Joep Thijssen

Implantation-Related Complications of Implantable Cardioverter-Defibrillators and Cardiac Resynchronization Therapy Devices: A Systematic Review of Randomized Clinical Trials

The number of implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy (CRT) implantations is increasing drastically worldwide, and hence, the number of implanting centers is also increasing. Despite abundant data on the beneficial effect of these devices, little is known regarding safety and complication rates. Eleven ICD and 7 CRT trials were systematically reviewed to provide data on the frequency of in-hospital mortality and complications related to the implantation. Average in-hospital mortality was 2.7% in trials using both thoracotomy and nonthoracotomy ICDs, 0.2% in trials using nonthoracotomy ICDs, and 0.3% in CRT trials. The pneumothorax rate was similar between the nonthoracotomy ICD and CRT trials (0.9%) Coronary sinus complications occurred in 2.0% of patients undergoing CRT. Lead dislodgement rates were higher in CRT trials (5.7%) than in nonthoracotomy ICD trials (1.8%).

Implantable cardioverter-defibrillator longevity under clinical circumstances: An analysis according to device type, generation, and manufacturer

BACKGROUND One of the major drawbacks of implantable cardioverter-defibrillator (ICD) treatment is the limited device service life. Thus far, data concerning ICD longevity under clinical circumstances are scarce. In this study, the ICD service life was assessed in a large cohort of ICD recipients. OBJECTIVE To assess the battery longevity of ICDs under clinical circumstances. METHODS All patients receiving an ICD in the Leiden University Medical Center were included in the analysis. During prospectively recorded follow-up visits, reasons for ICD replacement were assessed and categorized as battery depletion and non-battery depletion. Device longevity and battery longevity were calculated. The impact of device type, generation, manufacturer, the percentage of pacing, the pacing output, and the number of shocks on the battery longevity was assessed. RESULTS Since 1996, 4673 ICDs were implanted, of which 1479 ICDs (33%) were replaced. Mean device longevity was 5.0 ± 0.1 years. A total of 1072 (72%) ICDs were replaced because of battery depletion. Mean battery longevity of an ICD was 5.5 ± 0.1 years. When divided into different types, mean battery longevity was 5.5 ± 0.2 years for single-chamber ICDs, 5.8 ± 0.1 for dual-chamber ICDs, and 4.7 ± 0.1 years for cardiac resynchronization therapy-defibrillators (P <.001). Devices implanted after 2002 had a significantly better battery longevity as compared with devices implanted before 2002 (5.6 ± 0.1 years vs 4.9 ± 0.2 years; P <.001). In addition, large differences in battery longevity between manufacturers were noted (overall log-rank test, P <.001). CONCLUSIONS The majority of ICDs were replaced because of battery depletion. Large differences in longevity exist between different ICD types and manufacturers. Modern ICD generations demonstrated improved longevity.

Cardiac device infections are associated with a significant mortality risk.

BACKGROUND Cardiac device infections (CDIs) are a serious complication associated with the implantation of cardiac rhythm devices. However, the effect of CDI on the subsequent risk of mortality is unknown. OBJECTIVE To assess the prognostic importance of CDI in recipients of implantable cardioverter-defibrillator and cardiac resynchronization therapy - defibrillator. METHODS All patients who received their initial implantable cardioverter-defibrillator/cardiac resynchronization therapy - defibrillator between January 2000 and September 2009 were included. During follow-up, the occurrence of CDI and all-cause mortality were noted. The prognostic importance of the first CDI on mortality was assessed by modeling CDI as a time-dependent covariate in the Cox proportional hazards model. RESULTS A total of 2476 patients (79% men; mean age 62 ± 13 years) were included in this analysis. During follow-up, CDI occurred in 64 (2.6%) patients. The 1-year mortality following first CDI was 16.9% (95% confidence interval 6.7%-27.1%). Experiencing the first CDI was associated with a 1.9-fold (hazard ratio 1.87; 95% confidence interval 1.07-3.26) increased risk of mortality compared to patients who did not experience CDI. After controlling for possible confounders, this increased to a 2.4-fold (hazard ratio 2.40; 95% confidence interval 1.35-4.28) increased risk of mortality. CONCLUSIONS In a large cohort of patients who receive implantable cardioverter-defibrillator/cardiac resynchronization therapy - defibrillator after their initial implant, the 3-year incidence of CDI was 2.6%. The occurrence of CDI was associated with substantial 1-year mortality, and patients experiencing CDI had a more than 2-fold increased risk of mortality compared with patients who remained free from CDI.

Implantable cardioverter-defibrillator patients who are upgraded and respond to cardiac resynchronization therapy have less ventricular arrhythmias compared with nonresponders.

