Utilization of Defibrillators and Resynchronization Therapy at the Time of Evaluation at a Heart Failure and Cardiac Transplantation Center

Background: Internal cardioverter defibrillators (ICDs) and cardiac resynchronization therapy (CRT) reduce mortality, but are underutilized in routine clinical practice. The use of these devices in patients at the time of an initial evaluation at an advanced heart failure and cardiac transplantation center is unknown. Methods: We retrospectively analyzed consecutive patients who were enrolled in a database examining parameters of cardiopulmonary exercise testing in chronic heart failure (CHF) patients at the time of an initial outpatient evaluation at a tertiary care center. Rates of ICD and CRT use in eligible patients were determined. Results: Two hundred two patients had an average age of 54 ± 13 years and an average peak oxygen consumption (pVO₂) of 12.5 ± 4.5 mL/kg/min. Of 97 patients eligible for an ICD only, 57% had an ICD at the time of evaluation. Sixty‐four percent of ICD‐eligible male patients had an ICD compared to 36% of ICD‐eligible female patients (P = 0.015). Of 105 patients meeting criteria for CRT, 54% had a CRT device. There was no difference between CRT use in eligible male and female patients. Conclusions: ICDs and CRT are underutilized in patients with severe CHF at the time of evaluation at a tertiary care center despite young age, objective functional limitation, and active consideration for advanced CHF therapies. Female patients have lower rates of ICD use than male patients. (PACE 2010; 988–993)     

Patient understanding of disease and the use and outcome of implantable cardioverter defibrillators in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden cardiac death (SCD) in young individuals. Implantable cardioverter defibrillators (ICD) are the primary therapy for sudden death prevention; however, are associated with both physical and psychological complications. We sought to determine factors associated with ICD understanding and patient satisfaction. This was a cross‐sectional study, using patient/parent answered questionnaires distributed to patients enrolled in the Hypertrophic Cardiomyopathy Association. Patient characteristics and satisfaction data were obtained via questionnaire. Patients were compared based on age at diagnosis and presence of ICD. ICD patients with high satisfaction were compared to those with low satisfaction to determine factors associated with poor satisfaction. A total of 538 responses were obtained (53 ± 16 years); 46% were females. Seventy patients (13%) were diagnosed with HCM < 18 years of age and 356 (66%) had an ICD. Compared to those without an ICD, patients with ICDs were younger at age of diagnosis (P = 0.001) and time of study (P = 0.008). Patients with ICDs were more likely to have presented with syncope and have family history of ICD, SCD, or HCM‐related death. Nineteen patients (5%) felt that issues surrounding their ICD outweighed its benefit. Compared to patients with a favorable satisfaction, the only significant difference was the preimplant ICD discussion (P < 0.001) and history of lead replacement (P = 0.01). In conclusion, the majority of HCM patients with ICDs are satisfied with their ICD management and feel the benefits of ICDs outweigh issues associated with ICDs. Additionally, these data highlight the importance of the preimplant patient‐physician discussion around the need for ICD prior to implantation.     

Implantable Cardioverter‐Defibrillator Recipient Attitudes towards Device Deactivation: How Much do Patients Want to Know?

Background: Patients receiving implantable cardioverter‐defibrillators (ICDs) often have severely impaired left ventricular function and a poor prognosis. Having an ICD in situ effectively denies them the possibility of a quick, arrhythmic death. It is still unclear if and when the end of life and device deactivation should be discussed with patients and how much patients want to know prior to ICD implantation. Methods: Patients with an active ICD for chronic heart failure were interviewed regarding their attitude toward the ICD, their recollection of the consent procedure, and how they felt the end of life should be discussed with ICD patients (n = 54). Patients who had received ICD therapies (n = 25) were reviewed as a subgroup with extended questions regarding attitudes toward device deactivation. Results: Fifty‐four patients were recruited. Most patients were not aware that the ICD could be deactivated. The vast majority of patients (84%) wanted to be involved in the deactivation decision; 40% felt this discussion should be prior to ICD implantation but others felt the discussion should only occur if the patient was terminally ill (16%) or in the last few days of life (5%). Conclusion: Patients with ICDs are routinely counseled about the benefits of ICDs, but options for device deactivation are not well understood by patients. Most patients would like to be involved in deactivation decisions and we feel this should be discussed well in advance. (PACE 2011; 34:1628–1633)     

