The Role of High-Sensitivity Troponin in Diagnosing Acute Coronary Syndromes

The development of assays to detect plasma elevations of cardiac troponins has revolutionized our current clinical practice in the diagnosis and management of acute coronary syndromes. . Recently new highly sensitive assays for troponin measurement have been developed in an effort to detect even minimal elevations suggestive of subclinical injury providing thus the clinicians with additional diagnostic and prognostic information. These assays can facilitate an earlier diagnosis of myocardial ischemia or necrosis and add substantial prognostic information to improve our risk stratification and accordingly our treatment strategy. This increased sensitivity, however, may come in expense to decreased specificity.  Nevertheless, accumulating evidence suggests that high sensitive troponins, if used appropriately regarding proper timing and evaluation of serial samples and in conjunction with clinical data can improve clinical care of patients with acute coronary syndrome

Cardiac Resynchronization Therapy in Heart Failure: Patients with Narrow QRS

Heart failure remains a significant health problem in the Western countries despite the evolution achieved in terms of heart disease prevention and medical treatment. Its incidence and its prevalence reach 550,000/year and 5 million respectively in the United States. As a consequence, heart failure causes about 287,000 deaths in the US each year and puts a financial burden to the health system of $29.6 billion dollars due to the increasing number of hospitalizations especially in elderly patients.Cardiac resynchronization therapy (CRT) is a relatively recent advance in the management of heart failure patients, which has been very hopeful since its development. Large trials have established the efficacy of CRT in improving functional capacity (MUSTIC, MIRACLE) and reducing mortality (COMPANION, CARE HF) in patients with advanced heart failure (NYHA III-IV), reduced ejection fraction (EF<35%) and wide QRS complex >120 - 130 ms (MIRACLE). Data from meta-analyses also confirm the beneficial effect of CRT with respect to mortality from worsening heart failure and all cause mortality in patients with wide QRS complex.Nevetheless, not all patients suffering from heart failure have a prolonged QRS. On the contrary, it has been reported that nearly 50% of heart failure patients have a QRS < 120 ms. Moreover, CRT has been shown to improve haemodynamic variables in patients with heart failure and narrow QRS. Achilli et al, who studied 52 patients, reported that CRT produced similar clinical and functional benefit in patients with wide or narrow QRS, the cut-off point being 120 ms provided they had mechanical dyssynchrony. Bleeker at al came up with similar results when they compared 33 patients with normal QRS duration with an equal number of subjects with wide QRS. All participants ought to have mechanical dyssynchrony >65 ms on tissue Doppler imaging (TDI) study... (excerpt

Device Therapy in Refractory Heart Failure

Advanced heart failure (HF) has been defined as persistent symptoms that limit daily life despite optical medical therapy, corresponding to New York Heart Association (NYHA) class III/IV symptoms or to the newer classification of stage D HF (ACC/AHA staging classification). It affects 10% of the HF population and is associated with a poor quality of life, recurrent hospitalizations and a mortality approaching 50% at 1 year and 80% at 5 years. Despite the widespread use of angiotensin converting enzyme (ACE) inhibitors, beta adrenergic blocking agents and spironolactone which improve the prognosis in mild to moderate stages, HF remains a progressive disease leading to decompensation and demand of both inotropic agents (class III recommendation according to ACC/AHA guidelines, considered solely for palliation in patients with end-stage disease) and diuretics to treat hypotension, impaired renal function and pulmonary congestion.Heart transplantation (HT) is associated with nearly 90% 1-year survival, 60% 10-year survival and 95% freedom from symptoms and activity limitations in survivors throughout the follow-up period. Nevertheless, the lack of available donors and the large number of patients, who do not meet the criteria for transplantation, have spurred interest in cardiac resynchronization therapy (CRT) and mechanical circulatory support (MCS), providing alternatives for patients waiting for HT (bridge to transplantation, BTT), patients who are ineligible for HT (destination therapy, DT) or patients who are anticipated to recover after left ventricular unloading (bridge to recovery, BTR)... (excerpt

