Impact of frailty on outcomes of elderly patients undergoing percutaneous coronary intervention: A systematic review and meta-analysis

Table 1 Search strategy of electronic databases

Database	Search string	No. of records
PubMed/MEDLINE	("Frailty"[MeSH] OR "Frail Elderly"[MeSH] OR "Frailty, Psychological"[MeSH] OR "Physical Frailty"[MeSH] OR "Frailty Phenotype"[MeSH] OR "Frailty Scale"[MeSH] OR "Clinical Frailty Scale"[MeSH] OR "Frailty Index"[MeSH] OR "Fried Frailty Criteria" OR "Frailty assessment" OR "Frailty evaluation") AND ("Aged"[MeSH] OR "Elderly"[MeSH] OR "Geriatric"[MeSH] OR "Older Adults" OR "Seniors" OR "Aging" OR "Elderly population") AND ("Percutaneous Coronary Intervention"[MeSH] OR "Coronary Angioplasty"[MeSH] OR "PCI" OR "PTCA" OR "Coronary stenting")	66
EMBASE	('frailty'/exp OR 'frail elderly'/exp OR 'psychological frailty'/exp OR 'physical frailty'/exp OR 'frailty phenotype'/exp OR 'frailty scale'/exp OR 'clinical frailty scale'/exp OR 'frailty index'/exp OR 'fried frailty criteria' OR 'frailty assessment' OR 'frailty evaluation') AND ('aged'/exp OR 'elderly'/exp OR 'geriatric'/exp OR 'older adults' OR 'seniors' OR 'aging' OR 'elderly population') AND ('percutaneous coronary intervention'/exp OR 'coronary angioplasty'/exp OR 'PCI' OR 'PTCA' OR 'coronary stenting') AND ('human'/exp AND 'english'/exp)	158
Cochrane Library (CENTRAL)	("Frailty"[MeSH] OR "Frail Elderly"[MeSH] OR "Frailty, Psychological"[MeSH] OR "Physical Frailty"[MeSH] OR "Frailty Phenotype"[MeSH] OR "Frailty Scale"[MeSH] OR "Clinical Frailty Scale"[MeSH] OR "Frailty Index"[MeSH] OR "Fried Frailty Criteria" OR "Frailty assessment" OR "Frailty evaluation") AND ("Aged"[MeSH] OR "Elderly"[MeSH] OR "Geriatric"[MeSH] OR "Older Adults" OR "Seniors" OR "Aging" OR "Elderly population") AND ("Percutaneous Coronary Intervention"[MeSH] OR "Coronary Angioplasty"[MeSH] OR "PCI" OR "PTCA" OR "Coronary stenting")	104
Web of Science	TS=("frailty" OR "frail elderly" OR "physical frailty" OR "frailty phenotype" OR "clinical frailty scale" OR "fried frailty criteria" OR "frailty assessment" OR "frailty evaluation") AND TS=("aged" OR "elderly" OR "geriatric" OR "older adults" OR "seniors" OR "aging" OR "elderly population") AND TS=("percutaneous coronary intervention" OR "coronary angioplasty" OR "PCI" OR "PTCA" OR "coronary stenting")	111

Table 2 Characteristics of included studies

Ref.	Country	Study design	Frailty criteria	Population	Sample size	Age (yr)	Male (%)	Frail (%)	Follow-up period	Outcomes
Shimono et al[13], 2023	Japan	RC	CFS	Stable coronary artery disease	239	79.5 + 7.5	68.40%	15.90%	962 d	MACEs, major bleeding, all-cause death, ischaemic events
Özbek and Balun[14], 2023	Turkey	RC	CFS	PCI	244	84.6 + 3.4	53.70%	46.30%	1 yr	Major bleeding, all-cause death, revascularization, stroke
Mangale et al[15], 2023	India	PC	Clinical frailty scale by Rockwood et al[43], AFN, DFI	STEMI	402	75 + 6	64.70%	32%	28 d	MACEs
Noike et al[16], 2023	Japan	RC	CFS	Stable angina pectoris	608	77 + 9.2	66%	23.19%	529 d	MACEs, all-cause death, stroke, cardiac death
Heaton et al[17], 2023	United States	RC	Gilbert’s hospital frailty score	STEMI	584918	63.58 + 13.08	69.37%	all	1 mo	30-d readmission, mortality
Borovac et al[18], 2022	United States	RC	Hospital Frailty Risk Score (HFRS)	STEMI		64.6 + 13.7	66.80%	28.40%	NA	Death, cerebrovascular event, and major bleeding
Kanwar et al[19], 2021	United States	PC	Fried criteria	CAD	629	69	69%	18.60%	35 mo	All-cause mortality, MACEs
Kurobe et al[20], 2021	Japan	RC	CFS	STEMI	331	77.3 + 10.5	57.60%	22.20%	35.6 mo	MACEs, all-cause death, stroke
Kanenawa et al[21], 2021	Japan	RC	CFS	PCI	2439	71.9 + 10.1	72.70%	28.30%	1 yr	All-cause death, MI, stroke, major bleeding
Nishihara et al[22], 2021	Japan	PC	Walking, cognition, and ADL	AMI	546	84.5 (82–88)	47.80%	27.80%	589 d	All-cause mortality, bleeding
Kwok et al[23], 2020	United Kingdom	RC	Validated Hospital Frailty Risk Score	CAD	73,06,007	66.1 + 12.3	65.30%	1836 patients	In hospital	All-cause mortality, MACEs
Yoshioka et al[24], 2019	Japan	RC	CSHA-CFS	STEMI	273	84.6 + 3.8	46.20%	12.50%	565 d	All-cause mortality
Nguyen et al[25], 2019	Vietman	CS	REFS	PCI	163	73.5 + 8.3	60.80%	41.70%	30 d	30-d mortality
Damluji et al[26], 2019	United States	CS	Frail index	AMI	140089	> 75	46.80%	9.90%	NA	In-hospital mortality
Herman et al[27], 2019	Netherlands	RC	VMS	STEMI	206	79 + 6.4	57.80%	27.70%	30 d	All-cause mortality
Calvo et al[28], 2019	Spain	PC	CFS	STEMI	259	82.6 + 6	57.90%	19.70%	In hospital	In-hospital mortality
Batty et al[29], 2019	United Kingdom	PC	Fried criteria	NSTEACS	280	81.0 + 3.5	60.00%	27.50%	1 yr	MACEs
Dodson et al[30], 2018	United States	CS	FPSS	NSTEMI	100	75.3 + 7.7	60.20%	19.80%	In-hospital	In-hospital bleeding
Patel et al[31], 2018	Australia	CS	Frail index	STEMI	1275	> 65	NA	52.60%	NA	All-cause death, major bleeding
Sujino et al[32], 2015	Japan	RC	CSHA-CFS	STEMI	42	88.1 + 2.5	58.10%	26.20%	In hospital	In-hospital mortality
Murali Krishnan et al[33], 2015	United Kingdom	PC	CSHA-CFS	CAD	746	62.2 + 7.4	70.10%	10.85%	1 yr	All-cause mortality

