Dipeptidyl Amino-Peptidase 3 (DPP3) as an Early Marker of Severity in a Patient Population with Cardiogenic Shock.

Dipeptidyl amino-peptidase 3 (DPP3) is an aminopeptidase that is released into circulation upon cell death. DPP3 is involved in the degradation of angiotensins, enkephalines, and endomorphines. It has been shown that circulating DPP3 (cDPP3) plasma concentration increases in cardiogenic shock (CS) patients and correlates with high mortality risk. Cardiogenic shock is a life-threatening syndrome associated with organ hypoperfusion. One of the common causes of CS is acute myocardial infarction (AMI). This study aimed to investigate if cDPP3 levels are associated with CS severity and the need for ventilation in patients suffering from CS. Fifteen patients with CS were included in this study. Six patients were invasively ventilated. The values of cDPP3 were higher in ventilated patients than in non-ventilated patients at admission, 3 h, and 24 h after admission in the intensive care unit. Patients with pulmonary hypertension at admission also showed high cDPP3 values at all time points. Furthermore, high cDPP3 levels were associated with reduced stroke volume. Our results suggest that cDPP3 could predict CS progression and guide therapy escalation.

Incidental pseudoaneurysm of the mitral-aortic intervalvular fibrosa in asymptomatic patient: A case report.

Pseudoaneurysm of the mitral-aortic intervalvular fibrosa (P-MAIVF) can be a rare but life-threatening complication of infective endocarditis, cardiac surgery, or blunt chest trauma. Congenital heart diseases especially in young patients are reported as additionally predisposing factors. We present the case of an asymptomatic 52 years-old male with bicuspid aortic valve and gastrointestinal polyposis syndrome in whom a P-MAIVF was incidentally detected. The patient successfully underwent pseudoaneurysm surgical repair and aortic valve replacement and despite no evident causes were found we hypothesized addiotional underlying mechanism of P-MAIVF.

Toll-like receptor 4 activation in platelets from myocardial infarction patients.

INTRODUCTION: Platelet toll-like receptor 4 (TLR4) is overexpressed in patients with myocardial infarction (MI) but it remains to elucidate if it is activated and the potential trigger. METHODS: Serum levels of lipopolysaccharides (LPS) and platelet aggregation (PA) by collagen alone or in combination with a TLR4 inhibitor (TLR4i) were studied ex vivo in platelets from 40 MI patients and 40 controls matched for age, sex and atherosclerotic risk factors; platelet TIR domain-containing adaptor protein (TIRAP) and TIRAP-MyD88 interaction were also investigated by western blot and co-immunoprecipitation, respectively. In vitro experiments were conducted to see if LPS triggers platelet TIRAP phosphorylation. RESULTS: Serum LPS was significantly higher in patients compared to controls (29.5±7.1 vs 16.2±3.8 pg/mL; p<0.001). Collagen-stimulated platelets from MI pre-treated with TLR4i showed a significant decrease of PA compared to platelets stimulated with collagen. Ex vivo study showed that TIRAP phosphorylation as well as TIRAP-MyD88 co-immunoprecipitation were higher in patients compared to controls. In vitro study showed that LPS, at concentrations like those found in MI, dose-dependently activated TIRAP and amplified the platelet response to the agonist, an effect blunted by TLR4i. CONCLUSION: The study provides evidence that in MI patients platelet TLR4 is activated and suggests circulating LPS as potential trigger.

The role of cardiopulmonary exercise tests in pulmonary arterial hypertension.

Despite recent advances in the therapeutic management of patients affected by pulmonary arterial hypertension (PAH), survival remains poor. Prompt identification of the disease, especially in subjects at increased risk of developing PAH, and prognostic stratification of patients are a necessary target of clinical practice but remain challenging. Cardiopulmonary exercise test (CPET) parameters, particularly peak oxygen uptake, end-tidal carbon dioxide tension and the minute ventilation/carbon dioxide production relationship, emerged as new prognostic tools for PAH patients. Moreover, CPET provides a comprehensive pathophysiological evaluation of patients' exercise limitation and dyspnoea, which are the main and early symptoms of the disease. This review focuses on the role of CPET in the management of PAH patients, reporting guideline recommendations for CPET and discussing the pathophysiology of exercise limitation and the most recent use of CPET in the diagnosis, prognosis and therapeutic targeting of PAH.

