Lipoprotein(a) is a risk factor for occurrence of acute myocardial infarction in patients with coronary vasospasm

Coronary Artery Spasm-Related Heart Failure Syndrome: Literature Review

Although heart failure (HF) is a clinical syndrome that becomes worse over time, certain cases can be reversed with appropriate treatments. While coronary artery spasm (CAS) is still underappreciated and may be misdiagnosed, ischemia due to coronary artery disease and CAS is becoming the single most frequent cause of HF worldwide. CAS could lead to syncope, HF, arrhythmias, and myocardial ischemic syndromes such as asymptomatic ischemia, rest and/or effort angina, myocardial infarction, and sudden death. Albeit the clinical significance of asymptomatic CAS has been undervalued, affected individuals compared with those with classic Heberden's angina pectoris are at higher risk of syncope, life-threatening arrhythmias, and sudden death. As a result, a prompt diagnosis implements appropriate treatment strategies, which have significant life-changing consequences to prevent CAS-related complications, such as HF. Although an accurate diagnosis depends mainly on coronary angiography and provocative testing, clinical characteristics may help decision-making. Because the majority of CAS-related HF (CASHF) patients present with less severe phenotypes than overt HF, it underscores the importance of understanding risk factors correlated with CAS to prevent the future burden of HF. This narrative literature review summarises and discusses separately the epidemiology, clinical features, pathophysiology, and management of patients with CASHF.

Apolipoprotein (a)/Lipoprotein(a)-Induced Oxidative-Inflammatory α7-nAChR/p38 MAPK/IL-6/RhoA-GTP Signaling Axis and M1 Macrophage Polarization Modulate Inflammation-Associated Development of Coronary Artery Spasm

Objective. Apolipoprotein (a)/lipoprotein(a) (Lp(a)), a major carrier of oxidized phospholipids, and α7-nicotinic acetylcholine receptor (α7-nAChR) may play an important role in the development of coronary artery spasm (CAS). In CAS, the association between Lp(a) and the α7-nAChR-modulated inflammatory macrophage polarization and activation and smooth muscle cell dysfunction remains unknown. Methods. We investigated the relevance of Lp(a)/α7-nAChR signaling in patient monocyte-derived macrophages and human coronary artery smooth muscle cells (HCASMCs) using expression profile correlation analyses, fluorescence-assisted cell sorting flow cytometry, immunoblotting, quantitative real-time polymerase chain reaction, and clinicopathological analyses. Results. There are increased serum Lp(a) levels (3.98-fold, $p=0.011$ ) and macrophage population (3.30-fold, $p=0.013$ ) in patients with CAS compared with patients without CAS. Serum Lp(a) level was positively correlated with high-sensitivity C-reactive protein ( $r^2=0.48$ , $p<0.01$ ), IL-6 ( $r^2=0.38$ , $p=0.03$ ), and α7-nAChR ( $r^2=0.45$ , $p<0.01$ ) in patients with CAS, but not in patients without CAS. Compared with untreated or low-density lipoprotein- (LDL-) treated macrophages, Lp(a)-treated macrophages exhibited markedly enhanced α7-nAChR mRNA expression ( $p<0.01$ ) and activity ( $p<0.01$ ), in vitro and ex vivo. Lp(a) but not LDL preferentially induced CD80+ macrophage (M1) polarization and reduced the inducible nitric oxide synthase expression and the subsequent NO production. While shRNA-mediated loss of α7-nAChR function reduced the Lp(a)-induced CD80+ macrophage pool, both shRNA and anti-IL-6 receptor tocilizumab suppressed Lp(a)-upregulated α7-nAChR, p-p38 MAPK, IL-6, and RhoA-GTP protein expression levels in cultures of patient monocyte-derived macrophages and HCASMCs. Conclusions. Elevated Lp(a) levels upregulate α7-nAChR/IL-6/p38 MAPK signaling in macrophages of CAS patients and HCASMC, suggesting that Lp(a)-triggered inflammation mediates CAS through α7-nAChR/p38 MAPK/IL-6/RhoA-GTP signaling induction, macrophage M1 polarization, and HCASMC activation.

