Table 2.
The association of several risk factors with QTc-prolongation in the development cohort (Bazett formula)
| Potential determinant | QTc- prolongation n = 27 |
No QTc-prolongation n = 80 |
OR | 95% CI |
|---|---|---|---|---|
| Age (in years) median; IQR | 58.0; 14.0 | 54.5; 23.0 | 1.02 | 0.99–1.05 |
| ≤ 25, n (%) | 1 (3.7) | 4 (5.0) | Ref. | Ref. |
| 26–50, n (%) | 5 (18.5) | 28 (35.0) | 0.71 | 0.07–7.79 |
| 51–75, n (%) | 17 (63.0) | 43 (53.8) | 1.58 | 0.17–15.19 |
| ≥ 76, n (%) | 4 (14.8) | 5 (6.3) | 3.20 | 0.25–41.21 |
| Female gender, n (%) | 4 (14.8) | 42 (52.5) | 0.16 | 0.05–0.50* |
| Caucasian race, n (%) | 26 (96.3) | 74 (92.5) | 2.11 | 0.24–18.35 |
| BMI (kg m2–1) a, mean ± SD | 25.7 ± 4.3 | 27.3 ± 5.3 | 0.93 | 0.85–1.03 |
| Clinical departments, n (%) | ||||
| Medical Units | 14 (51.9) | 69 (86.3) | Ref. | Ref. |
| Surgical Units | 9 (33.3) | 8 (10.0) | 5.55 | 1.82–16.86* |
| Cardiac Units | 4 (14.8) | 3 (3.8) | 6.57 | 1.32–32.66* |
| Comorbidities | ||||
| Myocardial infarction | 1 (3.7) | 1 (1.3) | 3.04 | 0.18–50.32 |
| Heart failure | 1 (3.7) | 3 (3.8) | 0.99 | 0.10–9.91 |
| Arrhythmia | 6 (22.2) | 6 (7.5) | 3.52 | 1.03–12.07* |
| Hypertension | 12 (48.1) | 17 (21.3) | 3.44 | 1.36–8.68* |
| Diabetes Mellitus | 5 (18.5) | 8 (10.0) | 2.05 | 0.61–6.89 |
| COPD/Asthma | 1 (3.7) | 11 (13.8) | 0.24 | 0.03–1.96 |
| Hematological malignancies | 12 (44.4) | 55 (68.8) | 0.36 | 0.15–0.89* |
| Hepatic dysfunction b, n (%) | ||||
| Increased ASAT (> 170 / 150 U L− 1) | – | 3 (3.8) | – | – |
| Increased ALAT (> 220 / 160 U L− 1) | – | 1 (1.3) | – | – |
| Increased bilirubin (> 16 μmol L− 1) | 2 (7.4) | 16 (20.0) | 0.33 | 0.07–1.55 |
| eGFR ≤50 ml min− 1 (MDRD) c, n (%) | 3 (11.1) | 6 (7.5) | 1.50 | 0.35–6.47 |
| Electrolyte disturbances d, n (%) | ||||
| Hyponatremia (< 136 mmol L− 1) | 2 (7.4) | 19 (23.8) | 0.25 | 0.06–1.17 |
| Hypokalemia (< 3.5 mmol L− 1) | 2 (7.4) | 3 (3.8) | 2.03 | 0.32–12.83 |
| Hypocalcemia (< 2.2 mmol L− 1) | 7 (25.9) | 17 (21.3) | 1.29 | 0.39–4.22 |
| Hypomagnesemia (< 0.7 mmol L− 1) | 4 (14.8) | 10 (12.5) | 1.33 | 0.34–5.29 |
| Concomitant medication, median; IQR | 8.0; 4.0 | 8.0; 4.0 | 1.02 | 0.86–1.20 |
| Loop diuretics, n (%) | 8 (29.6) | 15 (18.8) | 1.83 | 0.67–4.95 |
| QTc-prolonging drugs e, n (%) | ||||
| 0 | 4 (14.8) | 11 (13.8) | Ref. | Ref. |
| 1 | 6 (22.2) | 28 (35.0) | 0.59 | 0.14–2.50 |
| ≥ 2 | 17 (63.0) | 41 (51.3) | 1.14 | 0.32–4.09 |
Abbreviations: Ref. reference value; eGFR, estimated glomular filtration rate; IQR, interquartile range; BMI, body mass index; SD, standard deviation; OR, odds ratio; 95% CI, 95% confidence interval
* Statistically significant
a Missing values: BMI: no QTc, n = 1
b Missing values: ASAT/ASAT: QTc, n = 5; no QTc, n = 7; Bili: QTc, n = 4; no QTc, n = 9
c Missing values: eGFR: no QTc, n = 2
d Missing values: Na+/K+: no QTc, n = 1; Ca2+: QTc, n = 12; no QTc, n = 38; Mg2+: QTc, n = 14; no QTc, n = 40
e Other than the QTc-prolonging drugs with a known risk of TdP [13]