Noninvasive electrocardiographic risk factors for sudden cardiac death in dilated ca rdiomyopathy: is ambulatory electrocardiography still relevant?

Risk stratification for sudden cardiac death in dilated cardiomyopathy is a field of constant debate, and the currently proposed criteria have been widely questioned due to their low positive and negative predictive value. In this study, we conducted a systematic review of the literature utilizing the PubMed and Cochrane library platforms, in order to gain insight about dilated cardiomyopathy and its arrhythmic risk stratification utilizing noninvasive risk markers derived mainly from 24 h electrocardiographic monitoring. The obtained articles were reviewed in order to register the various electrocardiographic noninvasive risk factors used, their prevalence, and their prognostic significance in dilated cardiomyopathy. Premature ventricular complexes, nonsustained ventricular tachycardia, late potentials on Signal averaged electrocardiography, T wave alternans, heart rate variability and deceleration capacity of the heart rate, all have both some positive and negative predictive value to identify patients in higher likelihood for ventricular arrhythmias and sudden cardiac death. Corrected QT, QT dispersion, and turbulence slope-turbulence onset of heart rate have yet to establish a predictive correlation in the literature. Although ambulatory electrocardiographic monitoring is frequently used in clinical practice in DCM patients, no single risk marker can be used for the selection of patients at high-risk for malignant ventricular arrhythmic events and sudden cardiac death who could benefit from the implantation of a defibrillator. More studies are needed in order to establish a risk score or a combination of risk factors with the purpose of selecting high-risk patients for ICD implantation in the context of primary prevention.

Arrhythmic risk stratification in post-myocardial infarction patients with preserved ejection fraction: the PRESERVE EF study.

AIMS: Sudden cardiac death (SCD) annual incidence is 0.6-1% in post-myocardial infarction (MI) patients with left ventricular ejection fraction (LVEF)≥40%. No recommendations for implantable cardioverter-defibrillator (ICD) use exist in this population. METHODS AND RESULTS: We introduced a combined non-invasive/invasive risk stratification approach in post-MI ischaemia-free patients, with LVEF ≥ 40%, in a multicentre, prospective, observational cohort study. Patients with at least one positive electrocardiographic non-invasive risk factor (NIRF): premature ventricular complexes, non-sustained ventricular tachycardia, late potentials, prolonged QTc, increased T-wave alternans, reduced heart rate variability, abnormal deceleration capacity with abnormal turbulence, were referred for programmed ventricular stimulation (PVS), with ICDs offered to those inducible. The primary endpoint was the occurrence of a major arrhythmic event (MAE), namely sustained ventricular tachycardia/fibrillation, appropriate ICD activation or SCD. We screened and included 575 consecutive patients (mean age 57 years, LVEF 50.8%). Of them, 204 (35.5%) had at least one positive NIRF. Forty-one of 152 patients undergoing PVS (27-7.1% of total sample) were inducible. Thirty-seven (90.2%) of them received an ICD. Mean follow-up was 32 months and no SCDs were observed, while 9 ICDs (1.57% of total screened population) were appropriately activated. None patient without NIRFs or with NIRFs but negative PVS met the primary endpoint. The algorithm yielded the following: sensitivity 100%, specificity 93.8%, positive predictive value 22%, and negative predictive value 100%. CONCLUSION: The two-step approach of the PRESERVE EF study detects a subpopulation of post-MI patients with preserved LVEF at risk for MAEs that can be effectively addressed with an ICD. CLINICALTRIALS.GOV IDENTIFIER: NCT02124018.

Biomarkers Associated with Bleeding Risk in the Setting of Atrial Fibrillation.

