Table 2.
Mean Changes in Echocardiographic Parameters From Baseline to 6 Months
| CRT OFF | CRT ON | P Value | |||||||
|---|---|---|---|---|---|---|---|---|---|
| n | Baseline | 6-Month | Change (SD) | n | Baseline | 6-Month | Change (SD) | ||
| Eessb, mm Hg/mL | 150 | 0.81 | 0.81 | 0.00 (0.43) | 325 | 0.85 | 0.91 | 0.06 (0.46) | 0.15 |
| Stroke work, mL mm Hg | 167 | 6177 | 6211 | 34 (2104) | 352 | 6379 | 6323 | −55 (2322) | 0.66 |
| Stroke work/LVEDV, mm Hg | 167 | 23.5 | 24.1 | 0.6 (7.0) | 352 | 24.6 | 28.1 | 3.4 (8.8) | 0.0001 |
| PRSW, g/cm2 | 104 | 38.1 | 38.2 | 0.0 (12.2) | 200 | 40.3 | 43.7 | 3.4 (13.4) | 0.03 |
| Ea, mm Hg/mL | 167 | 1.75 | 1.73 | −0.02 (0.70) | 352 | 1.78 | 1.80 | 0.03 (0.70) | 0.49 |
| Ea/Eessb | 150 | 2.47 | 2.42 | −0.05 (1.26) | 324 | 2.30 | 2.27 | −0.03 (1.32) | 0.87 |
| V0, mL | 150 | 34.3 | 36.0 | 2 (93) | 323 | 37.9 | 16.2 | −22 (84) | 0.007 |
| Stroke volume, mL | 167 | 69.6 | 69.7 | 0.1 (20) | 353 | 70.7 | 69.6 | −1 (24) | 0.52 |
| LVEDV, mL | 167 | 274 | 269 | −5 (49) | 353 | 268 | 239 | −29 (66) | <0.0001 |
| LVESV, mL | 167 | 204 | 199 | −5 (42) | 353 | 197 | 170 | −27 (55) | <0.0001 |
| LVEF, % | 167 | 26.4 | 27.2 | 0.8 (6.6) | 353 | 27.2 | 30.8 | 3.6 (8.3) | <0.0001 |
P value compares the mean changes (2-sample t test) between CRT OFF and CRT ON. CRT OFF indicates control group; CRT ON, active cardiac resynchronization therapy group; Ea, effective arterial elastance; Eessb, single beat–derived end-systolic elastance; LVEDV, left ventricular end-diastolic volume; LVEF, left ventricular ejection fraction; LVESV, left ventricular end-systolic volume; PRSW, preload recruitable stroke work; V0, volume intercept.