Prognostic role of non-sustained ventricular tachycardia detected with remote interrogation in a pacemaker population.

BACKGROUND: Non-sustained ventricular tachycardia (NSVT) can occur asymptomatically and can be incidentally detected in the internal records of pacemakers (PM). The clinical value of NSVT in the population of PM patients is still uncertain.Our aim was to assess the prevalence of NSVT detected by remote PM control, to describe the clinical and demographic characteristics of patients with NSVT, and to assess the prognostic significance of NSVT in terms of both overall and cardiovascular mortality. METHODS: Consecutive patients followed with PM remote interrogations from September 2010 to December 2015 were included. The transmissions pertaining to the first 12 months of remote control were analysed and the patients were divided by those presenting NSVT and those without NSVT. The two groups were compared in terms of total mortality and cardiovascular mortality based on the administrative data provided by the regional administration of the Italian National Health System. RESULTS: The prevalence of NSVT in 408 patients (62% males, mean age 75.6; SD 10.6 years old) was 21% in a year. During a mean follow-up duration of 44 months, NSVT did not emerge as independently associated with overall mortality, but was associated with cardiovascular mortality in a competing risk regression model with older age, male gender, diabetes, chronic renal insufficiency, ischemic cardiomyopathy and chronic obstructive pulmonary disease. CONCLUSIONS: We show that NSVT episodes recorded by remote control in a PM population are independently associated with cardiovascular mortality with possible implications for risk stratification and therapeutic options.

Improving atrial fibrillation detection in patients with implantable cardiac devices by means of a remote monitoring and management application.

BACKGROUND: Atrial fibrillation (AF) is common in patients with cardiac implantable electronic devices (CIED) and has been associated with an increased stroke risk. The aim of our project was to assess the clinical value of a web-based application, Discovery Link AFinder, in improving AF detection in CIED patients. METHODS AND RESULTS: Seven Italian hospitals performed an observational study consisting of four phases. During phase 1, expert nurses and cardiologists prospectively followed-up CIED patients via in-hospital examinations and remote monitoring, and classified clinically relevant events, particularly AF occurrence. During phase 2, Discovery Link AFinder was exploited to identify patients who had suffered AF in the previous 12 months through the systematic scanning of device data remote transmissions. Phases 3 and 4 were repetitions of phases 1 and 2, respectively, and were implemented 6 months after the previous phases. A total of 472 consecutive patients were included in phase 1; AF occurred in 170 patients, 61 of whom were identified as new AF patients. Evidence of AF during this phase prompted prescription of oral anticoagulation (OAC) therapy in 30 patients. In phase 2, AFinder uncovered new AF, unidentified in phase 1, in 54 patients and prompted implementation of OAC therapy in 11 patients. During phase 3, 30 new AF patients were identified by means of remote monitoring, while during phase 4, a further three AF patients were identified by AFinder only. CONCLUSIONS: The AFinder web-based software, applied on top of standard in-hospital and remote monitoring, improved AF detection and enabled OAC treatment to be undertaken.

Pulmonary fluid overload monitoring in heart failure patients with single and dual chamber defibrillators.

AIMS: Heart failure has a relevant healthcare impact. Monitoring of pulmonary fluid overload (PFO), measured by intrathoracic impedance, has been proposed to alert to heart failure worsening before symptoms become patent. The aim of our research was to evaluate whether PFO diagnostics reduce heart failure hospitalizations in heart failure patients receiving single-chamber or dual-chamber implantable cardioverter-defibrillator (ICD) for primary prevention of sudden death. METHODS: Twenty-five Italian cardiological centers prospectively followed 221 ICD patients (86% men, 66 ±â€Š11 years, 79% New York Heart Association II and left ventricular ejection fraction 28 ±â€Š5%), of whom 123 received an ICD with PFO monitoring (diagnostics group) and 98 an ICD without such a diagnostics (control group). The association of each patient to a group was assigned a priori, independently of patients' characteristics but based on regional device allocation policies. RESULTS: Patient clinical characteristics and observation period were similar between groups. In a mean follow-up of 17 ±â€Š11 months, heart failure hospitalizations or emergency-room admissions occurred in eight (7%) patients of the diagnostics group and in 16 of the control group (16%; P = 0.02), with an incidence, measured by Kaplan-Meier analysis, of 23% at 2 years and 34% at 3 years in patients of the control group compared with 8% at 2 and 3 years in patients of the diagnostics group (Log rank test P = 0.044). CONCLUSION: Our data show that in heart failure patients receiving single-chamber or dual-chamber ICD, the use of intrathoracic impedance monitoring is associated with a significant reduction of heart failure hospitalizations. Our results support the hypothesis that PFO diagnostics improve the likelihood of timely detection of heart failure worsening.

Clinical outcomes in patients with implantable cardioverter defibrillators and Sprint Fidelis leads.

