Table 1.

Summary of baseline characteristics of included studies in meta-analysis

Authors (Year)	Trial name	Comparison	Number of patients	Age (years)	Male (%)	Clinical symptom	Hypertension	Prior MI	Prior PCI	Prior CABG	Prior stroke
Thiele (2012, 2013) [12, 13]	IABP-SHOCK II	IABP	301	70 (58, 78)a	67.1	MI complicated by CS	213/296 (72.0 %)	71/300 (23.7 %)	63/299 (21.1 %)	20/300 (6.7 %)	24/300 (8.0 %)
		without IABP	299	69 (58, 76)a	70.6		199/299 (66.6 %)	61/299 (20.4 %)	52/299 (17.4)%	12/299 (4.0 %)	20/299 (6.7 %)
Gu (2011) [24]	--	IABP	51	67.4 (9.6)	56.9	Acute STEMI or non-STEMI without CS	35 (68.6 %)	2 (3.9 %)	NR	NR	NR
		without IABP	55	66.6 (8.0)	65.5		33 (60.0 %)	3 (5.5 %)	NR	NR	NR
Patel (2011) [23]	CRISP AMI	IABP	161	56.1 (48.3, 64.3)a	82.0	Acute STEMI without CS	39 (24.2 %)	NR	3 (1.9 %)	NR	0
		without IABP	176	57.7 (48.6, 66.4)a	81.8		60 (34.1 %)	NR	2 (1.1 %)	NR	1 (0.6 %)
Perera (2010, 2013) [26, 27]	BCIS-1	IABP	151	71 (9)	81	High risk PCI without CS	95 (63 %)	113 (75 %)	17 (11 %)	25 (17 %)	12 (8 %)
		without IABP	150	71 (10)	78		91 (61)	108 (73 %)	14 (9 %)	20 (13 %)	11 (7 %)
Prondzinsky (2010) [28]	IABP SHOCK	IABP	19	62.1 (38, 82)b	74	Acute MI complicated by CS	8 (42.1 %)	4 (21.1 %)	NR	NR	NR
		without IABP	21	66.1 (49, 82)b	81		10 (47.6 %)	5 (23.8 %)	NR	NR	NR
van't Hof (1999) [29]	--	IABP	118	59 (10)	84	High risk PCI without CS	NR	17 (14 %)	NR	3 (3 %)	NR
		without IABP	120	56 (11)	84		NR	16 (13 %)	NR	7 (6 %)	NR
Stone (1997) [25]	PAMI-II TRIAL	IABP	211	64.7 (11.9)	74.9	High risk MI without CS	116 (54.8 %)	45 (21.4 %)	NR	16 (7.5 %)	NR
		without IABP	226	63.7 (13.0)	75.2		126 (55.7 %)	49 (21.7 %)	NR	13 (5.9 %)	NR

Abbreviations: IABP intra-aortic balloon pump, CS cardiogenic shock, MI myocardial infarction, STEMI ST-elevation MI, PCI percutaneous coronary intervention, CABG coronary artery bypass graft, NR no reported

Data presented in mean (SD), median (IQR)^a, or mean (range)^b