Geriat Med. 2011;27(1):1-15.
• ⁸
  Craig CL, Marshall AL, Sjostrom M, Bauman AE, Booth ML, Ainsworth BE, et al. International physical activity questionnaire: 12-country reliability and validity. Med Sci Sports Exerc. 2003;35(8):1381-95.
• ⁹
  Laboratories ACoPSfCPF. ATS statement: guidelines for the six-minute walk test. Am J Respir Crit Care. 2002;166(1):111-7.
• ¹⁰
  Afilalo J, Mottillo S, Eisenberg MJ, Alexander KP, Noiseux N, Perrault LP, et al. Addition of frailty and disability to cardiac surgery risk scores identifies elderly patients at high risk of mortality or major morbidity. Circ Cardiovasc Qual Outcomes.2012;5(2):222-8.
• ¹¹
  Bagnall NM, Faiz O, Darzi A, Athanasiou T. What is the utility of preoperative frailty assessment for risk stratification in cardiac surgery? Interact Cardiovasc Thorac Surg. 2013;17(2):398-402.
• ¹²
  Lee DH, Buth KJ, Martin BJ, Yip AM, Hirsch GM. Frail patients are at increased risk for mortality and prolonged institutional care after cardiac surgery. Circulation. 2010;121(8):973-8.
• ¹³
  Sepehri A, Beggs T, Hassan A, Rigatto C, Shaw-Daigle C, Tangri N, et al. The impact of frailty on outcomes after cardiac surgery: a systematic review. J Thorac Cardiovasc Surg. 2014;148(6):3110-7.
• ¹⁴
  Sundermann SH, Dademasch A, Seifert B, Rodriguez C, Biefer H, Emmert MY, Walther T, et al. Frailty is a predictor of short- and mid-term mortality after elective cardiac surgery independently of age. Interact Cardiovasc Thorac Surg. 2014;18(5):580-5.
• ¹⁵
  Fried L, Walston J. Frailty and failure to thrive. In: Hazzard WR BJ, Halter JB, et al., editor. Principles of geriatric medicine and gerontology: New York: McGraw Hill; 2003. p. 1487–502.
• ¹⁶
  Powell R, Scott NW, Manyande A, Bruce J, Vogele C, Byrne-Davis LM, et al. Psychological preparation and postoperative outcomes for adults undergoing surgery under general anaesthesia. Cochrane Database of Systematic Reviews. 2016(5):CD008646.
• ¹⁷
  Santos-Eggimann B, Cuenoud P, Spagnoli J, Junod J. Prevalence of frailty in middle-aged and older community-dwelling Europeans living in 10 countries. J Gerontol A Biol Sci Med. 2009;64(6):675-81.
• ¹⁸
  Brothers TD, Theou O, Rockwood K. Frailty and migration in middle-aged and older Europeans. Arch Gerontol Geriatr. 2014;58(1):63-8.
• ¹⁹
  Barili F, Pacini D, Capo A, Rasovic O, Grossi C, Alamanni F, et al. Does EuroSCORE II perform better than its original versions? A multicentre validation study. Eur Heart J. 2013;34(1):22-9.
• ²⁰
  Nashef SA, Roques F, Sharples LD, Nilsson J, Smith C, Goldstone AR, et al. EuroSCORE II. Eur J Cardio-Thorac Surg. 2012;41(4):734-44; discussion 44-5.
• ²¹
  Prins C, de Villiers Jonker I, Botes L, Smit FE. Cardiac surgery risk-stratification models. Cardiovasc J Afr., 2012;23(3):160-4.
• ²²
  Fortes JVS, Silva MGB, Baldez TE, Costa MAG, Silva LN, et al. Mortality Risk After Cardiac Surgery: Application of Inscor in a University Hospital in Brazil's Northeast. Braz J Cardiovasc Surg. 2016; 31(5):96-9.
• ²³
  Lazam S, Vanoverschelde JL, Tribouilloy C, Grigion, F, Suri R, Avierinos, JF, et al. Twenty-Year Outcome after Mitral Repair Versus Replacement for Severe Degenerative Mitral Regurgitation: Analysis of a Large, Prospective, Multicenter, International Registry. Circulation, 2017;135(5):410-22.
• ²⁴
  McIsaac DI, Bryson GJ, Van Walraven C. Association of frailty and 1-year postoperative mortality following major elective noncardiac surgery: A population-based cohort study. JAMA Surg. 2016;151(6):538-45.
• ²⁵
  Barillaro C, Liperoti R, Martone AM, Onder G, Landi F. The new metabolic treatments for sarcopenia. Clin Exp Res. 2013;25(2):119-27.
• ²⁶
  Theou O, Stathokostas L, Roland KP, Jakobi JM, Patterson C, Vandervoort AA, et al. The effectiveness of exercise interventions for the management of frailty: a systematic review. J Aging Res. 2011;2011:569194.
• ²⁷
  Yamamoto K, Nagatsuma Y, Fukuda Y, Hirao M, Nishikawa K, Miyamoto A, et al. Effectiveness of a preoperative exercise and nutritional support program for elderly sarcopenic patients with gastric cancer. Gastric Cancer. 2017;20(5):913-8.
• ²⁸
  Sawatzky JA, Kehler DS, Ready AE, Lerner N, Boreskie S, Lamont D, et al. Prehabilitation program for elective coronary artery bypass graft surgery patients: a pilot randomized controlled study. Clin Rehab. 2014;28(7):648-57.
• ²⁹
  Waite I, Deshpande R, Baghai M, Massey T, Wendler O, Greenwood S. Home-based preoperative rehabilitation (prehab) to improve physical function and reduce hospital length of stay for frail patients undergoing coronary artery bypass graft and valve surgery. J Cardio thorac Surg. 2017;12(1):91.
• ³⁰
  Tieland M, van de Rest O, Dirks ML, van der Zwaluw N, Mensink M, van Loon LJ, et al. Protein supplementation improves physical performance in frail elderly people: a randomized, double-blind, placebo-controlled trial. J Am Med Dir Assoc. 2012;13(8):720-6.
• ³¹
  Freiberger E, Kemmler W, Siegrist M, Sieber C. Frailty and exercise interventions : Evidence and barriers for exercise programs. Z Gerontol Geraitr. 2016;49(7):606-11.
• ³²
  Katsura M, Kuriyama A, Takeshima T, Fukuhara S, Furukawa TA. Preoperative inspiratory muscle training for postoperative pulmonary complications in adults undergoing cardiac and major abdominal surgery. Cochrane Database of System Rev. 2015(10):CD010356.

Publication Dates

• Publication in this collection
  23 Oct 2020
• Date of issue
  Oct 2020

History

• Received
  06 Feb 2019
• Reviewed
  14 Aug 2019
• Accepted
  10 Sept 2019