Zsolt Szelid

Concomitant Phosphodiesterase 5 Inhibition Enhances Myocardial Protection by Inhaled Nitric Oxide in Ischemia-Reperfusion Injury

Enhanced cyclic guanosine monophosphate (cGMP) signaling may attenuate myocardial ischemia-reperfusion injury (I/R) and improve left ventricular (LV) functional recovery after myocardial infarction (MI). We investigated the cardioprotection afforded by inhaled NO (iNO), the phosphodiesterase 5 (PDE5)-specific inhibitor tadalafil (TAD), or their combination (iNO+TAD) in C57Bl6J mice subjected to 6-minute left anterior descending artery ligation followed by reperfusion. We measured plasma and cardiac concentrations of cGMP during early reperfusion, quantified myocardial necrosis and inflammation by serial troponin-I (TnI) and myeloperoxidase-positive cell infiltration at day 3, and evaluated LV function and remodeling after 4 weeks using echocardiography and pressure-conductance catheterization. Administration of iNO, TAD, or both during I/R was safe and hemodynamically well tolerated. Compared with untreated mice (CON), only iNO+TAD increased plasma and cardiac-cGMP levels during early reperfusion (80 ± 12 versus 36 ± 6 pmol/ml and 0.15 ± 0.02 versus 0.05 ± 0.01 pmol/mg protein, P < 0.05 for both). Moreover, iNO+TAD reduced TnI at 4 hours to a greater extent (P < 0.001 versus CON) than either alone (P < 0.05 versus CON) and was associated with significantly less myocardial inflammatory cell infiltration at day 3. After 4 weeks and compared with CON, iNO+TAD was associated with increased fractional shortening (43 ± 1 versus 33 ± 2%, P < 0.01), larger stroke volumes (14.9 ± 1.2 versus 10.2 ± 0.9 μl, P < 0.05), enhanced septal and posterior wall thickening (P < 0.05 and P < 0.001, respectively), and attenuated LV dilatation (P < 0.001), whereas iNO or TAD alone conferred less benefit. Thus, iNO+TAD has superior efficacy to limit early reperfusion injury and attenuate adverse LV remodeling. Combination of inhaled NO with a long-acting PDE5 inhibitor may represent a promising strategy to reduce ischemic damage following reperfusion and better preserve LV function.

The coexistence of dynamin 2 mutation and multiple mitochondrial DNA (mtDNA) deletions in the background of severe cardiomyopathy and centronuclear myopathy.

Dynamin2 (DNM2) gene mutations may result in Charcot-Marie-Tooth disease and centronuclear myopathy. Here, we present a patient suffering from cardiomyopathy and centronuclear myopathy with repetitive discharges and mild axonal neuropathy due to DNM2 mutation. Detailed cardiological and neurological examinations, electrophysiological tests, muscle biopsy, and molecular genetic analysis were performed. The patient developed left bundle branch block at age 40 and was fitted with a pacemaker at the age of 43. The patient has severe heart failure, ptosis, strabism, facial and proximal muscle weakness. Electrophysiological investigations found myopathy, complex repetitive discharges, and axonal neuropathy. Skeletal muscle biopsy detected centronuclear myopathy and cytochrome C oxidase (COX) negative fibers. Genetic analysis detected a pathogenic c.1105C>T (p.R369W) DNM2 gene mutation and heteroplasmic multiple mitochondrial DNA (mtDNA) deletion. Our data broadens the phenotypic spectrum of DNM2 mutations. The presence of the multiple mtDNA deletions may provide new aspects to understanding the pathogenesis of multisystemic symptoms in patients with DNM2 mutations.

Ultrastructure and composition of thrombi in coronary and peripheral artery disease: Correlations with clinical and laboratory findings

