Angiotensin-converting enzyme gene 2350 G/A polymorphism and susceptibility to atrial fibrillation in Han Chinese patients with essential hypertension

ACE Gene Variants Rise the Risk of Severe COVID-19 in Patients With Hypertension, Dyslipidemia or Diabetes: A Spanish Pilot Study

Coronavirus disease 19 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection continues to scale and threaten human health and public safety. It is essential to identify those risk factors that lead to a poor prognosis of the disease. A predisposing host genetic background could be one of these factors that explain the interindividual variability to COVID-19 severity. Thus, we have studied whether the rs4341 and rs4343 polymorphisms of the angiotensin converting enzyme (ACE) gene, key regulator of the renin-aldosterone-angiotensin system (RAAS), could explain the different outcomes of 128 COVID-19 patients with diverse degree of severity (33 asymptomatic or mildly symptomatic, 66 hospitalized in the general ward, and 29 admitted to the ICU). We found that G allele of rs4341 and rs4343 was associated with severe COVID-19 in hypertensive patients, independently of gender (p<0.05). G-carrier genotypes of both polymorphisms were also associated with higher mortality (p< 0.05) and higher severity of COVID-19 in dyslipidemic (p<0.05) and type 2 diabetic patients (p< 0.01). The association of G alleles with disease severity was adjusted for age, sex, BMI and number of comorbidities, suggesting that both the metabolic comorbidities and the G allele act synergistically on COVID-19 outcome. Although we did not find a direct association between serum ACE levels and COVID-19 severity, we found higher levels of ACE in the serum of patients with the GG genotype of rs4341 and rs4343 (p<0.05), what could explain the higher susceptibility to develop severe forms of the disease in patients with the GG genotype, in addition to hypertension and dyslipidemia. In conclusion, our preliminary study suggests that the G-containing genotypes of rs4341 and rs4343 confer an additional risk of adverse COVID-19 prognosis. Thus, rs4341 and rs4343 polymorphisms of ACE could be predictive markers of severity of COVID-19 in those patients with hypertension, dyslipidemia or diabetes. The knowledge of these genetic data could contribute to precision management of SARS-CoV-2 infected patients when admitted to hospital.

Development of One-Step Tetra-primer ARMS-PCR for Simultaneous Detection of the Angiotensin Converting Enzyme (ACE) I/D and rs4343 Gene Polymorphisms and the Correlation with CAD Patients

BACKGROUND

The Angiotensin Converting Enzyme (ACE) Insertion/Deletion and rs-4343 gene polymorphisms could be associated with pathogenesis of essential hypertension and cardiovascular disorders and Coronary Artery Disease (CAD). In the present study, a fast and novel approach of multiplex Tetra-Primer Amplification Refractory Mutation System-PCR (T-ARMS-PCR) was developed for simultaneous detection of two SNPs including ACE I/D (rs4340) and 2350A>G (rs4343) of Angiotensin Converting Enzyme (ACE) gene.

METHODS

The present research was performed using 148 blood samples taken from patients with CAD and 135 healthy individuals. One set of inner primers (for rs4343) and one set of outer primer pairs were designed for genotyping of Insertion/Deletion and rs4343 polymorphisms in single tube T-ARMS-PCR.

RESULTS

Our results manifested that genotypes and alleles frequency of the ACE polymorphisms showed no statistically significant association between CAD patients and the control group. In addition, complete concordance was seen between sensitive Tetra-ARMS-PCR and sequencing method.

CONCLUSION

The technique is the first work for simultaneous detection of Insertion/Deletion polymorphism and rs4343 SNPs in ACE gene and the results were entirely according to those from an independent procedure.

NEURL rs6584555 and CAND2 rs4642101 contribute to postoperative atrial fibrillation: a prospective study among Chinese population

Postoperative atrial fibrillation (POAF) is a serious, common complication after coronary artery bypass grafting (CABG) surgery. Recently, 5 novel loci were identified to be associated with atrial fibrillation susceptibility using a combination of genotyping, eQTL mapping, and functional validation. In current study, we aim to evaluated the positive findings for POAF susceptibility after CABG among Chinese population, using a population-based, two-stage, nested case-control study with 1,400 patients. NEURL rs12415501 and CAND2 rs4642101 were significantly associated with POAF susceptibility after CABG among Chinese population in both stages. When pooled together, the ORs for each additional copy of minor allele was 1.29 (95% CI: 1.13-1.48, P = 1.7×10⁻⁴) for NEURL rs12415501, and 1.21 (95% CI: 1.08-1.36, P = 9.8×10⁻⁴) for CAND2 rs4642101. Functional validation experiments found the AF risk allele of NEURL rs6584555 and CAND2 rs4642101 correlated with an increased expression of its corresponding genes (P<0.001). In this independently collected cardiac surgery cohort, we replicated the previous findings, and 2 novel loci are independently associated with POAF risk in patients who undergo CABG surgery in Chinese population.

