Salem Kacet

Systemic Infection Related to Endocarditis on Pacemaker Leads Clinical Presentation and Management

BACKGROUND Endocarditis related to pacemaker (PM)-lead infection is a rare but serious complication of permanent transvenous pacing. To determine in which situations the diagnosis should be evoked and to determine optimal management, we reviewed our experience with endocarditis related to PM-lead infection. METHODS AND RESULTS Fifty-two patients were admitted for endocarditis related to PM-lead infection. The presentation was acute in 14 patients, with onset of symptoms in the first 6 weeks after the last procedure on the implant site, and chronic in 38 patients. Fever occurred in 86.5%. Clinical and/or radiological evidences of pulmonary involvement were observed in 38.4%. Pulmonary scintigraphy disclosed pulmonary infarcts in 31.2%. Local complications were found in 51.9%. Elevated C-reactive protein was found in 96.2%. A germ was isolated in 88.4% of patients and was a Staphylococcus in 93.5%. Transthoracic echocardiography demonstrated vegetations in only 23% of patients, whereas transesophageal echocardiography disclosed abnormal appearances on the PM lead in 94%. We systematically tried to ablate all the material. Two techniques were used: percutaneous ablation or surgical removal during extracorporeal circulation. All patients were treated with antibiotics after removal of the infected material. Two patients died before lead removal and 2 after surgical removal; the predischarge mortality was 7.6%, and the overall mortality was 26.9% after a follow-up of 20.1+/-13 months. CONCLUSIONS The diagnosis of endocarditis related to PM-lead infection should be suspected in the presence of fever, complications, or pulmonary lesions after PM insertion. Transesophageal echocardiography should be performed to look for vegetations. Staphylococci are involved in the majority of these infections. The endocardial system must be entirely removed and appropriate antibiotic therapy pursued for 6 weeks.

Risk Factors Related to Infections of Implanted Pacemakers and Cardioverter-Defibrillators Results of a Large Prospective Study

Background— The Prospective Evaluation of Pacemaker Lead Endocarditis study is a multicenter, prospective survey of the incidence and risk factors of infectious complications after implantation of pacemakers and cardioverter-defibrillators. Methods and Results— Between January 1, 2000, and December 31, 2000, 6319 consecutive recipients of implantable systems were enrolled at 44 medical centers and followed up for 12 months. All infectious complications were recorded, and their occurrence was related to the baseline demographic, clinical, and procedural characteristics. Among 5866 pacing systems, 3789 included 2 and 117 had >2 leads; among 453 implantable cardioverter-defibrillators, 178 were dual-lead systems. A total of 4461 de novo implantations occurred and 1858 pulse generator or lead replacements. Reinterventions were performed before hospital discharge in 101 patients. Single- and multiple-variable logistic regression analyses were performed to identify risk factors; adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated. At 12 months, device-related infections were reported in 42 patients (0.68%; 95% CI, 0.47 to 0.89). The occurrence of infection was positively correlated with fever within 24 hours before the implantation procedure (aOR, 5.83; 95% CI, 2.00 to 16.98), use of temporary pacing before the implantation procedure (aOR, 2.46; 95% CI, 1.09 to 5.13), and early reinterventions (aOR, 15.04; 95% CI, 6.7 to 33.73). Implantation of a new system (aOR, 0.46; 95% CI, 0.24 to 0.87) and antibiotic prophylaxis (aOR, 0.4; 95% CI, 0.18 to 0.86) were negatively correlated with risk of infection. Conclusions— This study identified several factors of risk of device infection and confirmed the efficacy of antibiotic prophylaxis in recipients of new or replacement pacemakers or implantable cardioverter-defibrillators.

Biventricular pacing in patients with congestive heart failure: two prospective randomized trials

