Table S1. Cardiothoracic surgical centers included in our study.

No.	Institution	State
1	University of Alabama	AL
2	Stanford University	CA
3	University of California, Davis	CA
4	University of California, Irvine	CA
5	University of California, San Diego	CA
6	University of California, Los Angeles	CA
7	University of California, San Francisco	CA
8	University of Southern California	CA
9	University of Colorado	CO
10	Yale University	CT
11	University of Florida	FL
12	University of Miami	FL
13	Emory University	GA
14	Georgia Regents Medical Center	GA
15	University of Iowa	IA
16	Loyola University	IL
17	Northwestern University	IL
18	Rush University	IL
19	University of Chicago	IL
20	Indiana University	IN
21	University of Kentucky	KY
22	Beth Israel Deaconess Medical Center	MA
23	Brigham and Women's Hospital	MA
24	Massachusetts General Hospital	MA
25	Johns Hopkins University	MD
26	University of Maryland	MD
27	University of Michigan	MI
28	Mayo Clinic	MN
29	University of Minnesota	MN
30	Washington University in St. Louis	MO
31	Duke University	NC
32	University of North Carolina	NC
33	Wake Forest University	NC
34	University of Nebraska	NE
35	Dartmouth-Hitchcock Medical Center	NH
36	Rutgers Robert Wood Johnson Medical School	NJ
37	Albert Einstein College of Medicine	NY
38	Columbia University Medical Center	NY
39	New York University	NY
40	University of Rochester	NY
41	Weill Cornell Medical College	NY
42	Cleveland Clinic	OH
43	Ohio State University	OH
44	University of Cincinnati	OH
45	Penn State Hershey Medical Center	PA
46	University of Pennsylvania	PA
47	University of Pittsburgh	PA
48	Medical University of South Carolina	SC
49	Vanderbilt University	TN
50	Baylor College of Medicine	TX
51	MD Anderson Cancer Center	TX
52	University of Texas Medical Branch - Galveston	TX
53	University of Utah	UT
54	University of Virginia	VA
55	University of Washington	WA
56	Medical College of Wisconsin	WI
57	University of Wisconsin	WI

Centers are arranged by alphabetical order by state.