Association of the interleukine-6 polymorphism with catheter-induced coronary artery spasm in Egyptians.

BACKGROUND: The role of coronary artery spasm (CAS) was extended beyond variant angina to ischemic heart disease in general, including effort angina, unstable angina, acute myocardial infarction (MI) and sudden death. It is difficult and cumbersome to examine CAS during coronary angiography. Risk factors for CAS include smoking and genetic polymorphisms. AIM: We aimed to investigate the association of the interleukin-6 (IL-6) polymorphism with catheter-induced CAS in Egyptian patients who undergo coronary angiography. METHODS: This is a case-control study. Two hundred patients with chronic coronary artery disease who underwent elective coronary angiography were included in the study. Patients were divided into two groups: the non-CAS group (100 patients) and the CAS group (100 patients). The subjects were genotyped to the -572 C>G (rs 1800796) polymorphism of the IL-6 gene by PCR-restriction fragment length polymorphism. RESULTS: We found that patients with CAS have more risk factors for atherosclerosis compared to those without CAS. Smoking, the IL-6 GG genotype, and the G allele were independent risk factors for CAS. CONCLUSION: We concluded that the GG genotype and G allele of the IL-6 gene are associated with CAS. Smoking, the GG genotype, and the G allele of the IL-6 gene are independent predictors of catheter-induced CAS.

Familial risk of vasospastic angina: a nationwide family study in Sweden.

OBJECTIVES: Vasospastic angina (VSA) is a complex coronary vasomotor disorder associated with an increased risk of myocardial infarction and sudden death. Despite considerable advances in understanding VSA pathophysiology, the interplay between genetic and environmental factors remains elusive. Accordingly, we aimed to determine the familial VSA risk among first-degree relatives of affected individuals. METHODS: A population-based multigenerational cohort study was conducted, including full-sibling pairs born to Swedish parents between 1932 and 2018. Register-based diagnoses were ascertained through linkage to the Swedish Multigeneration Register and National Patient Register. Incidence rate ratios (IRRs) and adjusted HRs were calculated for relatives of individuals with VSA compared with relatives of individuals without VSA. RESULTS: The total study population included 5 764 770 individuals. Overall, 3461 (0.06%) individuals (median age at disease onset 59 years, IQR: 63-76) were diagnosed with VSA. Of these, 2236 (64.61%) were women. The incidence rate of VSA for individuals with an affected sibling was 0.31 (95% CI: 0.24 to 0.42) per 1000 person-years compared with 0.04 (95% CI: 0.04 to 0.04) per 1000 person-years for those without an affected sibling, yielding an IRR of 7.58 (95% CI: 5.71 to 10.07). The risk of VSA for siblings with an affected sibling was significantly increased in the fully adjusted model (HR: 2.56; 95% CI: 1.73 to 3.79). No increased risk of VSA was observed in spouses of affected individuals (HR: 0.63; 95% CI: 0.19 to 2.09). CONCLUSIONS: In this nationwide family study, we identified high familial risk for VSA independent of shared environmental risk factors. Our findings indicate that VSA tends to cluster in families, emphasising the need to explore genetic and non-genetic factors that may contribute.

SIRT1-mediated deacetylation of NF-κB inhibits the MLCK/MLC2 pathway and the expression of ET-1, thus alleviating the development of coronary artery spasm.

Coronary artery spasm (CAS) is an intense vasoconstriction of coronary arteries that causes total or subtotal vessel occlusion. The cardioprotective effect of sirtuin-1 (SIRT1) has been extensively highlighted in coronary artery diseases. The aims within this study include the investigation of the molecular mechanism by which SIRT1 alleviates CAS. SIRT1 expression was first determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis in an endothelin-1 (ET-1)-induced rat CAS model. Interaction among SIRT1, nuclear factor-kappaB (NF-κB), myosin light chain kinase/myosin light chain-2 (MLCK/MLC2), and ET-1 was analyzed using luciferase reporter assay, RT-qPCR, and Western blot analysis. After ectopic expression and depletion experiments in vascular smooth muscle cells (VSMCs), contraction and proliferation of VSMCs and expression of contraction-related proteins (α-SMA, calponin, and SM22α) were measured by collagen gel contraction, 5-ethynyl-2'-deoxyuridine (EdU) assay, RT-qPCR, and Western blot analysis. The obtained results showed that SIRT1 expression was reduced in rat CAS models. However, overexpression of SIRT1 inhibited the contraction and proliferation of VSMCs in vitro. Mechanistic investigation indicated that SIRT1 inhibited NF-κB expression through deacetylation. Moreover, NF-κB could activate the MLCK/MLC2 pathway and upregulate ET-1 expression by binding to their promoter regions, thus inducing VSMC contraction and proliferation in vitro. In vivo experimental results also revealed that SIRT1 alleviated CAS through regulation of the NF-κB/MLCK/MLC2/ET-1 signaling axis. Collectively, our data suggested that SIRT1 could mediate the deacetylation of NF-κB, disrupt the MLCK/MLC2 pathway, and inhibit the expression of ET-1 to relieve CAS, providing a theoretical basis for the prospect of CAS treatment and prevention.NEW & NOTEWORTHY Rat coronary artery spasm models exhibit reduced expression of SIRT1. Overexpression of SIRT1 inhibits contraction and proliferation of VSMCs. SIRT1 inhibits NF-κB through deacetylation to modulate VSMC contraction and proliferation. NF-κB activates the MLCK/MLC2 pathway. NF-κB upregulates ET-1 to modulate VSMC contraction and proliferation.

Association of the genetic ancestry with resistant hypertension in the ReHOT (Resistant Hypertension Optimal Treatment) randomized study.

Resistant hypertension (RH) is defined as uncontrolled blood pressure despite treatment with three or more antihypertensive medications, including, if tolerated, a diuretic in adequate doses. It has been widely known that race is associated with blood pressure control. However, intense debate persists as to whether this is solely explained by unadjusted socioeconomical variables or genetic variation. In this scenario, the main aim was to evaluate the association between genetic ancestry and resistant hypertension in a large sample from a multicenter trial of stage II hypertension, the ReHOT study. Samples from 1,358 patients were analyzed, of which 167 were defined as resistant hypertensive. Genetic ancestry was defined using a panel of 192 polymorphic markers. The genetic ancestry was similar in resistant (52.0% European, 36.7% African and 11.3% Amerindian) and nonresistant hypertensive patients (54.0% European, 34.4% African and 11.6% Amerindian) (p > 0.05). However, we observed a statistically suggestive association of African ancestry with resistant hypertension in brown patient group. In conclusion, increased African genetic ancestry was not associated with RH in Brazilian patients from a prospective randomized hypertension clinical trial.

East Asians Variant Mitochondrial Aldehyde Dehydrogenase 2 Genotype Exacerbates Nitrate Tolerance in Patients With Coronary Spastic Angina.

BACKGROUND: Aldehyde dehydrogenase 2 (ALDH2) plays a central role in the biotransformation of glyceryl trinitrate (GTN) or nitroglycerin, which is widely used for the treatment of coronary artery disease (CAD). The deficient variant ALDH2 genotype (ALDH2*2) is prevalent among East Asians. This study examined whether there are differences in nitroglycerine-mediated dilation (NMD) and flow-mediated dilation (FMD) response between wildALDH2*1/*1and variantALDH2*2patients with CAD.Methods and Results:The study subjects comprised 55 coronary spastic angina (CSA) patients, confirmed by coronary angiography and intracoronary injection of acetylcholine (42 men and 13 women, mean age 68.0±9.0 years). They underwent NMD and FMD tests in the morning before and after continuous transdermal GTN administration for 48 h. NMD was lower at baseline inALDH2*2than in theALDH2*1/*1group (P=0.0499) and decreased significantly in both groups (P<0.0001 and P<0.0001, respectively) after GTN, with significantly lower levels in theALDH2*2group (P=0.0002). FMD decreased significantly in bothALDH2*1/*1andALDH2*2groups (P<0.0001and P=0.0002, respectively) after continuous GTN administration, with no significant differences between the 2 groups both before and after GTN. CONCLUSIONS: Continuous administration of GTN produced endothelial dysfunction as well as nitrate tolerance in bothALDH2*1/1andALDH2*2patients with CSA.ALDH2*2attenuated GTN response and exacerbated GTN tolerance, but not endothelial dysfunction, as compared toALDH2*1/*1in patients with CSA.

Association of East Asian Variant Aldehyde Dehydrogenase 2 Genotype (ALDH2*2*) with Coronary Spasm and Acute Myocardial Infarction.

Coronary spasm plays an important role in the pathogenesis of ischemic heart disease, including angina pectoris, acute myocardial infarction (AMI), silent myocardial ischemia, and sudden death. The prevalence of coronary spasm is higher among East Asians probably due to genetic as well as environmental factors. ALDH2 eliminates toxic aldehydes including 4-hydroxy-2-nonenal (4-HNE) derived from lipid peroxidation and acrolein in tobacco smoking as well as ethanol-derived acetaldehyde and thereby protects tissues and cells from oxidative damage. Deficient variant ALDH2*2 genotype is prevalent among East Asians and is a significant risk factor for both coronary spasm and AMI through accumulation of toxic aldehydes, thereby contributing to oxidative stress, endothelial damage, vasoconstriction, and thrombosis. Toxic aldehydes are thus identified as risk factors to be targeted for the treatment of coronary spasm and AMI.

The importance of genetic counseling and genetic screening: a case report of a 16-year-old boy with resistant hypertension and severe hypokalemia.

Liddle's syndrome, an autosomal dominant form of monogenic hypertension, is characterized by salt-sensitive hypertension with early penetrance, hypokalemia, metabolic alkalosis, suppression of plasma rennin activity and aldosterone secretion, and a clear-cut response to epithelial sodium channel blockers but not spironolactone therapy. Here, we describe the case of a 16-year-old boy patient with resistant hypertension (maintain 170-180/100-110 mm Hg after administration four kinds of antiypertensive drugs) and severe hypokalemia. After a series of checks, we exclude primary aldosteronism and renal artery stenosis and other diseases. Finally, the Liddle syndrome was diagnosed because of the DNA sequencing found that the proband's mother and himself had mutations P616L (c.1847 C>T) in the SCNN1B gene. Liddle syndrome should be considered as a cause of hypertension in children or adolescents particularly with suppressed renin activity. Early diagnosis and appropriately tailored treatment avoid complications of long-term unrecognized or inappropriately managed hypertension. Genetic testing has made it possible to make accurate diagnoses and develop tailored therapies for mutation carriers. The role of genetic testing and genetic counseling in establishing the early diagnosis of Liddle's syndrome is important.

Enhanced transient receptor potential channel-mediated Ca2+ influx in the cells with phospholipase C-δ1 overexpression: its possible role in coronary artery spasm.

We reported that coronary spasm was induced in the transgenic mice with the increased phospholipase C (PLC)-δ1 activity. We investigated the effect of enhanced PLC-δ1 on Ca2+ influx and its underlying mechanisms. We used human embryonic kidney (HEK)-293 and coronary arteries smooth muscle cells (CASMC). Intracellular free Ca2+ concentration ([Ca2+ ]i ; nm) was measured by fura-2, and Ca2+ influx was evaluated by the increase in [Ca2+ ]i after addition of extracellular Ca2+ . Acetylcholine (ACh) was used to induce Ca2+ influx. ACh-induced peak Ca2+ influx was 19 ± 3 in control HEK-293 cells and 71 ± 8 in the cells with PLC-δ1 overexpression (P < 0.05 between two groups). Nifedipine partially suppressed this Ca2+ influx, whereas either 2-APB or knockdown of classical transient receptor potential channel 6 (TRPC6) blocked this Ca2+ influx. In the human CASMC, ACh-induced peak Ca2+ influx was 29 ± 6 in the control and was increased to 45 ± 16 by PLC-δ1 overexpression (P < 0.05). Like HEK-293 cells, pretreatment with nifedipine partially suppressed Ca2+ influx, whereas either 2-APB or knockdown of TRPC6 blocked it. ACh-induced Ca2+ influx was enhanced by PLC-δ1 overexpression, and was blocked partially by nifedipine and completely by 2-APB. TRPC-mediated Ca2+ influx may be related to the enhanced Ca2+ influx in PLC-δ1 overexpression.

Variant Aldehyde Dehydrogenase 2 (ALDH2*2) in East Asians Interactively Exacerbates Tobacco Smoking Risk for Coronary Spasm　- Possible Role of Reactive Aldehydes.

BACKGROUND: Coronary spastic angina (CSA) is common among East Asians and tobacco smoking (TS) is an established risk factor for CSA. Aldehyde dehydrogenase 2 (ALDH2) plays a key role in removing reactive toxic aldehydes and a deficient variant ALDH2 genotype (ALDH2*2) is prevalent among East Asians. We examined the interaction between TS andALDH2*2as a risk factor for CSA to better understand the disease pathogenesis.Methods and Results:The study subjects comprised 410 patients (258 men, 152 women; mean age, 66.3±11.5) in whom intracoronary injection of acetylcholine was performed on suspicion of CSA.ALDH2genotyping was performed by direct application of the Taqman polymerase chain reaction system. Of the study subjects, 244 had CSA proven and 166 were non-CSA. The frequencies of male sex,ALDH2*2, alcohol flushing syndrome, TS, coronary organic stenosis, and plasma levels of uric acid were higher (P<0.001, P<0.001, P<0.001, P<0.001, P<0.001, and P=0.015, respectively) and that of high-density lipoprotein cholesterol lower (P=0.002) in the CSA than non-CSA group. Multivariable logistic regression analysis revealed thatALDH2*2and TS were significant risk factors for CSA (P<0.001 and P=0.002, respectively).ALDH2*2exacerbated TS risk for CSA more than the multiplicative effects of each. CONCLUSIONS: ALDH2*2synergistically exacerbates TS risk for CSA, probably through aldehydes.

High susceptibility of atherosclerotic coronary arteries to the onset of vasospasm and angina pectoris-like symptoms due to coronary spasm in WHHLMI rabbits.

We examined the relationship between atherosclerosis and the provocation of coronary spasm as well as the influence of coronary spasm on the onset of acute ischemic myocardial disease. Coronary spasm was provoked in anesthetized normal Japanese white (JW) rabbits and myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits, an animal model for coronary atherosclerosis and myocardial infarction, by injecting ergonovine during the infusion of norepinephrine through a marginal ear vein. A decrease in contrast flow in the left circumflex artery was observed on coronary angiograms. Ischemic changes were observed on the electrocardiograms of 29% (2/7) of JW and 79% (27/34, P=0.007) of WHHLMI rabbits. The frequency of coronary spasm was significantly high in rabbits with severe coronary plaques showing diffuse lesions. Left ventricle motility in vasospasm-positive rabbits, which was evaluated with echocardiograms, was decreased by 29% following the ergonovine injection (P<0.001), and every serum ischemic marker markedly increased 4 h after the provocation of vasospasm. These results demonstrate that atherosclerotic coronary arteries are positively related to the provocation of vasospasm, and vasospasm in severe atherosclerotic coronary segments evokes angina pectoris-like findings and/or non-fatal myocardial infarction. WHHLMI rabbits may be a novel animal model for angina pectoris and acute ischemic heart disease.

Variant Aldehyde Dehydrogenase 2 (ALDH2*2) Is a Risk Factor for Coronary Spasm and ST-Segment Elevation Myocardial Infarction.

BACKGROUND: Mitochondrial aldehyde dehydrogenase 2 (ALDH2) plays a key role in removing toxic aldehydes. Deficient variant ALDH2*2 genotype is prevalent in up to 40% of the East Asians and reported to be associated with acute myocardial infarction (AMI). To elucidate the mechanisms underlying the association of ALDH2*2 with AMI, we compared the clinical features of AMI patients with ALDH2*2 to those with wild-type ALDH2*1/*1. METHODS AND RESULTS: The study subjects consisted of 202 Japanese patients with acute ST-segment elevation myocardial infarction (STEMI) (156 men and 46 women; mean age, 67.3±12.0) who underwent primary percutaneous coronary intervention (PCI). In 85 patients, provocation test for coronary spasm was also done 6 month post-PCI. ALDH2 genotyping was performed by direct application of the TaqMan polymerase chain system. Of the 202 patients, 103 (51.0%) were carriers of ALDH2*2 and 99 (49.0%) those of ALDH2*1/*1. There were no differences in clinical features between ALDH2*2 and ALDH2*1/*1 carrier groups except higher frequencies of coronary spasm and alcohol flush syndrome (AFS) (88.6% vs 56.1%; P=0.001 and 94.3% vs 17.6%; P<0.001), less-frequent alcohol habit (14.6% vs 51.5%; P<0.001), and higher peak plasma creatine phophokinase levels (2224 vs 1617 mg/dL; P=0.002) in the ALDH2*2 than the ALDH2*1/*1 carrier group. CONCLUSIONS: ALDH2*2 is prevalent (51.0%) among Japanese STEMI patients, and those with ALDH2*2 had higher frequencies of coronary spasm and AFS and more-severe myocardial injury compared to those with ALDH2*1/*1.

East asian variant of aldehyde dehydrogenase 2 is associated with coronary spastic angina: possible roles of reactive aldehydes and implications of alcohol flushing syndrome.

BACKGROUND: Coronary spastic angina (CSA) is a common disease among East Asians, including Japanese. The prevalence of alcohol flushing syndrome associated with deficient activity of the variant aldehyde dehydrogenase 2 (ALDH2*2) genotype is prevalent among East Asians. We examined whether CSA is associated with the ALDH2*2 genotype in Japanese. METHODS AND RESULTS: The study subjects consisted of 202 patients in whom intracoronary injection of acetylcholine was performed by angiography on suspicion of CSA (119 men and 83 women; mean age, 66.2±11.4 years). They were divided into CSA (112 patients) and control groups (90 patients). ALDH2 genotyping was performed by the direct application of the TaqMan polymerase chain reaction system on dried whole blood. Clinical and laboratory data were examined using conventional methods. The frequencies of male sex, ALDH2*2 genotype carriers, alcohol flushing syndrome, tobacco smoking, and the plasma level of uric acid were higher (P<0.001, P<0.001, P<0.001, P<0.001, and P=0.007, respectively) and the plasma high-density lipoprotein cholesterol levels were lower (P<0.001) in the CSA group than in the control group. The multivariable logistic regression analysis revealed that ALDH2*2 genotype and smoking were significantly associated with CSA (P<0.001 and P=0.024, respectively). CONCLUSIONS: East Asian variant ALDH2*2 genotypes and, hence, deficient ALDH2 activity were associated with CSA in Japanese. These data support further investigation of treatment targeting aldehydes for CSA.

Alcohol flushing and positive ethanol patch test in patients with coronary spastic angina: possible role of aldehyde dehydrogenase 2 polymorphisms.

OBJECTIVE: Coronary spasm plays an important role in the pathogenesis of coronary heart disease (CHD) and angina pectoris caused by coronary spasm or coronary spastic angina (CSA) is prevalent in Japan. However, the precise mechanisms underlying coronary spasm are unclear. Alcohol intolerance is prevalent among East Asians, and we previously reported that coronary spasm could be induced by alcohol intake in CSA patients. We herein examined whether CSA is associated with alcohol intolerance in Japanese subjects. METHODS: The study subjects consisted of 80 CSA patients (57 men/ 23 women, mean age 62 ± 12) and 52 non-CSA patients (25 men/27 women, mean age 63 ± 10). The ethanol patch test (EPT) and questionnaire which evaluates flushing after ethanol intake, along with an examination of clinical features and laboratory chemistry data for CHD risk factors were done. Gender (male) and smoking were higher (p=0.007, and p=0.019, respectively) and plasma HDL cholesterol level was lower (p=0.035) in the CSA patients than in the non-CSA patients. Multivariable logistic regression analysis including age, EPT, smoking, and plasma HDL cholesterol level as independent variables revealed that positive EPT and smoking were significant predictors of CSA (p=0.011 and p=0.016, respectively). CONCLUSION: Positive EPT and alcohol flushing following alcohol intake, as well as smoking and plasma levels of HDL cholesterol, were significantly associated with CSA in Japanese patients. Therefore, alcohol ingestion as well as smoking is a significant risk factor for CSA in Japanese.

