Global perspective of familial hypercholesterolaemia: a cross-sectional study from the EAS Familial Hypercholesterolaemia Studies Collaboration (FHSC)

BACKGROUND

The European Atherosclerosis Society Familial Hypercholesterolaemia Studies Collaboration (FHSC) global registry provides a platform for the global surveillance of familial hypercholesterolaemia through harmonisation and pooling of multinational data. In this study, we aimed to characterise the adult population with heterozygous familial hypercholesterolaemia and described how it is detected and managed globally.

METHODS

Using FHSC global registry data, we did a cross-sectional assessment of adults (aged 18 years or older) with a clinical or genetic diagnosis of probable or definite heterozygous familial hypercholesterolaemia at the time they were entered into the registries. Data were assessed overall and by WHO regions, sex, and index versus non-index cases.

FINDINGS

Of the 61 612 individuals in the registry, 42 167 adults (21 999 [53·6%] women) from 56 countries were included in the study. Of these, 31 798 (75·4%) were diagnosed with the Dutch Lipid Clinic Network criteria, and 35 490 (84·2%) were from the WHO region of Europe. Median age of participants at entry in the registry was 46·2 years (IQR 34·3-58·0); median age at diagnosis of familial hypercholesterolaemia was 44·4 years (32·5-56·5), with 40·2% of participants younger than 40 years when diagnosed. Prevalence of cardiovascular risk factors increased progressively with age and varied by WHO region. Prevalence of coronary disease was 17·4% (2·1% for stroke and 5·2% for peripheral artery disease), increasing with concentrations of untreated LDL cholesterol, and was about two times lower in women than in men. Among patients receiving lipid-lowering medications, 16 803 (81·1%) were receiving statins and 3691 (21·2%) were on combination therapy, with greater use of more potent lipid-lowering medication in men than in women. Median LDL cholesterol was 5·43 mmol/L (IQR 4·32-6·72) among patients not taking lipid-lowering medications and 4·23 mmol/L (3·20-5·66) among those taking them. Among patients taking lipid-lowering medications, 2·7% had LDL cholesterol lower than 1·8 mmol/L; the use of combination therapy, particularly with three drugs and with proprotein convertase subtilisin-kexin type 9 inhibitors, was associated with a higher proportion and greater odds of having LDL cholesterol lower than 1·8 mmol/L. Compared with index cases, patients who were non-index cases were younger, with lower LDL cholesterol and lower prevalence of cardiovascular risk factors and cardiovascular diseases (all p<0·001).

INTERPRETATION

Familial hypercholesterolaemia is diagnosed late. Guideline-recommended LDL cholesterol concentrations are infrequently achieved with single-drug therapy. Cardiovascular risk factors and presence of coronary disease were lower among non-index cases, who were diagnosed earlier. Earlier detection and greater use of combination therapies are required to reduce the global burden of familial hypercholesterolaemia.

FUNDING

Pfizer, Amgen, Merck Sharp & Dohme, Sanofi-Aventis, Daiichi Sankyo, and Regeneron.

What have we learned from Turkish familial hypercholesterolemia registries (A-HIT1 and A-HIT2)?

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) is a common genetic disease of high-level cholesterol leading to premature atherosclerosis. One of the key aspects to overcome FH burden is the generation of large-scale reliable data in terms of registries. This manuscript underlines the important results of nation-wide Turkish FH registries (A-HIT1 and A-HIT2).

METHODS

A-HIT1 is a survey of homozygous FH patients undergoing low density lipoprotein (LDL) apheresis (LA). A-HIT2 is a registry of adult FH patients (homozygous and heterozygous) admitted to outpatient clinics. Both registries used clinical diagnosis of FH.

