Table 3.
Electrocardiogram characteristics before, during, and after pembrolizumab-based combination therapy
| ECG characteristics | Baseline (n = 41) |
†During treatment (n = 37) |
‡p-value (vs. baseline) |
†Post-treatment (n = 41) |
‡p-value (vs. baseline) |
|---|---|---|---|---|---|
| HR (beats/min), mean (+/-SD) | 72 (+/- 12) | 81 (+/- 17) | 0.036 | 76 (+/-17) | 0.91 |
| PR interval, median (IQR) | 147 (+/-23) | 150 (+/-22) | 0.91 | 146 (22.6) | 0.25 |
| QTc length, median (IQR) | 428 (+/-23) | 441 (+/-23) | 0.060 | 430 (+/-25) | 0.46 |
| QTc prolongation ≥ 450ms | 6 (14.6%) | 14 (38.9%) | 0.025 | 10 (24.4%) | 0.26 |
| Conduction disorder | 1 (2.4%) | 2 (5.4%) | > 0.99 | 3 (7.3%) | 0.25 |
| PVC/PAC | 0 | 2 (5.4%) | > 0.99 | 3 (7.3%) | 0.50 |
| Normal sinus rhythm | 32 (80.0%) | 25 (67.6%) | 0.41 | 28 (68.3%) | 0.48 |
| Sinus tachycardia | 1 (2.5%) | 7 (18.9%) | 0.16 | 3 (7.3%) | > 0.99 |
| Sinus bradycardia | 3 (7.5%) | 3 (8.1%) | 0.16 | 5 (12.2%) | 0.69 |
| Atrial fibrillation/flutter | 0 | 0 | - | 0 | - |
| LVH | 0 | 0 | - | 2 (4.9%) | > 0.99 |
| Low QRS voltage | 2 (4.9%) | 5 (13.5%) | 0.50 | 4 (9.8%) | > 0.99 |
| Abnormal P wave | 0 | 0 | - | 0 | - |
| Pathologic Q wave | 0 | 0 | - | 0 | - |
The most abnormal data obtained during treatment, and the most recent data obtained after treatment, are shown
Data are presented as number of patients (column %), mean (± SD), or median (IQR, interquartile range)
P-value is calculated by a paired t-test or signed rank test for continuous variables, and McNemar’s test for categorical variables
†Some variables may have smaller sample due to availability of reported parameter
‡Statistical analysis was done in patients with both baseline and post-treatment electrocardiogram
Abbreviations: ECG, electrocardiogram; HR, heart rate; SD, standard deviation; IQR, interquartile range; QTc, corrected QT interval; PVC, premature ventricular contractions; PAC, premature atrial contractions; LVH, left ventricular hypertrophy