植入型心律转复除颤器在心脏性猝死一级预防中的应用

目的随访观察植入型心律转复除颤器（ICD）／心室再同步心律转复除颤器（CRT．D）在中国单中心心脏性猝死（SCD）高危患者一级预防中的临床应用。方法入选2009年1月至2011年12月入住浙江大学医学院附属第一医院心内科符合一级预防适应证并植入ICD／CRT．D的患者共80例,其中33例植入单腔／双腔ICD,47例植入CRT．D。基础病因主要为扩张性心肌病（55．0％）和冠状动脉性心脏病（27．5％）。植入ICD／CRT．D后第1个月末和第3个月末各随访1次,以后每6个月随访1次,若患者发生电击等ICD治疗事件,则即时进行检查。结果80例患者平均随访（23±7）个月,非计划性再入院11例（13．7％）,死亡4例（5．0％）。记录ICD治疗事件共38次,其中有26次（68．4％）为ICD识别持续性VT／VF发作而进行的适当治疗,12次（31．6％）为由于心房颤动而进行的不适当治疗事件。结论ICD,CRT—D能在短时间内对发生恶性快速性心律失常的患者进行识别及实施治疗,在SCD一级预防中疗效明确,可使SCD的高危患者获益。     

Late Gadolinium Enhancement in Patients with Nonischemic Dilated Cardiomyopathy

One‐third of all patients with heart failure have nonischemic dilated cardiomyopathy (NIDM). Five‐year mortality from NIDM is as high as 20% with sudden cardiac death (SCD) as the cause in 30% of the deaths. Currently, the left ventricular ejection fraction (LVEF) is used as the main criteria to risk stratify patients requiring an implantable cardioverter defibrillator (ICD) to prevent SCD. However, LVEF does not necessarily reflect myocardial propensity for electrical instability leading to ventricular tachycardia (VT) or ventricular fibrillation (VF). Due to the differential risk in various subgroups of patients for arrhythmic death, it is important to identify appropriate patients for ICD implantation so that we can optimize healthcare resources and avoid the complications of ICDs in individuals who are unlikely to benefit. We performed a systematic search and review of clinical trials of NIDM and the use of ICDs and cardiac magnetic resonance imaging with late gadolinium enhancement (LGE) for risk stratification. LGE identifies patients with NIDM who are at high risk for SCD and enables optimized patient selection for ICD placement, while the absence of LGE may reduce the need for ICD implantation in patients with NIDM who are at low risk for future VF/VT or SCD.     

Predictors of Early Mortality in Patients Age 80 and Older Receiving Implantable Defibrillators

Background: There are no upper age restrictions for implantable defibrillators (ICDs) but their benefit may be limited in patients ≥ 80 years with strong competing risks of early mortality. Risk factors for early (1‐year) mortality in ICD recipients ≥ 80 years of age have not been established. Methods: Two‐center retrospective cohort study to assess predictors of one‐year mortality in ICD recipients ≥ 80 years of age. Results: Of 2,967 ICDs implanted in the two centers from 1990–2006, 225 (7.6%) patients were ≥80 years of age and followed‐up at one of the two centers. Mean age was 83.3 ± 3.1 years and follow‐up time 3.3 ± 2.6 years. Median survival was 3.6 years (95% confidence interval 2.3–4.9). Multivariate predictors of 1‐year mortality included ejection fraction (EF) ≤ 20% and the absence of beta‐blocker use. Actuarial 1‐year mortality of ICD recipients ≥ 80 with an EF ≤ 20% was 38.2% versus 13.1% in patients 80+ years with an EF > 20% and 10.6% for patients < 80 years with an EF ≤ 20% (P < 0.001 for both). There was no significant difference in the risk of appropriate ICD therapy between those patients 80+ years with EF above and below 20%. Conclusion: In general, patients ≥ 80 years of age who meet current indications for ICD implantation live sufficiently long to warrant device implantation based on anticipated survival alone. However, those with an EF ≤ 20% have a markedly elevated 1‐year mortality with no observed increase in appropriate ICD therapy, thus reducing the benefit of device implantation in this population. (PACE 2010; 981–987)     