OBJECTIVE: The performances of implantable cardioverter defibrillators and leads are important issues for healthcare providers and patients. In 2007 Sprint Fidelis leads were found to be associated with an increased failure rate and so the purpose of the study was to evaluate long-term mortality and clinical outcomes in patients implanted with Sprint Fidelis leads compared with Sprint Quattro leads. DESIGN, SETTING, PATIENTS: 508 patients with Sprint Fidelis leads and 468 with Sprint Quattro leads were prospectively followed in 12 Italian cardiology centres. MAIN OUTCOME MEASURES: Information on hospitalisations and other clinical events were collected during scheduled and unscheduled hospital visits. Deaths were identified from medical records or via phone contacts with patients' family members or through the National Office of Vital Statistics. RESULTS: Over a mean follow-up of 27±18 months 141 deaths occurred in the overall population. No death was observed in patients with diagnosed failing lead. Kaplan-Meier patient survival differed between the two lead groups (80±2% in Fidelis leads vs 70±4% in the Sprint Quattro leads at 4 years, p=0.002). Multivariate analyses showed that mortality was neither associated with lead type nor with diagnosed failed lead. The annual rate of lead failure was 1.8% patient-year for Fidelis leads and 0.2% for the Sprint Quattro leads. CONCLUSIONS: In our multicentre research, the clinical outcomes of patients with Fidelis leads differed from those of patients with Sprint Quattro leads. Nevertheless, neither mortality nor the combined endpoint of mortality and heart failure hospitalisations was associated with the lead type. http://clinicaltrials.gov/ct2/show/NCT01007474.

Remote follow-up of pacemakers in a selected population of debilitated elderly patients.

AIMS: The majority of patients with pacemakers are very elderly, many being >85-years old. They often suffer from serious illnesses and have great difficulty in walking. The aim of our study was to compare remote pacemaker monitoring with in-home checks of pacemakers, in terms of applicability, efficacy, and cost in a selected population of debilitated elderly patients. METHODS AND RESULTS: We selected 72 subjects (mean age 87 ± 8 years) among elderly debilitated patients with Medtronic pacemakers, compatible with the Carelink(®) remote monitoring system (13 patients with DDD pacemaker; 59 patients with single-lead VDD pacemaker). Remote follow-up was compared with in-home checks performed by nurses in 326 patients in similar clinical conditions. A total of 190 transmissions were received by remote monitoring (mean transmissions per month: 7.0; mean per patient: 2.6; range 1-6) during 27 months of follow-up. In this period, seven pacemakers were replaced owing to battery exhaustion, after a mean of 6.7 years from implantation. The occurrence of atrial or ventricular high-rate episodes was reported in 98 transmissions (53%). Nineteen patients died (annual mortality: 11.7%). On comparing the costs borne by the hospital for in-home checks, both for medical personnel and transportation, the estimated average saving was €32 per year per patient. CONCLUSION: Our study shows that the remote follow-up of pacemakers is a reliable, effective, and cost-saving procedure in elderly, debilitated patients. Moreover, remote controls provided an accurate and early diagnosis of arrhythmia occurrence.

Intrathoracic impedance and ultrasound lung comets in heart failure deterioration monitoring.

PURPOSE: Echographic examination of the lung surface may reveal multiple ultrasound lung comets (ULCs) originating from water-thickened interlobular septa. These images were demonstrated to be useful for noninvasive assessment of interstitial pulmonary edema. Similarly, the correlation between implantable defibrillator-measured intrathoracic impedance and pulmonary capillary wedge pressure (PCWP) was demonstrated in heart failure (HF) patients. The aims of this analysis were to assess the agreement between defibrillator-detected impedance decrease and the presence of ULCs, as well as to compare the performance of the impedance-detection algorithm and the ULCs assessment in predicting HF worsening. METHODS AND RESULTS: We studied 23 HF patients implanted with a defibrillator capable of intrathoracic impedance measurement and alerting for fluid accumulation diagnosis. At regular follow-up and at visits for HF decompensation or device alert, clinical status was assessed, chest ultrasound was performed, and PCWP was noninvasively estimated with Doppler echocardiography. During 23 ± 11 months of follow-up, 45 paired assessments of defibrillator-measured intrathoracic impedance and ULCs were performed. The number of ULCs resulted significantly correlated to the paired PCWP estimations (r = 0.917, P < 0.001) and to the impedance fluid index (r = 0.669, P < 0.001). During follow-up, 12 episodes of HF decompensation were reported in 12 patients. The impedance alert detected clinical HF deterioration with 92% sensitivity and 69% positive predictive value. The presence of ≥5 ULCs showed 83% sensitivity and 91% positive predictive value. CONCLUSIONS: These data demonstrate the correlation between intrathoracic impedance and the number of ULCs at chest ultrasound, and a good agreement between the defibrillator warning for fluid index and the detection of multiple ULCs.

ICD and neuromodulation devices: is peaceful coexistence possible?

