Genetic architecture of spatial electrical biomarkers for cardiac arrhythmia and relationship with cardiovascular disease

The 3-dimensional spatial and 2-dimensional frontal QRS-T angles are measures derived from the vectorcardiogram. They are independent risk predictors for arrhythmia, but the underlying biology is unknown. Using multi-ancestry genome-wide association studies we identify 61 (58 previously unreported) loci for the spatial QRS-T angle (N = 118,780) and 11 for the frontal QRS-T angle (N = 159,715). Seven out of the 61 spatial QRS-T angle loci have not been reported for other electrocardiographic measures. Enrichments are observed in pathways related to cardiac and vascular development, muscle contraction, and hypertrophy. Pairwise genome-wide association studies with classical ECG traits identify shared genetic influences with PR interval and QRS duration. Phenome-wide scanning indicate associations with atrial fibrillation, atrioventricular block and arterial embolism and genetically determined QRS-T angle measures are associated with fascicular and bundle branch block (and also atrioventricular block for the frontal QRS-T angle). We identify potential biology involved in the QRS-T angle and their genetic relationships with cardiovascular traits and diseases, may inform future research and risk prediction.

QTc-interval prolongation and increased risk of sudden cardiac death associated with hydroxychloroquine

AIMS:

Hydroxychloroquine and chloroquine ([hydroxy]chloroquine) are drugs used to treat malaria and rheumatological disorders and were recently suggested as beneficial for prevention and treatment of patients with coronavirus disease 2019 (COVID-19) due to SARS-CoV-2 infection. However, longitudinal studies to assess the electrocardiographic and cardiotoxic effects of these drugs are limited. In this study, we aimed to investigate the effect of these drugs on QTc-interval and incidence of sudden cardiac death (SCD).

METHODS

We designed a longitudinal follow-up study of individuals within the prospective population-based Rotterdam Study. Eligible individuals had available data on medication and repeated ECG measurements. The study period was between 1 January 1991 and 1 January 2014. We studied on current and past use of [hydroxy]chloroquine as a time-varying exposure; high versus low daily dose of [hydroxy]chloroquine. QTc-interval duration, and the occurrence of SCD were the main outcomes. SCD was defined as an unexpected and sudden death due to cardiac arrhythmia within one hour of the onset of acute symptoms, and in patients without cardiac symptoms within 24 hours before death.

RESULTS

Among the study population of 14 594 individuals (58.8% women) with an average age of 65 years, 346 patients used [hydroxy]chloroquine at any time during follow-up. The total number of SCD cases was 609. In a multiple linear mixed model analysis, the current use of [hydroxy]chloroquine was associated with a significantly increased duration of the QTc-interval of 8.1 ms (95% CI: 3.6; 12.6) compared with non-users. The association was stronger among current-high daily dosage [15.3 (95%CI: 7.0; 23.6)] compared with current-low daily dosage [5.5 (95%CI: 0.4; 10.7)] users. In a Cox proportional hazard regression analysis, the risk of SCD was significantly higher in participants who were current users of [hydroxy]chloroquine than in non-users [adjusted hazard ratio; 3.7 (95%CI: 1.1; 12.6)].

CONCLUSIONS

In this longitudinal study, persons who received [hydroxy]chloroquine had an increased QTc-interval duration and the association was dose-dependent. [Hydroxy]chloroquine was associated with a significantly increased risk of SCD. As long as their activity against COVID-19 is controversial, cardiotoxicity is a strong argument against using these drugs to treat COVID-19 infections.

Effect of Liraglutide on Cardiometabolic Risk Profile in People with Coronary Artery Disease with or without Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Whether liraglutide use improves cardiometabolic risk factors in different subsets of subjects with coronary artery disease (CAD) remains unclear. In a systematic review and meta-analysis, we quantified the effects of liraglutide on cardiometabolic risk profile in subjects with CAD with or without type 2 diabetes mellitus (T2D).

Methods: Online database searches were conducted in PubMed, Scopus, EMBASE, Web of Science, Cochrane library, and Google Scholar from incept up to 15th January 2021. We identified randomized controlled trials (RCTs) assessing the effects of liraglutide compared to placebo on cardiometabolic risk profile. We used the random- or fixed-effect models to pool the weighted mean differences (WMDs) and 95% confidence intervals (CIs).

Results: Out of a total of 7,320 citations, six articles (seven RCTs) with 294 subjects with CAD (mean age, 61.21 years; 19% women) were included. Our findings presented as WMD and 95% CI showed a statistical significant decrease in hemoglobin A1c (HbA1c) [−0.36%; −0.47; −0.26, p < 0.001; I² = 0.0% (with 6 RCTs)], body mass index (BMI) [−0.61 kg/m²; −1.21; −0.01, p = 0.047; I² = 72.2% (with five RCTs)], and waist circumference [−2.41 cm; −3.47; −1.36, p < 0.001; I² = 0.0% (with three RCTs)]. Through a set of subgroup analyses, we found a significant reduction in BMI in CAD patients with T2D [WMD = −1.06; 95% CI, −1.42, −0.70, p < 0.001; I² = 0.0% (with three RCTs)] compared to CAD only patients [WMD = −0.08; 95% CI, −0.45, 0.29, p = 0.66; I² = 0.0% (with two RCTs)] in the liraglutide group compared with the placebo group. No significant changes in heart rate, blood pressure, and lipid profiles were observed.

