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.

Echocardiography for prediction of 6-month and late response to cardiac resynchronization therapy: implementation of stress echocardiography and comparative assessment along with widely used dyssynchrony indices.

Non-response cardiac resynchronization therapy (CRT) remains an issue, despite the refinement of selection criteria. The purpose of this study was to investigate the role of stress echocardiography along with dyssynchrony parameters for identification of CRT responders or late responders. 106 symptomatic heart failure patients were examined before, 6 months and 2-4 years after CRT implementation. Inotropic contractile reserve (ICR) and inferolateral (IL) wall viability were studied by stress echocardiography. Dyssynchrony was assessed by: (1) Septal to posterior wall motion delay (SPWMD) by m-mode. (2) Septal to lateral wall delay (SLD) by TDI. (3) Interventricular mechanical delay (IVMD) by pulsed wave Doppler for (4) difference in time to peak circumferential strain (TmaxCS) by speckle tracking. (5) Apical rocking (ApR) and septal flash (SF) by visual assessment. At 6 months there were 54 responders, with 12 additional late responders. TmaxCS had the greatest predictive value with an area under curve (AUC) of 0.835, followed by the presence of both ICR and viability of IL wall (AUC 0.799), m-mode (AUC = 0.775) and presence of either ApR or SF (AUC = 0.772). Predictive ability of ApR and of ICR is augmented if late responders are also included. Performance of dyssynchrony parameters is enhanced, in patients with both ICR and IL wall viability. Stress echocardiography and dyssynchrony parameters are simple and reliable predictors of 6-month and late CRT response. A stepwise approach with an initial assessment of ICR and viability and, if positive, further dyssynchrony analysis, could assist decision making.

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.

Renal resistive index in hypertensive patients.

Spectral Doppler ultrasonography provides the evaluation of renal resistive index (RRI), a noninvasive and reproducible measure to investigate arterial compliance and/or resistance. RRI seems to possess an important role in the evaluation of diverse cases of secondary hypertension. In essential hypertension, RRI is associated with subclinical markers of target organ damage and reflects renal disease progression beyond albuminuria and creatinine clearance. Also, RRI can estimate cardiovascular and renal risk. The evaluation of RRI may also help the therapeutic decisions. Given its simple assessment, RRI emerges as a simple method and a "multifunctional" tool that could help on the cardiovascular risk evaluation of the hypertensive patient.

Programmed ventricular stimulation predicts arrhythmic events and survival in hypertrophic cardiomyopathy.

BACKGROUND: Sudden cardiac death (SCD) risk stratification in hypertrophic cardiomyopathy (HCM) in the context of primary prevention remains suboptimal. The purpose of this study was to examine the additional contribution of programmed ventricular stimulation (PVS) on established risk assessment. METHODS: Two-hundred-and-three consecutive patients with diagnosed HCM and ≥1 noninvasive risk factors were prospectively enrolled over 19years. Patients were risk stratified, submitted to PVS and received an implantable cardioverter-defibrillator (ICD) according to then-current American Heart Association (AHA) guidelines and inducibility. Participants were prospectively followed-up for primary endpoint occurrence (appropriate ICD therapy or SCD). Contemporary (2015) AHA and European Society of Cardiology (ESC) guidelines were retrospectively assessed. RESULTS: During a median follow-up period of 60months the primary endpoint occurred in 20 patients, 19 of whom were inducible and received an ICD. Overall, 79 patients (38.9%) were inducible and 92 patients (45.3%) received an ICD (PVS sensitivity=95%, specificity=67.2%, positive predictive value=24%, negative predictive value=99.2%). AHA and ESC guidelines application misclassified 3 and 9 primary endpoint-meeting patients, respectively. Inducibility was the most important determinant of event-free survival in multivariate Cox regression (hazard ratio=33.3). A combined approach of ESC score≥6% or AHA indication for ICD with PVS inducibility yielded absolute sensitivity and negative predictive value, the former at a more cost-effective and specific way. CONCLUSIONS: Inducibility at PVS predicts SCD or appropriate device therapy in HCM. Non-inducibility is associated with prolonged event-free survival, while the procedure was proven safe. Reintegration of PVS into established risk stratification models in HCM may improve patient assessment.

Heart failure study of multipoint pacing effects on ventriculoarterial coupling: Rationale and design of the HUMVEE trial.