RESULTS

A-HIT1 evaluated 88 patients (27 ± 11 years, 41 women) in 19 centers. All patients were receiving regular LA. There was a 7.37 ± 7.1-year delay between diagnosis and initiation of LA. LDL-cholesterol levels reached the target only in 5 cases. Mean frequency of apheresis sessions was 19 ± 13 days. None of the centers had a standardized approach for LA. Mean frequency of apheresis sessions was every 19 ± 13 (7-90) days. Only 2 centers were aware of the target LDL levels. A-HIT2 enrolled 1071 FH patients (53 ± 8 years, 606 women) from 31 outpatients clinics specialized in cardiology (27), internal medicine (1), and endocrinology (3); 96.4% were heterozygous. 459 patients were on statin treatment. LDL targets were attained in 23 patients (2.1% of the whole population, 5% receiving statin) on treatment. However, 66% of statin-receiving patients were on intense doses of statins. Awareness of FH was 9.5% in the whole patient population.

CONCLUSIONS

The first nationwide FH registries revealed that FH is still undertreated even in specialized centers in Turkey. Additional effective treatment regiments are urgently needed.

Assessment of serum hepcidin levels in patients with non-ST elevation myocardial infarction

OBJECTIVE

Hepcidin is an acute-phase reactant produced in the liver displaying intrinsic antimicrobial activity. There are few studies about hepcidin considered to be acute and chronic inflammatory marker in acute coronary syndromes patients. We investigated in our study whether the level of hepcidin has increased in the acute phase of non-ST elevation myocardial infarction patients (NSTEMI) known as acute inflammatory aggravation of chronic atherosclerotic process.

METHODS

Seventy patients with NSTEMI and twenty healthy people were recruited as controls in this observational cross-sectional study. Serum hepcidin levels were determined by ELISA, and troponin levels were measured by standard laboratory methods. Levels of hepcidin and troponin were measured at admission and 6 hours later. Mean values of continuous variables were compared between groups using the Student t-test or Mann-Whitney U test, according to whether normally distributed or not, as tested by the Kolmogorov-Smirnov test. Serum troponin and hepcidin levels measured at admission and after 6th hours were compared using paired t-test.

RESULTS

Hepcidin level was similar between NSTEMI and controls at admission (24.55±32.13, 23.67±33.62 ng/mL, p>0.05, respectively). Also, serum hepcidin levels did not change significantly from baseline in blood samples taken after 6 hour from admission in NSTEMI patients (24.55±32.13 ng/mL, 29.75±31.48 ng/mL, p=0.62, respectively). However, serum troponin levels were increased significantly compared to baseline (0.29±3.56, 2.92±7.2 ng/mL, p<0.01).

CONCLUSION

Our findings suggest that hepcidin could not be use as a marker of myocardial necrosis in acute phase such as troponin in patients with NSTEMI.

Arrhythmia risk assessment using heart rate variability parameters in patients with frequent ventricular ectopic beats without structural heart disease

BACKGROUND

Ventricular ectopic beats (VEBs) are usually considered a benign condition that can be managed with conservative measures. Heart rate variability (HRV), which is one of the most important methods for assessing autonomic activity, is a noninvasive, quantitative method of analyzing autonomic effects on the heart. We aimed to investigate the risk of arrhythmia in patients with VEBs and without cardiovascular disease by using HRV parameters.

METHODS

Patients with frequent VEBs (more than 30 times in 1 hour, according to the Lown classification) were identified. Identified patients were evaluated by 24-hour ECG recording. Our study included 43 patients with frequent VEBs and 43 controls.

RESULTS

General characteristics of the study population were similar. The LF (low frequency)/HF (high frequency) ratio was significantly higher in the frequent VEBs group than in the control group (P < 0.001). The rate of paroxysmal atrial fibrillation (PAF) was higher in the frequent VEB group than in the control group (P = 0.003). The number of VEBs was correlated with LF/HF ratio and PAF (r = 0.339, P = 0.001 and r = 0.294, P = 0.006, respectively).

CONCLUSIONS

Our study showed that the sympathetic nervous system is dominant in young patients with VEBs and without significant comorbidities. There is a higher risk of atrial fibrillation in patients with VEBs and they should be monitored closely for atrial fibrillation.

Association between resistin level and renal function in patients undergoing coronary artery bypass graft surgery

AIM

The purpose of this study was to evaluate the association between resistin levels and renal function in patients undergoing coronary artery bypass graft (CABG) surgery.