Conclusions: Among people with established CAD, liraglutide significantly improved HbA1c, BMI, and waist circumference values. The effect of liraglutide on BMI was more robust in individuals with T2D compared to those without.

Association between digoxin use and sudden cardiac death in individuals with the rs10494366 variant of the NOS1AP gene

Background

Digoxin is one of the oldest cardiovascular medications still used to treat heart failure and atrial fibrillation. Due to its narrow therapeutic window, it is associated with life threatening intoxication and arrhythmias, and with QTc-shortening. Common genetic variation in the nitric oxide synthase-1 adaptor protein (NOS1AP) has been associated with QTc interval prolongation.

Purpose

We investigated whether the rs10494366 variant of the NOS1AP gene modified the risk of SCD in patients using digoxin.

Methods

In a prospective population-based cohort study, we included data of the three cohorts, started as of January 1st, 1991 until January 1st 2014. Digoxin current use on the date of cardiac death in cases and the same day of follow-up in the remainder of the cohort was a time-dependent exposure. The main outcome was SCD defined as sudden and unexpected death as a result of cardiac causes, according to international criteria. Identification and adjudication of SCD was performed independently, before the start of this study. We used Cox proportional hazard regression analysis to investigate the associations between NOS1AP rs10494366 variant and incident SCD among digoxin users compared to non-users. Associations were adjusted for age, sex (model 1) in addition to BMI, prevalent diabetes, myocardial infarction, baseline hypertension and smoking status (past, current, never) (model 2).

Results

We included 14,594 individuals, with a mean age of 65.3 (SD 10.3) years. Almost 59% were female. The cumulative incidence of SCD was 9.5% (609 cases) by the end of follow up. Among them, 98 (16%) individuals were exposed to digoxin at the time of death.

In model 1, NOS1AP rs10494366 variant was not associated with SCD in the total study population. However, an interaction term of the gene with the daily dose of digoxin was significantly associated with increased risk of SCD (p-value 0.0001). In model 2, the risk of SCD in current users of digoxin was 4.2 [95% CI 1.3–13.8] for the GG genotype; 2.1 [95% CI 1.1–4.2] for the GT genotype, and 1.5 [95% CI 0.7–3.2] for the TT genotype.

Conclusion

NOS1AP rs10494366 variant modified the risk of sudden cardiac death in users of digoxin. Our study suggests that individuals with the homozygous minor GG allele have a fourfold increased risk of sudden cardiac death.

Funding Acknowledgement

Type of funding source: None

eNOS gene Glu298Asp variant confer risk in sudden sensorineural hearing loss

BACKGROUND

Sudden sensorineural hearing loss (SSNHL) causes the loss of hearing of 30 dB or greater on at least three contiguous frequencies. It is known to be a multifactorial disease which the exact cause is unknown, rendering it as an idiopathic disorder of patients.

AIMS/OBJECTIVES

This study aims to shed further light on pathogenesis of this disease by studying the association between eNOS gene Glu298Asp polymorphism and VDR gene FokI polymorphism with SSNHL in Iranian population.

MATERIAL AND METHODS

This study involves a total of 77 cases and 100 controls, with patients inflicted with SSNHL categorized in case group and healthy subjects as control group. Genotyping of the VDR and eNOS genes was conducted by the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

Our results showed a statistically significant association between genotype frequencies of eNOS gene Glu298Asp polymorphism in case group compared to healthy individuals in the control group (p = .01). Also, TT genotype was significantly the most prevalent genotype in case group in comparison to control group (TT vs GT + GG, OR = 3.5; 95% CI = 1.18-11.79). On the other hand, analysis of VDR gene FokI polymorphism frequencies showed no statistically significant association with SSNHL.

CONCLUSIONS AND SIGNIFICANCE

Our findings showed a significant association between the eNOS gene Glu298Asp polymorphism and SSNHL in the Iranian population; and "TT" genotype might be considered as a risk factor for SSNHL.

Vitamin D receptor gene FokI variant in diabetic foot ulcer and its relation with oxidative stress

PURPOSE

The patient's suffering and financial costs affiliated with Diabetic Foot Ulcer (DFU), as one of the most important complications of diabetes, are highly undesirable and this highlights the importance of preventive medicine about this disorder. Furthermore hyperglycemia causes generation of free radicals which leads to oxidative stress (OS). Hence, this study aims to examine the association between vitamin D receptor (VDR) gene FokI polymorphism and DFU in Iranian population and also its correlation with OS biomarkers.

MATERIALS AND METHODS

In a case-control study, a total of 212 patients with type 2 diabetes with and without diabetic foot ulcer were included. Genotyping was conducted by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis. Samples were analyzed for thiobarbituric reactive substances (TBARS) and ferric reducing ability of plasma (FRAP) as markers of OS.

RESULTS

The results indicated a significant difference in genotype frequencies of VDR gene FokI polymorphism in patients with diabetic foot ulcer in comparison to those without diabetic foot ulcer (TT+TC vs. CC p=0.04; OR=1.76; 95% CI=1.02-3.05). Moreover, the patients carrying the T allele had a significantly higher level of TBARS (p=0.01).

CONCLUSIONS

We found a significant association between FokI functional variant of VDR gene and diabetic foot ulcer in an Iranian population. Increased levels of TBARS in patients carrying the T allele of FokI polymorphism indicate an association between this variant and OS in patients with diabetes.