Aortic valve stenosis: drivers of disease progression and drug targets for therapeutic opportunities.

INTRODUCTION: Recommended therapy for calcific degenerative aortic stenosis (AS) is still aortic valve replacement (AVR), either transcatheter or surgical, since no conclusive efficacy has been determined in slowing the degenerative process by medical therapy. AREAS COVERED: This paper offers a brief overview of molecular mechanisms leading to calcification of aortic valve. It is then focused on potential markers of disease progression, as observed in many observational studies. Finally it provides a comprehensive review of drugs already tested in in vitro and human studies in order to slow aortic valve stenosis process. EXPERT OPINION: Despite research providing numerous molecular pathways underlying the calcification process, further efforts must be made to understand risk factors linked to disease progression. Some existing treatments that have already provided survival benefits in many features of cardiovascular diseases are currently being tested with promising results. In the near future new drugs acting on specific pathways by techniques such as monoclonal antibodies and RNA interference, are expected to provide better medical solutions for this ever growing number of patients.

Myocardial fibrosis in asymptomatic patients undergoing surgery for mitral and aortic valve regurgitation.

BACKGROUND: Chronic heart valve regurgitation induces left ventricular (LV) volume overload, leading to the development of hypertrophy and progressive dilatation of the ventricle to maintain physiological cardiac output. In order to prevent potential irreversible LV structural changes, the identification of the best timing for treatment is pivotal. OBJECTIVE: To assess the presence and extent of fibrosis in myocardial tissue in asymptomatic patients with valvular heart disease (VHD) and preserved LV dimensions and function undergoing cardiac surgery. METHODS: Thirty-nine patients were enrolled. Sixteen patients were affected by aortic or mitral regurgitation: they were all asymptomatic, undergoing valve surgery according to VHD European Society of Cardiology guidelines. Twenty-three patients with end-stage nonischemic dilated cardiomyopathy (DCM) and severe LV dysfunction undergoing cardiac surgery for implantation of a durable left ventricular assist device (LVAD) served as controls. During surgery, VHD patients underwent three myocardial biopsies at the level of the septum, the lateral wall and LV apex, while in LVAD patients the coring of the apex of the LV was used. For both groups, the tissue samples were analyzed on one section corresponding to the apical area. All slides were stained with hematoxylin and eosin and Masson's trichrome staining and further digitalized. The degree of fibrosis was then calculated as a percentage of the total area. RESULTS: Of 39 patients, 23 met the inclusion criteria: 12 had mitral or aortic insufficiency with a preserved ejection fraction and 11 had idiopathic dilated cardiomyopathy. Quantitative analysis of apical sections revealed a myocardial fibrosis amount of 10 ±â€Š6% in VHD patients, while in LVAD patients the mean apical myocardial fibrosis rate was 38 ±â€Š9%. In VHD patients, fibrosis was also present in the lateral wall (9 ±â€Š4%) and in the septum (9 ±â€Š6%). CONCLUSION: Our case series study highlights the presence of tissue remodeling with fibrosis in asymptomatic patients with VHD and preserved LV function. According to our results, myocardial fibrosis is present at an early stage of the disease, well before developing detectable LV dysfunction and symptoms. Since the relationship between the progressive magnitude of myocardial fibrosis and potential prognostic implications are not yet defined, further studies on this topic are warranted.

Real-Life Indications to Sacubitril/Valsartan Treatment in Patients With Chronic Systolic Heart Failure.

OBJECTIVE: International guidelines recommend the introduction of sacubitril/valsartan (Entresto) in patients with heart failure (HF) and reduced ejection fraction (EF), who remain symptomatic, despite optimal uptitrated therapy. The purpose of the following analysis is to verify the real-life eligibility for sacubitril/valsartan in a population of patients suffering from chronic HF, regularly monitored in a single HF clinic and treated according to guideline-directed medical therapy (GDMT). METHODS: From a total of 1070 patients regularly monitored in our HF Clinic between January 2011 and September 2017, the clinical records of 224 patients with HF and reduced EF on optimized GDMT were retrospectively analyzed. RESULTS: Of 224 analyzed patients, 75 improved their EF or were asymptomatic after uptitration of GDMT during follow-up; 50 were not on angiotensin-converting enzyme inhibitor or angiotensin receptor blocker for different reasons; 13 patients had systolic blood pressure ≤100 mm Hg, so they were not eligible for sacubitril/valsartan introduction. The remaining patients were still symptomatic (NYHA ≥2), and therefore, sacubitril/valsartan introduction was indicated in these 86 patients (38.4%) of 224 enrolled. CONCLUSION: In patients with HF and reduced EF, where GDMT is appropriately achieved, indication to sacubitril/valsartan treatment is around 38%.

