Adam Ioannou

Transvenous Implantable Cardioverter‐Defibrillator (ICD) Lead Performance: A Meta‐Analysis of Observational Studies

Background Despite the widespread use of implantable cardioverter‐defibrillators (ICDs) in clinical practice, concerns exist regarding ICD lead durability. The performance of specific lead designs and factors determining this in large populations need clarification. Methods and Results The Medline, Embase, and Cochrane Collaboration databases were searched for studies including ≥2 of the most commonly implanted leads. The Mantel‐Haenszel random‐effects model was used. Seventeen studies were selected, including a total of 49 871 patients—5538 implanted with Durata (St. Jude Medical Inc), 10 605 with Endotak Reliance (Boston Scientific), 16 119 with Sprint Quattro (Medtronic Corp), 11 709 with Sprint Fidelis (Medtronic Corp), and 5900 with Riata (St. Jude Medical Inc)—with follow‐up of 136 509 lead‐years. Although the Durata lead presented a numerically higher rate, no statistically significant differences in the mean incidence of lead failure (0.29%–0.45% per year) were observed in comparison of the 3 nonrecalled leads. A higher event rate was documented with the Riata (1.0% per‐year increase) and Sprint Fidelis (>2.0% per‐year increase) leads compared with nonrecalled leads. An indication of increased incidence of Durata lead failure versus Sprint Quattro and Endotak Reliance leads was observed in 1 of 3 included studies, allowing for comparison of purely electrical lead failure, but this requires further evaluation. Conclusions Endotak Reliance (8F), Sprint Quattro (8F), and Durata (7F) leads displayed low annual incidence of failure; however, long‐term follow‐up data are still scarce. More data are needed to clarify the performance and safety of the Durata lead.

Inflammatory biomarkers in atrial fibrillation.

During the last few years, a significant number of studies have attempted to clarify the underlying mechanisms that lead to the presentation of atrial fibrillation (AF). Inflammation is a key component of the pathophysiological processes that lead to the development of AF; the amplification of inflammatory pathways triggers AF, and, in tandem, AF increases the inflammatory state. Indeed, the plasma levels of several inflammatory biomarkers are elevated in patients with AF. In addition, the levels of specific inflammatory biomarkers may provide information regarding to the AF duration. Several small studies have assessed the role of anti-inflammatory treatment in atrial fibrillation but the results have been contradictory. Large-scale studies are needed to evaluate the role of inflammation in AF and whether anti-inflammatory medications should be routinely administered to patients with AF.

Impact of an Age-Adjusted Co-morbidity Index on Survival of Patients With Heart Failure Implanted With Cardiac Resynchronization Therapy Devices

Age is an adverse prognostic factor in patients with heart failure. We aimed to assess the impact of age and noncardiac co-morbidities in the outcome of patients undergoing cardiac resynchronization therapy (CRT), and determine which of these two factors is the most important predictor of survival. The study involved a single-center retrospective assessment of 697 consecutive CRT implants during a 12-year period. Patient co-morbidity profile was assessed using the Charlson Co-morbidity Index (CCI) and the Charlson Age-Co-morbidity Index (CACI). Predictors of survival free from heart transplantation were assessed. CRT-related complications and cause of death analysis were assessed within tertiles of the CACI. During a mean follow-up of 1,813 ± 1,177 days, 347 patients (49.9%) died and 37 (5.3%) underwent heart transplantation. On multivariate Cox regression, female gender (HR = 0.78, 95% confidence interval [CI] 0.62 to 0.99, p = 0.041), estimated glomerular filtration rate (HR per ml/min = 0.99, 95% CI 0.98 to 0.99, p < 0.001), left ventricular ejection fraction (HR per % = 0.99, 95% CI 0.98 to 1.00, p = 0.022), New York Heart Association class (HR = 1.83, 95% CI 1.53 to 2.20, p < 0.001), presence of left bundle branch block (HR = 0.70, 95% CI 0.56 to 0.87, p = 0.001), and CACI tertile (HR = 1.37, 95% CI 1.18 to 1.59, p < 0.001) were independent predictors of all-cause mortality or heart transplantation. Compared with age and the CCI, the CACI was the best discriminator of all-cause mortality. Inappropriate therapies occurred less frequently in higher co-morbidity tertiles. In conclusion, patient co-morbidity profile adjusted to age impacts on mortality after CRT implantation. Use of the CACI may help refine guideline criteria to identify patients more likely to benefit from CRT.

