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Updated: Mar 26, 2026

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation
Published on: January 16, 2019
Interleukin-1β gene variants are associated with QTc interval prolongation following cardiac surgery: a prospective
Miklos D Kertai1, Yunqi Ji2, Yi-Ju Li1,2
1Duke Perioperative Genomics Program, Department of Anesthesiology, Duke University Medical Center, DUMC 3094, Durham, NC, 27710, USA.
Background:
We characterized cardiac surgery-induced dynamic changes of the corrected QT (QTc) interval and tested the hypothesis that genetic factors are associated with perioperative QTc prolongation independent of clinical and procedural factors.
Methods:
All study subjects were ascertained from a prospective study of patients who underwent elective cardiac surgery during August 1999 to April 2002. We defined a prolonged QTc interval as > 440 msec, measured from 24-hr pre- and postoperative 12-lead electrocardiograms. The association of 37 single nucleotide polymorphisms (SNPs) in 21 candidate genes -involved in modulating arrhythmia susceptibility pathways with postoperative QTc changes- was investigated in a two-stage design with a stage I cohort (n = 497) nested within a stage II cohort (n = 957). Empirical P values (Pemp) were obtained by permutation tests with 10,000 repeats.
Results:
After adjusting for clinical and procedural risk factors, we selected four SNPs (P value range, 0.03-0.1) in stage I, which we then tested in the stage II cohort. Two functional SNPs in the pro-inflammatory cytokine interleukin-1β (IL1β), rs1143633 (odds ratio [OR], 0.71; 95% confidence interval [CI], 0.53 to 0.95; Pemp = 0.02) and rs16944 (OR, 1.31; 95% CI, 1.01 to 1.70; Pemp = 0.04), remained independent predictors of postoperative QTc prolongation. The ability of a clinico-genetic model incorporating the two IL1B polymorphisms to classify patients at risk for developing prolonged postoperative QTc was superior to a clinical model alone, with a net reclassification improvement of 0.308 (P = 0.0003) and an integrated discrimination improvement of 0.02 (P = 0.000024).
Conclusion:
The results suggest a contribution of IL1β in modulating susceptibility to postoperative QTc prolongation after cardiac surgery.