Physiological insights of exercise hyperventilation in arterial and chronic thromboembolic pulmonary hypertension.

BACKGROUND: Pulmonary hypertension (PH) patients show, during exercise, an excessive increase in ventilation (VE) compared to carbon dioxide output (VCO2), determining a high VE/VCO2 slope. There are several possible causes, including an elevated dead space ventilation (VD), VE/perfusion (Q) mismatch and/or an enhanced peripheral or central chemoreceptor activity. We evaluated the causes of exercise hyperventilation in PH patients. METHODS: Eighteen group I and IV PH patients underwent cardiopulmonary exercise test with blood gas analysis at every minute. VE, alveolar ventilation (VA) and VD vs. VCO2 relationship were calculated. Resting chemoreceptor sensitivity was analyzed through hypoxia/hypercapnia tests. RESULTS: PeakVO2 and VE/VCO2 slopes were 1.06±0.24l/min and 39.1±9.0, respectively. Throughout the exercise, 30% of VE was due to VD. VE/VCO2 slope significantly correlated with VD/VCO2 slope (r=0.82, p<0.001) but not with VA/VCO2 slope (r=0.3, p=ns). Peak exercise end-tidal CO2 (PetCO2) correlated with VD/VCO2 slope (r=-0.79, p<0.001) and VE/VCO2 slope (r=-0.91, p<0.001). Dead space(DS)/Tidal volume and P(arterial-et)CO2 were elevated without arterial hypoxemia suggesting a high VE/Q mismatch. Chemoreceptor peripheral response to hypoxia and central CO2 response were both enhanced being peripheral responses to hypoxia and hypercapnia 0.416±0.402 (normal ref values=0.285±0.221) l/min/O2Sat and 0.076±0.047 (0.066±0.430) l/min/mmHg, respectively; central hypercapnic chemosensitivity was 4.475±3.99 (2.352±0.936) l/min/mmHg. CONCLUSIONS: Increased DS, VE/Q mismatch and chemorecptor response are among the main mechanisms involved in exercise hyperventilation in PH. ClinicalTrial.govNCT02892981.

Mineralocorticoid receptor antagonists for heart failure: a real-life observational study.

AIMS: Mineralocorticoid receptor antagonists (MRAs) have been demonstrated to improve outcomes in reduced ejection fraction heart failure (HFrEF) patients. However, MRAs added to conventional treatment may lead to worsening of renal function and hyperkalaemia. We investigated, in a population-based analysis, the long-term effects of MRA treatment in HFrEF patients. METHODS AND RESULTS: We analysed data of 6046 patients included in the Metabolic Exercise Cardiac Kidney Index score dataset. Analysis was performed in patients treated (n = 3163) and not treated (n = 2883) with MRA. The study endpoint was a composite of cardiovascular death, urgent heart transplantation, or left ventricular assist device implantation. Ten years' survival was analysed through Kaplan-Meier, compared by log-rank test and propensity score matching. At 10 years' follow-up, the MRA-untreated group had a significantly lower number of events than the MRA-treated group (P < 0.001). MRA-treated patients had more severe heart failure (higher New York Heart Association class and lower left ventricular ejection fraction, kidney function, and peak VO2 ). At a propensity-score-matching analysis performed on 1587 patients, MRA-treated and MRA-untreated patients showed similar study endpoint values. CONCLUSIONS: In conclusion, MRA treatment does not affect the composite of cardiovascular death, urgent heart transplantation or left ventricular assist device implantation in a real-life setting. A meticulous patient follow-up, as performed in trials, is likely needed to match the positive MRA-related benefits observed in clinical trials.

Cardiopulmonary Exercise Testing in Pulmonary Hypertension.

