Table 1.
Baseline Characteristics of the Study Population According to Treatment Assignment in Patients With and Without Chronic Kidney Disease (eGFR Above/Below 60 mL/min per 1.73 m2)
| No CKD eGFR ≥60 mL/min per 1.73 m2 N=797 | CKD eGFR <60 mL/min/1.73 m2 N=316 | |||||
|---|---|---|---|---|---|---|
| Control group N=403 | ICD group N=394 | P value | Control group N=155 | ICD group N=161 | P value | |
| Age, y, median (interquartile range) | 61 (54–67) | 62 (54–70) | 0.40 | 67 (61–73) | 70 (63–75) | 0.10 |
| Male sex, N (%) | 274 (68.0) | 277 (70.3) | 0.48 | 128 (82.6) | 128 (79.5) | 0.49 |
| Physiologic measures, median (interquartile range) | ||||||
| Systolic blood pressure, mm Hg | 125 (112–139) | 123 (110–138) | 0.17 | 120 (109–135) | 123 (108–140) | 0.53 |
| Heart rate, bpm | 69 (61–78) | 69 (61–77) | 0.60 | 70 (60–78) | 68 (60–76) | 0.65 |
| Body mass index, kg/m2 | 26 (23–30) | 27 (24–30) | 0.19 | 28 (25–32) | 28 (24–31) | 0.35 |
| N‐terminal pro‐B‐type natriuretic peptide, pg/mL | 924 (501–1905) | 1095 (526–2135) | 0.17 | 1522 (808–3067) | 1795 (887–3191) | 0.73 |
| eGFR, mL/min per 1.73 cm2 | 83 (71–97) | 82 (72–97) | 0.88 | 50 (41–57) | 47 (39–54) | 0.05 |
| QRS duration, msec | 140 (108–164) | 145 (111–165) | 0.46 | 150 (119–166) | 150 (122–168) | 0.90 |
| Left ventricular ejection fraction, %, mean (SD) | 24.4 (6.3) | 24.2 (6.3) | 0.62 | 23.1 (5.5) | 23.9 (6.3) | 0.27 |
| Duration of HF, median (interquartile range), months | 15 (8–51) | 16 (8–58) | 0.65 | 20 (10–93) | 50 (12–96) | 0.14 |
| Main cause of HF, N (%) | 0.82 | 0.89 | ||||
| Idiopathic | 314 (77.9) | 309 (78.4) | 109 (70.3) | 114 (70.8) | ||
| Valvular | 12 (3.0) | 13 (3.3) | 9 (5.8) | 7 (4.4) | ||
| Hypertension | 33 (8.2) | 36 (9.1) | 22 (14.2) | 26 (16.2) | ||
| Other | 44 (10.9) | 36 (9.1) | 15 (9.7) | 14 (8.7) | ||
| New York Heart Association class, N (%) | 0.58 | 0.28 | ||||
| II | 239 (59.3) | 226 (57.4) | 59 (38.1) | 71 (44.1) | ||
| III/IV | 164 (40.7) | 168 (42.6) | 96 (61.9) | 90 (55.9) | ||
| Medical history, N (%) | ||||||
| Hospitalization for HF | 263 (65.8) | 246 (62.8) | 0.38 | 98 (64.1) | 113 (70.2) | 0.25 |
| Hypertension | 99 (24.6) | 114 (28.9) | 0.16 | 67 (43.5) | 67 (41.6) | 0.73 |
| Diabetes | 69 (17.1) | 53 (13.5) | 0.15 | 41 (26.5) | 46 (28.6) | 0.67 |
| Atrial fibrillation | 128 (31.8) | 145 (36.8) | 0.13 | 80 (51.6) | 92 (57.1) | 0.32 |
| Stroke | 45 (11.2) | 35 (8.9) | 0.28 | 19 (12.3) | 16 (10.0) | 0.52 |
| Treatment, N (%) | ||||||
| Angiotensin‐converting enzyme inhibitor/angiotensin receptor blocker | 396 (98.3) | 388 (98.5) | 0.81 | 146 (94.2) | 144 (89.4) | 0.12 |
| Beta blocker | 378 (93.8) | 363 (92.1) | 0.36 | 137 (88.4) | 145 (90.1) | 0.63 |
| Mineralocorticoid receptor antagonist | 237 (58.8) | 237 (60.2) | 0.70 | 81 (52.3) | 88 (54.7) | 0.67 |
| Amiodarone | 15 (3.7) | 14 (3.6) | 0.90 | 17 (11.0) | 20 (12.4) | 0.69 |
| Loop diuretic | 278 (69.0) | 273 (69.3) | 0.93 | 138 (89.0) | 141 (87.6) | 0.69 |
| Thiazide | 31 (7.7) | 29 (7.4) | 0.86 | 14 (9.0) | 17 (10.6) | 0.65 |
| Metolazone | 4 (1.0) | 4 (1.0) | 0.97 | 2 (1.3) | 0 (0) | 0.15 |
| Erythropoietin | 0 (0) | 1 (0.3) | 0.31 | 3 (1.9) | 1 (0.6) | 0.30 |
| CRT‐P/CRT‐D | 222 (55.1) | 223 (56.6) | 0.67 | 100 (64.5) | 98 (60.9) | 0.50 |
CKD indicates chronic kidney disease; CRT‐D, cardiac resynchronization therapy defibrillator; CRT‐P, cardiac resynchronization therapy pacemaker; eGFR, estimated glomerular filtration rate; HF, heart failure; and ICD, implantable cardioverter‐defibrillator. According to the protocol, patients fulfilling criteria for CRT devices received a CRT‐D if randomized to the ICD arm or received a CRT‐P device if randomized to the control arm.