Two-year cardiac mortality after MitraClip treatment of functional mitral regurgitation in ischemic and non-ischemic dilated cardiomyopathy.

BACKGROUND: MitraClip implantation has evolved as a new tool for treatment of inoperable or high-risk patients with severe functional mitral regurgitation (FMR) due to dilated cardiomyopathy (DCM). Limited data are available regarding MitraClip outcomes comparing patients with ischemic and non-ischemic DCM. METHODS: From 2008 to 2016, 314 patients received MitraClip for FMR at four institutions: Brescia, Zurich and Milan. Patients were stratified according to MR aetiology in non-ischemic FMR (n = 99) and ischemic FMR (n = 215). Preoperative risk factors, operative variables and outcomes up to 2-year were evaluated. A multivariable Cox Proportional Hazards survival model with covariate adjustments was used to assess the relationship between FMR aetiology and 2-year cardiac mortality. RESULTS: As expected, patients with ischemic FMR had significantly more risk factors and comorbidities. Overall procedural success rate was 80% and in-hospital cardiac mortality was 3% without significant differences between aetiology. Two-year overall (25% vs. 19%, p = 0.574) and cardiac (18% vs. 16%, p = 0.990) mortality rates were comparable. No differences were detected in terms of re-hospitalization rates (32%), LVAD implantation (4.5%) and mitral valve surgery (1%). LVEF ≤ 25%, LVEDV > 216 ml, NT-proBNP ≥ 10.000 pg/ml and AF were the strongest baseline predictors of 2-year cardiac mortality. Greater improvements of 6MWT and NYHA functional class were observed in patients with non-ischemic FMR. CONCLUSIONS: The ischemic or non-ischemic aetiology of DCM did not affect in-hospital and 2-year cardiac mortality after MitraClip in patients with FMR. In case of unfavorable baseline clinical condition, the indication for MitraClip should be carefully weighed in favour of conservative medical therapy alone or left ventricular assist device.

Pathophysiological Mechanisms and Correlates of Therapeutic Pharmacological Interventions in Essential Arterial Hypertension.

Treating arterial hypertension (HT) remains a hard task. The hypertensive patient is often a subject with several comorbidities and metabolic abnormalities. Clinicians everyday have to choose the right drug for the single patient among the different classes of antihypertensives. Apart from lowering blood pressure, a main therapeutic target should be that of counteracting all the possible pathophysiological mechanisms involved in HT itself and in existing/potential comorbidities. All the ancillary positive and negative effects of the administered drugs should be considered: in particular, since hypertensive patients are often glucose intolerant/diabetic, carrier of serum lipids disorder, have already developed atherosclerotic diseases and endothelial dysfunction, they should not be treated with drugs negatively interfering with these conditions but with molecules that, if possible, improve them. The main pathophysiological mechanisms and correlates of therapeutic pharmacological interventions in essential HT are reviewed here.

Early left atrial tissue features in patients with chronic mitral regurgitation and sinus rhythm: Alterations of not remodeled left atria.

OBJECTIVE: Left atrial (LA) enlargement, a compensatory mechanism in chronic mitral regurgitation (MR) increasing the risk of atrial fibrillation (AF) and predictive of cardiac events, involves structural alterations. We characterized LA features in patients in sinus rhythm with severe degree of MR, similar degrees of left ventricular remodeling but divergent LA size. METHODS: Among a consecutive series of 163 patients in stable sinus rhythm undergoing isolated mitral valve surgery for severe non-rheumatic MR, two groups were arbitrarily selected according to their LA size (antero-posterior): NRLA group (non-remodeled LA) included 8 patients with LA≤40mm, RLA group (remodeled LA) included 8 patients with LA>55mm. LA biopsies were processed for paraffin inclusion and sectioning. Fibrosis, cardiomyocytes morphology, capillaries density, cytochrome c and F-actin expression were evaluated by microscopy. RESULTS: Histology and immunohistochemistry demonstrated alteration of moderate entity: higher amounts of endomysial fibrosis (not of collagen type III) and of hypertrophic cardiomyocytes in RLA than in NRLA. Confocal microscopy displayed focally disorganized F-actin and no nuclear fragmentation in both groups, but more intra-cytoplasm cytochrome c in RLA vs. NRLA, possibly indicative of more successful escape to apoptosis by NRLA cardiomyocytes. CONCLUSIONS: Our study shows the presence of early cellular and interstitial alterations in LA tissue in patients with chronic MR and sinus rhythm. These features were analogous to those of patients with AF, and suggest that macroscopic remodeling LA in the settings of MR is preceded by structural changes, paving the way to further investigation on the preventive role of early mitral valve repair.