AIM: The aim of this study was to investigate the potential cross-talk between implantable cardioverter defibrillator device (ICD) and implantable neuromodulation device (IND) during the implantation procedure and the ventricular fibrillation induction test and in daily life. METHODS: We present two cases of patients with an IND who underwent ICD implantation and one case of a patient implanted with a biventricular ICD who received an IND 6 months later. Two of these patients had a spinal cord stimulator (SCS), while the other had a sacral neuromodulator. RESULTS: No cross-talk was recorded in the patient with the sacral neuromodulator and the ICD. Temporary damage to one of the SCSs was observed after multiple ICD shocks. CONCLUSIONS: When implanted contemporarily with sacral or spinal neurostimulators, cardiac devices appear to be safe, as confirmed by the appropriate detection and interruption of arrhythmic episodes. On the other hand, neuromodulation devices could be temporarily or permanently damaged by multiple ICD discharges. It is recommended that the neurostimulator be interrogated after an ICD shock, in order to check the state of the device.

Safety and performance of a system specifically designed for selective site pacing.

INTRODUCTION: In the right ventricle, selective site pacing (SSP) has been shown to avoid detrimental hemodynamic effects induced by right ventricular apical pacing and, in the right atrium, to prevent the onset of atrial fibrillation and to slow down disease progression. The purpose of our multicenter observational study was to describe the use of a transvenous 4-French catheter-delivered lead for SSP in the clinical practice of a large number of centers. METHODS: We enrolled 574 patients in whom an implantable device was indicated. In all patients, SSP was achieved by using the Select Secure System™ (Medtronic Inc., Minneapolis, MN, USA). RESULTS: In 570 patients, the lead was successfully implanted. In 125 patients, atrial SSP was performed: in 75 (60%) the lead was placed in the interatrial septum, in 31 (25%) in the coronary sinus ostium, and in 19 (15%) in the Bachman bundle. Ventricular SSP was undertaken in 138 patients: in 105 (76%) the high septal right ventricular outflow tract (RVOT) position was paced, in seven (5%) the high free-wall RVOT, in 25 (18%) the low septal RVOT, and in one (1%) the low free-wall RVOT. In the remaining 307 patients, the His zone was paced: in 87 (28%) patients, direct His-bundle pacing and in 220 (72%) patients para-hisian pacing was achieved. Adequate pacing parameters and a lead-related complication rate of 2.6% were recorded during a follow-up of 20 ± 10 months. CONCLUSIONS: Our results demonstrated that many sites, in the right atrium, in the right ventricle, and in His-bundle region, can be paced using the Select Secure System™.

Intrathoracic impedance and pulmonary wedge pressure for the detection of heart failure deterioration.

AIMS: The aims of this analysis were to assess the agreement between implantable defibrillator (ICD)-measured intrathoracic impedance and pulmonary capillary wedge pressure (PCWP) collected during long-term follow-up, as well as to evaluate whether PCWP measures may improve the performance of the impedance detection algorithm in predicting heart failure (HF) worsening. METHODS AND RESULTS: We studied 23 HF patients implanted with an ICD capable of intrathoracic impedance measurement and alerting for fluid accumulation diagnosis. At regular follow-up and at visits for HF decompensation or device alert, clinical status was assessed and PCWP was non-invasively estimated with a validated echo-Doppler method. During 23 +/- 11 months, 45 paired assessments of impedance and PCWP were performed. The Kappa analysis revealed good agreement between impedance and PCWP (k = 0.701, SE 0.113, P < 0.001). Moreover, PCWP estimations and the paired values of the impedance fluid index resulted significantly correlated (r = 0.677, P < 0.001). The impedance-alert detected clinical HF deterioration with 92% sensitivity and 69% positive predictive value. The combined finding of decreased impedance and increased PCWP resulted in enhanced positive predictive value (92%) and no change in sensitivity (92%). CONCLUSION: These data confirm the inverse correlation between impedance and PCWP at long-term follow-up and suggest the potential clinical value of a combined impedance and pressure assessment for the improved detection of HF deterioration.

Selective-site pacing in paediatric patients: a new application of the Select Secure system.

AIMS: The aim of this study was to evaluate the feasibility and reliability of selective-site pacing by means of a new lead system in a paediatric population. This lead system is composed of a 4.1 Fr, active-fixation lead and a steerable catheter that allows easy positioning in selective sites. METHODS AND RESULTS: Thirty young patients (mean age 9.0 +/- 4.5 years, range 2-16 years) received a single- (10) or dual- (20) chamber pacemaker. The 3830 lead was implanted successfully in the targeted chambers in all patients. The selective RV sites of pacing in 26 of the patients were: 18 mid-septum, 5 outflow tract, 1 low-septum, and 2 LEVO-RV-Apex. In all patients, an intracardiac loop was left in order to avoid stretching of the lead with growth. Mean follow-up duration was 11 +/- 10 months. Atrial sensing and pacing thresholds were 3.2 +/- 1.7 mV and 0.8 +/- 0.6 V at 0.5 ms at implantation and 3.4 +/- 2.1 mV and 0.6 +/- 0.3 V at 0.5 ms at follow-up. Ventricular sensing and pacing thresholds were 12.1 +/- 4.9 and 0.7 +/- 0.4 V at 0.5 ms on implantation and 12.7 +/- 6.1 mV and 0.8 +/- 0.5 V at 0.5 ms at follow-up (P = NS). No adverse events were reported. CONCLUSION: Select Secure is a promising system for selective-site pacing in children.