Elevated plasma levels of lipoprotein(a) in psychiatric patients: a possible contribution to increased vascular risk

An increased incidence of adverse cardiovascular events has been reported in psychiatric patients, but the exact mechanisms underlying this association are still uncertain. Elevated plasma level of lipoprotein(a) [Lp(a)] is an independent risk factor for atherothrombotic disease in the general population. To study the implications of Lp(a) in psychiatric patients, we measured the plasma levels of Lp(a) in 74 patients with psychiatric disorders (39 schizophrenia, 10 major depression, 13 bipolar disorder and 12 personality disorder) and 74 healthy controls. The Lp(a) levels of the patient groups with schizophrenia, major depression and bipolar disorder were significantly higher than that of the control group. The median Lp(a) value of these diagnostic groups was comparable with those reported in patients with prior atherothrombotic events. On the other hand, no differences were found among personality disorder and controls. Our findings suggest that the elevation of plasma Lp(a) may contribute to increased cardiovascular risk in several patients with psychiatric disorders.

The Biochemical Markers Associated with the Occurrence of Coronary Spasm

Coronary artery spasm (CAS) is one of the mechanisms of angina pectoris. Unlike the diagnosis of acute myocardial infarction which is based on the elevation of cardiac markers, the diagnosis of CAS is difficult and sometimes requires sophisticated and risky provocative test which is not widely accepted in China. There is no well-established biomarker for the diagnosis or prediction of CAS. However, there are some biomarkers proven to be associated with the occurrence of CAS. For example, inflammatory factors including C-reactive protein and cytokines, lipoprotein (a), and cystatin-C might be precipitating factor for CAS. Rho-kinase as a mediator involved in multiple mechanisms of CAS, serotonin, and endothelin-1 as powerful vasoconstrictors leading to vasospasm were all observed being elevated in patients with CAS. Thioredoxin and nitrotyrosine reflected the oxidative status and could be observed to be elevated after the occurrence of CAS. In some cases doubted to be CAS without the evidence of provocative test, the blood test for the biomarkers mentioned above could be useful for the diagnosis of CAS.

Lipoprotein(a): An independent, genetic, and causal factor for cardiovascular disease and acute myocardial infarction

Lipoprotein(a) [Lp(a)] is a circulating lipoprotein, and its level is largely determined by variation in the Lp(a) gene (LPA) locus encoding apo(a). Genetic variation in the LPA gene that increases Lp(a) level also increases coronary artery disease (CAD) risk, suggesting that Lp(a) is a causal factor for CAD risk. Lp(a) is the preferential lipoprotein carrier for oxidized phospholipids (OxPL), a proatherogenic and proinflammatory biomarker. Lp(a) adversely affects endothelial function, inflammation, oxidative stress, fibrinolysis, and plaque stability, leading to accelerated atherothrombosis and premature CAD. The INTER-HEART Study has established the usefulness of Lp(a) in assessing the risk of acute myocardial infarction in ethnically diverse populations with South Asians having the highest risk and population attributable risk. The 2018 Cholesterol Clinical Practice Guideline have recognized elevated Lp(a) as an atherosclerotic cardiovascular disease risk enhancer for initiating or intensifying statin therapy.

Coronary artery spasm due to intravenous atropine infusion in a child: possible Kounis syndrome

Coronary vasospasm can result from silent myocardial ischaemia to sudden death. There are many precipitant factors including different pharmacological agents. Kounis syndrome is defined by acute coronary syndromes associated with anaphylactic or anaphylactoid reactions. We report, to the best of our knowledge, the first paediatric case of Kounis syndrome due to intravenous atropine.

Clinical Application of Genetic Testing in Heart Failure

PURPOSE OF REVIEW

The purpose of this review is to present our current understanding of the genetic etiologies that may cause or predispose to heart failure. We highlight known phenotypes for which a genetic evaluation has clinical utility.

