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Published on: September 1, 2018
QTc intervals are not prolonged in former ELBW infants at pre-adolescent age
Thomas Salaets1, Anke Raaijmakers2,3, Zhen-Yu Zhang4
1Division of Pediatric Cardiology, Department of Pediatrics, University Hospitals Leuven, Leuven, Belgium.
Insights
Extreme low birth weight (ELBW) infants do not show cardiac conduction differences compared to term controls in pre-adolescence. This finding suggests similar QTc screening strategies for both groups, aiding pharmacovigilance.
Area of Science:
- Cardiology
- Neonatology
- Pediatrics
Background:
- Preterm birth, particularly extreme low birth weight (ELBW, <1000g), may impact long-term cardiac health.
- Existing data on QTc prolongation in former ELBW infants is conflicting.
- Cardiac conduction and repolarization abnormalities in later life following preterm birth remain underexplored.
Purpose of the Study:
- To evaluate differences in corrected QT time (QTc) and QT dispersion (QTd) between former ELBW individuals and term-born controls during pre-adolescence.
- To investigate associations between QTc intervals and perinatal factors in ELBW cases.
- To inform screening strategies for cardiovascular health in individuals with a history of ELBW.
Main Methods:
- Analysis of resting 12-lead electrocardiograms (ECGs) from the PREMATCH study cohort.
- Comparison of QTc (Bazett's formula) and QTd between 93 ELBW cases and 87 term controls (ages 8-14).
- Exploration of associations between ECG findings and clinical/biochemical data using Mann-Whitney and Spearman tests.
Main Results:
- No significant differences in QTc or QTd were observed between ELBW cases and term controls.
- Female sex and lower serum potassium levels were associated with a longer QTc interval.
- No significant associations were found between QTc interval and perinatal characteristics in ELBW cases.
Conclusions:
- Former ELBW individuals do not exhibit differences in resting QTc or QTd compared to term-born controls in pre-adolescence.
- QTc screening, including for pharmacovigilance, should not differentiate based on ELBW status.
- Further research may explore other long-term cardiovascular outcomes in this population.
Background:
Whether preterm birth is associated with cardiac conduction or repolarization abnormalities in later life is still poorly explored, with conflicting data on QTc prolongation in former extreme low birth weight (ELBW, <1000 g) infants.
Methods:
Twelve lead electrocardiograms (ECG) at rest, collected in the PREMATurity as predictor of children's Cardiovascular-renal Health (PREMATCH) study in former ELBW cases and term controls during pre-adolescence (8-14 years) were analyzed on corrected QT time (QTc, Bazett) and QT dispersion (QTd). ECG findings were compared between groups (Mann-Whitney), and associations with clinical and biochemical findings were explored (Spearman). In ELBW cases, associations between QTc and perinatal characteristics (at birth, neonatal stay) were explored (Mann-Whitney, Spearman).
Results:
QTc and QTd were similar between 93 ELBW cases and 87 controls [409 (range 360-465) versus 409 (337-460); 40 (0-100) versus 39 (0-110)] ms. Age, height, weight, or body mass index were not associated with the QTc interval, while female sex (median difference 11.4 ms) and lower potassium (r = -0.26) were associated with longer QTc interval. We could not observe any significant association between QTc interval and perinatal characteristics.
Conclusions:
There were no differences in QTc or QTd between ELBW and term controls in ECGs at rest in pre-adolescents.
Impact:
This study aimed to assess the differences in QTc and QTd intervals between extreme low birth weight infants (ELBW) and term controls in electrocardiographic measurements at rest during pre-adolescence. This analysis confirmed the absence of significant differences in QTc or QTd findings between ELBW cases and term controls, while female sex and lower potassium were associated with a prolonged QTc interval. These data suggest that QTc screening strategies-including for pharmacovigilance-should not differentiate between former ELBW cases and term controls.
Clinical Trial Registration:
ClinicalTrials.gov Identifier NCT02147457.
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