ICD implantation and arrhythmia-free survival in patients with depressed LV function following surgery for valvular heart disease

Background: Although prophylactic implantable cardioverter‐defibrillator (ICD) implantation is beneficial in patients with severe ischemic cardiomyopathy, it is unclear whether patients with cardiomyopathy due to valvular heart disease have a similar benefit. Methods: We followed 17 patients (14 men/three women, age 62 ± 13 years, left ventricular ejection fraction [LVEF] 29 ± 10%) who had nonischemic valvular cardiomyopathy, underwent valvular heart surgery (aortic valve replacement, mitral valve replacement, and/or mitral valve repair), and subsequently had an electrophysiology study (EPS), for a median of 2.8 years. These patients were compared with 34 patients with prior myocardial infarction and no significant valvular heart disease, who were matched (1:2) for age, gender, LVEF, EPS result, T‐wave alternans result, and ICD placement. Occurrence of arrhythmias was ascertained from ICD device clinic follow‐up and vital status was determined using the National Death Index. Results: There were no differences between the groups in overall survival (P = 0.24) or arrhythmia‐free survival (P = 0.38), and the 2‐year arrhythmia‐free survival was 82% for the valvular patients versus 73% for the ischemic patients. Among patients with ICDs, there was no difference between the groups in overall survival (P = 0.34), time to first appropriate ICD therapy (P = 0.54), and arrhythmia‐free survival (P = 0.51). Conclusion: Patients with valvular cardiomyopathy and residual left ventricular dysfunction following valvular surgery who underwent a tailored approach to ICD implantation had similar overall and arrhythmia‐free survival as patients with ischemic cardiomyopathy.     

Effect of bioimpedance body composition analysis on function of implanted cardiac devices

Background: It is routinely recommended that patients with pacemakers, implantable cardioverter defibrillators (ICD), and cardiac resynchronization therapy‐defibrillators (CRT‐D) avoid bioelectrical impedance analysis (BIA)—a commonly used method to estimate body composition—because of the concern for the potential for BIA interference with pacemaker or ICD function. However, the prevalence of such interference is not known. Objective: Assess for incidence of interference between BIA and ICD or CRT‐D devices. Methods and Results: Twenty patients with heart failure and cardiac implanted electronic devices (50% ICD, 50% CRT‐D) underwent BIA during real‐time device interrogation to detect interference. Study patients were 90% male, with mean age 54 ±14 years, and mean LVEF 23 ± 11%. Devices from all four leading cardiac device manufacturers were included. Device therapies were temporarily disabled to prevent inappropriate shocks. During body composition testing using BIA, no evidence of interference with ICD function was seen in any patient, including no telemetry disruption, no oversensing on any lead, and no patient symptoms. Conclusions: Despite the manufacturers’ recommendation to avoid BIA in patients with ICDs, this study showed no evidence of any interference in 20 patients. Bioimpedance analysis might be safe in such patients, but further confirmatory studies are required. (PACE 2012; 35:681–684)     

Prevalence and persistence of depression in patients with implantable cardioverter defibrillator: a 2-year longitudinal study