RECENT FINDINGS

The literature continues to demonstrate and confirm a genetic basis for conditions that cause heart failure. Evidence suggests a genetic model involving rare and common variants of strong or weak effect, in combination with environmental factors that may manifest as familial or simplex disease. Clinical genetic testing is available for several phenotypes, which can aid in the diagnosis and identification of at-risk family members. The evaluation of heart failure should include investigating etiologies with a genetic basis. Conducting a genetic evaluation in patients with heart failure requires the ability to identify possible genetic etiologies in an individual's phenotype, obtain relevant family history, and clinically interpret genetic testing results.

Potential of lipoproteins as biomarkers in acute myocardial infarction

Acute myocardial infarction (AMI), commonly known as heart attack, is a medical emergency that is potentially fatal if not promptly and properly managed. The early diagnosis of AMI is critically important for the timely institution of pharmacotherapy to prevent myocardial damage and preserve cardiac function. Ischemic insults during AMI cause myocardial tissue damage, releasing the cardiac muscle protein troponin T into the blood stream. Therefore, serum troponin T levels are used as a sensitive and specific indicator of myocardial injury for diagnosing AMI. However, there remains a requirement for developing technologies for more accurate biomarkers or signatures for AMI diagnosis or prognosis. Previous studies have implicated impaired lipid metabolism as a causative factor in AMI development. Lipoproteins are important constituents of lipid metabolism; their levels in the blood stream are a convenient biomarker tool for monitoring lipid metabolism. This review summarizes recent findings (data of studies from 2001 to 2016) regarding the biomarker potentials of various lipoproteins, including low-density lipoprotein, oxidized low-density lipoprotein, high-density lipoprotein, lipoprotein-a, and remnant lipoprotein, for the risk stratification of AMI.

Association of AGER gene G82S polymorphism with the severity of coronary artery disease in Chinese Han population

BACKGROUND AND OBJECTIVE

Advanced glycosylation end-product receptor (AGER) plays an important role in the development and progression of atherosclerosis. The G82S polymorphism (rs2070600) is located in the ligand-binding V-domain of AGER suggesting a possible influence of this variant on AGER function. The aim of this study is to evaluate the association of the G82S polymorphism with the severity of coronary artery disease (CAD) in patients with or without type 2 diabetes mellitus (T2DM).

DESIGN AND METHODS

The AGER gene G82S polymorphism was analysed in 270 nondiabetic and 270 type 2 diabetic Chinese Han patients with angiographically proven CAD (luminal stenosis ≥ 50%). The number of diseased vessels and Gensini score were used to determine the severity of CAD. Genotyping for the G82S polymorphism was performed by PCR-RFLP using restriction enzymes AluI.

RESULTS

The frequency of 82S allele was significantly lower in the diabetic CAD patients with multi-vessel disease than in those with single-vessel disease (P = 0·015). When controlled for confounding variables, the 82S allele was associated with decreased risk of multi-vessel disease [P = 0·038, adjusted OR = 0·565 (0·329-0·972)]. The protective effect of the 82S allele against the severity of CAD was not observed in patients with nondiabetic CAD.

CONCLUSIONS

AGER 82S allele showed a protective effect on CAD severity in the presence of T2DM in Chinese Han population.

Disruption of coronary vasomotor function: the coronary spasm syndrome

Abnormal coronary vasoconstriction, or coronary spasm, can be the result of several factors, including local and neuroendocrine aberrations. It can manifest clinically as a coronary syndrome and plays an important role in the genesis of myocardial ischemia. Over the past half century, coronary angiography allowed the in vivo demonstration of spasm in patients who fit the initial clinical description of the condition as reported by Prinzmetal et al. Several clinical, basic, and more recently, genetic studies have provided insight into the pathogenesis, manifestations, and therapy of this condition. It is not uncommonly encountered in patients with coronary syndromes and absence of clearly pathologic lesions on angiography. Provocation tests utilizing pharmacologic and nonpharmacologic stimuli combined with imaging (echocardiography or coronary angiography) can help make the correct diagnosis. The use of calcium channel blockers and long-acting nitrates is currently considered standard of care and the overall prognosis appears to be good. The recent discovery of genetic abnormalities predisposing to abnormal spasm of the coronaries has stimulated interest in the development of targeted therapies for the management of this condition.