BACKGROUND: Prevention of thromboembolic disease, mainly stroke, with oral anticoagulants remains a major therapeutic goal in patients with atrial fibrillation. Unfortunately, despite the high efficacy, anticoagulant therapy is associated with a significant risk of, frequently catastrophic, and hemorrhagic complications. Among different clinical and laboratory parameters related to an increased risk of bleeding, several biological markers have been recognized and various risk scores for bleeding have been developed. OBJECTIVES/METHODS: The aim of the present study is to review current evidence regarding the different biomarkers associated with raised bleeding risk in atrial fibrillation. RESULTS: Data originating from large cohorts or the recent large-scale trials of atrial fibrillation have linked numerous individual biomarkers to an increased bleeding risk. Such a relation was revealed for markers of cardiac physiology, such as troponin, BNP and NT-proBNP, markers of renal function, such as GFR and Cystatin or hepatic function, markers involving the system of coagulation, such as D-dimer and Von Willebrand factor, hematologic markers, such as low haemoglobin or low platelets, inflammatory markers, such as interleukin-6, other factors such as GDF-15 and vitamin-E and finally genetic polymorphisms. Many such biomarkers are incorporated in the bleeding risk schemata developed for the prediction of the hemorrhagic risk. CONCLUSIONS: Biomarkers were introduced in clinical practice in order to better estimate the potential risk of haemorrhage in these patients and increase the prognostic impact of clinical risk scores. In the last years this concept is gaining significant importance.

Percutaneous lead extraction and repositioning: An effective and safe therapeutic strategy for early ventricular lead perforation with dislocation both inside and outside the pericardial sac following a cardiac device implantation.

INTRODUCTION: Cardiac perforation of the right ventricle associated with pacemaker or implantable cardioverter defibrillator (ICD) leads' implantation is uncommon, albeit potentially life-threatening, complication. The aim of this study is to further identify the optimal therapeutic strategy, especially when lead dislocation has occurred outside the pericardial sac. METHODS AND RESULTS: The study population included 10 consecutive patients (six female, mean age: 66.5 years old) diagnosed with early ventricular lead perforation following a pacemaker or ICD implantation, with significant protrusion inside the pericardial sac (n = 2) or migration of the lead at the pleural space ( n = 3), the diaphragm ( n = 1), or the abdominal cavity ( n = 4), during the period 2013-2017. All patients were symptomatic; however, individuals presenting with hemodynamic instability were excluded. The outcome of the percutaneous therapeutic approach was retrospectively assessed. All patients underwent a successful removal of the perforating lead percutaneously at the electrophysiology lab, by direct traction, and repositioning in another location of the right ventricle. The operation was performed by a multidisciplinary team, under continuous hemodynamic and transesophageal echocardiographic monitoring and cardiac surgical backup. The periprocedural period was uneventful. Subjects were followed up for at least 1 year. Interestingly, all patients developed a type of postcardiac injury syndrome, successfully treated with a 3-month regimen of ibuprofen and colchicine. CONCLUSION: Percutaneous traction and repositioning of the perforating ventricular lead are effective, safe, and less invasive compared with the thoracotomy method in hemodynamically stable patients when dislocation has occurred outside the pericardial sac provided that there is no visceral organs injury.

Transvenous extraction of cardiac rhythm device leads: a report of the experience from a single referral centre in Greece.

INTRODUCTION: As rates of implanted cardiac electronic devices continue to rise, lead extraction procedures are crucial for the management of complications. The optimal method for such procedures has been constantly debated. We sought to review our experience of lead extraction using a conventional technique. METHODS: This was a retrospective study of lead extraction procedures in a major referral centre in Greece. Leads were extracted in a series of 66 consecutive patients (69% men, age range 53-90 years) who visited our centre between August 2008 and June 2012. The extraction procedure was performed in the catheterization lab with a widely used system composed of a locking stylet and sheath. RESULTS: A total of 120 leads were extracted (51 atrial, 69 ventricular) including 19 defibrillator leads and 9 coronary sinus leads. The most frequent indication for lead extraction was infective endocarditis (28 patients, 42%), followed by generator pocket infection (22 patients, 33%), and lead malfunction (16 patients, 24%). Extraction was achieved through the venous entry-site approach in all procedures. The leads were completely extracted in 65 patients (98.5%). Only one complication was recorded: perforation of the right atrium in one patient (1.5%), who eventually underwent emergency cardiac surgery with a good outcome. CONCLUSIONS: Our data confirm that a conventional mechanical technique is highly effective for successful extraction of all types of implanted cardiac electronic device leads and is associated with very limited complications.

Long-term outcome of patients with recurrent syncope of unknown cause in the absence of organic heart disease and relation to results of baseline tilt table testing.

Among 123 patients with unexplained syncope in the absence of heart disease who were followed up for 24 +/- 7 months, syncope recurred in a similar minority of them regardless of baseline tilt table testing results. An initially unsuspected cardiac or neuropsychiatric disorder was uncovered in 17 patients later on follow-up examination.