Genomics of Atrial Fibrillation

Atrial fibrillation (AF) is a common clinical arrhythmia that appears to be highly heritable, despite representing a complex interplay of several disease processes that generally do not manifest until later in life. In this manuscript, we will review the genetic basis of this complex trait established through studies of familial AF, linkage and candidate gene studies of common AF, genome wide association studies (GWAS) of common AF, and transcriptomic studies of AF. Since AF is associated with a five-fold increase in the risk of stroke, we also review the intersection of common genetic factors associated with both of these conditions. Similarly, we highlight the intersection of common genetic markers associated with some risk factors for AF, such as hypertension and obesity, and AF. Lastly, we describe a paradigm where genetic factors predispose to the risk of AF, but which may require additional stress and trigger factors in older age to allow for the clinical manifestation of AF.

Relationship of the MTHFD1 (rs2236225), eNOS (rs1799983), CBS (rs2850144) and ACE (rs4343) gene polymorphisms in a population of Iranian pediatric patients with congenital heart defects

Congenital heart defects are structural cardiovascular malformations that arise from abnormal formation of the heart or major blood vessels during the fetal period. To investigate the association of 4 single nucleotide polymorphisms (SNPs) in the MTHFD1, eNOS, CBS and ACE genes, we evaluated their relationship with CHD in Iranian patients. In this case-control study, a total of 102 children with CHD and 98 control children were enrolled. Four SNPs including MTHFD1 G1958A, eNOS G894T, CBS C-4673G and ACE A2350G were genotyped by PCR-SSCP, Multiplex ARMS PCR and PCR-RFLP methods and confirmed by direct sequencing. We genotyped 102 patients and 98 controls for four polymorphisms by statistically analysis. There were three SNPs including MTHFD1 G1958A, eNOS G894T and ACE A2350G which might increase the risk of CHD, but CBS C-4673G was not significantly different between patients and controls. (P = 0.017, P = 0.048, P = 0.025 and P = 0.081 respectively). The allele frequencies of three SNPs for MTHFD1 G1958A, eNOS G894T and ACE A2350G in CHD are higher than that in control. Our results show that there is a significant relationship between MTHFD1 G1958A, eNOS G894T and ACE A2350G polymorphisms with CHD. Therefore, The AA and GA genotypes of MTHFD1 G1958A, TT and GT genotypes of eNOS G894T and the AA and GA genotypes of ACE A2350G are susceptible factors for CHD and may increase the risk of CHD.

Serum YKL-40 is increased in patients with slow coronary flow

OBJECTIVES

There is accumulating evidence that inflammation plays a major role in the development of the slow coronary flow (SCF) phenomenon. YKL-40 has been suggested to be a potential biomarker of inflammation. In this study, we aimed to study YKL-40 as it relates to SCF.

MATERIALS AND METHODS

Patients who underwent coronary angiography before and had angiographically normal coronary arteries of varying coronary flow rates without any atherosclerotic lesion were enrolled in this study. Patients who had thrombolysis in myocardial infarction frame counts (TFC) above the normal cutoffs were considered to have SCF and those within normal limits were considered to have normal coronary flow (NCF). The YKL-40 levels and biochemical profiles of all patients were studied and analyzed.

RESULTS

There were 41 patients in the SCF group and 209 patients in the NCF group. Compared with the NCF patients, SCF patients had higher serum high-sensitivity C-reactive protein (hs-CRP) (P=0.0003) and YKL-40 (P=0.0007) levels. A positive correlation was detected between the YKL-40 levels and hs-CRP (r=0.7021, P<0.001), and the mean TFC (r=0.4038, P=0.0088) in SCF patients.

CONCLUSION

Our study showed that YKL-40 levels are higher and correlated positively with TFC and hs-CRP in SCF patients. This finding suggests that YKL-40 may be a useful marker and predictor for SCF.

In-hospital clinical outcomes of elderly patients (≥60 years) undergoing primary percutaneous coronary intervention

Elderly patients are at high risk of mortality when they present with ST-elevation myocardial infarction (STEMI). However, the clinical outcomes of this sub-group undergoing primary percutaneous coronary intervention (PPCI) have not been well established, despite recent advances in both devices and techniques. In the present retrospective cohort study from a Chinese single center, we assessed the clinical outcomes and predictors of mortality in elderly patients (≥60 years) underwent with PPCI. The primary endpoints were immediate angiographic success and in-hospital procedural success. The secondary endpoints were all-cause death in hospital. Between January 2011 and December 2013, a total of 184 consecutive patients with acute STEMI underwent PPCI were enrolled. 116 (63.04%) patients were in the elderly group. Despite the difference in lesion complexity between groups, the immediate angiographic success rate was similar (93.97% in the elderly group, and 94.12% in the non-elderly group, P=0.966). The procedural success rate were not significantly different between the two groups (90.52% in the elderly group, and 94.12% in the non-elderly group, P=0.389). However, in-hospital mortality was statistically higher in elderly group than in the non-elderly group (8.62% Vs 1.47%, P=0.048). The major causes of death were cardiac shock and malignant arrhythmias (ventricular tachycardia and fibrillation). Our results indicate that PPCI in the elderly is feasible and has a high likelihood of immediate angiographic and procedural success.

