Table 4.

Frequency of adverse events stratified by annual hospital volume

	Hospital Annual Volume				p-value
	<150 cases/year n=4,460	≥150-300 cases/year n=12,787	≥300-500 cases/year n=21,391	≥500 cases/year n=17,815
Major Adverse Events--no. (%)	123 (2.8)	198 (1.5)	431 (2.0)	262 (1.5)	< 0.001
Cardiac Arrest*	41 (0.9)	66 (0.5)	155 (0.7)	136 (0.8)	0.02
Arrhythmia (requiring PPM)†	4 (0.1)	1 (0.0)	6 (0.0)	5 (0.0)	0.05
Tamponade‡	11 (0.2)	7 (0.1)	28 (0.1)	24 (0.1)	0.01
Air Embolus§	1 (0.0)	4 (0.0)	7 (0.0)	8 (0.0)	0.86
Embolic Stroke∥	5 (0.1)	7 (0.1)	16 (0.1)	4 (0.0)	0.06
New Need for Dialysis¶	8 (0.2)	2 (0.0)	25 (0.1)	7 (0.0)	< 0.001
Event Requiring ECMO#	12 (0.3)	22 (0.2)	57 (0.3)	45 (0.3)	0.34
Event Requiring LVAD**	2 (0.0)	2 (0.0)	5 (0.0)	2 (0.0)	0.50
Unplanned Cardiac Surgery††	36 (0.8)	54 (0.4)	114 (0.5)	32 (0.2)	< 0.001
Unplanned Vascular Surgery‡‡	9 (0.2)	12 (0.1)	20 (0.1)	11 (0.1)	0.05
Unplanned Other Surgery§§	2 (0.0)	3 (0.0)	10 (0.0)	4 (0.0)	0.51
Subsequent Cardiac Cath.∥∥	17 (0.4)	60 (0.5)	112 (0.5)	38 (0.2)	< 0.001

Note: Individual adverse events do not add up to total adverse events because more than one adverse event could occur during a cath. lab visit

Abbreviations: no., number; PPM, permanent pacemaker; ECMO, extracorporeal membrane oxygenation; LVAD, left ventricular assist device; cath, catheterization

^*2 patients (1 from large, 1 from very large volume programs) with missing information for cardiac arrest

^†5 patients (1 from small, 2 from large, 2 from very large volume programs) with missing information for need for permanent pacemaker

^‡4 patients (2 from large, 2 from very large volume programs) with missing information for tamponade

^§4 patients (2 from large, 2 from very large volume programs) with missing information for air embolus

^∥5 patients (2 from large,3 from very large volume programs) with missing information for embolic stroke

^¶4 patients (2 from large, 2 from very large volume programs) with missing information for new requirement for dialysis

^#4 patients (2 from large, 2 from very large volume programs) with missing information for need for ECMO

^**4 patients (2 from large, 2 from very large volume programs) with missing information for need for LVAD

^††3 patients (1 from small, 1 from large, 1 from very large volume programs) with missing information for need for cardiac surgery

^‡‡4 patients (1 from small, 1 from large, 2 from very large volume programs) with missing information for need for vascular surgery

^§§6 (1 from small, 2 from large, 3 from very large volume programs) with missing information for need for other surgery

^∥∥6 patients (1 from small, 2 from large, 3 from very large volume programs) with missing information for need for subsequent cardiac cath.