Epidemiologic studies suggest that 20-30% of patients diagnosed with symptomatic congestive heart failure (CHF) have intraventricular conduction disorders characterized by a discoordinate contraction pattern and wide QRS. Biventricular pacing is an emerging therapy allowing simultaneous electrical stimulation of the right and left ventricles with the use of an implantable pacing system. The aim of this article is to describe 2 prospective randomized multicenter trials examining the effects of biventricular pacing on functional capacity, quality of life, and hemodynamic status in patients with dilated cardiomyopathy and intraventricular delay. The VIGOR CHF Trial is designed to assess functional and symptomatic improvement in heart failure patients with biventricular pacing and without a concomitant indication for conventional bradycardia pacemaker therapy. To assess for potential placebo effects, patients are randomized to receive either biventricular pacemaker therapy or no pacing therapy for the first 6 weeks, after which both groups receive pacing therapy. The VENTAK CHF trial uses an implantable cardioverter defibrillator system (ICD) designed to provide chronic biventricular pacing therapy in addition to treating ventricular tachyarrhythmias. All patients receive conventional ICD and CHF therapy throughout the study and are randomized in a 2-period crossover design to receive either no pacing or biventricular pacing for 3-month intervals. Patient enrollment in both studies is ongoing, with a closed analysis. The unique designs of these trials provide the opportunity to study this therapy in high-risk patients who have been optimally treated for heart failure.

Critical Analysis of Dual-Chamber Implantable Cardioverter-Defibrillator Arrhythmia Detection

Background—One of the perceived benefits of dual-chamber implantable cardioverter-defibrillators (ICDs) is the reduction in inappropriate therapy due to new detection algorithms. It was the purpose of the present investigation to propose methods to minimize bias during such comparisons and to report the arrhythmia detection clinical results of the PR Logic dual-chamber detection algorithm in the GEM DR ICD in the context of these methods. Methods and Results—Between November 1997 and October 1998, 933 patients received the GEM DR ICD in this prospective multicenter study. A total of 4856 sustained arrhythmia episodes (n=311) with stored electrogram and marker channel were classified by the investigators; 3488 episodes (n=232) were ventricular tachycardia (VT)/ventricular fibrillation (VF), and 1368 episodes (n=149) were supraventricular tachycardia (SVT). The overall detection results were corrected for multiple episodes within a patient with the generalized estimating equations (GEE) method with an excha...

Local symptoms at the site of pacemaker implantation indicate latent systemic infection

Background: To determine whether local complications at the site of pacemaker implantation indicate infection of the intravascular part of the lead as well as of the pacemaker pocket. Methods: 105 patients admitted for local inflammatory findings, impending pacemaker or lead exteriorisation, frank pacemaker or lead exteriorisation, or overt infection were studied prospectively. After systematic lead extraction, the initial clinical presentation was related to the results of lead cultures. Results: Regardless of the initial presentation, the intravascular parts of the leads gave positive cultures in 79.3% of patients. Additionally, 91.6% of the cultures of the extravascular lead segments were positive, in contrast to 38.1% positivity for wound swab cultures. No clinical observations or laboratory investigations permitted identification of patients with negative lead cultures. In a subgroup of 50 patients with manifestations strictly limited to the pacemaker implantation site, cultures of intravascular lead segments were positive in 72%. Infection recurred in 4/8 patients without complete lead body extraction (50%) v 1/97 patients (1.0%) whose leads were totally extracted (p < 0.001). Conclusions: Local complications at the site of pacemaker implantation are usually associated with infection of the intravascular part of the leads, with a risk of progressing to systemic infection. Such local symptoms should prompt the extraction of leads even in the absence of other infectious manifestations.

A randomized study of remote follow-up of implantable cardioverter defibrillators: safety and efficacy report of the ECOST trial

Aims The ECOST trial examined prospectively the long-term safety and effectiveness of home monitoring (HM) of implantable cardioverter defibrillators (ICD). Methods and results The trials primary objective was to randomly compare the proportions of patients experiencing ≥1 major adverse event (MAE), including deaths from all causes, and cardiovascular, procedure-related, and device-related MAE associated with HM (active group) vs. ambulatory follow-ups (control group) in a sample of 433 patients. The 221 patients assigned to the active group were seen once a year, unless HM reported an ICD dysfunction or a clinical event requiring an ambulatory visit, while the 212 patients in the control group underwent ambulatory visits every 6 months. The characteristics of the study groups were similar. Over a follow-up of 24.2 months, 38.5% of patients in the active and 41.5% in the control group experienced ≥1 MAE (P < 0.05 for non-inferiority). The overall number of shocks delivered was significantly lower in the active (n = 193) than in the control (n = 657) group (P < 0.05) and the proportion of patients who received inappropriate shocks was 52% lower in the active (n = 11) than in the control (n = 22) group (P < 0.05). At the end of the follow-up, the battery longevity was longer in the active group because of a lower number of capacitor charges (499 vs. 2081). Conclusion Our observations indicate that long-term HM of ICD is at least as safe as standard ambulatory follow-ups with respect to a broad spectrum of MAE. It also lowered significantly the number of appropriate and inappropriate shocks delivered, and spared the device battery. Clinical trials registration NCT00989417.