METHODS

Thirty-seven consecutive patients (mean ± SD, age 60 ± 10 years, 29 (78%) male) undergoing CABG surgery at our department were enrolled into our study. Blood samples were taken to examine quantities of resistin level and other blood parameters the day before surgery. The patients were categorized into 2 groups: lower resistin level (group 1) or higher resistin level (group 2) according to the median value of 9 ng/mL.

RESULTS

Mean ± SD resistin level, glomerular filtration rate (GFR), and urea and creatinine levels were 9.5 ± 4.2 ng/mL, 78 ± 25 mL/min per 1.73 m(2), 42 ± 14 mg/dL, and 1.08 ± 0.2 mg/dL, respectively. Resistin showed significant correlation with serum levels of urea (r = 0.448l P = 0.005), creatinine (r = 0.367; P = 0.026), inverse correlation with GFR (r = -0.398; P = 0.015), statin usage (r = -0.393; P = 0.016), and β-blocker usage (r = -0.365; P = 0.026). In the multivariate logistic regression model, only GFR (odds ratio, 0.960; 95 confidence interval, 0.928-0.993; P = 0.018) remained independently associated with higher resistin levels after adjustment of other potential confounders in patients undergoing CABG surgery. According to the receiver operating characteristics curve analysis, the optimal cutoff value of GFR to predict higher resistin levels was found as 91 mL/min or less per 1.73 m(2), with 100% sensitivity and 61.1% specificity.

CONCLUSION

The present study demonstrated that a lower glomerular filtration rate was associated with higher circulating resistin levels, independent of coronary heart disease risk factors in patients undergoing CABG surgery.

Prognostic Value of the Neutrophil-Lymphocyte Ratio in Patients With ST-Elevated Acute Myocardial Infarction

The predictive value of leukocyte counts has been reported in patients with acute myocardial infarction (AMI). We aimed to evaluate the predictive value of the total leukocyte count and neutrophil-lymphocyte (N/L) ratio for mortality due to AMI. A total of 522 patients with acute ST-elevated MI were included in the study. The study population was divided into tertiles based on admission N/L ratio values. High (n = 174) and low N/L (n = 348) ratio groups were defined as patients having values in the third tertile (>5.77) and lower 2 tertiles (≤ 5.77), respectively. The high N/L ratio group had a significantly higher incidence of in-hospital cardiovascular mortality (13.8% vs 4.6%, P < .001). An N/L ratio >5.77 was found to be an independent predictor of in-hospital cardiovascular mortality (hazard ratio: 3.78, 95% confidence interval: 1.71-8.30, P = .001). A high N/L ratio is a strong and independent predictor of in-hospital cardiovascular mortality of AMI with ST elevation.

Compartment syndrome of the vein donor leg following an uneventful coronary artery bypass surgery

Compartment syndrome (CS) is a very rare complication of coronary artery bypass surgery (CABG) due to elevated intra-compartmental pressure induced by ischemia-reperfusion injury. We report a patient with CS following an uneventful CABG and discuss its management.

Association between inherited thrombophilia and impaired right ventricular function in deep vein thrombosis without symptomatic pulmonary embolism

The aim was to evaluate the right ventricular function in patients with inherited thrombophilia and deep vein thrombosis (DVT) without pulmonary embolism. A total of 38 patients with DVT without symptomatic pulmonary embolism and 30 patients with varicose veins were enrolled. Clinical data, echocardiography, and 2 thrombophilic mutations were analyzed. Factor V Leiden (FVL) polymorphism was significantly frequent in the study group (P = .007). The difference in prothrombin G20210A polymorphism between the study and control groups was at a near-significant level (P = .058). There was statistically significant decrease in tricuspid annular plane systolic excursion values in patients with FVL and prothrombin G20210A polymorphism. Combined FVL and prothrombin G20210A polymorphisms were more closely related to the decrease in this value (P = .006). Deep vein thrombosis had no additional adverse effects on right ventricle. Impaired right ventricular systolic function occurs in FVL and prothrombin G20210A polymorphisms.