Cardiopulmonary exercise testing allows the assessment of the integrative cardiopulmonary response to exercise and is a useful tool to assess the underlying pathophysiologic mechanisms leading to exercise intolerance. Patients with pulmonary hypertension often face a considerable delay in diagnosis due to the rarity of the disease and nonspecific symptoms of dyspnea, fatigue, and exercise limitation. Cardiopulmonary exercise testing may be suggestive of pulmonary hypertension in patients with evidence of both circulatory impairment and ventilatory inefficiency. Other factors, such as mechanical ventilatory constraints from dynamic hyperinflation and peripheral muscle dysfunction, contribute to the profound dyspnea during exercise experienced by many patients with pulmonary hypertension. In patients with pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension, several exercise variables, such as low peak [Formula: see text]o2, high Vd/Vt, and high [Formula: see text]e/[Formula: see text]co2, have proven to be useful in establishing the severity of functional impairment, predicting prognosis, and assessing the efficacy of interventions.

A combined clinical and biomarker approach to predict diuretic response in acute heart failure.

BACKGROUND: Poor diuretic response in acute heart failure is related to poor clinical outcome. The underlying mechanisms and pathophysiology behind diuretic resistance are incompletely understood. We evaluated a combined approach using clinical characteristics and biomarkers to predict diuretic response in acute heart failure (AHF). METHODS AND RESULTS: We investigated explanatory and predictive models for diuretic response--weight loss at day 4 per 40 mg of furosemide--in 974 patients with AHF included in the PROTECT trial. Biomarkers, addressing multiple pathophysiological pathways, were determined at baseline and after 24 h. An explanatory baseline biomarker model of a poor diuretic response included low potassium, chloride, hemoglobin, myeloperoxidase, and high blood urea nitrogen, albumin, triglycerides, ST2 and neutrophil gelatinase-associated lipocalin (r(2) = 0.086). Diuretic response after 24 h (early diuretic response) was a strong predictor of diuretic response (ß = 0.467, P < 0.001; r(2) = 0.523). Addition of diuretic response after 24 h to biomarkers and clinical characteristics significantly improved the predictive model (r(2) = 0.586, P < 0.001). CONCLUSIONS: Biomarkers indicate that diuretic unresponsiveness is associated with an atherosclerotic profile with abnormal renal function and electrolytes. However, predicting diuretic response is difficult and biomarkers have limited additive value. Patients at risk of poor diuretic response can be identified by measuring early diuretic response after 24 h.

MicroRNAs relate to early worsening of renal function in patients with acute heart failure.

BACKGROUND: Deregulation of microRNAs (miRNAs) may be involved in the pathogenesis of heart failure (HF) and renal disease. Our aim is to describe miRNA levels related to early worsening renal function in acute HF patients. METHOD AND RESULTS: We studied the association between 12 circulating miRNAs and Worsening Renal Function (WRF; defined as an increase in the serum creatinine level of 0.3mg per deciliter or more from admission to day 3), absolute change in creatinine and Neutrophil Gelatinase Associated Lipocalin (NGAL) from admission to day 3 in 98 patients hospitalized for acute HF. At baseline, circulating levels of all miRNAs were lower in patients with WRF, with statistically significant decreased levels of miR-199a-3p, miR-423-3p, and miR-let-7i-5p (p-value<0.05). The increase in creatinine during the first 3 days of hospitalization was significantly associated with lower levels of miR-199a-3p, miR-27a-3p, miR-652-3p, miR-423-5p, and miR-let-7i-5p, while the increase in NGAL was significantly associated with lower levels of miR-18a-5p, miR-106a-5p, miR-223-3p, miR-199a-3p and miR-423-3p. MiR-199a-3p was the strongest predictor of WRF, with an Odds Ratio of 1.48 (1.061-2.065; p-value=0.021) and a C-index of 0.701. CONCLUSIONS: Our results show that the levels of circulating miRNAs at hospital admission for acute HF were consistently lower in patients who developed worsening of renal function. MiR-199a-3p was the best predictor of WRF in these patients.

Levosimendan improves renal function in acute decompensated heart failure: possible underlying mechanisms.

