Polymorphism of 9p21.3 locus is associated with 5-year survival in high-risk patients with myocardial infarction

Clinical application of chromosome 9p21.3 genotyping in patients with coronary artery disease

The aim of the present study was to investigate the susceptibility of two coronary artery disease (CAD)-associated single nucleotide polymorphisms on 9p21 (rs1333049 and rs10757278) to myocardial infarction (MI) in a primary (stratification of high risk group for MI) and secondary prevention setting. The prospective observational study included 500 patients with MI [411 males (82.2%) and 89 females (17.8%)] under 65 years. The risk of MI for carriers of the homozygous CC genotype of rs1333049 and homozygous GG genotype of rs10757278 was 1.77 [95% confidence interval (CI): 1.36-2.37], and 1.70 (95% CI: 1.24-2.32) respectively. The risk of MI for heterozygous allele carriers was slightly lower. Specifically, the risk of MI was 1.58 (95% CI: 1.18-2.11) for both heterozygous and homozygous carriers of the rs1333049 C allele, and 1.36 (95% CI: 1.01-1.83) for the carriers of the rs10757278 G allele. A logistic regression model including sex, age, presence of excess weight or obesity, abdominal obesity, diabetes mellitus, arterial hypertension, hypercholesterolemia, positive family history and smoking status parameters revealed that rs1333049 CC genotype was an independent predictive factor of myocardial infraction [OR=1.71 (95% CI: 1.16-2.52), P=0.006]. Patients who underwent percutaneous coronary intervention (PCI) during index hospitalization and patients who did not receive PCI were followed up for two years after discharge. Compared with patients with MI who underwent PCI, the risk of recurrent acute coronary syndrome (re-ACS) was higher among rs1333049 C allele carriers who did not receive PCI during index hospitalization. One year after MI, the OR of re-ACS was 4.91 (95% CI: 1.45-16.66), while two years after MI, OR was 3.77 (95% CI: 1.50-9.52) in those patients who did not receive PCI during index hospitalization. There was no statistically significant association between polymorphic variants of rs1333049 and MI follow-up outcomes in patients who underwent PCI. The present study indicated clinical utility of 9p21.3 genotyping to predict the outcomes for patients with MI without PCI. Due to the small sample size, this association study forms basis for larger, nationwide studies investigating clinical applications of genetic data.

ANRIL as a genetic marker for cardiovascular events in renal transplant patients - an observational follow-up cohort study

Cardiovascular disease is the leading cause of morbidity and mortality in kidney transplant recipients. Several single-nucleotide polymorphisms (SNPs) in the ANRIL gene pathway have been associated with cardiovascular events (CE). The main objective was to ascertain whether ANRIL (rs10757278) and CARD8 (rs2043211) SNPs could mediate susceptibility to CE. This was an observational follow-up cohort study of renal transplant recipients at Bellvitge University Hospital (Barcelona) from 2000 to 2014. A total of 505 recipients were followed up until achievement of a CE. Patients who did not achieve the endpoint were followed up until graft loss, lost to follow-up or death. Survival analysis was used to ascertain association between genetic markers, clinical data, and outcome. Fifty-three patients suffered a CE after renal transplantation. Results showed a significant association between ANRIL SNP and CE. Homozygous GG for the risk allele showed higher risk for CE than A carriers for the protective allele [HR = 2.93(1.69-5.11), P < 0.0001]. This effect was maintained when it was analyzed in combination with CARD8, suggesting that CARD8 SNP could play a role in the ANRIL mechanism. However, our study does not clarify the molecular mechanism for the CARD8 SNP regulation by ANRIL. ANRIL SNP may predispose to the development of CE after successful kidney transplantation.