N-acetylcysteine in preventing contrast-induced nephropathy assessed by cystatin C

AIMS

Prophylactic oral N-acetylcysteine (NAC) has been widely used for prevention of contrast-induced nephropathy (CIN). However, clinical studies have not been demonstrating this effect consistently because of evidence that NAC can alter serum creatinine levels without affecting glomerular filtration rate (GFR). We investigated NAC for the prevention of CIN by monitoring creatinine and cystatin C.

METHODS

We enrolled 113 patients (49 patients in NAC group and 64 patients in control group) with normal to subnormal GFR who were scheduled for cardiovascular procedures. Patients in NAC group receive acetylcysteine 600 mg twice a day, on the day before and on the day of cardiovascular procedure. All patients received a periprocedural intravenous infusion ("volume expansion") of 1 ml/kg/h with 0.45% saline for 24 h (12 h before and 12 h after exposure to contrast medium). Serum cystatin C and creatinine levels were measured before and at 12, 24, and 48 h after procedure.

RESULTS

The incidence of cystatin C-based CIN was 28.5% (n = 14) in NAC and 23.4% (n = 15) in control group (p = 0.663) and serum creatinine-based CIN was 12.2% (n = 6) in NAC and 17.2% (n = 11) in control group (P= 0.468). In this study, oral NAC had no effect on the prevention of CIN in patients undergoing cardiovascular procedures.

CONCLUSION

In this study, oral NAC administration does not reduce neither the incidence of cystatin C-based CIN nor serum creatinine-based CIN in patients undergoing cardiovascular procedures.

Left atrial appendage function in mitral stenosis: is it determined by cardiac rhythm?

BACKGROUND AND AIM OF THE STUDY

The left atrial appendage (LAA) is a common source of cardiac thrombus formation associated with systemic embolism in patients with mitral stenosis (MS). Low flow velocities in the LAA are important factors in the development of thrombosis. Whilst oral anticoagulant therapy is used routinely in MS with atrial fibrillation (AF), the characteristics of LAA contractile functions and the protective role of oral anticoagulant treatment in patients with MS in sinus rhythm (SR) are unclear. The study aim was to compare LAA contractile functions in patients with MS who were either in SR or had AF.

METHODS

The study population comprised 51 patients with MS, who had undergone both standard transthoracic and transesophageal echocardiography. The patients were allocated to two groups, according to the presence of AF or SR. Ten healthy, gender-matched subjects were included in the study as a control group.

RESULTS

Except for age, the characteristics of the groups were similar. In patients with SR and AF, the LAA contractile functions were significantly lower than in controls. While the LAA contractile functions of the SR group were significantly lower than the AF group (LAA emptying/filling velocity: 26 +/- 7/24 +/- 8 versus 19 +/- 5/17 +/- 5 cm/s; p = 0.002 and p = 0.001, respectively, LAA maximum/minimum area: 5.4 +/- 1.2/3.2 +/- 0.9 versus 6.2 +/- 1.1/3.7 +/- 0.8 cm2, p = 0.02 and p =0.02, respectively), no statistically significant differences were observed between patients in SR with mitral valve area (MVA) <1.5 cm2 and patients in AF. Four SR patients (13%) and six AF patients (27%) had LAA thrombus. A strong correlation was observed between the MVA and LAA peak emptying/filling velocity in patients with MS in SR (r = 0.739, p = 0.0001 and r = 0.728, p = 0.0001, respectively).

CONCLUSION

The study results showed that LAA contractile function is diminished in patients with moderate-severe MS in SR, and to a similar degree as patients in AF. It was concluded that patients with moderate-severe MS in SR have a higher risk for thromboembolic events than MS patients in AF.

