Outcomes in Cardiogenic Shock Patients with Extracorporeal Membrane Oxygenation Use: A Matched Cohort Study in Hospitals across the United States

Table 2

Unmatched variables between the two groups.

	Without ECMO		With ECMO		value
	N	% (95% CI)	N	% (95% CI)
Chronic condition body system indicator
Infectious and parasitic disease	207	25.7 (20.1–32.3)	315	39.3 (32.8–46.1)	0.004
Blood and blood-forming organs	257	31.9 (25.8–38.6)	519	64.8 (57.8–71.2)	<0.001
Mental disorders	264	32.8 (26.6–39.6)	128	16.0 (11.5–21.7)	<0.001
Circulatory system	779	96.8 (93.0–98.5)	802	100	0.014
Respiratory system	261	32.4 (26.2–39.3)	655	81.7 (76.0–86.4)	<0.001
Genitourinary system	343	42.6 (35.9–49.6)	580	72.3 (65.6–78.2)	<0.001
Skin and subcutaneous tissue	130	16.2 (11.7–21.9)	48	6.1 (3.5–10.3)	0.001
Musculoskeletal system	233	28.9 (23.1–35.5)	60	7.4 (4.7–11.7)	<0.001
Symptoms/signs/ill-defined conditions	307	38.1 (31.7–45.0)	604	75.3 (68.8–80.8)	<0.001
Injury and poisoning	285	35.5 (29.0–42.5)	478	59.6 (52.6–66.2)	<0.001
Health status/contact with health services factors	537	66.7 (59.9–72.9)	320	39.9 (33.6–46.5)	<0.001
Procedures^b
Extracorporeal membrane oxygenation (ECMO)	0	0	802	100	<0.001
Tracheostomy: temporary and permanent	20	2.5 (1.0–5.9)	81	10.2 (6.6–15.4)	0.002
Diagnostic bronchoscopy and biopsy of bronchus	25	3.0 (1.4–6.5)	95	11.8 (8.2–16.8)	0.001
Incision of pleura; thoracentesis; chest drainage	27	3.3 (1.5–7.2)	82	10.3 (6.8–15.2)	0.008
Other Operating Room Rx procedures on respiratory system and mediastinum	16	2.0 (0.7–5.6)	154	19.2 (14.3–25.2)	<0.001
Coronary artery bypass graft (CABG)	29	3.7 (1.9–6.9)	118	14.8 (10.8–19.9)	<0.001
Percutaneous transluminal coronary angioplasty (PTCA)	185	23.0 (17.8–29.3)	109	13.6 (9.5–19.1)	0.015
Other Operating Room heart procedures	39	4.9 (2.8–8.4)	401	50.0 (43.0–57.0)	<0.001
Other vascular catheterization, not heart	189	23.5 (18.1–29.9)	288	35.9 (29.8–42.6)	0.006
Other non-Operating Room therapeutic cardiovascular procedures	239	29.8 (23.9–36.3)	110	13.7 (9.6–19.2)	<0.001
Amputation lower extremity	42	5.2 (2.8–9.6)	11	1.4 (0.4–4.6)	0.04
Respiratory intubation and mechanical ventilation	101	12.5 (8.7–17.8)	456	56.9 (49.9–63.6)	<0.001
Blood transfusion	118	14.7 (10.5–20.3)	195	24.3 (19.0–30.6)	0.014
Conversion cardiac rhythm	28	3.5 (1.7–7.1)	146	18.2 (13.6–24.0)	<0.001

The following variables were not significantly different between cases and controls: chronic conditions of endocrine/nutritional/metabolic and immunity disorders, nervous system and sense organs, digestive system, and involving congenital anomalies; presence of injury diagnosis on record; or presence of unintentional injury. All procedures are based on Clinical Classification Software (CCS) procedures except ECMO which is based on the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes.