Santo Dellegrottaglie

Evaluation of pulmonary artery stiffness in pulmonary hypertension with cardiac magnetic resonance.

OBJECTIVES This study sought to evaluate indexes of pulmonary artery (PA) stiffness in patients with pulmonary hypertension (PH) using same-day cardiac magnetic resonance (CMR) and right heart catheterization (RHC). BACKGROUND Pulmonary artery stiffness is increased in the presence of PH, although the relationship to PH severity has not been fully characterized. METHODS Both CMR and RHC were performed on the same day in 94 patients with known or suspected PH. According to the RHC, patients were classified as having no PH (n = 13), exercise-induced PH (EIPH) only (n = 6), or PH at rest (n = 75). On CMR, phase-contrast images were obtained perpendicular to the pulmonary trunk. From CMR and RHC data, PA areas and indexes of stiffness (pulsatility, compliance, capacitance, distensibility, elastic modulus, and the pressure-independent stiffness index beta) were measured at rest. RESULTS All quantified indexes showed increased PA stiffness in patients with PH at rest in comparison with those with EIPH or no PH. Despite the absence of significant differences in baseline pressures, patients with EIPH had lower median compliance and capacitance than patients with no PH: 15 (interquartile range: 9 to 19.8) mm2/mm Hg versus 8.4 (interquartile range: 6 to 10.3) mm2/mm Hg, and 5.2 (interquartile range: 4.4 to 6.3) mm3/mm Hg versus 3.7 (interquartile range: 3.1 to 4.1) mm3/mm Hg, respectively (p < 0.05). The different measurements of PA stiffness, including stiffness index beta, showed significant correlations with PA pressures (r2 = 0.27 to 0.73). Reduced PA pulsatility (<40%) detected the presence of PH at rest with a sensitivity of 93% and a specificity of 63%. CONCLUSIONS Pulmonary artery stiffness increases early in the course of PH (even when PH is detectable only with exercise and before overt pressure elevations occur at rest). These observations suggest a potential contributory role of PA stiffness in the development and progression of PH.

Endogenous cardiac stem cell activation by insulin-like growth factor-1/hepatocyte growth factor intracoronary injection fosters survival and regeneration of the infarcted pig heart.

OBJECTIVES The purpose of this study was to test the ability of insulin-like growth factor (IGF)-1/hepatocyte growth factor (HGF) to activate resident endogenous porcine cardiac stem/progenitor cells (epCSCs) and to promote myocardial repair through a clinically applicable intracoronary injection protocol in a pig model of myocardial infarction (MI) relevant to human disease. BACKGROUND In rodents, cardiac stem/progenitor cell (CSC) transplantation as well as in situ activation through intramyocardial injection of specific growth factors has been shown to result in myocardial regeneration after acute myocardial infarction (AMI). METHODS Acute MI was induced in pigs by a 60-min percutaneous transluminal coronary angiography left anterior descending artery occlusion. The IGF-1 and HGF were co-administered through the infarct-related artery in a single dose (ranging from 0.5 to 2 μg HGF and 2 to 8 μg IGF-1) 30 min after coronary reperfusion. Pigs were sacrificed 21 days later for dose-response relationship evaluation by immunohistopathology or 2 months later for cardiac function evaluation by cardiac magnetic resonance imaging. RESULTS The IGF-1/HGF activated c-kit positive-CD45 negative epCSCs and increased their myogenic differentiation in vitro. The IGF-1/HGF, in a dose-dependent manner, improved cardiomyocyte survival, and reduced fibrosis and cardiomyocyte reactive hypertrophy. It significantly increased c-kit positive-CD45 negative epCSC number and fostered the generation of new myocardium (myocytes and microvasculature) in infarcted and peri-infarct/border regions at 21 and 60 days after AMI. The IGF-1/HGF reduced infarct size and improved left ventricular function at 2 months after AMI. CONCLUSIONS In an animal model of AMI relevant to the human disease, intracoronary administration of IGF-1/HGF is a practical and effective strategy to reduce pathological cardiac remodeling, induce myocardial regeneration, and improve ventricular function.