Impact of 9p21.3 region and atherosclerosis-related genes' variants on long-term recurrent hard cardiac events after a myocardial infarction

Atherosclerotic coronary artery disease (CAD) and myocardial infarction (MI) as its most severe clinical complication remain the leading causes of mortality in the majority of countries. Despite the progress in the treatment of MI, quite often the patients, after the first-time MI, develop subsequently a variety of adverse cardiovascular events. In this retrospective study we evaluated the contribution of allelic variations in 9p21.3 locus and in 21 atherogenesis-related genes to the development of hard cardiac events in a cohort of patients of Russian ethnicity after the first acute MI during long-term follow-up (7-10 years). Death from cardiac causes and recurrent nonfatal MI were considered as key clinical outcomes. We have shown the association of rs1333049 and rs10757278 in 9p21.3 and MTHFR rs1801133 with recurrent unfavorable events, the latter was observed in time-dependent manner. Multilocus analysis additionally suggested the influence of carriage of the CRP and ENOS genes variants at the development of subsequent adverse events after MI. The composite model built for prediction of the individual genetic risk of postinfarction hard cardiac events included 9p21.3 rs1333049*GG and MTHFR*TT and was characterized by area under the curve (AUC) = 0.65. Our data show that 9p21.3 locus and MTHFR gene polymorphisms could influence long-term prognosis of recurrent hard cardiac events in patients who underwent the first MI. It is possible that addition of genotyping at such loci to existing clinical scores could improve their predictability.

The rs2228145 polymorphism in the interleukin-6 receptor and its association with long-term prognosis after myocardial infarction in a pilot study

INTRODUCTION

Interleukin-6 (IL-6) is a cytokine with a complex function that is described as both pro- and anti-inflammatory. One factor that influences its function is the rs2228145 A/C single nucleotide polymorphism (SNP) of the IL-6 receptor (IL6R) gene. C allele carriers have a decreased inflammatory response and decreased prevalence of ischemic heart disease. The aim of the study was to investigate the association of the rs2228145 SNP of the IL6R gene with long-term total mortality in patients with ST-elevation myocardial infarction (STEMI) treated invasively.

MATERIAL AND METHODS

We analyzed the data of consecutive patients with ST elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI). Genotyping was performed with the TaqMan method. The analyzed end-point was total long-term mortality (median: 2875 days).

RESULTS

The registry comprised 553 patients (mean age: 62.4 ±11.9 years; 25.6% females, n = 142; TIMI 3 obtained in 91.7% of patients, n = 507). No significant differences in baseline characteristics were found between the genotypes. During long-term follow-up 171 (30.9%) patients died. There was non-significantly higher mortality in the rs2228145 AA homozygotes compared to C allele carriers (OR = 1.34, 95% CI: 0.93-1.93, p = 0.1).

CONCLUSIONS

The rs2228145 polymorphism of IL6R was not significantly associated with long-term mortality after STEMI. However, AA homozygotes (high-risk genotype for ischemic heart disease) showed a trend towards adverse outcome compared to C allele carriers. The observed trend is promising, but it requires independent replication studies.

Genome-Wide Association Study for Incident Myocardial Infarction and Coronary Heart Disease in Prospective Cohort Studies: The CHARGE Consortium

Background

Data are limited on genome-wide association studies (GWAS) for incident coronary heart disease (CHD). Moreover, it is not known whether genetic variants identified to date also associate with risk of CHD in a prospective setting.

Methods

We performed a two-stage GWAS analysis of incident myocardial infarction (MI) and CHD in a total of 64,297 individuals (including 3898 MI cases, 5465 CHD cases). SNPs that passed an arbitrary threshold of 5×10⁻⁶ in Stage I were taken to Stage II for further discovery. Furthermore, in an analysis of prognosis, we studied whether known SNPs from former GWAS were associated with total mortality in individuals who experienced MI during follow-up.

