Table 1. Demographic, Anthropometric, and Clinical Characteristics of Patients, Overall and by CO Estimate Classification Methods in the VA CART Cohorta.
| Variable | All (N = 12 232) | All, Excluding High CI (N = 11 426)b | Both Low (n = 2764) | eFick Low and Td Normal (n = 1602) | eFick Normal and Td Low (n = 1583) | Both Normal (n = 5477) | P Value for Overall | P Value for Discordant Groups |
|---|---|---|---|---|---|---|---|---|
| Demographic and Anthropometric Data | ||||||||
| Age, mean (SD), y | 66.2 (10.0) | 66.4 (9.9) | 66.8 (10.2) | 64.7 (9.6) | 68.6 (10.1) | 66.1 (9.7) | <.001 | <.001 |
| Female sex, No. (%) | 398 (3.3) | 360 (3.2) | 81 (2.9) | 74 (4.6) | 41 (2.6) | 164 (3.0) | .003 | .003 |
| Race, No. (%) | ||||||||
| White | 9464 (77.4) | 8857 (77.5) | 2038 (73.7) | 1246 (77.8) | 1186 (74.9) | 4387 (80.1) | <.001 | .07 |
| Black | 1852 (15.1) | 1711 (15.0) | 533 (19.3) | 232 (14.5) | 276 (17.4) | 670 (12.2) | ||
| Other | 916 (7.5) | 858 (7.5) | 193 (7.0) | 124 (7.7) | 121 (7.6) | 420 (7.7) | ||
| BMI category, No. (%) | ||||||||
| Underweight, <18.5 | 115 (0.9) | 103 (0.9) | 24 (0.9) | 16 (1.0) | 12 (0.8) | 51 (0.9) | <.001 | <.001 |
| Normal, 18.5 to <25 | 2338 (19.1) | 2169 (19.0) | 588 (21.3) | 234 (14.6) | 371 (23.4) | 976 (17.8) | ||
| Overweight, 25 to <30 | 3946 (32.3) | 3682 (32.2) | 975 (35.3) | 451 (28.2) | 530 (33.5) | 1726 (31.5) | ||
| Obese, 30 to <35 | 3070 (25.1) | 2893 (25.3) | 691 (25.0) | 437 (27.3) | 393 (24.8) | 1372 (25.1) | ||
| Severely obese, ≥35 | 2763 (22.6) | 2579 (22.6) | 486 (17.6) | 464 (29.0) | 277 (17.5) | 1352 (24.7) | ||
| Body surface area, mean (SD), m2 | 2.1 (0.2) | 2.1 (0.2) | 2.1 (0.2) | 2.1 (0.2) | 2.1 (0.2) | 2.1 (0.2) | <.001 | <.001 |
| Clinical Data | ||||||||
| Tricuspid valve disease, No. (%) | 240 (2.0) | 223 (2.0) | 71 (2.6) | 30 (1.9) | 34 (2.1) | 88 (1.6) | .03 | .67 |
| Other valve disease, No. (%) | 6186 (50.6) | 5833 (51.1) | 1360 (49.2) | 773 (48.3) | 832 (52.6) | 2868 (52.4) | .003 | .02 |
| Atrial fibrillation or flutter, No. (%) | 3235 (26.4) | 3095 (27.1) | 1066 (38.6) | 390 (24.3) | 523 (33.0) | 1116 (20.4) | <.001 | <.001 |
| Systemic hypertension, No. (%) | 10672 (87.2) | 9984 (87.4) | 2426 (87.8) | 1395 (87.1) | 1365 (86.2) | 4798 (87.6) | .45 | .51 |
| Mean pulmonary artery pressure >25 mm Hg, No. (%) | 6907 (56.5) | 6442 (56.4) | 1956 (70.8) | 935 (58.4) | 879 (55.5) | 2672 (48.8) | <.001 | .11 |
| Pulmonary vascular resistance, mean (SD), WUc | 2.4 (1.9) | 2.4 (1.9) | 3.6 (2.7) | 2.5 (1.7) | 2.5 (1.7) | 1.8 (1.1) | <.001 | .13 |
| Congestive heart failure, No. (%) | 6897 (56.4) | 6511 (57.0) | 2055 (74.3) | 874 (54.6) | 986 (62.3) | 2596 (47.4) | <.001 | <.001 |