AIMS: The cardio-renal syndrome plays a critical role in acute heart failure (HF). Levosimendan, an inodilator drug, has a positive but controversial effect on kidney. Our aim was to evaluate its effects on both renal and systemic haemodynamic parameters as well as on renal function, explaining the possible mechanisms involved. METHODS AND RESULTS: Patients with acute decompensated HF, moderate renal impairment, wedge pressure >20 mmHg and EF <40% were eligible. Twenty-one patients were randomized to infusion of levosimendan or placebo, on top of standard therapy. Systemic haemodynamic parameters (wedge and cardiac output) were evaluated at baseline and at 8, 16, 24, 48, and 72 h. An intravascular renal artery Doppler exam was performed at baseline, after levosimendan bolus, and 1 h thereafter. Renal blood flow, glomerular filtration rate (GFR), cystatin C, blood urea nitrogen (BUN), urinary output, sodium excretion, and plasma sodium were measured. The effect of levosimendan was beneficial and significantly different from placebo on several renal and cardiac parameters. Specifically, the levosimendan and placebo group exhibited significantly different changes over time in GFR (P = 0.037), renal blood flow (P = 0.037), and renal artery diameter (P = 0.033), with ensuing improvements in serum levels of BUN (P = 0.014), creatinine (P = 0.042), and cystatin C (P = 0.05). Concomitantly, levosimendan provided a significant increase in urine output up to 72 h (P = 0.02). These beneficial results on renal parameters were accompanied by similarly significant and favourable changes in cardiac index (P = 0.029) and PCWP (P < 0.001). CONCLUSION: Levosimendan, in acute decompensated HF, has an immediate renoprotective effect, mediated by an increase in renal blood flow, due to a selective renal arterial and venous vasodilating action. TRIAL REGISTRATION: NCT00527059.

Role of ion channels in coronary microcirculation: a review of the literature.

In normal coronary arteries, several different mechanisms of blood flow regulation exist, acting at different levels of the coronary tree: endothelial, nervous, myogenic and metabolic regulation. In addition, physiologic blood flow regulation is also dependent on the activity of several coronary ion channels, including ATP-dependent K(+) channels, voltage-gated K(+) channels and others. In this context, ion channels contribute by matching demands for homeostatic maintenance. They play a primary role in rapid response of both endothelium and vascular smooth muscle cells of larger and smaller arterial vessels of the coronary bed, leading to coronary vasodilation. Consequently, an alteration in ion channel function or expression could be directly involved in coronary vasomotion dysfunction.

Cost-effectiveness of levosimendan in patients with acute heart failure.

Heart failure is a major public health problem because of its high prevalence and impact on mortality, morbidity, quality of life, and social costs. The aim of this analysis was to estimate the effects of the novel inodilator levosimendan versus standard inotropic therapy (ST) of dobutamine in acute heart failure. A study population of 292 patients with acute heart failure was derived from an observational registry of patients referred to our department. Of these, 147 patients received iv levosimendan (0.05-0.1 µg·kg·min for 24 hours), and 145 patients were treated with ST. Duration of hospitalization, survival at 1 month, and the rehospitalization rate during the year after the index hospitalization were evaluated. Cost-effectiveness analysis was performed. The mean length of hospitalization was 12.08 and 13.57 days in the levosimendan and ST groups, respectively (P < 0.05). Rehospitalization rates were lower in the levosimendan group at 6 months (1.44% vs. 2.3%; P < 0.05) and 12 months (7.6% vs. 14.3%; P < 0.05). Mortality rate at 1 month was 2.1% versus 6.9% in the levosimendan and ST groups, respectively (P < 0.05). The per-capita cost of treatment with levosimendan was €78.86 higher than that with ST during the first hospitalization but €280.22 lower when the rehospitalization rate was considered.

Cardiovascular risk factors and HIV disease.

An increased rate of coronary heart diseases is becoming an important cause of morbidity and mortality among HIV-infected patients. This emerging problem is due to the antiretroviral therapy success that allows HIV-positive patients to live longer. Increased coronary heart disease rates in the HIV population, as in the noninfected population, may be related to traditional risk factors, including advancing age, higher smoking rates, dyslipidemia, insulin resistance, and impaired glucose tolerance. Some nontraditional factors have to be considered too: these are due to the direct effects of the virus on the vasculature, as well as to direct effects of specific antiretroviral drugs, including inflammation, endothelial dysfunction, metabolic disorders, prothrombotic state, and changes in body composition with loss of subcutaneous fat and/or accumulation of visceral fat. The aim of this paper is to review traditional and emerging cardiovascular risk factors and consider their possible interactions in HIV-infected patients.