What is New in the ESC Guidelines for the Management of Atrial Fibrillation

The European Society of Cardiology (ESC) and the European Heart Rhythm Association (EHRA) have developed the 2010 Clinical Practice Guidelines covering atrial fibrillation (AF), the most common cardiac arrhythmia occurring in 1-2% of the general population. Advance has been made regarding the dynamic development of AF from a preclinical state to an irreversible cardiac arrhythmia and a novel classification of AF has been adopted based on the presentation and duration of the arrhythmia: first diagnosed, paroxysmal, persistent, long-standing persistent and permanent AF are the 5 types of AF in use for clinical management of patients with AF.Structural and electrical remodelling are hallmarks of the pathophysiological changes facilitating the initiation and perpetuation of AF. While atrial fibrosis was the main cause of nonhomogeneity of conduction according to earlier ESC guidelines, nowadays any kind of structural abnormality (inflammatory changes, amyloid deposit, apoptosis, necrosis, hypertrophy, microvascular changes, etc.) is believed to trigger the electrical dissociation between muscle bundles and permit small re-entrant circuits to stabilize the arrhythmia. The adage ‘atrial fibrillation begets atrial fibrillation’ describes electrical remodelling due to shortening of atrial refractory period, which is attributed to down-regulation of the L-type Ca2+ inward current and up-regulation of inward rectifier K+ currents. Although the exact role of the genome in the pathogenesis of AF is not known, numerous inherited cardiac syndromes and mutations have lately been associated with AF and should be elucidated. Mutations in the gene coding for atrial natriuretic peptide, loss of function mutations in the cardiac sodium channel gene SCN5A or gain of function mutations in the cardiac potassium channel are related to familial AF and genetic loci close to the PITX2 and ZFHX3 genes are currently associated with enhanced risk for cardioembolic stroke... (excerpt

NEWS FROM THE INDUSTRY: Safety Announcements

Medtronic informs that a software problem has been noticed in the following models: Consulta CRT-D, Secura DR/VR, Concerto II CRT-D, Virtuoso II DR/VR, Maximo II CRT-D, Maximo IIDR/VR. By April, 19 2010 Medtronic has received 5 confirmed reports from 144000 devices none of them associated with adverse effects of any kind. A particular sequence of the following 3 facts must take place within a few ms to cause this problem.1. The high voltage capacitors obtain the programmed energy (termination of charge)2. Battery voltage measurement is in progress and3. The ventricular tachyarrhythmia is self-terminated and the subsequent therapy delivery is postponed.In that case, all future high voltage therapies would have an elongated charge time or would fail to deliver due to charge circuit time-out. The alert systems of the devices will notify the patients to seek medical attention and this problem will be fixed with a new software installed. The possibility of this malfunction is estimated about 1/27000 devices per year and the possibility of a patient needing therapy before the device alert is activated is about 1/291000 per year... (excerpt

“Broken Heart Syndrome”: What Women Should Know

The Takotsubo syndrome or apical ballooning, also known as “broken heart syndrome” (BHS) among a variety of suggested names, was first described by Sato et al in the Japanese population approximately 20 years ago. Since then, it has been increasingly recognized in other countries and in 2006 it was classified as a type of stress cardiomyopathy among acquired cardiomyopathies. The prevalence of the BHS is estimated to be 1-2% of patients presenting with an acute coronary syndrome but higher rates have been reported lately, due to a wider recognition of the syndrome. One of the hallmarks of the BHS is a strict predilection for postmenopausal women (over 90% in most series), whereas men account for less than 10% of cases. It has also been reported that among BHS patients, 43% had a preceding acute medical condition and 27% had a severe emotional or physical stressor associated with a “fight or flight” hypersympathetic response... (excerpt

Απρόσφορες Εκφορτίσεις Εμφυτεύσιμου Απινιδωτή σε Ασθενή με Long QT Syndrome από Ηλεκτρομαγνητική Παρεμβολή κατά τη Διέλευσή της από Δημόσια Έργα