Interleukin-10 promotor -592A/C polymorphism is associated with slow coronary flow in Han Chinese

An accumulating body of evidence suggests that slow coronary flow (SCF) phenomenon seems to be an early-form of atherosclerosis and low-grade inflammation plays a major role in the atherosclerotic vascular processes. Interleukin (IL)-10 is a multifunctional cytokine involved in both innate and adaptive immune response. The aim of the present study is to investigate the association of IL-10 gene -592A/C polymorphism with SCF in Han Chinese. 250 patients who underwent coronary angiography and had angiographically normal coronary arteries of varying coronary flow rates without any atherosclerotic lesion were enrolled in this study. Patients who had thrombolysis in myocardial infarction frame counts (TFC) above the normal cutoffs were considered to have SCF and those within normal limits were considered to have normal coronary flow (NCF). The PCR-based restriction fragment length polymorphism (PCR-RFLP) technique was used to assess the genotypes frequencies. The distribution of the IL-10 -592A/C genotypes (AA, AC, and CC) was 46.34%, 41.46%, and 12.20% in the NCF group, and 66.51%, 28.71%, and 4.78% in SCF subjects, respectively (P = 0.0280). The frequency of the A allele in the SCF group was significantly higher than that in the NCF group (80.86% vs. 67.07%, P = 0.0054). Compared with the CC genotype, the AA genotype had increased risk of SCF in both unadjusted and adjusted analyses. In SCF patients, the average serum IL-10 levels in AA genotype were statistically lower than in AC + CC genotype (P = 0.0000). These findings suggest that IL-10 -592A/C polymorphism is associated with SCF and the A allele has increased risk for SCF in Han Chinese.

A functional single-nucleotide polymorphism in interleukin-6 promoter is associated with p wave dispersion in hypertensive subjects with atrial fibrillation

Inflammation has been shown to be implicated in the pathophysiology of atrial fibrillation (AF). Interleukin-6 (IL-6) is a pleiotropic cytokine, functions as a mediator of inflammatory response and has both pro-inflammatory and anti-inflammatory properties. Little is known about genetic factors of inflammation in the accompanying atrial electrical remodeling expressed by P wave dispersion (Pdisp). The aim of the present study is to evaluate the association of -634C/G polymorphism of IL-6 gene with Pdisp in Han Chinese hypertensive patients with AF. A total of 100 patients with essential hypertension (EH) were eligible for this study. Patients with paroxysmal AF (n=50) were allocated to the AF group, and 50 subjects without AF to the control group. The PCR-based restriction fragment length polymorphism (PCR-RFLP) technique was used to assess the genotypes frequencies. The distribution of the IL-6 -634C/G genotypes (CC, CG, and GG) was 68.00%, 28.00%, and 4.00% in the controls, and 44.00%, 40.00%, and 16.00% in AF subjects, respectively (P=0.0269). The frequency of the G allele in the AF group was significantly higher than that in the control group (36.00% vs 18.00%, P=0.0041). Compared to the wild type CC, the G allele carriers (CG + GG genotypes) had a 2.7045-fold increased risk of AF (odds ratio =2.7045, 95% confidence interval =1.1966-6.1126, P=0.0156). AF patients with the CG + GG genotype had longer Pdisp (P=0.0032) than did patients with the CC genotype. The longer Pdisp in the subjects with the CG + GG genotype was also found in the control group (P=0.0016). These findings support that IL-6 -634C/G polymorphism is associated with Pdisp and AF, suggesting an active implication of inflammation in the atrial electrophysiological remodeling predisposing to AF.

Association of Interleukin-10 promotor polymorphisms with atrial fibrillation in Han Chinese

There is an accumulating body of evidence indicating strong association between inflammation and the pathogenesis of atrial fibrillation (AF). IL-10 is a multifunctional anti-inflammatory cytokine that down-regulates cell-mediated immune responses and cytotoxic inflammatory responses. The aim of the present study is to investigate the association of IL-10 gene -592A/C polymorphism with AF in Han Chinese. 117 AF patients and 100 healthy volunteers were eligible for this study. The PCR-based restriction fragment length polymorphism (PCR-RFLP) technique was used to assess the genotypes frequencies. The distribution of the IL-10 -592A/C genotypes (AA, AC, and CC) was 55.00%, 35.00%, and 10.00% in the controls, and 71.79%, 23.08%, and 5.13% in AF subjects, respectively (p = 0.0335). The frequency of the A allele in the AF group was significantly higher than that in the control group (83.33% vs 72.50%, p = 0.0063). Compared with the CC genotype, the AA genotype had increased risk of AF in both unadjusted and adjusted analyses. The average serum IL-10 levels in AA genotype were statistically lower than in AC + CC genotype (p = 0.0000). These findings suggest that IL-10 -592A/C polymorphism is associated with AF and the A allele has increased risk for AF in Han Chinese.