| Chronic obstructive pulmonary disease, No. (%) | 4063 (33.2) | 3809 (33.3) | 927 (33.5) | 578 (36.1) | 483 (30.5) | 1821 (33.2) | .01 | .001 |
| Chronic kidney disease, No. (%) | 3485 (28.5) | 3177 (27.8) | 871 (31.5) | 355 (22.2) | 477 (30.1) | 1474 (26.9) | <.001 | <.001 |
| Diabetes, No. (%) | 5597 (45.8) | 5227 (45.7) | 1241 (44.9) | 765 (47.8) | 690 (43.6) | 2531 (46.2) | .08 | .02 |
| Liver cirrhosis, No. (%) | 884 (7.2) | 749 (6.6) | 168 (6.1) | 108 (6.7) | 94 (5.9) | 379 (6.9) | .35 | .39 |
| Heart rate, mean (SD), beats/min | 71.9 (14.2) | 71.5 (14.1) | 73.8 (15.7) | 71.5 (14.1) | 69.9 (14.2) | 71.0 (13.2) | <.001 | .01 |
| Hemoglobin concentration, mean (SD), g/dL | 12.8 (2.0) | 12.9 (2.0) | 13.3 (1.9) | 13.4 (1.9) | 12.7 (1.9) | 12.5 (2.0) | .26 | <.001 |
| Oxygen saturation, mean (SD), % | 94.7 (3.9) | 94.6 (5.4) | 94.5 (5.6) | 94.3 (4.8) | 94.7 (7.0) | 94.6 (4.9) | .14 | .85 |
| CO, mean (SD), L/min | ||||||||
| eFick | 5.3 (1.6) | 5.1 (1.3) | 3.8 (0.7) | 4.1 (0.7) | 5.4 (0.9) | 6.0 (1.1) | <.001 | <.001 |
| Td | 5.3 (1.7) | 5.1 (1.5) | 3.7 (0.8) | 5.7 (1.1) | 4.1 (0.6) | 6.0 (1.2) | <.001 | <.001 |
| CI, mean (SD), L/min/m2 | ||||||||
| eFick | 2.5 (0.7) | 2.4 (0.6) | 1.8 (0.3) | 1.9 (0.3) | 2.6 (0.3) | 2.8 (0.4) | <.001 | <.001 |
| Td | 2.5 (0.7) | 2.4 (0.6) | 1.7 (0.3) | 2.6 (0.4) | 1.9 (0.2) | 2.8 (0.4) | <.001 | <.001 |
| Mortality, No. (%) | ||||||||
| 90 d | 794 (6.5) | 716 (6.3) | 252 (9.1) | 82 (5.1) | 110 (6.9) | 272 (5.0) | <.001 | .04 |
| 1 y | 1838 (15.0) | 1673 (14.6) | 550 (19.9) | 207 (12.9) | 244 (15.4) | 672 (12.3) | <.001 | .049 |
Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); CI, cardiac index; CO, cardiac output; eFick, estimated oxygen uptake Fick; Td, thermodilution; VA CART, Veterans Affairs Clinical Assessment, Reporting, and Tracking; WU, wood units.
SI conversion factor: To convert hemoglobin concentration to grams per liter, multiply by 10.0.
The left most column provides data for the overall cohort while the second column from the left presents data excluding the subset of patients with elevated CI of >4.0 L/min/m2, and the remaining columns to the right present data for patients classified as low or normal CI. Differences between the 4 columns on the right were assessed using analysis of variance or χ2 test. Differences between discordant estimates (eFick low and Td normal vs eFick normal and Td low) were analyzed using independent t test or χ2 test. Data were missing for the following variables (number for the overall cohort/number excluding CI>4.0 L/min/m2): pulmonary vascular resistance (61/56), heart rate (4616/4309), hemoglobin concentration (1930/1808), and oxygen saturation (757/695).
High CI was defined as exceeding 4.0 L/min/m2.
Calculated using the mean of Td and eFick CO estimates.