INTRODUCTION Fibrin structure and cellular composition of thrombi profoundly affect the clinical outcomes in ischemic coronary and peripheral artery disease. Our study addressed the interrelations of structural features of thrombi and routinely measured laboratory parameters. MATERIALS AND METHODS Thrombi removed by thromboaspiration following acute myocardial infarction (n=101) or thrombendarterectomy of peripheral arteries (n=50) were processed by scanning electron microscopy and immunostaining for fibrin and platelet antigen GPIIb/IIIa to determine fibrin fibre diameter and relative occupancy by fibrin and cells. Correlations between the structural characteristics and selected clinical parameters (age, sex, vascular localization, blood cell counts, ECG findings, antiplatelet medication, accompanying diseases, smoking) were assessed. RESULTS We observed significant differences in mean fibre diameter (122 vs. 135 nm), fibrin content (70.5% vs. 83.9%), fluorescent fibrin/platelet coverage ratio (0.18 vs. 1.06) between coronary and peripheral thrombi. Coronary thrombi from smokers contained more fibrin than non-smokers (78.1% vs. 62.2% mean occupancy). In the initial 24 h, fibrin content of coronary thrombi decreased with time, whereas in peripheral thrombi platelet content increased in the first 7 days. In coronaries, higher platelet content and smaller vessel diameter were associated with thinner fibrin fibres, whereas hematocrit higher than 0.35 correlated with larger intrathrombotic platelet occupancy. Smoking and dyslipidaemia strengthened the dependence of clot platelet content on systemic platelet count (the adjusted determination coefficient increased from 0.33 to 0.43 and 0.65, respectively). CONCLUSION Easily accessible clinical parameters could be identified as significant determinants of ultrastructure and composition of coronary and peripheral thrombi.

Nitric oxide for inhalation in ST-elevation myocardial infarction (NOMI): a multicentre, double-blind, randomized controlled trial

Aims Inhalation of nitric oxide (iNO) during myocardial ischaemia and after reperfusion confers cardioprotection in preclinical studies via enhanced cyclic guanosine monophosphate (cGMP) signalling. We tested whether iNO reduces reperfusion injury in patients with ST-elevation myocardial infarction (STEMI; NCT01398384). Methods and results We randomized in a double-blind, placebo-controlled study 250 STEMI patients to inhale oxygen with (iNO) or without (CON) 80 parts-per-million NO for 4 h following percutaneous revascularization. Primary efficacy endpoint was infarct size as a fraction of left ventricular (LV) size (IS/LVmass), assessed by delayed enhancement contrast magnetic resonance imaging (MRI). Pre-specified subgroup analysis included thrombolysis-in-myocardial-infarction flow in the infarct-related artery, troponin T levels on admission, duration of symptoms, location of culprit lesion, and intra-arterial nitroglycerine (NTG) use. Secondary efficacy endpoints included IS relative to risk area (IS/AAR), myocardial salvage index, LV functional recovery, and clinical events at 4 and 12 months. In the overall population, IS/LVmass at 48-72 h was 18.0 ± 13.4% in iNO (n = 109) and 19.4 ± 15.4% in CON [n = 116, effect size -1.524%, 95% confidence interval (95% CI) -5.28, 2.24; P = 0.427]. Subgroup analysis indicated consistency across clinical confounders of IS but significant treatment interaction with NTG (P = 0.0093) resulting in smaller IS/LVmass after iNO in NTG-naïve patients (n = 140, P < 0.05). The secondary endpoint IS/AAR was 53 ± 26% with iNO vs. 60 ± 26% in CON (effect size -6.8%, 95% CI -14.8, 1.3, P = 0.09) corresponding to a myocardial salvage index of 47 ± 26% vs. 40 ± 26%, respectively, P = 0.09. Cine-MRI showed similar LV volumes at 48-72 h, with a tendency towards smaller increases in end-systolic and end-diastolic volumes at 4 months in iNO (P = 0.048 and P = 0.06, respectively, n = 197). Inhalation of nitric oxide was safe and significantly increased cGMP plasma levels during 4 h reperfusion. The Kaplan-Meier analysis for the composite of death, recurrent ischaemia, stroke, or rehospitalizations showed a tendency toward lower event rates with iNO at 4 months and 1 year (log-rank test P = 0.10 and P = 0.06, respectively). Conclusions Inhalation of NO at 80 ppm for 4 h in STEMI was safe but did not reduce infarct size relative to absolute LVmass at 48-72h. The observed functional recovery and clinical event rates at follow-up and possible interaction with nitroglycerine warrant further studies of iNO in STEMI.

Right Ventricular Adaptation Is Associated with the Glu298Asp Variant of the NOS3 Gene in Elite Athletes