Background: It is unclear whether depression persists in patients with implantable cardioverter defibrillators (ICDs). We evaluated the prevalence and persistence of depression in ICD patients over a 2‐year period. Methods: The study included 90 consecutively hospitalized patients. Patients underlying heart disease was 24% coronary artery disease, 29% idiopathic dilated cardiomyopathy, 24% hypertrophic cardiomyopathy, 13% idiopathic VF/long QT syndrome and miscellaneous conditions 11%. A secondary indication for ICD implantation was present in 20 patients. All patients completed the Zung Self‐Rating Depression Scale (SDS) at study baseline and at the their routine follow‐up visit 2 years after the baseline questionnaire. Delivery of ICD therapies was tracked throughout the 2 years. Results: Depression, indicated by a Zung SDS index score exceeding 60, was present in 29 (32%) of patients at study baseline. Depression was present in 11/51 (21%) patients scheduled to undergo ICD implantation, 2/2 (100%) patients whose device was upgraded to a CRT‐D, 3/14 (21%) patients who had undergone pulse generator replacement, 7/14 (50%) patients who experienced electrical storm and 6/9 (66%) patients hospitalized with acute decompensated heart failure. NYHA functional class III was significantly associated with depression at baseline (HR 6.7, 95% CI 1.68–27.2, p = 0.0007). No differences were noted for female gender, demographics, β‐blocker use, or LVEF ≤35% (p = ns). Depression was present in 25 (28%) of patients at 2 years follow‐up, persisting in 21 (72%) of patients whose Zung SDS scores were elevated at baseline. The median time from ICD shock therapy to completion of the 2 year questionnaire was 9 months (range, 1–22). Patients who were depressed (9/25, 36%) experienced more shocks than non‐depressed patients (6/65, 9%) after 2 years (p = 0.002). Conclusions: Depression is not uncommon among patients who meet criteria for ICD implantation and persists over time particularly when functional status is impaired. Depression is associated with a higher incidence shock therapy. (PACE 2010; 33:1455–1461)     

The use of advance directives among patients with implantable cardioverter defibrillators

Background: We aimed to determine the prevalence of advance directives (ADs) among patients with implantable cardioverter defibrillators (ICDs) and of ADs that addressed ICD management at the end of life. Methods: The medical records of all patients who underwent ICD implantation during 2007 at a single institution were reviewed retrospectively to determine the number of patients with an AD and the number of ADs mentioning the ICD specifically (i.e. ICD management at end of life). Results: During 2007, 420 patients (males, 71%) underwent ICD implantation at our institution (mean age [range] at implantation, 63 [1–90] years). Primary prevention was the most common indication for device therapy (254 patients [61%]). Overall, 127 patients (30%) had an AD, with 83 ADs (65%) completed more than 12 months before ICD implantation and 10 (8%) completed after it. Several life‐sustaining treatments were mentioned in the ADs: tube feeding, 46 (37%); cardiopulmonary resuscitation, 25 (20%); mechanical ventilation, 22 (17%); and hemodialysis, nine (7%). Pain control was mentioned in 58 ADs (46%) and comfort measures in 38 (30%). However, only two ADs (2%) mentioned the ICD or its deactivation at end of life. Conclusions: About one‐third of patients with ICDs had an AD, but only a couple ADs mentioned the ICD. These results suggest that clinicians should not only encourage patients with ICDs to complete an AD, but also encourage them to address ICD management specifically. Not addressing ICD management in an AD may result in ethical dilemmas during end‐of‐life care. (PACE 2012; xx; 1–7)     

Recurrent Implantable Cardioverter‐Defibrillator Replacement Is Associated with an Increasing Risk of Pocket‐Related Complications