Peripheral Arterial Disease in Patients With End-Stage Renal Disease Observations From the Dialysis Outcomes and Practice Patterns Study (DOPPS)

Background— Patients with end-stage renal disease are at high risk for cardiovascular morbidity and mortality. The aims of the present study were to describe the prevalence of peripheral arterial disease (PAD) and its effects on prognosis and health-related quality of life (HRQOL) in an international cohort of patients on hemodialysis. Methods and Results— Data from the Dialysis Outcomes and Practice Patterns Study (DOPPS), a prospective, international, observational study of hemodialysis patients (n=29 873), were analyzed. Associations between baseline clinical variables and PAD were evaluated by logistic regression analysis. Cox regression models were used to test the association between PAD and risk for all-cause mortality, cardiac mortality, and hospitalization. PAD was diagnosed in 7411 patients (25.3%) with significant geographic variation. Traditional cardiovascular risk factors including age, male sex, diabetes, hypertension, and smoking were identified, together with the duration of hemodialysis, as significant correlates of PAD. Diagnosis of PAD was associated with increased all-cause mortality (hazard ratio [HR]=1.36; P<0.0001), cardiac mortality (HR=1.43; P<0.0001), all-cause hospitalization (HR=1.19; P<0.0001), and hospitalization for a major adverse cardiovascular event (HR=2.05; P<0.0001). HRQOL questionnaires revealed physical health scores that were significantly lower in PAD compared with non-PAD patients (P<0.0001). Conclusions— PAD is common in hemodialysis patients and is associated with increased risk of cardiovascular mortality, morbidity, and hospitalization and reduced HRQOL.

Natriuretic Peptide-Guided Therapy in Chronic Heart Failure: A Meta-Analysis of 2,686 Patients in 12 Randomized Trials

Background The role of cardiac natriuretic peptides in the management of patients with chronic heart failure (HF) remains uncertain. The purpose of this study was to evaluate whether natriuretic peptide-guided therapy, compared to clinically-guided therapy, improves mortality and hospitalization rate in patients with chronic HF. Methodology/Principal Findings MEDLINE, Cochrane, ISI Web of Science and SCOPUS databases were searched for articles reporting natriuretic peptide-guided therapy in HF until August 2012. All randomized trials reporting clinical end-points (all-cause mortality and/or HF-related hospitalization and/or all-cause hospitalization) were included. Meta-analysis was performed to assess the influence of treatment on outcomes. Sensitivity analysis was performed to test the influence of potential effect modifiers and of each trial included in meta-analysis on results. Twelve trials enrolling 2,686 participants were included. Natriuretic peptide-guided therapy (either B-type natriuretic peptide [BNP]- or N-terminal pro-B-type natriuretic peptide [NT-proBNP]-guided therapy) significantly reduced all-cause mortality (Odds Ratio [OR]:0.738; 95% Confidence Interval [CI]:0.596 to 0.913; p = 0.005) and HF-related hospitalization (OR:0.554; CI:0.399 to 0.769; p = 0.000), but not all-cause hospitalization (OR:0.803; CI:0.629 to 1.024; p = 0.077). When separately assessed, NT-proBNP-guided therapy significantly reduced all-cause mortality (OR:0.717; CI:0.563 to 0.914; p = 0.007) and HF-related hospitalization (OR:0.531; CI:0.347 to 0.811; p = 0.003), but not all-cause hospitalization (OR:0.779; CI:0.414 to 1.465; p = 0.438), whereas BNP-guided therapy did not significantly reduce all-cause mortality (OR:0.814; CI:0.518 to 1.279; p = 0.371), HF-related hospitalization (OR:0.599; CI:0.303 to 1.187; p = 0.142) or all-cause hospitalization (OR:0.726; CI:0.609 to 0.964; p = 0.077). Conclusions/Significance Use of cardiac peptides to guide pharmacologic therapy significantly reduces mortality and HF related hospitalization in patients with chronic HF. In particular, NT-proBNP-guided therapy reduced all-cause mortality and HF-related hospitalization but not all-cause hospitalization, whereas BNP-guided therapy did not significantly reduce both mortality and morbidity.

