Lack of protective role of HDL-C in patients with coronary artery disease undergoing elective coronary artery bypass grafting

AIMS

Primary prevention studies have confirmed that high-density lipoprotein cholesterol (HDL-C) levels are strongly associated with reduced cardiovascular events. However, recent evidence suggests that HDL-C functionality may be impaired under certain conditions. In the present study, we hypothesize that HDL-C may lose their protective role in the secondary prevention of coronary artery disease (CAD).

METHODS AND RESULTS

A consecutive series of 1548 patients undergoing isolated first-time elective CABG at one institution between 2004 and 2009 was studied. According to the ATPIII criteria, pre-operative HDL-C values were used to identify patients with high (Group A) vs. low HDL-C (Group B). To eliminate biased estimates, a propensity score model was built and two cohorts of 1:1 optimally matched patients were obtained. Cumulative survival and major adverse cardiovascular events (MACE) were analysed by means of Kaplan-Meier method. Cox proportional-hazards regression models were used to identify independent predictors of MACE and death. Propensity matching identified two cohorts of 502 patients each. At a median follow-up time of 32 months, there were 44 out of 502 (8.8%) deaths in Group A and 36 out of 502 deaths in Group B (7.2%, HR 1.19; P = 0.42). MACE occurred in 165 out of 502 (32.9%) in Group A and 120 out of 502 (23.9%) in Group B (P = 0.04). Regression analysis showed that pre-operative HDL-C levels were not associated with reduced but rather increased MACE occurrence during follow-up (HR 1.43, P = 0.11).

CONCLUSION

Higher HDL-C levels are not associated with reduced risk of vascular events in CAD patients undergoing CABG. Our findings may support efforts to improve HDL-C functionality instead of increasing their levels.

NT-proatrial natriuretic peptide as a possible biomarker of cardiopulmonary involvement in sarcoidosis

BACKGROUND

Lung diffusion for carbon monoxide (DLCO) has been shown to associate with the risk of pulmonary arterial hypertension development and, most likely, with right ventricular (RV) myocardial dysfunction in sarcoidosis patients. Besides its known role as a marker of left ventricular dysfunction, experimental evidence suggests a role of NT-proAtrial Natriuretic Peptide (NT-proANP) also in modulating pulmonary circulation. We therefore investigated possible relationships between NT-proANP, lung diffusion impairment and RV dysfunction.

METHODS

Thirty-two pulmonary sarcoidosis outpatients and eighteen volunteers underwent full clinical assessment, including full lung function tests and Doppler echocardiography integrated with tissue Doppler imaging (TDI) study. Resting circulating NT-proBNP and NT-proANP plasma levels were also determined.

RESULTS

NT-proANP and RV-myocardial performance index (RV-MPI) were significantly higher in those patients with the greatest DLCO impairment, whereas no differences were found for NT-proBNP values. At multivariable analysis, only DLCO (β: -0.496; standard error: 3.38; p=0.000) and RV-MPI (β: 0.373; standard error: 6.56; p=0.031) remained significantly associated with NT-proANP levels.

CONCLUSIONS

Our finding may support a key role of NT-proANP in the complex mechanisms underlying modulation of lung function. An early increase in pulmonary vascular resistance may stimulate NT-proANP increase, thus explaining its association with signs of early RV myocardial dysfunction. This hypothesis warrants further confirmation.

C2238 atrial natriuretic peptide molecular variant is associated with endothelial damage and dysfunction through natriuretic peptide receptor C signaling

RATIONALE

C2238 atrial natriuretic peptide (ANP) minor allele (substitution of thymidine with cytosine in position 2238) associates with increased risk of cardiovascular events.

OBJECTIVE

We investigated the mechanisms underlying the vascular effects of C2238-αANP.