Plasma levels of lipoprotein (a) in patients with major depressive disorders

Depression and cardiovascular disease are among the most prevalent health problems. The evidence that depression is a risk factor for the development and progression of coronary heart disease has strengthened over the past several years, but the exact reasons are not yet clear. Elevated lipoprotein (a) (Lp(a)) concentrations seem to be the major factor for the progression of the atherosclerosis and coronary heart disease. In this study, we measured the plasma levels of Lp(a) in 35 patients with major depressive disorder and 35 healthy controls. The two groups were matched by age and gender. Lp(a) measurement was performed using an immunoturbidimetric method. Total cholesterol was significantly lower in the patient group (mean +/-SD: 144.65+/-22.13 vs. 186.14+/-34.48 mg/dl. The Lp(a) levels of the patient group differed significantly from control values. Patients with major depressive disorder had higher plasma levels of Lp(a) than healthy controls (34.94+/-18.01 vs. 20.08+/-11.27 mg/dl). The results of the present study suggest that the increase of Lp(a) may contribute to higher cardiovascular risk in patients with major depressive disorder.

Age-related effects of regular physical activity on hemostatic factors in men

BACKGROUND

Age-related changes in blood coagulation and fibrinolytic factors are associated with an increase in risk of thrombotic events. The purpose of this study was to assess the effects of age, regular aerobic exercise and detraining on blood coagulation and fibrinolytic factors in men.

METHODS

Initially, 41 sedentary and 42 physically active men (20-64 years) were analyzed for plasma levels of coagulation and fibrinolytic factors. Twelve sedentary men were then subjected to 16-week aerobic exercise training and subsequent 2-week detraining. Their blood samples taken at rest were assayed for activity levels of prothrombin, coagulation factor (F) V, VII, VIII, IX, X, XI and XIII, antithrombin III, protein C and plasminogen, and for antigen levels of fibrinogen, prothrombin fragment 1 + 2 (F1 + 2), FIX, protein C, tissue-type plasminogen activator (tPA), plasminogen activator inhibitor 1 (PAI-1) and tPA/PAI-1 complex.

RESULTS

Plasma levels of most coagulation factors, particularly for fibrinogen and FIX antigens as well as FXIII activity significantly increased with aging in sedentary men, while that tendency disappeared in physically active men. By the exercise training, plasma antigen and/or activity levels of most blood coagulation factors except for prothrombin and FIX decreased. These training-effects, however, disappeared after detraining, and in some cases even rebounded to higher levels than those of pre-training. Plasma antigen levels of tPA, PAI-1 and tPA/PAI-1 complex decreased with the training and remained low even after detraining.

CONCLUSION

Regular aerobic exercises give complex effects on expression of hemostatic factors, overall favoring the hemostatic balance to less thrombotic, partly cancelling out the age effects.

Thyrotoxicosis with coronary spasm that required coronary artery bypass surgery

We describe a 47-year-old woman with severe coronary vasospasm induced by hyperthyroidism. The patient complained of anginal chest pain without specific characteristics of thyrotoxicosis. Coronary arteriography was performed and revealed 90% stenosis of both the left and right coronary os. She was treated with emergent coronary artery bypass graft surgery. Postoperatively, she exhibited a comatose mentality. Severe thyrotoxicosis was indicated on thyroid function tests and thyrotoxic storm was diagnosed. Nineteen days after the surgery and following the initiation of propylthiouracil treatment, coronary arteriography revealed entirely normal coronary arteries.

Relationship between serum lipoprotein(a) concentrations and coronary vasomotion in coronary spastic angina

BACKGROUND

Elevated lipoprotein(a) (Lp(a)) concentrations are reported to impair endothelium-dependent vasodilatation of the epicardial coronary artery. However, the effects on vasomotor abnormalities in coronary spastic angina (CSA) have not been thoroughly investigated.

METHODS AND RESULTS

In the present study 80 sites of spasm (spastic sites) without significant organic stenosis (% diameter stenosis <50%) were assessed in 80 patients with CSA diagnosed by intracoronary ergonovine (EM) test. Spastic sites were divided into 2 groups: Group 1 included 30 sites provoked by the full dose (=50 microg) of EM, and Group 2 included 50 sites provoked with less than 50 microg (34.7+/-8.2 microg). Control subjects (n=22) did not show coronary spasm with the EM test. Serum Lp(a) concentrations were measured in all patients. Group 2 had a significantly greater basal coronary artery tone in the spastic sites than Group 1 (p<0.001). Lp(a) level in Group 2 was significantly higher compared with both the control group and Group 1 (p<0.05 by analysis of variance). Multivariate analysis confirmed that only serum Lp(a) concentration was associated with low-dose EM spasm provocation.

CONCLUSIONS

Serum Lp(a) concentration could be a marker for high disease activity in CSA.

−374T/A polymorphism of the RAGE gene promoter in relation to severity of coronary atherosclerosis

BACKGROUND

We have recently reported that homozygosity for the minor A-allele of RAGE (receptor for advanced glycation end products) -374T/A polymorphism may exert a protective effect toward the development of angiographic coronary artery disease (CAD). Here we focused on the putative involvement of this functional RAGE polymorphism on the severity of coronary atherosclerosis as assessed by angiography.

METHODS

In a total of 234 consecutive Caucasian patients with angiographically proven CAD, the severity of coronary atherosclerosis was assessed by the number of diseased vessels (greater than 50% stenosis). Genotyping for the -374T/A variant was performed by means of PCR-RFLPs.

RESULTS

The mean number of diseased vessels was significantly lower in patients with the AA genotype (1.47+/-0.68) than in those with the AT or TT genotype (1.88+/-0.82, p=0.029). After confounding variables were controlled for, the number of diseased vessels remained significantly different in the AA genotype carriers from that in the AT or TT carriers (p=0.041, ANCOVA).

CONCLUSIONS

Our data suggest that the RAGE -374T/A polymorphism is one of the likely candidate determinants for the genetic variance of disease phenotype in coronary atherosclerosis.

Plasma lipoprotein Lp(a), markers of haemostasis and inflammation, and risk and severity of coronary heart disease

BACKGROUND

Elevated plasma (Lp(a)) levels may represent an independent risk factor for atherothrombotic complications but the relation between Lp(a) levels and the extent of coronary artery disease (CHD) has been discussed controversially. Little is known about potential atherothrombogenic mechanisms of Lp(a).

DESIGN

Case-control study.

METHODS

We assessed the relationship between plasma Lp(a) and angiographically defined CHD, evaluating the severity of coronary atherosclerosis by three different scores. A total of 312 patients with stable angina aged 40-68 years with at least one coronary stenosis > 50% were studied. A group of 479 voluntary blood donors matched for age and sex served as controls. A complete lipid profile and a large number of markers of coagulation, fibrinolysis and inflammation were measured.

RESULTS

Plasma levels of Lp(a) were significantly higher in patients (14.8 mg/dl; 5.4-47.1 mg/dl; median/interquartile range) than in controls (9.7 mg/dl; 3.5-25.3) (P<0.0001). In a logistic regression model, the fully adjusted Odds Ratio for CHD was 3.3 (95% confidence interval (CI) 1.8-5.6, P<0.0001) for patients in the upper quartile of the Lp(a) distribution compared to the bottom quartile. There was no appreciable association between Lp(a) and apolipoproteins, markers of haemostasis, fibrinolysis and inflammation and the severity of CHD.