OBJECTIVES The purpose of this study was to evaluate the impact of upgrading implantable cardioverter-defibrillator (ICD) therapy to cardiac resynchronization therapy (CRT) combined with defibrillator (CRT-D) on the occurrence of ventricular arrhythmia (VA) and appropriate ICD therapies. BACKGROUND CRT has been shown to improve left ventricular (LV) systolic function and induce reverse LV remodeling. In addition, it has been hypothesized that CRT may reduce the incidence of VA. METHODS Heart failure patients receiving an upgrade from ICD to CRT-D were evaluated. Patients were considered responders to CRT if LV end-systolic volume reduced ≥15% at 6 months of follow-up. Episodes of VA, triggering device therapy (anti-tachycardia pacing and shocks) were recorded before and after upgrade for the overall population. In addition, these outcomes were compared between CRT responders and nonresponders during the follow-up period after CRT response was assessed. RESULTS One hundred fifteen patients (93 males [81%], age 65 ± 12 years) were evaluated during a mean follow-up of 54 ± 34 months before CRT-D upgrade and 37 ± 27 months after upgrade. In CRT responders (n = 70), the frequency of VA requiring appropriate device therapy demonstrated a trend toward a decrease from 0.51 ± 0.79 to 0.30 ± 0.59 per patient per year after CRT-D upgrade (p = 0.052). In CRT nonresponders (n = 45), the frequency of VA requiring appropriate device therapy significantly increased from 0.40 ± 0.69 to 1.21 ± 2.53 per patient per year after CRT-D upgrade (p = 0.014). CONCLUSIONS After upgrade from ICD to CRT-D, nonresponders to CRT showed a significant increase in VA burden requiring appropriate device therapy.

The clinical course of patients with implantable cardioverter-defibrillators: Extended experience on clinical outcome, device replacements, and device-related complications

BACKGROUND Large randomized trials demonstrated the beneficial effect of implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy-defibrillator (CRT-D) treatments in selected patients. Data on long-term follow-up of patients outside the setting of clinical trials are scarce. OBJECTIVE The aim of this study was to evaluate the long-term outcome of ICD and CRT-D recipients. METHODS All patients who underwent ICD (n = 1729 [57%]) or CRT-D (n = 1326 [43%]) implantation at the Leiden University Medical Center since 1996 were evaluated. Follow-up visits were performed every 3-6 months, and events were registered. Cumulative incidence curves of device therapy and device-related complications were adjusted for the competing risk of all-cause mortality. RESULTS After a median follow-up of 5.1 years (25th-75th percentile 3.1-7.8 years), 842 patients (28%) died. The cumulative incidence of all-cause mortality was 49% (95% confidence interval [CI] 45%-54%) in ICD recipients after 12 years of follow-up and 55% (95% CI 52%-58%) in CRT-D recipients after 8 years of follow-up. A total of 1081 patients (35%) received appropriate defibrillator therapy. The cumulative incidence of appropriate therapy in ICD patients was 58% (95% CI 54%-62%) after 12 years of follow-up and 39% (95% CI 35%-43%) in CRT-D patients after 8 years of follow-up. Twelve-year cumulative incidences of adverse events were 20% (95% CI 18%-22%) for inappropriate shock, 6% (95% CI 5%-8%) for device-related infection, and 17% (95% CI 14%-21%) for lead failure. CONCLUSION After long-term follow-up of ICD (12 years) and CRT-D (8 years) recipients, 49% of ICD recipients and 55% of CRT-D recipients had died. Appropriate ICD therapy was received by the majority (58%) of ICD recipients and by almost 40% of CRT-D recipients.

Comparison of Long-Term Survival of Men Versus Women With Heart Failure Treated With Cardiac Resynchronization Therapy

Cardiac resynchronization therapy (CRT) is an established treatment of patients with heart failure. Several baseline characteristics can influence the CRT outcomes, and little is known about the effect of gender. The aim of the present study was to elucidate the gender-related differences in long-term survival after CRT. A total of 578 consecutive patients with heart failure underwent CRT. At baseline and 6 months after CRT, the clinical and echocardiographic parameters were obtained. All-cause mortality was compared between the men and women. The study population included 431 men (67 ± 9 years) and 147 women (65 ± 11 years). No differences in the clinical and echocardiographic characteristics were observed between the men and women, except for left bundle branch block and a nonischemic etiology of heart failure, which were more frequent in women (81% vs 68% and 63% vs 33%, respectively; p <0.01), and atrial fibrillation, which was more prevalent in men (20% vs 10%, respectively; p = 0.01). During a mean follow-up of 34 ± 25 months, 197 patients died (158 men and 39 women). Kaplan-Meier analysis showed a significant difference in long-term survival between the women and men (p = 0.007). The 2-year all-cause mortality rate was 15% in men and 8% in women (p = 0.025). Cox proportional hazard analysis revealed female gender is an independent predictor of long-term survival, together with heart failure etiology and renal function. In particular, women with heart failure due to a nonischemic etiology showed the best long-term survival rate. In conclusion, female gender and nonischemic etiology were independently associated with better long-term survival after CRT.