Reducing unnecessary right ventricular pacing with the managed ventricular pacing mode in patients with sinus node disease and AV block.

Background: Frequent and unnecessary right ventricular apical pacing increases the risk of atrial fibrillation or congestive heart failure. We evaluated a new pacing algorithm, managed ventricular pacing (MVP) which automatically changes modes between AAI/R and DDD/R in patients receiving pacemakers for symptomatic bradycardia.

Preliminary clinical experience with the first dual chamber pacemaker defibrillator.

The lack of specificity of VT detection is a significant shortcoming of current ICDs. In a French multicenter study, 18 patients underwent implantation of the Defender 9001 (ELA Medical), an ICD utilizing dual chamber pacing and arrhythmia detection. Over a mean follow‐up period of 7.1 ± 4.5 months, 176 tachycardia episodes recorded in the device memory were analyzed, and physician diagnosis was compared with that by the device. All 122 VT/VF episodes were correctly diagnosed, as were 51 of 53 supraventricular tachyarrhythmias. Two episodes of AF with rapid regular ventricular rates were treated as VT, and a third episode, treated as VT, could not be diagnosed with certainty. A dual chamber pacemaker defibrillator offers improved diagnostic specificity without loss of sensitivity, in addition to the hemodynamic benefit of dual chamber pacing. (PACE 1997;20

Pacemaker Lead Infection in Young Patients

Transvenous pacing has become widespread in the pediatric population, but related pacemaker lead infection in young patients has rarely been reported. To determine prevalence and optimal management of pacemaker lead infection in children and young adults, the authors reviewed their pacing database including 4,476 patients who previously had pacemaker implantations from 1975 to 2001. A pacemaker was implanted in 304 patients under the age of 40. Of these patients 217 of them had congenital heart disease: 108 with structural defect, 109 without (mainly complete AV blocks). Among patients with congenital heart disease, 12 developed a pacemaker lead infection (5.5%, 6 patients with structural defect, 6 without). This incidence was significantly higher than in patients < 40 years at first implantation without congenital heart disease (2.3%) and in > 40‐year‐old patients (1.2%, P < 0.001) . However, the number of reinterventions at the pulse generator site was higher in patients having had their first implantation before the age of 40. In patients with structural cardiac defect: two died after surgical lead extraction and one died before the scheduled lead extraction. The three remaining patients had successful surgical (n = 1) or percutaneous (n = 2) lead extractions. In patients without structural cardiac defect successful percutaneous extraction (5/6) or surgical extraction (1/6 with vegetation > 25 mm) was performed. One patient with percutaneous extraction developed chronic cor pulmonale during follow‐up. One infection recurred in one patient with structural cardiac defect although complete removal of the pacing material had been performed. The prevalence of pacemaker lead infection is higher in younger patients, perhaps in part due to a higher number of procedures at the pacemaker site than in the general population of patients with a pacemaker. Patients with structural cardiac defect who underwent surgical lead removal were at high risk for death. Patients with percutaneous lead extraction may develop cor pulmonale. (PACE 2003; 26[Pt. I]:1489–1493)

Contributions of remote monitoring to the follow-up of implantable cardioverter–defibrillator leads under advisory

Aims Automatic daily transmission of data from implantable cardioverter–defibrillators (ICDs) enables the remote monitoring of device status and leads function. We report on a 2-year experience with remote monitoring in 40 recipients of high-voltage ICD leads, prone to fracture and under advisory since October 2007. Methods and results The ICDs were remotely monitored as well as systematically interrogated in the ambulatory department every 3 months. The patients were also seen in case of abnormal lead impedance, or other manifestations consistent with lead dysfunction. Over a mean follow-up of 22 ± 4 months after ICD implantation, four lead dysfunctions were suspected because of remotely transmitted oversensing of noise artifacts, abrupt rise in pacing impedance, or both. A lead fracture needing lead replacement was confirmed in three patients (7.5%), two of them before any inappropriate therapy and one after the delivery of three inappropriate shocks. No lead failure was observed in the remaining 36 patients, either at the time of ambulatory visits or during remote monitoring. Conclusion Remote monitoring allowed the early and reliable detection of ICD leads failure without requiring any patient intervention.