High inflammatory activity related to the number of metabolic syndrome components

It has been known that each component of the metabolic syndrome (MS) has an atherogenic potential and increases the risk of cardiovascular events. Therefore, patients who have MS are candidates for the development of atherosclerosis and accompanying complications. In this study, the authors assessed the levels of acute phase reactants as an indicator of inflammation in patients with MS. Twenty-five patients with recently diagnosed MS and not treated before who had at least 3 of 5 diagnostic criteria of MS listed in the Third Report of the Adult Treatment Panel National Cholesterol Education Program (NCEP-ATP III) guidelines were included in the study. Twenty healthy patients constituted the control group. Inflammatory parameters were compared between the groups. There was no significant difference between the MS and control group with regard to age and sex. White blood cell count (/mm(3)), high-sensitivity C-reactive protein (hs-CRP), uric acid, interleukin (IL) 6, and fibrinogen levels were found to be significantly higher in the MS group. Number of MS components was strongly correlated with serum levels of hs-CRP (r=0.688, P=.0001), IL-6 (r=0.546, P=.0001), fibrinogen (r=0.551, P=.0001), uric acid (r=0.517, P=.0001), and leucocyte count (/mm(3)) (r=0.456, P=.002). Inflammation plays an important role in atherosclerotic complications, which is activated in MS. Increased number of MS components are strongly associated with elevated inflammatory and metabolic markers. Measurement of serum inflammatory parameters in patients with MS may be beneficial in detection and management of cardiovascular events and in the assessment of efficacy of treatment.

Effect of mean platelet volume on postintervention coronary blood flow in patients with chronic stable angina pectoris

OBJECTIVES

In our study we sought to determine whether mean platelet volume (MPV), measured on admission, could be used in determining decreased coronary blood flow (CBF) in stable coronary artery disease (CAD) patients after percutaneous coronary intervention (PCI).

BACKGROUND

Platelets play a crucial role in the pathophysiology of CAD. MPV reflects platelet function and activity. There are no reports regarding the effect of MPV on CBF in patients with stable CAD undergoing PCI.

METHODS

A total of 66 consecutive patients (mean age: 58 +/- 5 years, 74% male) with the diagnosis of stable CAD who were hospitalized for PCI were prospectively enrolled in our study. Coronary flow rates of all subjects were documented by corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) for each major coronary artery before and after PCI. Blood samples for MPV estimation, platelet count and other laboratory data obtained on admission were measured on the day of the scheduled PCI. Patients were divided into two groups according to MPV levels measured on admission: 1) high MPV group and 2) normal MPV group.

RESULTS

A final TIMI 3 flow was achieved in all patients with no complications. Procedural characteristics of PCI, except left anterior descending artery intervention, were similar in the two groups. Patients with high MPV had significantly higher CTFC than those with a normal MPV (24 +/- 3 vs. 17 +/- 5; p = 0.001). The MPV correlated strongly with post-PCI CTFC (R = 0.625; p = 0.0001). Multiple logistic regression analysis showed that only MPV was an independent predictor of post-PCI CTFC after adjustment for baseline characteristics (OR 1.9, 95% CI 1.2-2.3; p = 0.001).

CONCLUSIONS

MPV may be considered a useful hematological marker, allowing for early and easy identification of patients with stable CAD who are at a higher risk of post-PCI low-reflow.

Myocardial bridge: a bridge to atherosclerosis

OBJECTIVE

Myocardial bridge (MB) is a congenital anomaly characterized by narrowing during systole of some of the epicardial coronary arterial segments running in the myocardium. Although, it is considered as a benign anomaly, it may lead to such complications as acute myocardial infarction, ventricular tachycardia, syncope, atrioventricular block and sudden cardiac death. In this study, we aimed to investigate demographic, clinical and angiographic characteristics of the patients with MB found on coronary angiography.

METHODS

The present study included 71 patients with MB found on coronary angiographies performed in our institution between January 1999 and September 2003. Based on the findings on angiography, the patients were subdivided into group A (n=41) and group B (n=30). The patients in the group A had no atherosclerotic lesion and the patients in the group B had coronary artery disease in addition to MB. Angiographic, demographic and clinical characteristics of both groups were compared.

