Cardiac sympathetic innervation and cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) is a disease modifying, device-driven treatment that can reduce morbidity and mortality in patients with heart failure. According to the current guidelines, the indication for CRT is only based on QRS duration and functional class of heart failure. However, a substantial amount of patients do not respond to therapy. In addition, CRT is accompanied by significant cost and potential morbidity. It is therefore vital to improve patient selection for CRT to improve patient outcome and minimize therapy-related complications. In this regard, cardiac sympathetic innervation may be of interest. This review addresses the currently available literature, 9 studies with a total number of 225 patients, on CRT and cardiac innervation scintigraphy with (123)I-metaiodobenzylguanidine.

Biomarkers for Prediction of Central Venous Catheter Related-Thrombosis in Patients With Hematological Malignancies

OBJECTIVE

In a prospective setting, we aimed to find associations between biomarkers of the hemostatic system and the occurrence of central venous catheter (CVC)-related thrombosis in patients with hematological malignancies undergoing intensive chemotherapy.

METHODS

The study was conducted between July 2006 and August 2010 at the University Hospital Maastricht, the Netherlands. Consecutive adult patients with hematological malignancies who were going to receive a CVC for intensive chemotherapy were included. The primary end points were (a) symptomatic CVC-related thrombosis and (b) CVC-related infections. Blood samples were taken directly after catheterization, and easy to determine biomarkers (platelet count, leukocyte count, and hemoglobin level) in combination with blood group, factor VIII (FVIII), plasminogen activator inhibitor 1 (PAI-1), activated protein C (APC) resistance, and free protein S antigen were determined.

RESULTS

Blood was collected and analyzed from 168 patients. The incidence of symptomatic CVC-related thrombosis was 9%. In univariate analysis, white blood cell count >10.6 × 10⁹/L, mean FVIII activity, and PAI-1 >12.2 IU/mL were found to be associated with the development of symptomatic CVC-related thrombosis.

CONCLUSION

Elevated leukocyte count, high PAI-1, and high FVIII were associated with an increased incidence of symptomatic CVC-related thrombosis. We hope in future that simple, easy to determine laboratory tests that reflect the hemostatic and fibrinolytic activity in combination with clinical parameters may help to identify hematological patients at highest risk of CVC-related thrombosis and help to tailor the management of thromboprophylaxis in hematological patients undergoing CVC placement.

Obesity in haemophilia patients: effect on bleeding frequency, clotting factor concentrate usage, and haemostatic and fibrinolytic parameters

The prevalence of obesity in patients with haemophilia (PWH) is increasing. We investigated the effect of obesity on bleeding frequency and clotting factor concentrate (CFC) usage in PWH and assessed whether prothrombotic changes observed in obesity differ between controls and PWH. Number of bleeds and CFC usage were compared between obese (N = 51) and non-obese (N = 46) haemophilia A patients. Markers of haemostasis and fibrinolysis were compared between PWH, and gender-, age- and body mass index (BMI)-matched non-haemophilic controls (N = 91). Median number of bleeds/patient-month was comparable between obese and non-obese patients with severe haemophilia (P = 0.791). Obese patients with severe haemophilia used 1.4 times more CFC/patient-month than non-obese patients (P = 0.036). When adjusting for weight this difference disappeared (P = 0.451). von Willebrand factor plasma concentration (VWF:Ag), factor VIII activity and endogenous thrombin potential were higher in obese than in non-obese controls. Obesity did not influence these markers in PWH. Plasminogen activator inhibitor type 1 levels were higher in obese vs. non-obese PWH (P < 0.001), whereas levels were comparable between PWH and controls (P = 0.912). Plasmin-α2-antiplasmin complex (PAP) levels appeared to be lower in obese vs. non-obese subjects, both within controls (P = 0.011) and PWH (P = 0.008). However, in PWH, PAP levels were higher than in controls (P < 0.001). Obesity is associated with an increase in net CFC usage in PWH, but has no effect on bleeding frequency. In addition, obesity attenuates hyperfibrinolysis in PWH. Future research investigating whether obese PWH need CFC treatment dosed on weight or whether a lower dosage would suffice to prevent and treat bleedings is needed.

Anticoagulation therapy in haemophilia. Managing the unknown

Patients with haemophilia (PWH) are relatively protected from cardiovascular death. Recent insights have shown that this is not due to less formation of atherosclerosis than in non-haemophilic men, therefore protection from the final occlusive thrombus will be the major determinant. Prevalence and incidence rates of cardiovascular disease (especially non-fatal events) are scarce, although ongoing studies are addressing this issue. Meanwhile, because the haemophilia population is aging, we are increasingly confronted with cardiovascular events. The main cardiovascular risk factors that should be part of regular screening programs are hypertension, overweight, lipometabolic disorders and smoking. Anticoagulation therapy in haemophilia is feasible, provided that individual tailored coagulation therapy and close monitoring is provided. Here, we present our view on anticoagulation management in PWH. There is an absolute need for risk assessment tools and prospective validation of suggested anticoagulation management strategies in PWH. Until then, we are managing the unknown.