Cardiac resynchronization therapy (CRT) is an established therapy for symptomatic heart failure (HF). Unfortunately, many recipients remain nonresponders. Studies have revealed the potential role of multipoint pacing (MPP) in improving response and outcomes. The aim of this study is to compare the effects of MPP against those of standard biventricular pacing (BVP) on (i) ventriculoarterial coupling (VAC) and energy efficiency of the failing heart, (ii) diastolic function, (iii) quality of life, and (iv) NT-proBNP levels and glomerular filtration rate (GFR) during a follow-up of 13 months. HUMVEE is a single-center, prospective, observational, crossover cohort study. Seventy-six patients with BVP indication will be implanted with a system able to deliver both pacing modes. BVP will be activated at implantation and optimized 1 month after. At 6 months postoptimization MPP will be activated and optimized. Optimization will be performed based on stroke volume maximization, as assessed by ultrasound. Laboratory measurements (GFR and NT-proBNP) and echocardiographic studies (VAC calculation, strain rate, diastolic function) will be performed at implantation, 6 months post-BVP optimization and at the end of 13 months of follow-up (6 months post-MPP optimization). Potential reduction in arrhythmogenesis by MPP will also be assessed. MPP is a pacing modality with the potential to improve HF patients' outcomes. The HUMVEE trial will attempt to associate any potential added beneficial effects of MPP over standard BVP with alterations in VAC and energy efficiency of the heart, thus uncovering a novel mechanistic link between MPP and improved outcomes in HF.

Leadless Cardiac Pacemakers: Current status of a modern approach in pacing.

Since the first transvenous pacemaker implantation, which took place 50 years ago, important progress has been achieved in pacing technology. Consequently, at present, more than 700,000 pacemakers are implanted annually worldwide. However, conventional pacemakers' implantation has a non-negligible risk of periprocedural and long-term complications associated with the transvenous leads and pacemaker pocket. Recently, leadless pacing systems have emerged as a therapeutic alternative to conventional pacing systems that provide therapy for patients with bradyarrhythmias, while eliminating potential transvenous lead- and pacemaker pocket-related complications. Initial studies have demonstrated favorable efficacy and safety of currently developed leadless pacing systems, compared to transvenous pacemakers. In the present paper, we review the current evidence and highlight the advantages and disadvantages of this novel technology. New technological advances may allow the next generation of leadless pacemakers to further expand, thereby offering a wireless cardiac pacing in future.

The subcutaneous ICD as an alternative to the conventional ICD system: Initial experience in Greece and a review of the literature.

The introduction of an implantable cardioverter defibrillator (ICD) in clinical practice has revolutionized our therapeutic approach for both primary and secondary prevention of sudden cardiac death (SCD), as it has proven to be superior to medical therapy in treating potentially life-threatening ventricular arrhythmias and has resulted in reduced mortality rates. However, implantation of a conventional ICD carries a non-negligible risk of periprocedural and long-term complications associated with the transvenous ICD leads. The entirely subcutaneous implantable cardioverter defibrillator (S-ICD) has recently emerged as a therapeutic alternative to the conventional ICD for patients with various cardiopathies and who are at high risk of SCD. The main advantage is the avoidance of vascular access and thus avoidance of complications associated with transvenous leads. Patients without pacing indications, such as bradycardia, a need for antitachycardia pacing or cardiac resynchronization, as well as those at higher risk of complications from transvenous lead implantation are perfect candidates for this novel technology. The subcutaneous ICD has proven to be equally safe and effective compared to transvenous ICD systems in early clinical trials. Further technical improvements of the system will likely lead to the expansion of indications and widespread use of this technology. In the present review, we discuss the indications for this system, summarize early clinical experiences and highlight the advantages and disadvantages of this novel technology. In addition, we present the first two cases of subcutaneous cardioverter defibrillator system implantation in Greece.

Sustained ventricular tachycardia as a first manifestation of hypertrophic cardiomyopathy with mid-ventricular obstruction and apical aneurysm in an elderly female patient.

Sustained ventricular tachycardia complicating left ventricular apical aneurysms has been reported previously solely in middle-aged patients with hypertrophic cardiomyopathy and mid-cavity obstruction. We report a case of an elderly female patient who presented with incessant ventricular tachycardia as the first clinical manifestation of hypertrophic cardiomyopathy with mid-ventricular obstruction and apical aneurysm.

Subclinical Organ Damage in White-Coat Hypertension: The Possible Role of Cystatin C.

The authors investigated the relationship of white-coat hypertension (WCH) with subclinical organ damage and potential relevant mechanisms. A total of 386 untreated patients were enrolled and divided into 204 patients with WCH and 183 with normotension. Flow-mediated dilation (FMD), pulse wave velocity (PWV), intima-media thickness, left ventricular mass index (LVMI), and cystatin C levels were measured. All tests were two-sided, and a P value <.05 was considered statistically significant. The WCH group exhibited higher LVMI and PWV values, decreased E/A ratio and FMD values, and increased prevalence for left ventricular hypertrophy compared with controls (P<.001 for all). Cystatin C was significantly higher in the WCH group compared with controls (P=.035) and was positively associated with LVMI (P<.05 for both). The presence of WCH is associated with more pronounced subclinical organ damage compared with normotension. Cystatin C may play a significant role and therefore warrants further investigation.