Deranged Cardiac Metabolism and the Pathogenesis of Heart Failure.

Activation of the neuro-hormonal system is a pathophysiological consequence of heart failure. Neuro-hormonal activation promotes metabolic changes, such as insulin resistance, and determines an increased use of non-carbohydrate substrates for energy production. Fasting blood ketone bodies as well as fat oxidation are increased in patients with heart failure, yielding a state of metabolic inefficiency. The net result is additional depletion of myocardial adenosine triphosphate, phosphocreatine and creatine kinase levels with further decreased efficiency of mechanical work. In this context, manipulation of cardiac energy metabolism by modification of substrate use by the failing heart has produced positive clinical results. The results of current research support the concept that shifting the energy substrate preference away from fatty acid metabolism and towards glucose metabolism could be an effective adjunctive treatment in patients with heart failure. The additional use of drugs able to partially inhibit fatty acids oxidation in patients with heart failure may therefore yield a significant protective effect for clinical symptoms and cardiac function improvement, and simultaneously ameliorate left ventricular remodelling. Certainly, to clarify the exact therapeutic role of metabolic therapy in heart failure, a large multicentre, randomised controlled trial should be performed.

Primary Cardiac Lymphoma in an Immunocompetent 71-Year-Old Man.

Isolated cardiac lymphomas are very rare, especially in immunocompetent patients. As a consequence, little is known about the best therapeutic management and about patients' outcomes in these cases. Diffuse large B-cell lymphoma is the most frequent subtype; anthracycline-based chemotherapy has been the most successful treatment. We describe the case of a primary cardiac lymphoma in an immunocompetent 71-year-old man. As of December 2015, the patient had been in clinical remission for 2 years. The most relevant literature on primary cardiac lymphoma is reported and discussed.

[Cardiovascular involvement in Erdheim-Chester syndrome: clinical and therapeutic implications]. / Coinvolgimento cardiovascolare nella sindrome di Erdheim-Chester: aspetti clinici e terapeutici.

Erdheim-Chester disease (ECD) is a rare form of non-Langerhans' cell histiocytosis of unknown etiology and its incidence is constantly increasing. ECD is characterized by a xantomatous or xanthogranulomatous infiltration of various tissues by foamy histiocytes surrounded by fibrosis. ECD is characterized by multi-organ involvement and is generally associated with a poor prognosis with a median survival of 32 months after diagnosis. Cardiovascular involvement concerns mainly the thoraco-abdominal aorta and pericardium. Less frequently, infiltration affects the myocardial tissue, especially the right atrium, and the valvular endocardium. Recently, the involvement of the vena cava has also been described. The diagnosis of ECD is made by the identification of foamy histiocytes CD68 positive and CD1a/S100 negative embedded in a polymorphic inflammatory tissue on biopsy. Despite the adoption of several therapeutic strategies until now prognosis has remained poor. Interferon-α can be considered the first line therapy, but its effects on central nervous system and cardiovascular localization have been shown to be often poor. In this context a combined treatment with the anti-TNFα monoclonal antibody infliximab and methotrexate seems to be effective and well tolerated.

Feasibility and safety of transcatheter closure of atrial septal defects with deficient posterior rim.

OBJECTIVES: To evaluate the feasibility and safety of percutaneous closure of complex secundum-type atrial septal defects (ASD) in patients with posterior-inferior rim deficiency. BACKGROUND: Transcatheter approach is the method of choice for ASD closure; however, up to now 20% of the defects are not considered suitable for percutaneous intervention because of the lack of surrounding rims, especially the posterior-inferior. METHODS: A total of 268 patients were evaluated between March 2005 and April 2011 for ASD closure. Twenty-four patients (9%) were not considered suitable for a percutaneous intervention and referred to surgery due to inadequate rims or a large defect diameter. Out of the remaining 244 patients, 25 (10,2%) had posterior-inferior rim deficiency and represent our study group. RESULTS: After failure of the conventional approach, alternative techniques were attempted. In 16 patients, an adjusted deployment and alignment maneuver approach was successful. In 5 other patients, a slide out technique was successfully performed by exploiting the right upper pulmonary vein. Finally in the remaining 4 patients, ASD closure was obtained by completely re-orienting the system with a jugular approach. No peri-procedural complications occurred, and at 12-month transesophageal echocardiography evaluation no residual shunt could be detected. CONCLUSIONS: Our data show the feasibility of percutaneous approach for ASD closure in presence of a deficient posterior-inferior rim. The procedural success is strictly related to correct sizing and demonstration of a balloon notch on fluoroscopy. Long-term follow-up supports efficacy of the procedure in these selected cases.