Radiation Dose and Cancer Risk Estimates in 16-Slice Computed Tomography Coronary Angiography

BackgroundRecent advances have led to a rapid increase in the number of computed tomography coronary angiography (CTCA) studies performed. Whereas several studies have reported the effective dose, there are no data available on cancer risk for current CTCA protocols.Methods and ResultsEffective and organ doses were estimated, by use of scanner-derived parameters and Monte Carlo methods, for 50 patients having 16-slice CTCA performed for clinical indications. Lifetime attributable risks were estimated with models developed in the National Academies’ Biological Effects of Ionizing Radiation VII report. The effective dose of a complete CTCA averaged 9.5 mSv, whereas that of a complete study, including calcium scoring when indicated, averaged 11.7 mSv. Calcium scoring increased effective dose by 25%, whereas tube current modulation reduced it by 34% and was more effective at lower heart rates. Organ doses to the lungs and female breast were highest. The lifetime attributable risk of cancer incidence from CTCA averaged approximately 1 in 1,600 but varied widely among patients, being highest in younger women. For all patients, the greatest risk was from lung cancer.ConclusionsCTCA is associated with non-negligible risk of malignancy. Doses can be reduced by careful attention to scanning protocol.

The Prognostic Value of Normal Stress Cardiac Magnetic Resonance in Patients with Known or Suspected Coronary Artery Disease: A Meta-analysis

Background—Ischemia detection with stress cardiac magnetic resonance (CMR) is typically based on induction of either myocardial perfusion defect or wall motion abnormality. Single-center studies have shown the high value of stress CMR for risk stratification. The aim of this study was to define the prognostic value of stress CMR for prediction of adverse cardiac events in patients with known or suspected coronary artery disease. Methods and Results—Studies published between January 1985 and April 2012 were identified by database search. We included studies using stress CMR to evaluate subjects with known or suspected coronary artery disease and providing primary data on clinical outcomes of nonfatal myocardial infarction or cardiac death with a follow-up time ≥3 months. Total of 14 studies were finally included, recruiting 12 178 patients. The negative predictive value for nonfatal myocardial infarction and cardiac death of normal CMR was 98.12% (95% confidence interval, 97.26–98.83) during a weighted mean follow-up of 25.3 months, resulting in estimated event rate after a negative test equal to 1.88% (95% confidence interval, 1.17–2.74). The corresponding annualized event rate after a negative test was 1.03%. Comparable negative predictive values for major coronary events were obtained in studies considering the absence of inducible perfusion defect compared with those evaluating the absence of inducible wall motion abnormality (98.39% versus 97.31%, respectively; P=0.227 by meta-regression analysis). Conclusions—Stress CMR has a high negative predictive value for adverse cardiac events, and the absence of inducible perfusion defect or wall motion abnormality shows a similar ability to identify low-risk patients with known or suspected coronary artery disease.

Changes in serum uric acid levels and cardiovascular events: A meta-analysis

BACKGROUND AND AIMS The association between serum uric acid (SUA) levels and cardiovascular (CV) risk or all-cause death has been repeatedly reported. However, it has not been assessed whether reduction of SUA levels is associated with reduced CV risk. The aim of the current study was to evaluate the relationship between changes of SUA levels and CV events as well as all-cause death. METHODS AND RESULTS Randomised trials reporting SUA at baseline and at the end of follow-up and clinical end-points (all-cause death, myocardial infarction (MI), stroke, heart failure (HF) and CV death) were included in the study. Meta-regression analysis was performed to test the relationship between SUA changes and clinical end-points. Eleven trials enrolling 21,373 participants followed up for 2.02 ± 1.76 years and reporting 4533 events were included. In meta-regression analysis, no relationship between SUA changes from baseline to end of follow-up and the composite outcome including CV death, stroke, MI and HF was found (change in Tau(2) (t) = -0.64; p Tau (p) = 0.541). Similarly, no relationship was found between SUA changes and single components of the composite outcome (MI: t = -0.83; p = 0.493; stroke: t = 0.46; p = 0.667; HF: t = 2.44; p = 0.162; CV death: t = -0.54; p = 0.614) and all-cause death (t = -0.72; p = 0.496). Results were confirmed by sensitivity analysis. No heterogeneity among studies or publication bias was detected. CONCLUSIONS Changes in SUA levels observed during pharmacologic treatments do not predict the risk of all-cause death or CV events. As SUA levels are associated with increased CV risk, additional studies with direct xanthine-oxidase inhibitors are requested.