Background: Despite beneficial effects of implantable cardioverter‐defibrillator (ICD) therapy, limited service life results in replacement within the majority of patients. Data concerning the effect of replacement procedures on the occurrence of pocket‐related adverse events are scarce. In this study, the requirement for pocket‐related surgical re‐interventions following ICD treatment and the effect of device replacement were evaluated. Methods: From 1992 to 2008, 2,415 patients receiving an ICD at the Leiden University Medical Center were analyzed. Pocket‐related complications requiring surgical re‐intervention following ICD implantation or replacement were noted. Elective device replacement, lead failure, and device malfunction were not considered pocket‐related complications. Results: A total of 3,161 ICDs were included in the analysis. In total, 145 surgical re‐interventions were required in 122 (3.9%) ICDs implanted in 114 (4.7%) unique patients. Three‐year cumulative incidence for first surgical re‐intervention in all ICDs was 4.7% (95% confidence interval [CI] 3.9–5.5%). Replacement ICDs exhibited a doubled requirement for surgical re‐intervention (rate ratio 2.2, 95% CI 1.5–3.0). Compared to first implanted ICDs, the occurrence of surgical re‐intervention in replacements was 2.5 (95% CI 1.6–3.7) times higher for infectious and 1.7 (95% CI 0.9–3.0) for noninfectious causes. Subdivision by the number of ICD replacements showed an increase in the annual risk for surgical re‐intervention, ranging from 1.5% (95% CI 1.2–1.9%) for the first, to 8.1% (95% CI 1.7–18.3%) for the fourth implanted ICD. Conclusions: ICD replacement is associated with a doubled risk for pocket‐related surgical re‐interventions. Furthermore, the need for re‐intervention increases with every consecutive replacement. (PACE 2010; 1013–1019)     

Implantation Trends and Patient Profiles for Pacemakers and Implantable Cardioverter Defibrillators in the United States: 1993–2006

Background: Prior studies of cardiac rhythm management devices (pacemakers [PM] and implantable cardioverter defibrillators [ICD]) utilization in the United States have been limited to the Medicare population. We evaluated the national trends for the implantation of PMs and ICDs including the burden of device replacement. Methods: The Nationwide Inpatient Sample was queried to identify PM and ICD patients between 1993 and 2006 using ICD‐9‐CM codes, including demographics, health profile, and economic data. The Charlson Comorbidity Index (CCI) and replacement burden were calculated, and changes over time studied. Results: From 1993 to 2006, 2.4 million patients received a primary PM and 0.8 million received an ICD, while there were 369,000 PM replacements and 74,000 ICD replacements. Women comprised 49% of PM and 24% of ICD patients. The mean ICD replacement burden was 8.4% (range 5–22%) and decreased significantly over time (P < 0.0001) while the replacement burden for PMs was constant (mean = 13.4%, range 11–16%). ICD patients had more comorbidities than PM patients (CCI: 0.8 vs 1.1, P < 0.0001). Conclusions: The replacement burden for PMs has remained constant, while the replacement burden for ICDs has decreased. This is likely due to the stability of the patient population receiving PMs and technology maturity. Alternatively, the indications for ICD implantation have broadened, resulting in an increased number of primary ICD implantations. The age and comorbidities are increasing in those patients receiving ICDs while the PM population is stable. These data suggest that monitoring of replacement burden is warranted, given the changing populations, their disparate clinical outcomes, and economic implications to the health care system. (PACE 2010; 33:705–711)     

Patient and cardiologist perceptions on decision making for implantable cardioverter-defibrillators: a qualitative study