Survey of the use of domperidone and the association with QTc prolongation in general practice

Purpose of the study Domperidone is associated with QTc prolongation, predisposing to the development of ventricular arrhythmias. In 2014, The Medicines and Healthcare Regulatory Agency (MHRA) recommended restricting its use. We assessed whether these recommendations have been implemented in a general practice. Study design We conducted a prospective study using the general practitioner (GP) computer database on patients who had at least one repeat prescription for domperidone in 12 months. Data were presented to the doctors and the survey was repeated 7 months later. Results Sixty-four patients (mean age 61.3±16.4 years) were identified who had received at least one repeat prescription of domperidone. Twenty patients were being prescribed over the recommended daily dose. Nineteen patients were coprescribed medications known to prolong the QTc interval and two CYP3A4 inhibitors. The repeat survey performed 7 months later demonstrated a 70% reduction in the number of patients prescribed domperidone to a total of 19 (three patients prescribed above the recommended dose) none of which had a history of cardiac disease or were being coprescribed drugs known to prolong the QTc interval. Conclusions Following the publication of the MHRA recommendations and presentation of our initial survey, there has been a significant reduction in the number of patients treated with domperidone and those coprescribed drugs known to prolong the QTc interval. We suggest that regular review of GP practice database should be performed to identify those patients prescribed domperidone and at risk of life-threatening arrhythmias and measures taken to use alternative pharmacological agents.

Non-valvular atrial fibrillation: impact of apixaban on patient outcomes

Atrial fibrillation is the most common arrhythmia worldwide, and carries a significantly increased risk of thromboembolic stroke. Initially, vitamin K antagonists were used as stroke prophylaxis; but more recently, a group of drugs known as novel oral anticoagulants have been developed. Apixaban belongs to this group of drugs, and is a factor Xa inhibitor that has emerged as a popular pharmacological agent worldwide. In this review, we will provide an overview of the pivotal trials in the development of apixaban, while also critically evaluating the new emerging real-world data, and discussing the effectiveness, safety, economic viability and future prospects of apixaban and how it impacts on patient outcomes in those with non-valvular atrial fibrillation.

Biomarkers Associated with Stroke Risk in Atrial Fibrillation

BACKGROUND Atrial fibrillation (AF) is associated with an increased risk of cardioembolic stroke. The risk of cardioembolism is not adequately reduced with the administration of oral anticoagulants, since a number of patients continue to experience thromboembolic events despite receiving treatment. Therefore, identification of a circulating biomarker to identify these high-risk patients would be clinically beneficial. OBJECTIVE In the present article, we aim to review the available data regarding use of biomarkers to predict cardioembolic stroke in patients with AF. METHODS We performed a thorough search of the literature in order to analyze the biomarkers identified thus far and critically evaluate their clinical significance. RESULTS A number of biomarkers have been proposed to predict cardioembolic stroke in patients with AF. Some of them are already used in the clinical practice, such as d-dimers, troponins and brain natriuretic peptide. Novel biomarkers, such as the inflammatory growth differentiation factor-15, appear to be promising, while the role of micro-RNAs and genetics appear to be useful as well. Even though these biomarkers are associated with an increased risk for thromboembolism, they cannot accurately predict future events. In light of this, the use of a scoring system, that would incorporate both circulating biomarkers and clinical factors, might be more useful. CONCLUSIONS Recent research has disclosed several biomarkers as potential predictors of cardioembolic stroke in patients with AF. However, further research is required to establish a multifactorial scoring system that will identify patients at high-risk of thromboembolism, who would benefit from more intensive treatment and monitoring.

