Table 2.

Level of evidence and quality assessment of the selected studies.

References	No. of Patients	Accurate Description of IC	Accurate Description of CRT	Accurate Description of Safety and Tolerance to IC + CRT	Accurate Description of Surgical Procedure	Newcastle–Ottawa Score
						Selection	Comparability	Outcome	Score
Kim et al., 2021 [18]	89	Yes	Yes	No	Yes	****	*	***	8
Truty et al., 2021 [19]	254	Yes	Yes	Yes	Yes	***	-	***	6
Hayashi et al., 2019 [20]	45	Yes	Yes	No	Yes	***	-	***	6
Murphy et al., 2019 [21]	49	Yes	Yes	Yes	Yes	***	-	***	6
Murphy et al., 2018 [22]	48	Yes	Yes	Yes	Yes	***	-	***	6
Takahashi et al., 2018 [23]	38	Yes	Yes	Yes	Yes	***	-	***	6
Pietrasz et al. [14]	203	Yes	Yes	No	Yes	****	*	***	8
Grose et al., 2017 [24]	85	Yes	Yes	Yes	No	****	*	***	8
Fiore et al., 2017 [25]	41	Yes	Yes	Yes	No	****	*	***	8
Abbott et al., 2013 [26]	164	Yes	Yes	No	No	****	*	***	8
Denost et al., 2012 [27]	111	Yes	Yes	No	Yes	****	*	***	8
Habermehl et al., 2012 [28]	215	Yes	Yes	Yes	No	***	-	***	6

Newcastle–Ottawa Quality Assessment Scale (*: the study met the criteria for a domain of the Newcastle–Ottawa Scale, each * represents if individual criterion within the subsection was fulfilled; -: the criteria were not met). Newcastle-Ottava Scale for Case-Control studies (Selection: 1. Adequacy of case definition, 2. Representativeness of the cases, 3. Selection of controls, 4. Definition of Controls; Comparability: 1. Comparability of cases and controls on the basis of the design; Exposure: 1. Ascertainment of exposure, 2. Same method of ascertainment for cases and con-trols, 3. Non-Response rate) and Cohort studies (Selection: 1. Representativeness of the exposed cohort, 2. Selection of the non-exposed cohort, 3. Ascertainment of exposure, 4. Demonstration that outcome of interest was not present at start of study; Compa-rability: 1. Comparability of cohorts on the basis of the design or analysis; Outcome: 1. Assessment of outcome, 2. Was follow-up long enough for outcomes to occur, 3. Adequacy of follow up of cohorts).