Shorter (GT)_n repeats in the haem-oxygenase 1 gene promoter are associated with better mid-term survival in subjects with coronary artery disease and abnormal ejection fraction

Abstract

Background

Haem oxygenase (HO)-1 is a rate-limiting enzyme for degrading haem into carbon monoxide. Subjects with longer GT repeats in the HO-1 gene (HMOX1) promoter are more likely to have coronary artery disease (CAD) and cardiovascular events.

Methods

We retrospectively enrolled CAD subjects with an abnormal ejection fraction (EF) <50% from our catheterisation data (N = 670). Polymerase chain reactions were performed for amplifying the HMOX1 promoter GT repeating segment to determine the number of repeats.

Results

In a median follow-up period of 40 months, 213 patients died. The distribution of genotype for HMOX1 promoter GT repeating segments SS, SL, and LL were significantly different (p < 0.001) between the dead (44.6%, 36.2%, 19.2%, respectively) and the survived (53.8%, 37.4%, 8.8%, respectively) (S allele: ≤30 repeats, L allele: >30 repeats). In Cox regression analysis, carrier of S allele (hazard ratio 0.665, p = 0.027), a higher EF (hazard ratio 0.037, p = 0.001), and revascularization with PCI were all negatively associated with all-cause death in subjects with CAD and abnormal EF.

Conclusions

Carrier of shorter (GT)_n repeats of HMOX1 gene promoter was negatively correlated with death events in CAD patients with abnormal EF.

Keywords:

• Coronary artery disease (CAD)
• haem oxygenase (HO)-1
• HMOX1
• left ventricular ejection fraction
• promoter polymorphism

Disclosure statement

The authors have no conflicts of interest to disclose.

Data availability statement

The data used to support the findings of this study are available from the corresponding author.

Additional information

Funding

This study was supported in part by grants from Taichung Veterans General Hospital, Taiwan (TCVGH-1083105C, 1087314C, 1093105C, 1093107D, 1097315C, 1097330D, 1103101C, 1103102D).