METHODS AND RESULTS

In vitro, human umbilical vein endothelial cell were exposed to either wild-type (T2238)- or mutant (C2238)-αANP. Cell survival and apoptosis were tested by Trypan blue, annexin V, and cleaved caspase-3 assays. C2238-αANP significantly reduced human umbilical vein endothelial cell survival and increased apoptosis. In addition, C2238-αANP reduced endothelial tube formation, as assessed by matrigel. C2238-αANP did not differentially modulate natriuretic peptide receptor (NPR)-A/B activity with respect to T2238-αANP, as evaluated by intracellular cGMP levels. In contrast, C2238-αANP, but not T2238-αANP, markedly reduced intracellular cAMP levels in an NPR-C-dependent manner. Accordingly, C2238-αANP showed higher affinity binding to NPR-C, than T2238-αANP. Either NPR-C inhibition by antisense oligonucleotide or NPR-C gene silencing by small interfering RNA rescued survival and tube formation of human umbilical vein endothelial cell exposed to C2238-αANP. Similar data were obtained in human aortic endothelial cell with NPR-C knockdown. NPR-C activation by C2238-αANP inhibited the protein kinase A/Akt1 pathway and increased reactive oxygen species. Adenovirus-mediated Akt1 reactivation rescued the detrimental effects of C2238-αANP. Overall, these data indicate that C2238-αANP affects endothelial cell integrity through NPR-C-dependent inhibition of the cAMP/protein kinase A/Akt1 pathway and increased reactive oxygen species production. Accordingly, C2238-αANP caused impairment of acetylcholine-dependent vasorelaxation ex vivo, which was rescued by NPR-C pharmacological inhibition. Finally, subjects carrying C2238 minor allele showed early endothelial dysfunction, which highlights the clinical relevance of our results.

CONCLUSIONS

C2238-αANP reduces endothelial cell survival and impairs endothelial function through NPR-C signaling. NPR-C targeting represents a potential strategy to reduce cardiovascular risk in C2238 minor-allele carriers.

MELD-XI score and cardiac mortality or transplantation in patients after Fontan surgery

OBJECTIVE

The Fontan operation is a staged palliation for complex congenital heart disease and single ventricle physiology. Perioperative survivors of the Fontan operation experience long-term cardiac complications, including death. Liver and renal dysfunction are reported in these patients and have a direct effect on morbidity and mortality. This study aims to investigate whether the Model for End-stage Liver Disease eXcluding INR score (function of creatinine and total bilirubin, MELD-XI) predicts risk for cardiac mortality or transplantation in patients with Fontan circulation.

DESIGN AND SETTING

Retrospective, single-centre study. Time of first evaluation was the time of the earliest available MELD-XI score measurement, and follow-up was terminated by a cardiac event or by the last clinical evaluation.

PATIENTS

Patients surviving after Fontan surgery and evaluated at Boston Children's Hospital between 1993 and 2008.

MAIN OUTCOME MEASURE

Composite endpoint of sudden death, death from congestive heart failure or cardiac transplantation.

RESULTS

The MELD-XI score was calculated as MELD-XI=11.76(loge creatinine)+5.112(loge total bilirubin)+9.44. Ninety-six patients were included (52 male, median age 26 years). After a mean follow-up period of 5.7 years, 18 patients (19%) experienced the composite end point. Baseline MELD-XI score was independently and directly related to the incidence of the composite endpoint (HR for high MELD-XI score group of 7.76, 95% CI 2.05 to 29.33, p=0.008).

CONCLUSIONS

Fontan patients with a higher MELD-XI score have shorter freedom from sudden cardiac death, death from congestive heart failure and cardiac transplantation.

Transcatheter Closure of Post-myocardial Infarction Ventricular Septal Rupture

Background—

Ventricular septal rupture (VSR) after acute myocardial infarction (AMI) is a potentially lethal mechanical complication of acute coronary syndromes. Given high surgical mortality, transcatheter closure has emerged as a potential strategy in selected cases. We report our single-center experience with double-umbrella device percutaneous closure of post-AMI VSR.