Background: Although implantable cardioverter‐defibrillators (ICDs) reduce mortality in selected patients, they are also associated with potential risks. Periprocedural decision making requires understanding both benefits and risks. Methods: This qualitative study aims to understand cardiologists’ and patients’ perspectives about decision making surrounding ICD implantation using semi‐structured, in‐depth interviews. We interviewed 11 cardiologists (including four electrophysiologists) and 20 patients (14 with ICDs; six who declined ICDs). The data were analyzed through the theoretical lens of patient‐centered care using the constant comparative method. Results: Cardiologists emphasized the benefits of ICD therapy but varied substantially in the extent to which they emphasized the various risks associated with ICD implantation with patients. Cardiologists indicated that they were influenced by the benefits of therapy as presented in published guidelines. Many patients who chose to receive an ICD indicated that they followed the advice of their physician without questioning the risks and benefits of the device. Some ICD recipients described not learning many of the risks until after device implantation or when they experienced these side effects. Patients who declined ICD implantation were concerned that the ICD was unnecessary or believed that the risks related to sudden death without an ICD did not apply to them. Only one patient considered the trade‐off between dying quickly versus living longer with progressive heart failure. Conclusions: In our sample, cardiologists’ desire to adhere to published guidelines appears to inhibit shared decision making. The marked variability in the discussions surrounding ICD decisions highlights a need for an improved process of ICD decision making. (PACE 2011; 34:1634–1644)     

Predictors of Appropriate Implantable Cardioverter Defibrillator (ICD) Therapy in Primary Prevention Patients with Ischemic and Nonischemic Cardiomyopathy

Background: We sought to assess predictors of appropriate implantable cardioverter defibrillator (ICD) therapy in patients receiving primary prevention ICDs. Methods: Four hundred twenty‐one consecutive patients (ischemic and nonischemic) undergoing primary prevention ICD implantation were studied. Patients were grouped based on the presence/absence of appropriate ICD therapy. Summary data and stored electrograms from ICDs were reviewed to determine appropriateness of therapy. Predictors of therapy were assessed by both univariate and multivariate Cox regression analysis. Results: Of 421 primary prevention patients undergoing ICD implantation, 79 (19%) had received appropriate ICD therapies. By univariate comparison, nonsustained ventricular tachycardia (NSVT), male sex, left ventricle diastolic diameter (LVDD), and hypertension were all significant predictors for ICD therapy over a mean follow‐up time of 751 ± 493 days (P ≤ 0.05). The use ofβ‐blockers was found to be a negative predictor. In the ischemic cardiomyopathy (ICM) population, 55 (17%) patients received ICD therapy and this was predicted by NSVT, hypertension, LVDD, and left atrial diameter.β‐blockers were protective. In the nonischemic dilated cardiomyopathy (NIDCM) population, 24 (23%) received appropriate therapies, which were predicted by NSVT, male sex, dual chamber device, lack of biventricular device, and lack ofβ‐blockers. By multivariate analysis, NSVT, hypertension, and lack ofβ‐blockers were significant for ICM, while NSVT and absence ofβ‐blockers were predictive for NIDCM. Ejection fraction, New York Heart Association class, and QRS width were not significantly different between therapy and no‐therapy groups in any population. Conclusions: ICD‐delivered therapy occurred in 19% of primary prevention patients with both ischemic and dilated cardiomyopathy and was predicted by NSVT and a lack ofβ‐blocker use. (PACE 2010; 33:320–329)     

Female gender is associated with a better outcome after cardiac resynchronization therapy

Background: Some studies have suggested that women respond differently to cardiac resynchronization therapy (CRT). We sought to determine whether female gender influences long‐term clinical outcome, symptomatic response as well as echocardiographic response after CRT. Methods and Results: A total of 550 patients (age 70.4 ± 10.7 yrs [mean ± standard deviation]) were followed up for a maximum of 9.1 years (median: 36.2 months) after CRT‐pacing (CRT‐P) or CRT‐defibrillation (CRT‐D) device implantation. Outcome measure included mortality as well as unplanned hospitalizations for heart failure or major adverse cardiovascular events (MACE). Female gender predicted survival from cardiovascular death (hazard ratio [HR]: 0.52, P = 0.0051), death from any cause (HR: 0.52, P = 0.0022), the composite endpoints of cardiovascular death /heart failure hospitalizations (HR: 0.56, P = 0.0036) and death from any cause/hospitalizations for MACE (HR: 0.67, P = 0.0214). Female gender predicted death from pump failure (HR: 0.55, P = 0.0330) but not sudden cardiac death. Amongst the 322 patients with follow‐up echocardiography, left ventricular (LV) reverse remodelling (≥15% reduction in LV end‐systolic volume) was more pronounced in women (62% vs 44%, P = 0.0051). In multivariable Cox proportional hazards analyses, the association between female gender and cardiovascular survival was independent of age, LV ejection fraction, atrial rhythm, QRS duration, CRT device type, New York Heart Association (NYHA) class, and LV reverse remodelling (adjusted HR: 0.48, P = 0.0086). At one year, the symptomatic response rate (improvement by ≥1 NYHA classes or ≥25% increase in walking distance) was 78% for both women and men. Conclusions: Female gender is independently associated with a lower mortality and morbidity after CRT. (PACE 2011; 82–88)     