Πρόκειται για γυναίκα ασθενή 33 ετών στην οποία εμφυτεύθηκε ICD τον Δεκέμβριο του 2006 λόγω επεισοδίου καρδιακής ανακοπής σε έδαφος συνδρόμου μακρού QT. Μέχρι το επεισόδιο που περιγράφουμε δεν είχε συμβεί εκφόρτιση του απινιδωτή, δόκιμη ή απρόσφορη. Η ασθενής περιγράφει τις εκφορτίσεις του απινιδωτή κατά την προσέλευσή της στην εργασία της περνώντας δίπλα από πεζοδρόμιο όπου εκτελούνταν δημόσια έργα και λειτουργούσαν διάφορα μηχανήματα (κομπρεσέρ, εκσκαφείς). Στην εικόνα παρατίθεται το ηλεκτρόγραμμα και το ΗΚΓ που καταγράφηκαν τη στιγμή των εκφορτίσεων του απινιδωτή. Είναι σαφές πως ο απινιδωτής αναγνωρίζει τα παράσιτα ως κοιλιακή μαρμαρυγή και εκφορτίζεται απρόσφορα σύμφωνα με τους προγραμματισμένους αλγόριθμους. Συνολικά η ασθενής υπέστη 5 απρόσφορες εκφορτίσεις με 18, 24, και 29,5 Joules... (excerpt

Lethal Proarrhythmic Effect of Propafenone

A 67-year-old man with history of paroxysmal atrial fibrillation and known ischemic cardiomyopathy, dyslipidemia, hypertension, and chronic renal failure, was admitted via the emergency room with complaints of palpitations. Past medical history was remarkable for prior myocardial infarction in 2007 followed by percutaneous coronary intervention in the left anterior descending and right coronary arteries. Recent echocardiography showed a left ventricular ejection fraction of 30-35%. During the admission he was found to be in atrial fibrillation with a ventricular rate of 110 bpm (Fig. 1) and was given orally a dose of 450 mg of propafenone... (excerpt

Cardiology News /Recent Literature Review / Mid Quarter 2012

The ESC Congress will be held in Munich, 25-29/8/2012 TCT Meeting will take place in Miami, 22-26/10/12  HCS Meeting to be held in Athens, 1-3/11/12  AHA 2012 is scheduled for Los Angeles, 3-7/11/12 TWENTE Trial: the Resolute Zotarolimus Eluting Stents are Noninferior to Xience V Everolimus Eluting Stents in Treating “Real-World” Patients with Complex Lesions and “Off-label” Indications for DES A total of 1,391 patients were randomly assigned to zotarolimus eluting stents (ZES) (n = 697) or everolimus eluting stents (EES) (n = 694). Acute coronary syndromes were present in 52% and “off-label” feature in 77% of patients. Of the lesions, 70% were type B2/C; the post-dilation rate was very high (82%). In ZES and EES, target vessel failure (TVF) occurred in 8.2% and 8.1%, respectively (absolute risk-difference 0.1%; p (noninferiority) = 0.001). The definite-or-probable stent thrombosis rates were relatively low and similar for ZES and EES (0.9% and 1.2%, respectively, p = NS). Definite stent thrombosis rates were also low (0.58% and 0%, respectively, p = NS). In EES, probable stent thrombosis beyond day 8 was observed only in patients not adhering to dual antiplatelet therapy. The authors concluded that resolute ZES were noninferior to Xience V EES in treating “real-world” patients with a vast majority of complex lesions and “off-label” indications for drug-eluting stents (DES), which were implanted with liberal use of post-dilation (von Birgelen C et al, J Am Coll Cardiol 2012;59:1350–1361). The TARGET Study: Placement of the LV Lead to the Latest Sites of Contraction and Away from the Scar Confers the Best Response to CRT   Among 220 patients receiving cardiac resynchronization therapy (CRT), the left ventricular (LV) lead was positioned at the latest site of peak contraction (as determined by echocardiographic speckle-tracking 2-dimensional radial strain imaging) with an amplitude of >10% to signify freedom from scar (n=110, TARGET group), while in the control group (n=110) standard unguided CRT was performed. In the TARGET group, there was a greater proportion of responders at 6 months (70% vs 55%, p = 0.031) with an absolute difference in the primary endpoint (>15% reduction in LV end-systolic volume at 6 months) of 15%. Compared with controls, TARGET patients had a higher clinical response (83% vs 65%, p = 0.003) and lower rates of the combined endpoint (all-cause mortality and heart failure–related hospitalization) (p = 0.031). The authors concluded that compared with standard CRT treatment, the use of speckle-tracking echocardiography to the target LV lead placement yields significantly improved response and clinical status and lower rates of combined death and heart failure–related hospitalization (Khan FZ et al, J Am Coll Cardiol 2012;59:1509–1518)... (excerpt