Table 1.
Baseline and follow-up characteristics of the study population by coronary artery disease.
| Clinical characteristics | CAD n = 137 |
No CAD n = 883 |
P-value |
|---|---|---|---|
| Female sex % | 55 | 66 | 0.022 |
| ECG parameters | |||
| RR, ms | 898 ± 193 | 900 ± 188 | 0.907 |
| QT, ms | 462 ± 66 | 456 ± 67 | 0.180 |
| QTc, ms | 491 ± 42 | 483 ± 49 | 0.014 |
| QTc ≥500 ms % | 36 | 30 | 0.166 |
| Prior cardiac events before age 40 years | |||
| Syncope% | 30 | 37 | 0.118 |
| Aborted cardiac arrest (ACA) % | 5 | 6 | 0.833 |
| Appropriate ICD shock % | 1 | 2 | 0.710 |
| Cardiac events% | 31 | 39 | 0.077 |
| ACA or appropriate ICD shock % | 5 | 6 | 0.546 |
| LQTS Genotypea | |||
| LQT1 % | 19 | 31 | <.001 |
| LQT2 % | 26 | 32 | |
| LQT3 % | 9 | 8 | |
| No mutation found (tested) % | 11 | 8 | |
| Unknown mutation status (not tested) % | 34 | 20 | |
| Comorbidities before age 40 years and during follow-up | |||
| Sleep apnea % | 9 | 7 | 0.498 |
| Asthma % | 23 | 15 | 0.020 |
| Cancer % | 12 | 8 | 0.072 |
| Diabetes mellitus % | 19 | 10 | 0.003 |
| Hypertension % | 62 | 33 | <.001 |
| Hyperlipidemia % | 26 | 16 | 0.004 |
| Stroke % | 15 | 4 | <.001 |
| Smoking % | 56 | 35 | <.001 |
| Therapies during follow-up after age 40 years | |||
| β-blockers % | 80 | 63 | <.001 |
| Selective β-blockers % | 64 | 41 | <.001 |
| Non-selective β-blockers % | 39 | 34 | 0.223 |
| Pacemaker % | 9 | 3 | 0.002 |
| ICD % | 33 | 19 | <.001 |
| LCTSD % | 1 | 0 | 0.515 |
| Cardiac events during follow-up after age 40 years | |||
| Syncope % | 29 | 14 | 0.001 |
| ACA % | 9 | 2 | <.001 |
| LQTS-related SCD % | 0 | 0 | 1.000 |
| Appropriate ICD shocks % | 4 | 3 | 0.765 |
| Cardiac event % | 36 | 17 | <.001 |
| Life-threatening event % | 12 | 5 | 0.014 |
| All-cause mortality % | 12 | 4 | 0.053 |
ACA, aborted cardiac arrest; ICD, implantable cardioverter-defibrillator; LCSD, left cervical sympathetic denervation; LQTS, long QT syndrome; SCD, sudden cardiac death; QTc, corrected QT.
a
A total of 800 (78%) subjects were genotyped. Of them, 710 (89%) subjects were identified as carriers of an LQTS 1-3 mutation.
P-values < 0.05 are highlighted in bold.