Factor VIII deficiency does not protect against atherosclerosis

BACKGROUND

Hemophilia A patients have a lower cardiovascular mortality rate than the general population. Whether this protection is caused by hypocoagulability or decreased atherogenesis is unclear.

OBJECTIVES

To evaluate atherosclerosis and endothelial function in hemophilia A patients with and without obesity as well as in matched, unaffected controls.

METHODS

Fifty-one obese (body mass index [BMI] ≥ 30 kg m(-2)) and 47 non-obese (BMI ≤ 25 kg m(-2)) hemophilia A patients, and 42 obese and 50 matched non-obese male controls were included. Carotid and femoral intima–media thickness [IMT] and brachial flow-mediated dilatation (FMD) were measured as markers of atherogenesis and endothelial function.

RESULTS

The overall population age was 50 ± 13 years. Carotid IMT was increased in obese subjects (0.77 ± 0.22 mm) as compared with non-obese subjects (0.69 ± 0.16 mm) [mean difference 0.07 mm (95% confidence interval [CI] 0.02–0.13, P = 0.008)]. No differences in mean carotid and femoral IMT between obese hemophilic patients and obese controls were found (mean difference of 0.02 mm [95% CI ) 0.07–0.11, P = 0.67], and mean difference of 0.06 mm [95% CI ) 0.13–0.25, P = 0.55], respectively). Thirty-five per cent of the obese hemophilic patients and 29% of the obese controls had an atherosclerotic plaque (P = 0.49), irrespective of the severity of hemophilia. Brachial FMD was comparable between obese hemophilic patients and obese controls (4.84% ± 3.24% and 5.32% ± 2.37%, P = 0.45).

CONCLUSION

Hemophilia A patients with obesity develop atherosclerosis to a similar extent as the general male population. Detection and treatment of cardiovascular risk factors in hemophilic patients is equally necessary.

Rationale, objectives, and design of the EUTrigTreat clinical study: a prospective observational study for arrhythmia risk stratification and assessment of interrelationships among repolarization markers and genotype

Aims

The EUTrigTreat clinical study has been designed as a prospective multicentre observational study and aims to (i) risk stratify patients with an implantable cardioverter defibrillator (ICD) for mortality and shock risk using multiple novel and established risk markers, (ii) explore a link between repolarization biomarkers and genetics of ion (Ca²⁺, Na⁺, K⁺) metabolism, (iii) compare the results of invasive and non-invasive electrophysiological (EP) testing, (iv) assess changes of non-invasive risk stratification tests over time, and (v) associate arrythmogenomic risk through 19 candidate genes.

Methods and results

Patients with clinical ICD indication are eligible for the trial. Upon inclusion, patients will undergo non-invasive risk stratification, including beat-to-beat variability of repolarization (BVR), T-wave alternans, T-wave morphology variables, ambient arrhythmias from Holter, heart rate variability, and heart rate turbulence. Non-invasive or invasive programmed electrical stimulation will assess inducibility of ventricular arrhythmias, with the latter including recordings of monophasic action potentials and assessment of restitution properties. Established candidate genes are screened for variants. The primary endpoint is all-cause mortality, while one of the secondary endpoints is ICD shock risk. A mean follow-up of 3.3 years is anticipated. Non-invasive testing will be repeated annually during follow-up. It has been calculated that 700 patients are required to identify risk predictors of the primary endpoint, with a possible increase to 1000 patients based on interim risk analysis.

Conclusion

The EUTrigTreat clinical study aims to overcome current shortcomings in sudden cardiac death risk stratification and to answer several related research questions. The initial patient recruitment is expected to be completed in July 2012, and follow-up is expected to end in September 2014.

Clinicaltrials.gov identifier: NCT01209494.

Cardiovascular disease in patients with hemophilia

Mortality due to ischemic heart disease in hemophilia patients is lower as compared to the general male population. Differences in the prevalence of cardiovascular risk factors cannot explain this finding. The hypocoagulable state of hemophilia patients might have a protective effect on thrombus formation, which precipitates infarction. It remains unclear whether the deficiency of coagulation factor VIII or IX exerts a protective effect on the development of atherosclerosis. Despite the relative protection against cardiovascular events, the incidence of ischemic cardiovascular disease in hemophilia patients is increasing, because life expectancy of these patients now approaches that of the general population. This review focuses on what is currently known about cardiovascular risk factors, atherosclerosis, arterial thrombosis and ischemic cardiovascular disease in hemophilia patients.