CONCLUSIONS

These results indicate that elevated plasma Lp(a) levels may be an independent risk factor for CHD but unrelated to the severity and extension of CHD. Furthermore, there is no good evidence that the presumed link between Lp(a) and CHD is mediated by increased levels of markers of inflammation, or interference with markers of fibrinolysis or coagulation.

Low density lipoprotein particles are small in patients with coronary vasospasm

Increased lipid oxidative stress has been recently implicated in the pathogenesis of coronary artery spasm. Small, dense LDL with high susceptibility to oxidation may be linked to the genesis of coronary vasospasm. The relative migratory distance of the predominant densitometric peak of LDL from that of VLDL to that of HDL in a 3% polyacrylamide gel electrophoresis was determined as a measure of LDL particle size in 49 patients with coronary spastic angina (CSA), in 56 patients with stable effort angina and a significant coronary artery stenosis (SEA) and also in 40 control subjects without coronary artery disease (Control). The incidence of detection of small, dense LDL (particle diameter <25.5 nm) or a relative migratory distance above 0.36 was significantly higher in CSA (57%) and also in SEA (39%) than in Control (20%). In SEA, a significantly higher serum level of triglyceride was noted in the subgroup with the small, dense LDL as compared with the subgroup without. In contrast, in CSA, the serum level of triglyceride was not significantly different between the subgroups with and without the small, dense LDL, although significantly lower serum levels of both HDL-cholesterol and alpha-tocopherol were noted in the former. In 16 patients of CSA, the detection of the small, dense LDL was significantly decreased after a >6-month angina-free period (69-->31%). We conclude that patients with coronary spastic angina had smaller LDL particles, associated not with hypertriglyceridemia but low serum levels of both HDL-cholesterol and vitamin E. Dyslipidemia with small, dense LDL may be related to the genesis of coronary vasospasm.

Risk factors that discriminate 'high- risk' from 'low-risk' Japanese patients with coronary artery disease

Although various risk factors have been implicated in the progression of coronary artery disease (CAD), coronary risk factors specifically related to the long-term prognosis for high-risk CAD have not been determined. The study enrolled 311 consecutive Japanese patients with CAD who underwent diagnostic coronary arteriography and divided them into 2 groups: (i) 135 high-risk patients with either impaired left ventricular function (ejection fraction <50%) or multivessel disease and (ii) 176 low-risk patients with normal left ventricular function and 0- or 1-vessel disease. The prevalence of risk factors including age, gender, smoking, hypertension, diabetes mellitus (DM), obesity and lipid variables were compared between the 2 groups. The prevalence of DM, a serum high-density lipoprotein (HDL)-cholesterol level below 35 mg/dl and a serum lipoprotein (Lp) (a) level above 25 mg/dl was significantly higher in the high-risk group as compared with the low-risk group. Multiple logistic regression analysis demonstrated that DM (odds ratio (OR): 1.72, 95% confidence intervals (CI): 1.02-2.92, p<0.05), a low HDL-cholesterol level (OR: 2.49, 95% CI: 1.49-4.17, p<0.001) and a high Lp(a) level (OR: 1.68, 95% CI: 1.02-2.76, p<0.05) were all independent risk factors for high-risk CAD. However, if the patients with 0-vessel disease were excluded from the low-risk group, a low HDL-cholesterol level was found to be the only independent predictor for high-risk CAD (OR: 2.07, 95% CI: 1.15-3.70, p<0.05). Among both men and smokers in this population, a higher Lp(a) level was found to be a significant predictor for high-risk CAD. A low serum level of HDL-cholesterol, a high serum level of Lp(a) and DM were significant predictors of high-risk in patients with CAD. Among patients with a significant coronary stenosis or left ventricular dysfunction, a low serum level of HDL-cholesterol was the only significant predictor for high-risk CAD.