Methods and Results—

In this single-center, retrospective, cohort study, patients who underwent transcatheter closure of post-AMI VSR between 1988 and 2008 at Boston Children’s Hospital were included. Data were analysed according to whether the patients underwent direct percutaneous VSR closure or closure of a residual VSR after a previous surgical approach. Primary outcome was mortality rate at 30 days. Clinical predictors of primary outcome were investigated using univariate logistic regression. Thirty patients were included in the study (mean age, 67±8 years). A total of 40 closure devices were implanted. Major periprocedural complications occurred in 4 (13%) patients. Cardiogenic shock, increasing pulmonary/systemic flow ratio, and the use of the new generation (6-arm) STARFlex device all were associated with higher risk of mortality. The Model for End-Stage Liver Disease Excluding international normalized ratio (MELD-XI) score at the time of VSR closure seemed to be most strongly associated with death (odds ratio, 1.6; confidence interval, 1.1–2.2; P <0.001).

Conclusions—

Transcatheter closure of post-AMI VSR using CardioSEAL or STARFlex devices is feasible and effective. The MELD-XI score, a marker of multiorgan dysfunction, is a promising risk stratifier in this population of patients. Early closure of post-AMI VSR is advisable before establishment of multiorgan failure.

An observational, prospective, open-label, multicentre evaluation of aliskiren in treated, uncontrolled patients: a real-life, long-term, follow-up, clinical practice in Italy

INTRODUCTION

The addition of the direct renin inhibitor aliskiren is demonstrated to improve blood pressure (BP) control rate and reduce progression of organ damage in treated hypertensive patients in clinical trials with a relatively short follow-up period.

AIM

The objective of this study was to assess the effectiveness, safety and tolerability of aliskiren as an add-on antihypertensive therapy in high-risk, treated, hypertensive patients, who were not controlled with concomitant treatment with at least two antihypertensive drugs under 'real-life' conditions, during a planned observation and treatment period of at least 12 months in Italy.

METHODS

Clinical data were derived from medical databases of treated, uncontrolled, hypertensive patients followed by specialized physicians operating in different clinical settings (hospital divisions or outpatient clinics) in Italy. Aliskiren was added to stable antihypertensive treatment, including at least two drug classes (independently of class or dosage) and unable to achieve BP control. Follow-up visits for measuring clinic BP levels and collecting data on drug safety and tolerability were planned at time intervals of 1, 6 and 12 months. At each predefined follow-up visit, aliskiren could be up-titrated from 150 to 300 mg daily if BP control was not achieved.

RESULTS

From May 2009 to June 2011, a total of 1186 treated, uncontrolled, hypertensive patients (46.3% female, aged 65.2 ± 11.7 years, mean duration of hypertension 13.2 ± 9.3 years, mean clinic BP levels 156.5 ± 15.9/90.3 ± 9.5 mmHg) were enrolled. Systolic and diastolic BP levels were 141.1/82.4, 134.9/79.8 and 133.6/78.9 mmHg at 1-, 6- and 12-month follow-up visits, respectively (p < 0.0001 vs baseline for all comparisons). These effects were consistent in all predefined subgroups, including those with left ventricular hypertrophy, renal disease, diabetes mellitus, coronary artery disease or cerebrovascular disease. Reduced levels of microalbuminuria were also reported, without affecting other renal and electrolyte parameters. Overall, compliance to study medication was high (93.0%), with a very low proportion of patients experiencing adverse events leading to drug discontinuation (3.6%).

CONCLUSIONS

In this observational, prospective, open-label, multicentre study, we reported the 12-month clinical effectiveness, safety and tolerability of adding aliskiren to treated, uncontrolled, hypertensive patients in a 'real-life' setting in Italy. This strategy leads to a significantly improved BP control rate and low incidence of drug-related side effects or discontinuations.