RC: Retrospective cohort; PC: Prospective cohort; CS: Cross-section; CFS: Clinical frailty scale; STEMI: ST elevated myocardial infarction; CAD: Coronary artery disease; PCI: Percutaneous coronary intervention; AMI: Acute myocardial infarction; MACEs: Major adverse cardiovascular events; NA: Not applicable; AFN: Acute frailty network; DFI: Derby frailty index; ADL: Activities of daily living; CSHA: Canadian study of health and aging; REFS: Reported Edmonton Frail Scale; VMS: Dutch Safety Management system; FPSS: Frailty point scoring system.

Table 3 Quality of included studies

Ref.	Selection				Comparability	Outcome			Total
	Representativeness of the exposed cohort	Selection of the nonexposed cohort	Ascertainment of exposure	Demonstration that outcome of interest	Basis of the design or analysis	Assessment of outcome	Follow-up long enough for outcomes	Adequate follow-up
Shimono et al[13], 2023	0	1	1	1	1	1	1	1	7
Özbek and Balun[14], 2023	0	1	1	1	1	1	1	1	7
Mangale et al[15], 2023	0	1	1	1	1	1	1	1	7
Noike et al[16], 2023	1	1	0	1	1	1	1	1	7
Heaton et al[17], 2023	1	1	1	1	2	1	1	1	9
Borovac et al[18], 2022	1	1	0	1	1	1	1	1	7
Kanwar et al[19], 2021	1	1	1	1	1	1	1	1	8
Kurobe et al[20], 2021	1	1	1	1	1	1	1	1	8
Kanenawa et al[21], 2021	1	1	1	1	1	1	1	1	8
Nishihara et al[22], 2021	0	1	1	1	1	1	1	1	7
Kwok et al[23], 2020	1	1	0	1	1	1	1	1	7
Yoshioka et al[24], 2019	1	1	0	1	1	1	1	1	7
Nguyen et al[25], 2019	1	1	0	1	1	1	1	1	7
Damluji et al[26], 2019	0	1	1	1	1	1	1	1	7
Herman et al[27], 2019	1	1	1	1	1	1	1	1	8
Calvo et al[28], 2019	1	1	0	1	1	1	1	1	7
Batty et al[29], 2019	1	1	1	1	1	1	1	1	8
Dodson et al[30], 2018	1	1	1	1	1	1	1	1	8
Patel et al[31], 2018	1	1	1	1	1	1	1	1	8
Sujino et al[32], 2015	1	1	1	1	1	1	1	1	8
Murali Krishnan et al[33], 2015	1	1	0	1	1	1	1	1	7

Table 4 Subgroup analysis for all-cause mortality

Criteria	Subgroup	HR (95%CI)	P value	I2 (%)
Overall		2.08 (1.78-2.43)	< 0.0001	98
Study design	Prospective	2.70 (1.78-2.43)	< 0.0001	98
	Retrospective	2.45 (1.51-3.98)	0.0003	90
Age	< 75 yr	2.24 (1.15-3.25)	< 0.0001	98
	> 75 yr	3.58 (1.29-9.94)	0.01	94
Frailty scale	CFS	3.89 (1.88-8.05)	0.0003	86
	Others	1.82 (1.53-2.17)	< 0.0001	99
Patients for PCI	CAD	1.74 (1.50-2.30)	< 0.0001	98
	STEMI	3.48 (2.00-6.03)	< 0.0001	64

CFS: Clinical Frailty Scale; CAD: Coronary artery disease; PCI: Percutaneous coronary intervention; HR: Hazard ratio; 95%CI: 95% confidence interval.