Table 1. Clinical and echocardiographic characteristics of CRT responders versus non-responders at baseline and 6-month follow-up.
| Variable | Responders (n = 17) | Non-responders (n = 8) | P |
| Baseline | |||
| Age, yrs | 65.9 ± 7.0 | 58.3 ± 13.7 | 0.172 |
| Female gender | 4 (24%) | 1 (13%) | 0.915 |
| Heart rate, beats/min | 71.9 ± 14.1 | 74.7 ± 18.5 | 0. 735 |
| SBP, mmHg | 120.9 ± 32.5 | 110.9 ± 10.5 | 0.444 |
| DBP, mmHg | 72.6 ± 8.7 | 71.6 ± 8.7 | 0.879 |
| QRS | |||
| Duration, ms | 161.1 ± 22.5 | 138.9 ± 25.9 | 0.057 |
| LBBB morphology | 10 (59%) | 5 (63%) | 0.861 |
| NYHA functional class | 2.8 ± 0.6 | 3.4 ± 0.7 | 0.068 |
| Class of recommendation for CRT | |||
| I/A | 12 (71%) | 5 (63%) | 0.686 |
| I/B | 3 (18%) | 2 (25%) | 0.668 |
| Coronary artery disease | 4 (24%) | 4 (50%) | 0.388 |
| Hypertension | 9 (53%) | 2 (25%) | 0.378 |
| Diabetes | 4 (24%) | 1 (13%) | 0.915 |
| Renal insufficiency | 2 (12%) | 1 (13%) | 0.958 |
| Atrial fibrillation | 6 (35%) | 3 (38%) | 0.915 |
| PVC burden in a 24-h period | |||
| < 1000 | 9 (53%) | 4 (50%) | 0.891 |
| 1000–10,000 | 6 (35%) | 3 (38%) | 0.915 |
| > 10,000 | 2 (12%) | 1 (13%) | 0.958 |
| Serum biomarkers | |||
| CK-MB, U/L | 10.9 ± 4.2 | 11.8 ± 3.7 | 0. 566 |
| CK-MM, U/L | 55.3 ± 28.13 | 58.7 ± 30.9 | 0.798 |
| Cre, µmol/L | 82.4 ± 41.0 | 88.2 ± 17.8 | 0.565 |
| hs CRP, mg/L | 7.9 ± 12.6 | 6.2 ± 9.2 | 0.930 |
| Uric acid, µmol/L | 472.4 ± 135.8 | 499.3 ± 178.2 | 0.643 |
| NT-proBNP, pg/mL | 3541.5 ± 3389.1 | 3537.6 ± 2849.2 | 0. 998 |
| cTnT, ng/mL | 0.019 ± 0.010 | 0.023 ± 0.020 | 0.107 |
| Medication | |||
| ACEI/ARBs | 10 (59%) | 5 (63%) | 0.861 |
| Beta-blockers | 8 (47%) | 3 (38%) | 0.986 |
| Diuretics and/or spironolactone | 8 (47%) | 3 (38%) | 0.986 |
| Antiarrhythmics | 11 (65%) | 5 (63%) | 0.915 |
| Mitral regurgitation > grade II | 7 (41%) | 4 (50%) | 0.678 |
| LVEDV, mL | 222.9 ± 92.9 | 268.6 ± 171.7 | 0.392 |
| LVESV, mL | 161.1 ± 75.2 | 195.0 ± 129.7 | 0.414 |
| LVEF, % | 28.0 ± 6.6 | 28.6 ± 5.3 | 0.817 |
| SPWMD, ms | 177 ± 82.2 | 124.9 ± 48.2 | 0.052 |
| IVMD, ms | 46.2 ± 35.4 | 37.6 ± 33.5 | 0.062 |
| Yu index, ms | 63.7 ± 36.7 | 42.8 ± 20.9 | 0.091 |
| Follow-up | |||
| NYHA functional class | 1.8 ± 0.6 | 3.8 ± 0.5 | < 0.001 |
| LVEDV, mL | 155.5 ± 72.2 | 314.6 ± 121.4 | < 0.001 |
| LVESV, mL | 94.9 ± 54.9 | 249.6 ± 107.3 | < 0.001 |
| LVEF, % | 41.9 ± 10.8 | 23.1 ± 7.7 | < 0.001 |
| SPWMD, ms | 93.6 ± 40.4 | 96.1 ± 76.1 | 0.900 |
| IVMD, ms | 24.3 ± 27.1 | 21.9 ± 31 | 0.079 |
| Yu index, ms | 36.6 ± 17.8 | 51.3 ± 22.6 | 0.049 |
Data are expressed as n (%) or mean ± SD. ACEI: angiotensin converting enzyme inhibitor; ARB: angiotensin receptor blocker; CK-MB: creatine kinase MB fraction; CK-MM: creatine kinase MM fraction; Cre: creatinine; CRT: cardiac resynchronization therapy; cTnT: cardiac troponin T; DBP: diastolic blood pressure; hs CRP: high-sensitive C-reactive protein; IVMD: interventricular mechanical delay; LBBB: Left bundle branch block; LVEDV: left ventricular end-diastolic volume; LVEF: left ventricular ejection fraction; LVESV: left ventricular end-systolic volume. NT-proBNP: N-terminal of the prohormone brain natriuretic peptide; NYHA: New York Heart Association; PVC: premature ventricular contraction; SBP: systolic blood pressure; SPWMD: septal-posterior wall motion delay; Yu index: the standard deviation of time from QRS to peak systolic velocity in ejection phase for 12 LV segments.