Arrhythmias & electrophysiologyCohort study
Progressive conduction system disease preceding hypertrophy in IVS4+919G>A Fabry variant: a population-based electrocardiographic study
- population-based electrocardiographic study
- regional genetic screening programme
- matched 1:2 to controls by age and sex
Authors' conclusion
The IVS4+919G>A variant is characterized by a progressive electrical phenotype dominated by conduction system disease preceding hypertrophy without excess major arrhythmic events. Electrocardiographic surveillance and phenotype-based risk stratification may be more informative than structural assessment alone for identifying individuals at risk of device therapy. Institutional Review Board: CMUH113-REC3-076
Study context
- Population
- IVS4+919G>A Fabry variant carriers identified from a regional genetic screening programme, and age- and sex-matched controlsIVS4+919G>A carriers identified among 457,581 patients
- Participants
- 905 carriers
- Exposure
- IVS4+919G>A carriers vs controls matched 1:2 by age and sex
- IVS4+919G>A carriersn = 905
Main finding
As reported in the abstract
Cumulative prevalence
0.198%
Observational data: associations, not effects.
Further findings
| Outcome | HR (95% CI) | P value | |
|---|---|---|---|
| Right bundle branch block and pacemaker implantation (males) — IVS4+919G>A carriers vs controls · right bundle branch block; males vs male controls | 9.286 (5.16–16.70) | P < 0.001 | |
| Right bundle branch block and pacemaker implantation (males) — IVS4+919G>A carriers vs controls · pacemaker implantation; males vs male controls | 9.197 (2.88–29.31) | P < 0.001 | |
| Stroke and atrial fibrillation (males) · male carriers vs male controls; risk similar | 1.435 (0.69–2.96) | P = 0.289 | |
| 0.050.21520Hazard ratio (log scale) |
- Right bundle branch block and pacemaker implantation (males): precedes the onset of echocardiographic left ventricular hypertrophy
Age-specific prevalence by sex
- Age-specific prevalence in females ∼2.5-fold higher than in males (0.11-0.15%), without significant change throughout different age categories
- ∼2.5-fold
Catch-up phenomenon in female carriers · after the age of 60
- Female carriers demonstrated the catch-up phenomenon after the age of 60
PR interval
- PR interval did not shorten but was prolonged instead
Detection sensitivity: Electrocardiographic (ECG) (left ventricular hypertrophy combined with conduction abnormalities) vs echocardiographic criteria alone
- ECG detection sensitivity
- 88%
- Echocardiographic criteria alone
- 51.5%
Original publication
Summarised from the published abstract; every number is checked against it