RESULTS

There were no differences between two groups in distribution of gender and risk factors of coronary artery disease whereas mean age of the patients in the group A was lower (47+/-5 years vs 55+/-11 years, p=0.01). Frequency of two or more risk factors for coronary artery disease in a particular patient was significantly higher in the group B (55% vs 30%, p=0.03). Myocardial bridge was located at proximal or mid segments of left anterior descending artery (LAD) in 40 patients whereas its presence in both LAD and right coronary artery was found only in one patient in group A. Mean bridging percent was 43+/-27% in group A. Localization of MB was LAD in 29 patients of group B. One patient with severe aortic valve stenosis in this group had MB at first septal branch. Mean bridging percent was 70+/-25% in group B, which was significantly higher than in group A (p<0.05). Atherosclerotic narrowing developed in only LAD in 14 patients, LAD and other vessels in 7 patients and in the vessels without MB in 9 patients. In patients with MB in LAD atherosclerotic narrowing of vessel developed proximally to the MB. Clinically, stable angina pectoris was seen more frequently in group A than group B (70% vs 35%, p=0.01), whereas the frequency of acute coronary syndrome was higher in group B (65% vs 30%, p=0.04). In regard to therapeutic approach, more patients in the group A received medical management (80% vs 50%, p=0.01), while more patients in the group B underwent surgical and percutaneous interventions (50% vs 18%, p=0.04).

CONCLUSION

Myocardial bridge probability should be considered in young patients presenting with angina or if the same symptoms are persistent in the patients without more than one risk factor for coronary artery disease. Myocardial bridge may initiate the development of atherosclerotic lesion or may facilitate progression of atherosclerosis in the proximal segment of the vessel. The risk of acute coronary syndrome rises when atherosclerosis is superimposed on MB. Myocardial bridge should be considered in the young patients, presenting with angina or its equivalents without atherosclerotic lesions on coronary angiography.

Impaired endothelial function in patients with myocardial bridge

OBJECTIVE

The relationship between myocardial bridging (MB) and ischemic heart disease is still controversial. In this study, we aimed to evaluate the existing atherosclerosis and noninvasive endothelial function of brachial artery in patients with MB.

METHODS

The present study included 50 patients (group I) who had MB in left anterior descending (LAD) on coronary angiography. All of the coronary artery segments were evaluated by intravascular ultrasound (IVUS). Endothelial function was assessed with measurement of flow-mediated dilatation (FMD) and nitrate-dependent dilatation in the brachial artery. The study also included 30 healthy control subjects (group II). Patients in the group I were further subdivided into two subgroups based on the findings on IVUS: group IA included 20 patients without atherosclerotic lesions and group IB included 30 patients with atherosclerotic coronary artery disease in addition to MB.

RESULTS

FMD values were found to be significantly lower in the patients with MB (group I) than in the control (6.4 +/- 3% vs 11 +/- 4%, P <0.001). In regard to FMD values in subgroups, FMD was 7 +/- 2% in the group IA and 5.8 +/- 1% in the group IB (P = 0.023). On IVUS, atherosclerotic plaque was found proximal to the bridge in the same coronary artery segment in addition to MB in 75% of the patients in group I (group IB). No atherosclerotic plaque was found in within or distal segments of MB.

CONCLUSION

Endothelial function is impaired in patients with MB and there is an increased tendency for atherosclerosis proximal to the bridge in the patients with MB. Endothelial dysfunction is more severe in the patients with atherosclerosis proximal to the bridge.

Aspergillus niger aortitis after aortic valve replacement diagnosed by transesophageal echocardiography

Aspergillus aortitis following cardiac surgery has an important role among the cardiac infections as almost all affected cases result in death. Survival of the patient with Aspergillus aortitis is dependent on early initiation of aggressive medical and surgical treatment. Transesophageal echocardiography proved very useful in the diagnosis of this uncommon case of aortitis. In this paper, we present a patient with aortitis caused by Aspergillus niger that hasn't been reported previously diagnosed by transesophageal echocardiography following cardiac surgery.

Myocardial infarction following a bee sting

We described here a patient envenomated by a bee sting that caused myocardial damage compatible with non-ST elevation acute myocardial infarction. She developed a typical course of myocardial infarction; the ECG changes were reversed to almost all normal limits. She had normal coronary angiography and reversible wall motion abnormalities. Myocardial damage following prolonged spasm in the coronary arteries may be the underlying factor.