Anticoagulation for the prevention of stroke in non-valvular AF in general practice: room for improvement.

Objective: Our aim was to assess whether the recommendations and guidelines for thromboprophylaxis in patients with atrial fibrillation (AF) have been adopted in general practice (GP). Methods: We conducted a retrospective study using the GP computer database (Hatfield, UK) on all 9400 patients to assess the quality of anticoagulation in patients with a recorded diagnosis of AF. Results: Of the 180 patients with a diagnosis of AF, 107 (59.4%) were treated with warfarin, 19 (10.6%) with a novel oral anticoagulant (NOAC), 31 (17.2%) with aspirin or clopidogrel, and 23 (12.8%) received none. Thirty-seven patients (34.6%) who were taking warfarin had a time in the therapeutic range (TTR) of less than 65%. Forty-five (27.6%) of the 163 patients who had a CHA2DS2VASc score of two or more were not prescribed a vitamin K antagonist (VKA) or a NOAC. None had a HAS-BLED greater than the CHA2DS2VASc score. Conclusion: Our study demonstrates that one in four patients with non-valvular AF, at risk of a stroke, is not being adequately treated with an oral anticoagulant in primary care. The majority were treated with warfarin, a third of which had a low TTR. A high proportion of patients are prescribed antiplatelet therapy instead. This is despite overwhelming evidence that VKAs and NOACs, and not aspirin or clopidogrel, improve outcome in patients with non-valvular AF. We suggest that a review of GP practice databases should be considered to identify patients with non-valvular AF, at risk of a disabling or fatal event, and measures taken to initiate anticoagulant therapy.

Dual-site right ventricular pacing in patients undergoing cardiac resynchronization therapy: Results of a multicenter propensity-matched analysis: PROVIDENCIA et al .

Dual‐site right ventricular pacing (Dual RV) has been proposed as an alternative for patients with heart failure undergoing cardiac resynchronization therapy (CRT) with a failure to deliver a coronary sinus (CS) lead. Only short‐term hemodynamic and echocardiographic results of Dual RV are available. We aimed to assess the long‐term results of Dual RV and its impact on survival.

Statins in Stable Angina Pectoris

BACKGROUND Stable angina is a debilitating and progressive disease caused by narrowing of the coronary arteries, which in turn affects cardiac perfusion. Statins have a well-established role, modifying symptoms and progression of the disease not only through lipid lowering, but also through pleiotropic effects. OBJECTIVE We sought to evaluate the effect of statins in stable angina pectoris Method: We performed a systematic review of the literature searching MEDLINE via Pubmed for all studies which examine the possible effects of statins in stable angina pectoris. RESULTS Statins have demonstrated favourable modification of both biochemical markers (oxidative stress, inflammatory and coagulation markers/factors) and clinical symptoms (anginal and ischemic) of the disease. These effects have been demonstrated in vitro, ex vivo and in vivo in animals and humans, independently of the lipid lowering effects. CONCLUSION With an excellent safety profile and evidence of efficacy in managing patients with stable angina, statins appear an essential part of the therapeutic armoury against atherosclerotic disease.

Ventricular Fibrillation following Varicella Zoster Myocarditis

Varicella-zoster virus (VZV) infection can rarely lead to serious cardiac complications and life-threatening arrhythmias. We present a case of a 46-year-old male patient who developed VZV myocarditis and presented with recurrent syncopal episodes followed by a cardiac arrest. He had a further collapse eight years later, and cardiac magnetic resonance imaging (MRI) demonstrated mild mid-wall basal and inferolateral wall fibrosis. He was treated with an implantable cardioverter defibrillator (ICD) and represented two years later with ICD shocks, and interrogation of the device revealed ventricular fibrillation episodes. This case demonstrates the life-threatening long-term sequelae of VZV myocarditis in adults. We suggest that VZV myocarditis should be considered in all patients who present with a syncopal event after VZV infection. In these patients, ICD implantation is a potentially life-saving procedure.