Implantable Cardioverter Defibrillator Therapy for Prevention of Sudden Cardiac Death in Children in The Netherlands

Introduction: Implantable cardioverter defibrillator (ICD) therapy is increasingly used in children. The purpose of this multicenter study is to evaluate mid‐term clinical outcome and to identify predictors for device discharge in pediatric ICD recipients. Methods and Results: From 1995 to 2006, 45 patients in The Netherlands under the age of 18 years received an ICD. Mean age at implantation was 10.8 ± 5.2 years. Primary prevention (N = 22) and secondary prevention (N = 23) were equally distributed. Underlying cardiac disorders were primary electrical disease (55%), cardiomyopathy (20%), and congenital heart disease (17%). The follow‐up was 44 ± 32.9 months. Three patients (7%) died and one patient (2%) underwent heart transplantation. ICD‐related complications occurred in eight patients (17%), seven of whom had lead‐related complications. Fourteen patients (31%) received appropriate ICD shocks; 12 patients (27%) received inappropriate ICD shocks. Fifty‐five percent of 22 ICD recipients under the age of 12 years received appropriate shocks, which was higher as compared with 9% of 23 older ICD recipients (P = 0.003). Although the incidence of appropriate shocks in the present study was larger in secondary prevention (9/23; 39%) as compared with primary prevention (5/22; 23%), this difference did not reach significance. Conclusions: In our population of patients, children <12 years of age had more appropriate shocks than patients 13–18 years. The complication rate is low, and is mainly lead related. (PACE 2010; 33:179–185)     

Right Ventricular Dysfunction and the Incidence of Implantable Cardioverter‐Defibrillator Therapies

Introduction: Implantable cardioverter‐defibrillator (ICD) therapy is well established in preventing sudden cardiac death in patients with left ventricular dysfunction. The influence of right ventricular (RV) function on ICD therapy for sudden cardiac death (SCD) is not known. Methods: We retrospectively studied 222 patients receiving an ICD for primary prevention of SCD. Baseline clinical and echocardiographic data were gathered. RV systolic function was qualitatively assessed as normal or abnormal (described as mildly, moderately, or severely reduced). Primary endpoint was combined ICD therapy or death and secondary endpoint was ICD therapy alone. Results: The mean follow‐up was 940 ± 522 days. The mean left ventricular ejection fraction was 0.23 ± 0.07. By Kaplan‐Meier analysis, RV dysfunction was predictive of combined ICD therapy or death when comparing between normal and abnormal RV function (P = 0.008) and among qualitative ranges of RV function (P = 0.012). RV dysfunction was not predictive of ICD therapy alone with either type of classification. After adjusting for clinical covariates, severe RV dysfunction was predictive of the combined endpoint of ICD therapy or death (HR 2.02, 95% CI 1.04–3.92, P = 0.037). Conclusion: Severe RV dysfunction appears to be an independent predictor of the combined endpoint of ICD therapy or death. RV dysfunction does not reliably predict the incidence of ICD therapy alone.     