Differential modulation of uncoupling protein 2 in kidneys of stroke-prone spontaneously hypertensive rats under high-salt/low-potassium diet

The stroke-prone spontaneously hypertensive rat (SHRsp) represents an animal model of increased susceptibility to high-salt diet-induced cerebral and renal vascular injuries. High blood pressure and genetic factors are viewed as major contributing factors. In high-salt-loaded SHRsp and stroke-resistant SHR animals, we determined blood pressure levels, degree of kidney lesions, renal uncoupling protein 2 (UCP2) gene and protein expression levels along with rattus norvegicus (rno)-microRNA (miR) 24 and 34a gene expression, nuclear factor-κB protein levels, and oxidative stress. In vitro, UCP2 gene silencing was performed in renal mesangial cells. We found more severe degree of renal damage in SHRsp at the end of 4-week high-salt dietary treatment as compared with stroke-resistant SHR, despite comparable blood pressure levels, along with increased rate of inflammation and oxidative stress. Kidney UCP2 gene and protein expression levels were significantly downregulated under high-salt diet in SHRsp, but not in stroke-resistant SHR. Differential UCP2 regulation was paralleled by differential expression of kidney rno-miR 24 and 34a, known to target UCP2 gene, in the 2 strains. UCP2 gene silencing in renal mesangial cells led to increased rate of reactive oxygen species generation, increased inflammation and apoptosis, reduced cell vitality, and increased necrosis. In conclusion, high-salt diet downregulates the antioxidant UCP2-dependent mechanism in kidneys of SHRsp, but not of stroke-resistant SHR. A parallel differential kidney miR regulation under high-salt diet in the 2 strains may contribute to the differential UCP2 modulation. UCP2 is a critical protein to prevent oxidative stress damage in renal mesangial cells in vitro.

Association of a single nucleotide polymorphism of the NPR3 gene promoter with early onset ischemic stroke in an Italian cohort

BACKGROUND

NPR3, located on human chromosome 5 (5p14-p13), encodes the natriuretic peptide receptor type C (NPR-C) that is mainly known as the natriuretic peptide clearance receptor. Involvement of NPR3 in susceptibility to cardiovascular diseases, i.e. hypertension, has been previously shown. With regard to stroke predisposition, evidence for a potential role of genetic variation within or nearby NPR3 has been suggested by a previous genome wide association study.

METHODS

We investigated the contribution to early-onset ischemic stroke susceptibility of the NPR3 -55 C>A transition by genotyping this variant in an Italian cohort of 368 cases and 335 controls.

RESULTS

In a multivariable logistic regression analysis adjusting for age, gender, hypertension, hypercholesterolemia, smoking habit and diabetes, a significant association of the -55 AA genotype with stroke was observed (OR=3.2, 95% CI 1.2-8.3, p=0.016). Remarkably, the polymorphism remained associated with stroke after adjusting for hypertensive status.

CONCLUSION

Our observation obtained in an Italian cohort of early onset ischemic strokes suggests that a NPR3 promoter gene variant could have a role on cerebrovascular disease susceptibility.

Breath tests sustainability in hospital settings: cost analysis and reimbursement in the Italian National Health System

The high demand of Breath Tests (BT) in many gastroenterological conditions in time of limited resources for health care systems, generates increased interest in cost analysis from the point of view of the delivery of services to better understand how use the money to generate value. This study aims to measure the cost of C13 Urea and other most utilized breath tests in order to describe key aspects of costs and reimbursements looking at the economic sustainability for the hospital. A hospital based cost-analysis of the main breath tests commonly delivery in an ambulatory setting is performed. Mean salary for professional nurses and gastroenterologists, drugs/preparation used and disposable materials, purchase and depreciation of the instrument and the testing time was used to estimate the cost, while reimbursements are based on the 2013 Italian National Health System ambulatory pricelist. Variables that could influence the model are considered in the sensitivity analyses. The mean cost for C13--Urea, Lactulose and Lactose BT are, respectively, Euros 30,59; 45,20 and 30,29. National reimbursement often doesn't cover the cost of the analysis, especially considering the scenario with lower number of exam. On the contrary, in high performance scenario all the reimbursement could cover the cost, except for the C13 Urea BT that is high influenced by the drugs cost. However, consideration about the difference between Italian Regional Health System ambulatory pricelist are done. Our analysis shows that while national reimbursement rates cover the costs of H2 breath testing, they do not cover sufficiently C13 BT, particularly urea breath test. The real economic strength of these non invasive tests should be considered in the overall organization of inpatient and outpatient clinic, accounting for complete diagnostic pathway for each gastrointestinal disease.