Molecular Determinants of Vascular Calcification: A Bench to Bedside View

Vascular calcification (VC) is an orchestrated event, evoking the programmed process of the osteogenesis and triggered by inflammatory cytokines active at vascular level. VC is a dynamic process in which the vessel wall intima, media and also cardiac valves may be involved. Intimal calcification is an endochondral ossification process in which type II collagen is mineralized by calcium deposition. In contrast, an intra-membranous ossification process leads to medial calcification, while a dystrophic calcification process is responsible for valvular calcification. Mechanisms involved in VC may be summarized as: 1. Activation of osteogenesis in the vessel wall, 2. Loss of inhibitory factors, 3. Enhanced bone turnover, and 4. Abnormalities in mineral metabolism. The signaling axis constituted by osteoprotegerin (OPG), receptor activator nuclear factor kB (RANK) and its ligand (RANKL), along with the monocyte colony stimulating factor (M-CSF) and the transcription factor core Binding protein (Cbfa-1), play a pivotal role in the control of VC. In contrast, fetuin-A, matrix G1a protein (MGP) and osteopontin (OPN) control the inhibition of VC. In addition, abnormal mineral metabolism with enhanced phosphates availability favors calcium deposition. The inflammatory cytokines interleukin (IL-1) and tumor necrosis factor (TNF)-alpha enhance OPG and RANKL function in the vessel wall leading to VC. VC is a controlled process, depending on the balance between osteoblastic and osteoclastic influences and further modulated by the influence of risk factors like diabetes, smoking, age, hypertension and dyslipidemia. Recent advances in diagnostic tools such as with multi-detector computed tomography (MDCT) and electron beam computed tomography (EBCT), may help diagnosis and delineation of VC in the clinical setting and aid in understanding its prognostic value.

Haemodynamics, exercise capacity and clinical events in pulmonary arterial hypertension

The purpose of this study was to clarify whether changes in cardiopulmonary haemodynamics induced by pharmacological therapy correlate with exercise capacity and clinical events in patients with pulmonary arterial hypertension. 16 randomised trials including 2353 patients, followed up for 16.4±10.6 weeks, measuring cardiopulmonary haemodynamics by right heart catheterisation and reporting clinical events were included. Meta-analysis and meta-regression analysis were performed to assess the effects of treatments on clinical events and the relationship between haemodynamic changes (pulmonary artery pressure, pulmonary vascular resistance, cardiac index and right atrial pressure) and clinical events. Treatments significantly reduced all-cause death (OR 0.5, 95% CI 0.3–0.7; p<0.01), hospitalisation for pulmonary arterial hypertension (OR 0.4, 95% CI 0.2–0.7; p<0.01), initiation of rescue therapy (OR 0.3, 95% CI 0.2–0.6; p<0.01) and the composite outcome (OR 0.3, 95% CI 0.3–0.5; p<0.01). No relationship was found between changes of haemodynamic parameters and clinical events, whereas changes of cardiac index and pulmonary vascular resistance significantly correlated with changes in the 6-min walking distance (r = 0.64, p = 0.03; r = -0.55, p = 0.04, respectively). In patients with pulmonary arterial hypertension, improvements of cardiopulmonary haemodynamics observed in randomised clinical trials correlate with exercise capacity changes but do not predict clinical events in a short-term follow-up.

Assessment of cardiac sympathetic activity by MIBG imaging in patients with heart failure: a clinical appraisal

Cardiac sympathetic activity can be assessed by 123I-labelled meta-iodobenzylguanidine (MIBG) scintigraphy. Abnormalities of sympathetic cardiac activity have been shown in patients with heart failure, resulting in reduced MIBG uptake. Abnormal MIBG uptake predicts cardiac death, arrhythmias and all-cause mortality in patients with heart failure with a prognostic power incremental to that of conventional risk markers, and may identify patients at low risk of arrhythmias despite current guideline indications for implantable cardioverter defibrillator or patients at high risk for arrhythmias not fulfilling implantable cardioverter defibrillator indications. Prospective outcome studies are needed to assess whether MIBG imaging will have an impact on the mortality and morbidity of patients with heart failure.