Psychopathology in Patients with ICDs over Time: Results of a Prospective Study

Introduction: The effects of implantable cardioverter defibrillators (ICDs) and ICD shocks on psychological state have previously been studied. However, it is still unclear how health‐related quality‐of‐life changes over time using standardized assessments. We sought to characterize the effects of ICDs and ICD shocks on psychological outcomes. Methods: Three hundred‐eight patients receiving ICDs were prospectively identified. Baseline QOL assessments including standardized psychological surveys [Hospital Anxiety and Depression Scale (HADS), Impact of Events Scale‐Revised (IES‐R), and Short Form 36 Health Survey (SF‐36)] were obtained within 2 months of device implantation and at 6 and 12 months, respectively. Outcomes including ICD shocks were followed over the 12‐month study period. Results: The number of patients meeting criteria for anxiety or posttraumatic stress disorder (PTSD) at baseline (78/223, 35%) was higher than at 6 (34/223, 15%) or 12 (34/223, 15%) months (P < 0.01). There was a significant improvement over time in HADS (P < 0.001) and IES‐R (PTSD) scores (P < 0.001). Amongst the 20 patients who received ICD shocks, no significant differences were observed in IES‐R, SF‐36, or HADS scores when compared with those who did not receive shocks at any time point. Patients who experienced electrical storms (N = 5) had significantly higher baseline PTSD scores (29.6 ± 11.4 vs 14.6 ± 11.6, P < 0.01). Conclusions: Patients receiving ICDs have significant rates of baseline psychopathology after implantation. However, psychological assessment scores tend to improve with time. ICD shocks do not appear to significantly impact psychological state. These results suggest the importance of close screening and referral for possible psychopathology in patients receiving ICDs, especially in the peri‐implant period. (PACE 2010; 33:198–208)     

Analysis of Implantable Defibrillator Longevity Under Clinical Circumstances: Implications for Device Selection

Introduction: Information about implantable cardioverter‐defibrillator (ICD) longevity is mostly calculated from measurements under ideal laboratory conditions. However, little information about longevity under clinical circumstances is available. This survey gives an overview on ICD service times and generator replacements in a cohort of consecutive ICD patients. Methods: Indications for replacement were classified as a normal end‐of‐service (EOS), premature EOS, system malfunction, infection and device advisory, or recall actions. From the premature and normal EOS group, longevity from single‐chamber (SC), dual‐chamber (DC), and cardiac resynchronization therapy defibrillator (CRT‐D), rate‐responsive (RR) settings, high output (HO) stimulation, and indication for ICD therapy was compared. Differences between brands were compared as well. Results: In a total of 854 patients, 203 ICD replacements (165 patients) were recorded. Premature and normal EOS replacements consisted of 32 SC, 98 DC and 24 CRT‐D systems. Longevity was significantly longer in SC systems compared to DC and CRT‐D systems (54 ± 19 vs. 40 ± 17 and 42 ± 15 months; P = 0.008). Longevity between non‐RR (n = 143) and RR (n = 11) settings was not significantly different (43 ± 18 vs. 45 ± 13 months) as it also was not for HO versus non‐HO stimulation (43 ± 19 vs. 46 ± 17 months). Longevity of ICDs was not significantly different between primary and secondary prevention (42 ± 19 vs. 44 ± 18 months). The average longevity on account of a device‐based EOS message was 43 ± 18 months. Average longevity for Biotronik (BIO, n = 72) was 33 ± 10 months, for ELA Medical (ELA, n = 12) 44 ± 17 months, for Guidant (GDT, n = 36) 49 ± 12 months, for Medtronic (MDT, n = 29) 62 ± 22 months, and for St. Jude Medical (SJM, n = 5) 31 ± 9 months (P < 0.001). Conclusion: SC ICD generators had a longer service time compared to DC and CRT‐D systems. No influence of indication for ICD therapy and HO stimulation on generator longevity was observed in this study. MDT ICDs had the longest service time.