Table 1.
Baseline characteristics of the cohort, divided by cases and controls, for the primary case–control analysis
| Characteristic | OVERALL | CASE Rehospitalized | CONTROL Not rehospitalized during same time interval from index hospital discharge |
|---|---|---|---|
| |
N = 3227 |
N = 1674 |
N = 1674 |
|
β-Blocker Intensification in Prior 30-Days |
|
39 (2.3%) |
27 (1.6%) |
|
Matching variables |
|
|
|
| Age, years, median (IQR) |
76.1 (67.2-83.5) |
75.8 (68.6-82.9) |
75.8 (68.5-82.9) |
| Female Gender |
1715 (53.2%) |
895 (53.5%) |
895 (53.5%) |
| Year of Index Hospitalization |
|
|
|
| 2001 |
409 (12.7%) |
229 (13.7%) |
229 (13.7%) |
| 2002 |
393 (12.2%) |
220 (13.1%) |
220 (13.1%) |
| 2003 |
362 (11.2%) |
222 (13.3%) |
222 (13.3%) |
| 2004 |
401 (12.4%) |
247 (14.8%) |
247 (14.8%) |
| 2005 |
438 (13.6%) |
261 (15.6%) |
261 (15.6%) |
| 2006 |
354 (11.0%) |
186 (11.1%) |
186 (11.1%) |
| 2007 |
358 (11.1%) |
176 (10.5%) |
176 (10.5%) |
| 2008 |
344 (10.7%) |
123 (7.3%) |
123 (7.3%) |
| 2009 |
168 (5.2%) |
10 (0.6%) |
10 (0.6%) |
| LVSD at index hosp |
1108 (37.0%) |
574 (34.3%) |
574 (34.3%) |
|
Covariates |
|
|
|
| History of Myocardial Infarction |
427 (13.2%) |
245 (14.6%) |
182 (10.9%) |
| History of Atrial Fibrillation |
1422 (44.1%) |
759 (45.3%) |
748 (44.7%) |
| History of Diabetes |
1457 (45.1%) |
836 (49.9%) |
732 (43.7%) |
| History of COPD |
1230 (38.1%) |
707 (42.2%) |
614 (36.7%) |
| History of Chronic Liver Disease |
67 (2.1%) |
33 (2.0%) |
25 (1.5%) |
| Systolic BP preceding readmission or matched time period, mmHg, median (IQR) |
122 (110–139) |
122 (110–138) |
124 (110–140) |
| Diastolic BP preceding readmission or matched time period, mmHg, median (IQR) |
68 (60–78) |
68 (60–78) |
70 (60–78) |
| Heart rate preceding readmission or matched control time period, bpm, median (IQR) |
54 (42–68) |
53 (42–67) |
55 (44–66) |
| CrCl preceding readmission or matched control time period, mL/min/1.73 m2, median (IQR) |
50.2 (34.9-65.6) |
49.8 (34.3-65.1) |
55.2 (41.0-71.2) |
|
β-Blocker Use (at anytime in follow up) |
|
|
|
| Atenolol |
551 (17.1%) |
307 (18.3%) |
334 (20.0%) |
| Carvedilol |
222 (6.9%) |
113 (6.8%) |
104 (6.2%) |
| Metoprolol Succinate |
526 (16.3%) |
266 (15.9%) |
261 (15.6%) |
| Metoprolol Tartrate |
1079 (33.4%) |
634 (37.9%) |
606 (36.2%) |
| Other β-Blocker |
57 (1.8%) |
31 (1.9%) |
38 (2.3%) |
| No β-Blocker |
792 (24.54%) |
322 (19.2%) |
331 (19.8%) |
| Switch β-Blocker Type During Follow Up | 538 (2.1%) | 343 (25.4%) | 311 (23.2%) |
*869 controls subsequently became cases due to hospital readmission at a time further from the index hospitalization, and thus are represented in both columns; 748 patients in the “all cohort” did not qualify as a case or a control.
SD = standard deviation; LVSD = left ventricular systolic dysfunction (LVEF < =40% or moderate/severe LV systolic dysfunction); LVEF = left ventricular ejection fraction; COPD = chronic obstructive pulmonary disease; BP = blood pressure; mmHg = millimeters mercury; CrCl = creatinine clearance; mL = milliliter; min = minute; m = meter.
All cells have complete data for the entire cohort, except for blood pressure and heart rate (n = 3,218), and serum creatinine (n = 3,202).