Results

In Stage I 15 loci passed the threshold of 5×10⁻⁶; 8 loci for MI and 8 loci for CHD, for which one locus overlapped and none were reported in previous GWAS meta-analyses. We took 60 SNPs representing these 15 loci to Stage II of discovery. Four SNPs near QKI showed nominally significant association with MI (p-value<8.8×10⁻³) and three exceeded the genome-wide significance threshold when Stage I and Stage II results were combined (top SNP rs6941513: p = 6.2×10⁻⁹). Despite excellent power, the 9p21 locus SNP (rs1333049) was only modestly associated with MI (HR = 1.09, p-value = 0.02) and marginally with CHD (HR = 1.06, p-value = 0.08). Among an inception cohort of those who experienced MI during follow-up, the risk allele of rs1333049 was associated with a decreased risk of subsequent mortality (HR = 0.90, p-value = 3.2×10⁻³).

Conclusions

QKI represents a novel locus that may serve as a predictor of incident CHD in prospective studies. The association of the 9p21 locus both with increased risk of first myocardial infarction and longer survival after MI highlights the importance of study design in investigating genetic determinants of complex disorders.

The 9p21 polymorphism is linked with atrial fibrillation during acute phase of ST-segment elevation myocardial infarction

The aim of the study was to find whether patients carrying polymorphic allele of the rs10757278 polymorphism from 9p21 locus have changed risk of arrhythmia (atrial fibrillation, AF; sustained ventricular tachycardia or ventricular fibrillation, sVT/VF) during acute phase of myocardial infarction. Retrospective analysis of data collected prospectively from two independent centers was performed. The clinical data were pooled from two independent cardiac registries: (1) the Warsaw ACS genetic registry (STEMI and NSTEMI/UA patients hospitalized in the years 2008-2011; only STEMI patients were analyzed); (2) the Bialystok STEMI genetic registry (STEMI patients hospitalized in years 2001-2005, who survived the first 48 h from hospital admission). Data regarding sVT/VF and AF within first 24 h were analyzed. The patients were genotyped with rs10757278 polymorphism. 1083 patients were included in the analysis; 62 (5.7 %) patients had sVT/VF during acute phase and 78 (7.2 %) patients had AF, 46 (4.2 %) patients had new-onset AF. Minor allele frequency in all patients with AF was significantly different from those without AF (0.40 vs 0.51, p = 0.0096). When only new-onset AF was analyzed, the trend was the same, with significant protective effect in recessive model [OR 0.41 (95 % CI 0.17-0.97), p = 0.025]. The effect was independent of age and GRACE score. No relationship was found between sVT/VF and rs10757278. Patients with STEMI, who survived until hospitalization with polymorphic allele of 9p21 rs10757278 SNP have less AF during acute phase of STEMI. SNP rs10757278 is not linked with sVT/VF in acute phase of STEMI.

Genetic Variant rs10757278 on Chromosome 9p21 Contributes to Myocardial Infarction Susceptibility

Large-scale genome-wide association studies (GWAS) have revealed that rs10757278 polymorphism (or its proxy rs1333049) on chromosome 9p21 is associated with myocardial infarction (MI) susceptibility in individuals of Caucasian ancestry. Following studies in other populations investigated this association. However, some of these studies reported weak or no significant association. Here, we reevaluated this association using large-scale samples by searching PubMed and Google Scholar databases. Our results showed significant association between rs10757278 polymorphism and MI with p = 6.09 × 10-22, odds ratio (OR) = 1.29, 95% confidence interval (CI) 1.22-1.36 in pooled population. We further performed a subgroup analysis, and found significant association between rs10757278 polymorphism and MI in Asian and Caucasian populations. We identified that the association between rs10757278 polymorphism and MI did not vary substantially by excluding any one study. However, the heterogeneity among the selected studies varies substantially by excluding the study from the Pakistan population. We found even more significant association between rs10757278 polymorphism and MI in pooled population, p = 3.55 × 10-53, after excluding the study from the Pakistan population. In summary, previous studies reported weak or no significant association between rs10757278 polymorphism and MI. Interestingly, our analysis suggests that rs10757278 polymorphism is significantly associated with MI susceptibility by analyzing large-scale samples.