Primary prevention implantable cardioverter defibrillator recipients: the need for defibrillator back-up after an event-free first battery service-life.

ICD Replacement After a Therapy‐Free First Service‐Life. Introduction: In primary prevention implantable cardioverter defibrillator (ICD) patients, the relatively low incidence of ventricular arrhythmias (VA) combined with the limited battery service‐life potentially results in a large group of patients who have had no benefit of the ICD during first service‐life. Data on the occurrence of VA after device replacement remain scarce. The purpose of this study was to give clinicians better insight in the dilemma whether or not to replace an ICD after an event‐free first battery service‐life.

Driving restrictions after implantable cardioverter defibrillator implantation: an evidence-based approach

Aims Little evidence is available regarding restrictions from driving following implantable cardioverter defibrillator (ICD) implantation or following first appropriate or inappropriate shock. The purpose of the current analysis was to provide evidence for driving restrictions based on real-world incidences of shocks (appropriate and inappropriate). Methods and results A total of 2786 primary and secondary prevention ICD patients were included. The occurrence of shocks was noted during a median follow-up of 996 days (inter-quartile range, 428–1833 days). With the risk of harm (RH) formula, using the incidence of sudden cardiac incapacitation, the annual RH to others posed by a driver with an ICD was calculated. Based on Canadian data, the annual RH to others of 5 in 100 000 (0.005%) was used as a cut-off value. In both primary and secondary prevention ICD patients with private driving habits, no restrictions to drive directly following implantation, or an inappropriate shock are warranted. However, following an appropriate shock, these patients are at an increased risk to cause harm to other road users and therefore should be restricted to drive for a period of 2 and 4 months, respectively. In addition, all ICD patients with professional driving habits have a substantial elevated risk to cause harm to other road users during the complete follow-up after both implantation and shock and should therefore be restricted to drive permanently. Conclusion The current analysis provides a clinically applicable tool for guideline committees to establish evidence-based driving restrictions.

Suitability for subcutaneous defibrillator implantation: results based on data from routine clinical practice

Objective To assess the proportion of current implantable cardioverter defibrillator (ICD) recipients who would be suitable for a subcutaneous lead ICD (S-ICD). Design A retrospective cohort study. Setting Tertiary care facility in the Netherlands. Patients All patients who received a single- or dual-chamber ICD in the Leiden University Medical Center between 2002 and 2011. Patients with a pre-existent indication for cardiac pacing were excluded. Main outcome measure Suitability for an S-ICD defined as not reaching one of the following endpoints during follow-up: (1) an atrial and/or right ventricular pacing indication, (2) successful antitachycardia pacing without a subsequent shock or (3) an upgrade to a CRT-D device. Results During a median follow-up of 3.4 years (IQR 1.7–5.7 years), 463 patients (34% of the total population of 1345 patients) reached an endpoint. The cumulative incidence of ICD recipients suitable for an initial S-ICD implantation was 55.5% (95% CI 52.0% to 59.0%) after 5 years. Significant predictors for the unsuitability of an S-ICD were: secondary prevention, severe heart failure and prolonged QRS duration. Conclusions After 5 years of follow-up, approximately 55% of the patients would have been suitable for an S-ICD implantation. Several baseline clinical characteristics were demonstrated to be useful in the selection of patients suitable for an S-ICD implantation.

Early reperfusion therapy affects inducibility, cycle length, and occurrence of ventricular tachycardia late after myocardial infarction.

Background— This study aimed to evaluate the impact of early reperfusion during acute myocardial infarction (MI) on ventricular tachycardia (VT) inducibility, inducible VT cycle length (CL), and occurrence of spontaneous VT late after MI. Methods and Results— Five hundred six patients (440 men; age, 63±11 years) with prior MI who underwent electrophysiology study before implantation of an implantable cardioverter-defibrillator for primary or secondary prevention were assessed. Patients were classified according to the reperfusion strategy (reperfusion: thrombolysis, n=44, or percutaneous coronary intervention, n=65, versus no reperfusion, n=397) during acute MI. Monomorphic sustained VT was inducible in 351 (69%) patients. Inducibility in reperfused and nonreperfused patients was similar in primary prevention patients (56% versus 58%) but significantly higher for nonreperfused patients in secondary prevention patients (56% versus 79%, P=0.001). Induced VTCL was shorter (247±40 versus 287±63, P<0.001) and very fast VT (CL ⩽250 ms) was more often induced in reperfused patients (71% versus 47%, P=0.001). In primary prevention patients, nonreperfusion was associated with a doubled risk for first spontaneous VT during follow-up. Conclusions— There are important differences in VT inducibility, induced VTCL, and occurrence of spontaneous VT in the chronic infarct healing phase between patients with and those without successful reperfusion during acute MI. These findings suggest differences in the chronic arrhythmogenic substrate.