Beneficial effects of beta-blockers on left ventricular function and cellular energy reserve in patients with heart failure.

Beta-blockers have been shown to improve left ventricular (LV) function in patients with heart failure. The aim of this study is to non-invasively assess, by means of in vivo 31P-magnetic resonance spectroscopy (31P-MRS), the effects of beta-blockers on LV cardiac phosphocreatine and adenosine triphosphate (PCr/ATP) ratio in patients with heart failure. Ten heart failure patients on full medical therapy were beta-blocked by either carvedilol or bisoprolol. Before and after 3 months of treatment, exercise testing, 2D echocardiography, MRS, New York Heart Association (NYHA) class, ejection fraction (EF), maximal rate-pressure product and exercise metabolic equivalent system (METS) were evaluated. Relative concentrations of PCr and ATP were determined by cardiac 31P-MRS. After beta-blockade, NYHA class decreased (from 2.2 ± 0.54 to 1.9 ± 0.52, P = 0.05), whereas EF (from 33 ± 7 to 44 ± 6%, P = 0.0009) and METS (from 6.74 ± 2.12 to 8.03 ± 2.39, P = 0.01) increased. Accordingly, the mean cardiac PCr/ATP ratio increased by 33% (from 1.48 ± 0.22 to 1.81 ± 0.48, P = 0.03). Beta-blockade-induced symptomatic and functional improvement in patients with heart failure is associated to increased PCr/ATP ratio, indicating preservation of myocardial high-energy phosphate levels.

Increased low-grade inflammation is associated with lack of functional response to carvedilol in patients with systolic heart failure.

BACKGROUND: The aim of this study was to evaluate, according to functional response, the neuroendocrine and inflammatory status in patients with chronic heart failure before and after therapy with carvedilol. METHODS AND RESULTS: Serum tumor necrosis factor-α (TNF-α) soluble receptors (sTNF-R1 and sTNF-R2), interleukin (IL)-10 and IL-18, chromogranin A (CgA) and brain natriuretic peptide (pro-BNP) were measured in 37 New York Heart Association class II to IV heart failure patients, at baseline and after 6 months of therapy with carvedilol. Patients were divided in two groups according to whether, following carvedilol, left-ventricular ejection fraction (LVEF) had increased by at least 5% (17 patients) or not (20 patients). Baseline LVEF was higher in nonresponders (38 ± 5 vs. 31 ± 7%, P = 0.002). In responders, LVEF increased from 31 ± 7 to 51 ± 7% (P < 0.0001), whereas in nonresponders it decreased from 38 ± 5 to 33 ± 7%, (P = 0.02). sTNF-R1 (P = 0.019) and sTNF-R2 (P = 0.025) increased in nonresponders, whereas they did not change in responders. After carvedilol, IL-10 was significantly higher in responders (P = 0.03). Conversely, no significant IL-18 and CgA changes were observed in either group. CgA was not significantly different between groups at baseline and after carvedilol in either group, whereas pro-BNP significantly increased in nonresponders (from 438 ± 582 to 1324 ± 1664 pg/ml, P = 0.04) and decreased in responders (from 848 ± 1221 to 420 ± 530 pg/ml, P = 0.08). CONCLUSION: Increased inflammatory activation observed only in heart failure patients not improving left-ventricular function after carvedilol may indicate that inflammation, either as a direct cause or as a consequence, is associated with progressive ventricular dysfunction.

Resting cardiac energy metabolism is inversely associated with heart rate in healthy young adult men.

BACKGROUND: 31-Phosphorus-magnetic resonance spectroscopy may provide pathophysiological insights into the high-energy phosphate metabolism of the myocardium as measured by phosphocreatine to adenosine triphosphate (PCr/ATP) ratio. Aim of the present study was to determine in vivo the relation between cardiac PCr/ATP ratio and heart rate in normal male subjects. METHODS: One hundred twelve apparently healthy, young male individuals (age 34 ± 10 years) were prospectively evaluated. They underwent cardiac cine magnetic resonance imaging to assess left ventricular (LV) function and morphology and 3D-ISIS (31)P-magnetic resonance spectroscopy of the LV to assess the PCr/ATP ratio (a recognized in vivo marker of myocardial energy metabolism). Data were analyzed after segregation by tertiles of the resting PCr/ATP ratio. RESULTS: A significant inverse association between PCr/ATP ratios and resting heart rate was observed (Spearman ρ: r=-0.37; P < .0001). PCr/ATP ratios were also inversely associated with body mass index, diastolic blood pressure, wall mass and with insulin resistance, but in multiple regression analysis heart rate was found to be independently related to PCr/ATP. CONCLUSIONS: The present study shows that resting heart rate is proportionally lower across tertiles of increasing PCr/ATP ratio of the LV in apparently healthy young male individuals, supporting the hypothesis that heart rate is a major determinant of cardiac energy stores. These findings may explain the prognostic role of heart rate in the general population as evidenced by previous large epidemiological studies.