Nitric oxide (NO), an important endogenous pulmonary vasodilator is synthetized by the endothelial NO synthase (NOS3). Reduced NO bioavailability and thus the Glu298Asp polymorphism of NOS3 may enhance right ventricular (RV) afterload and hypertrophic remodeling and influence athletic performance. To test this hypothesis world class level athletes (water polo players, kayakers, canoeists, rowers, swimmers, n = 126) with a VO2 maximum greater than 50ml/kg/min were compared with non-athletic volunteers (n = 155). Cardiopulmonary exercise tests and cardiac magnetic resonance imaging (cMRI) were performed to determine structural or functional changes. Genotype distribution of the NOS3 Glu298Asp polymorphism was not affected by gender or physical performance. Cardiac MRI showed increased stroke volume with eccentric hypertrophy in all athletes regardless of their genotype. However, the Asp allelic variant carriers had increased RV mass index (32±6g versus 27±6g, p<0.01) and larger RV stroke volume index (71±10ml versus 64±10ml, p<0.01) than athletes with a Glu/Glu genotype. Genotype was not significantly associated with athletic performance. In the non-athletic group no genotype related differences were detected. The association between the NOS3 Glu298Asp polymorphism and RV structure and dimension in elite athletes emphasizes the importance of NOS3 gene function and NO bioavailability in sport related cardiac adaptation.

Association between VEGF Gene Polymorphisms and In-Stent Restenosis after Coronary Intervention Treated with Bare Metal Stent

Background. In-stent restenosis (ISR) is the gradual narrowing of the vessel lumen after coronary stent implantation due to the increase in vascular smooth muscle cell proliferation. Vascular endothelial growth factor (VEGF) protein plays an important role in this process. Our aim was to analyze the association of single nucleotide polymorphisms of the VEGF gene (rs2010963 and rs6999447) with the occurrence of ISR after coronary artery bare metal stent (BMS) implantation. Methods. 205 patients with a history of BMS implantation and a repeated coronarography were prospectively enrolled. Patients were assigned to diffuse restenosis group (n = 105) and control group (n = 100) and VEGF genotypes were determined. Results. Diffuse ISR was significantly more frequently observed in patients with homozygous normal genotype of rs2010963 polymorphism, and this polymorphism was independently associated with diffuse ISR. Conclusions. RS2010963 is associated with higher incidence of development of diffuse coronary ISR in patients treated with BMS implantation.

High rate of in-stent restenosis after coronary intervention in carriers of the mutant mannose-binding lectin allele

BackgroundIn-stent restenosis occurs in 10–30% of patients following bare metal stent (BMS) implantation and has various risk factors. Mannose-binding lectin (MBL) is known to have effect on the progression of atherosclerosis. Single nucleotide polymorphisms (SNP) of the MBL2 gene intron 1 (codon 52, 54, 57) are known to modulate the bioavailability of the MBL protein. Our aim was to identify the association of these polymorphisms of the MBL gene in the occurrence of in-stent restenosis after coronary artery bare metal stent implantation.MethodsIn a non-randomized prospective study venous blood samples were collected after recoronarography from 225 patients with prior BMS implantation. Patients were assigned to diffuse restenosis group and control group based on the result of the coronarography. MBL genotypes were determined using quantitative real-time PCR. Proportion of different genotypes was compared and adjusted with traditional risk factors using multivariate logistic regression.ResultsAverage follow-up time was 1.0 (+ − 1.4) year in the diffuse restenosis group (N = 117) and 2.7 (+ − 2.5) years in the control group (N = 108). The age, gender distribution and risk status was not different between study groups. Proportion of the MBL variant genotype was 26.8% (29 vs. 79 normal homozygous) in the control group and 39.3% (46 vs. 71 normal homozygous) in the restenosis group (p = 0.04). In multivariate analysis the mutant allele was an independent risk factor (OR = 1.96, p = 0.03) of in-stent restenosis.ConclusionsMBL polymorphisms are associated with higher incidence of development of coronary in-stent restenosis. The attenuated protein function in the mutant allelic genotype may represent the underlying mechanism.

Cardiovascularis szuroprogram a közép-magyarországi régióban. Budakalász Vizsgálat

INTRODUCTION The reduction in mortality due to prevention programmes observed in some European countries is not currently reached in Hungary. Effective prevention is based on the screening of risk factors and health state of the population. AIM The goal of this study was to develop a longitudinal, population-based screening programme in the Central Hungarian region in order to collect information on the health state and cardiovascular risk profile of the citizens and discover new potential cardiovascular risk factors. METHOD The Budakalász Study is a self-voluntary programme involving the adult population (>20 yrs, approx. 8000 persons), and it consists of questionnaires, non-invasive tests (anthropometry, cardiac echo, carotid duplex scan, blood pressure measurement, ankle-brachial index), venous blood sample collection and laboratory tests. RESULTS Until January, 2014, 2420 persons (30% of the population, male: 41.2%, average age 54.8 years) participated in the programme. Cardiovascular morbidity was higher in contrast to a former national survey. The number of risk factors and, therefore, 10-year cardiovascular risk were also elevated in this population. CONCLUSIONS These findings underline the importance of screening programmes and effective therapies.