Vasospasm of atherosclerotic coronary arteries precipitates acute ischemic myocardial damage in myocardial infarction-prone strain of the Watanabe heritable hyperlipidemic rabbits.

OBJECTIVE: This study tested the hypothesis that vasospasm can trigger coronary plaque injury and acute ischemic myocardial damage. APPROACH AND RESULTS: Myocardial infarction-prone strain of the Watanabe heritable hyperlipidemic rabbits received an intravenous bolus of ergonovine maleate (0.45 µmol/kg) during intravenous infusion of norepinephrine (12 nmol/kg per minute) to provoke coronary spasm in vivo. After this treatment, coronary angiography demonstrated vasospasm, and the ECG showed ischemic abnormalities (ST depression/elevation and T-wave inversion) in 77% of animals (23/30). These changes normalized after nitroglycerin injection. In rabbits that demonstrated these ECG findings for >20 minutes, echocardiograms showed left ventricular wall motion abnormality. Serum levels of heart-type fatty acid-binding protein, cardiac troponin-I, and myoglobin increased markedly 4 hours after spasm provocation. In coronary lesions of myocardial infarction-prone strain of the Watanabe heritable hyperlipidemic rabbits with provoked coronary spasm, we observed intimal injury in 60.9% in the form of endothelial cell protrusions (39.1%), denudation (30.4%), and macrophage extravasation (56.5%). Plaque disruption with luminal thrombus, however, was only seen in 2 of 23 animals (8.7%), and mural microthrombus was rarely observed (4.3%). CONCLUSIONS: These observations show that provocation of vasospasm in myocardial infarction-prone strain of the Watanabe heritable hyperlipidemic rabbits associates with subsequent ischemic myocardial damage. Although treatment with spasmogens altered aspects of plaque morphology, for example, endothelial protrusion and macrophage emigration, thrombosis was rare in these animals with chronic atherosclerotic disease.

Coronary spasm and acute myocardial infarction due to a mutation (V734I) in the nucleotide binding domain 1 of ABCC9.

BACKGROUND: Alterations in coronary vasomotor tone may participate in the pathogenesis of acute myocardial infarction (AMI). Vascular ATP-sensitive K(+) (KATP) channels, formed by Kir6.x/SUR2B, are key regulators of coronary tone and mutations in cardiac (Kir6.2/SUR2A) KATP channels result in heart disease. Here we explore the pathophysiological mechanism of a rare mutation (V734I) found in exon 17 of the ABCC9 gene, estimated to cause a 6.4-fold higher risk of AMI before the age of 60. METHODS AND RESULTS: Eleven patients carrying the mutation were identified; they presented AMI of vasospastic origin associated with increased plasma levels of endothelin-1 and increased leukocyte ROCK activity. The effects of the mutation on the functional properties of the two splice variants of ABCC9 (SUR2A and SUR2B) were studied using patch-clamp electrophysiology. The mutation reduced the sensitivity to MgATP inhibition of Kir6.2/SUR2B channels but not of Kir6.2/SUR2A and Kir6.1/SUR2B channels. Furthermore, the stimulatory effects of MgNDP (MgADP, MgGDP and MgUDP) were unaltered in mutant Kir6.2/SUR2A and Kir6.1/SUR2B channels. In contrast, mutant channels composed of Kir6.2 and SUR2B were less sensitive to MgNDP activation, assessed in the presence of MgATP. The antianginal drug nicorandil activated Kir6.2/SUR2B-V734I channels, thus substituting for the loss of MgNDP stimulation, suggesting that this drug could be of therapeutic use in the treatment of AMI associated with V734I. CONCLUSIONS: The 734I allele in ABCC9 may influence susceptibility to AMI by impairing the response of vascular, but not cardiac, KATP channels to intracellular nucleotides. This is the first human mutation in an ion channel gene to be implicated in AMI.