Prevalence of late potentials on signal-averaged ECG in patients with psychiatric disorders.

BACKGROUND: Sudden cardiac death (SCD) occurs three times more often in psychiatric patients than in the general population. QRS fragmentation (QRSfr) and signal-averaged electrocardiography (SAECG) are simple, inexpensive, readily available tools for detecting the presence of abnormal depolarization and late potentials (LPs) in these patients, a result of either the underlying disease or treatment. METHODS: Frequency of LP detection by SAECG and QRSfr was studied in 52 psychiatric patients and compared with 30 healthy (without known structural heart disease or occurrence of ventricular arrhythmia) controls. Patients were then prospectively followed up and incidence of SCD was recorded. RESULTS: LP prevalence was significantly higher in patients than in controls (16/52-31% vs 2/30-7%, p=0.012), while QRSfr was similar between these two groups (p=0.09). Of the LP presence criteria, the root mean square value at terminal 40msec of the QRS (RMS40) was significantly lower in patients (32µV, SD=19µV, vs 46µV, SD=32µV, p=0.015). Among patients, no differences were noted between the LP positive and negative groups regarding age, sex, number of medications, class of antipsychotics and defined daily doses. Mean follow-up was 46months (SD=11) and during it 3 patients suffered SCD. Although 2 SCD victims had both LPs and QRSfr concurrently present, neither of them, nor their simultaneous presence could definitely account for the events. CONCLUSIONS: LP prevalence in psychiatric patients was significantly higher than in controls. SAECG performance was feasible in all cases and constitutes a readily available tool for assessing myocardial electrophysiological alterations in this patient group.

Outcomes of Same Day Pacemaker Implantation after TAVI.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is often associated with conduction disturbances, followed by permanent pacemaker (PPM) implantation. Because of the potential reversibility of these conduction disorders, controversy exists regarding the right timing of PPM implantation. TAVI is routinely performed under dual-antiplatelet and antithrombotic therapy, which poses an additional hemorrhagic risk on a same-day procedure. The aim of the present study was to evaluate the safety and effectiveness of same-day PPM implantation in patients undergoing TAVI. METHODS: Consecutive patients undergoing TAVI with Medtronic Corevalve bioprosthesis (Medtronic Inc., Minneapolis, MN, USA) in a tertiary center were divided into two study groups. Group A included patients undergoing PPM implantation the same day with TAVI, and Group B patients were implanted with a PPM later after TAVI and before hospital discharge. The two study groups were compared for all complications associated with PPM implantation. RESULTS: In total, 168 patients were included in the study. PPM was implanted in 65 patients (38.7%). In 23 patients, a PPM was implanted the same day with TAVI (Group A) and in 42 patients PPM implantation was postponed at least 1 day (Group B). Cephalic vein was the access used for the leads in the majority of cases. There was only one case of pneumothorax in Group B. There were no differences in the incidence of pocket hematomas between the study groups. CONCLUSIONS: Same-day PPM implantation after TAVI is safe and feasible. Strategies reducing pocket hematomas are essential in such patients of high hemorrhagic risk.

Left Ventricular Pacing through Coronary Sinus Is Feasible and Safe for Patients with Prior Tricuspid Valve Intervention.

BACKGROUND: In the presence of tricuspid valve intervention, right ventricular lead implantation is associated with the potential risk of tricuspid valve malfunction leading to a tricuspid regurgitation. Few cases have been reported with successful left ventricular pacing via the coronary sinus (CS) after tricuspid valve replacement or repair. In this retrospective study, we present the long-term clinical outcomes of 17 patients who underwent CS lead implantation and left ventricular pacing. METHODS: Seventeen consecutive patients referred to our institution with an indication of postprocedural pacemaker (PM) implantation after tricuspid valve intervention were retrospectively included in the study. The indication for device implantation in all patients was atrial fibrillation with a symptomatic pause ≥ 3.0 seconds. Thus, all devices implanted were ventricular rate responsive (VVIR). RESULTS: All device implantations were successful and uncomplicated. Mean operation time was 60 ± 8 minutes. Mean fluoroscopy time was 8.3 ± 2.1 minutes. Mean R-wave sensing was 7.5 ± 2.0 mV with a mean slew rate of 2.2 V/s. A mean pacing threshold of 1.9 ± 0.3 V/0.4 ms was accepted as patients were not PM-dependent. The pacing impedance was 743.5 ± 109.71 Ohm. At 2-year follow-up, pacing sensing, threshold, and impedance values were unchanged and no lead dislodgement has been noted. CONCLUSIONS: In patients with tricuspid valve intervention, left ventricular pacing might be the treatment of choice for permanent ventricular pacing, with all the advantages of the endovenous route as a minimally invasive approach.