[Cardiac stem cell therapy for the treatment of chronic stable angina refractory to conventional therapy. State of the art and current clinical experience of the San Raffaele Hospital of Milan, Italy]. / La terapia cellulare cardiaca nel trattamento dei pazienti con angina cronica refrattaria alle terapie convenzionali. Excursus sullo stato dell'arte e descrizione dell'esperienza clinica in corso all'Ospedale San Raffaele di Milano.

BACKGROUND: Cardiac stem cell therapy is a field of scientific research with the goal to translate into clinical benefit the initial findings obtained in basic research laboratories. We have moved into clinical trials in different disease categories: acute myocardial infarction, chronic stable angina refractory to conventional therapy and heart failure. So far we have faced with contradictory results. Some previous studies suggested that bone marrow cell injection may improve myocardial perfusion and left ventricular function in patients with chronic myocardial ischemia. METHODS: In this paper we present a brief review about stem cell use in clinical cardiology and describe our research protocol evaluating the effects of direct intramyocardial injection of autologous bone marrow cells (CD34+ selected cells versus all mononuclear cells) in patients with chronic myocardial ischemia. RESULTS: Preliminary results show that this procedure seems to be safe and generally well tolerated by patients. An improvement in symptoms, in the first 6 months, appears to be achieved in approximately 50% of patients, with concomitant improvement of quantitative scintigraphic stress test imaging. CONCLUSIONS: Before drawing any definitive conclusions, we need to wait for the end of enrollment and unblinding of study randomization.

Cardiotoxicity after low-dose chloroquine antimalarial therapy.

Previous reports on antimalarial toxicity have only been related to long-term continuous treatments for nonmalarial indications, which require prolonged use of large doses, up to 1000 g or more every year. We describe a patient with recurrent malaria, prophylactically treated with low-dose chloroquine, who developed heart failure due to biventricular cardiac dysfunction. The right ventricle endomyocardial biopsy was suggestive of chloroquine toxicity. The heart failure improved after drug withdrawal. As a consequence, the potential for reversibility and the severity in undiagnosed cases of these toxic cardiomyopathies emphasize the importance of recognizing early signs of toxicity in order to withdraw antimalarials before the occurrence of life-threatening cardiac toxicity.

Effects of metabolic modulation by trimetazidine on left ventricular function and phosphocreatine/adenosine triphosphate ratio in patients with heart failure.

AIMS: The addition of trimetazidine to standard treatment has been shown to improve left ventricular (LV) function in patients with heart failure. The aim of this study is to non-invasively assess, by means of in vivo 31P-magnetic resonance spectroscopy (31P-MRS), the effects of trimetazidine on LV cardiac phosphocreatine and adenosine triphosphate (PCr/ATP) ratio in patients with heart failure. METHODS AND RESULTS: Twelve heart failure patients were randomized in a double-blind, cross-over study to placebo or trimetazidine (20 mg t.i.d.) for two periods of 90 days. At the end of each period, all patients underwent exercise testing, 2D echocardiography, and MRS. New York Heart Association (NYHA) class, ejection fraction (EF), maximal rate-pressure product, and metabolic equivalent system (METS) were evaluated. Relative concentrations of PCr and ATP were determined by cardiac 31P-MRS. On trimetazidine, NYHA class decreased from 3.04+/-0.26 to 2.45+/-0.52 (P = 0.005), whereas EF (34+/-10 vs. 39+/-10%, P = 0.03) and METS (from 7.44+/-1.84 to 8.78+/-2.72, P = 0.03) increased. The mean cardiac PCr/ATP ratio was 1.35+/-0.33 with placebo, but was increased by 33% to 1.80+/-0.50 (P = 0.03) with trimetazidine. CONCLUSION: Trimetazidine improves functional class and LV function in patients with heart failure. These effects are associated to the observed trimetazidine-induced increase in the PCr/ATP ratio, indicating preservation of the myocardial high-energy phosphate levels.