Cost-effectiveness of primary prevention implantable cardioverter defibrillator treatment: data from a large clinical registry.

BACKGROUND: Although randomized trials have shown the beneficial effect on survival of an implantable cardioverter defibrillator (ICD) as primary prevention therapy in selected patients, data concerning the cost-effectiveness in routine clinical practice remain scarce. Accordingly, the purpose of this study was to assess the cost-effectiveness of primary prevention ICD implantation in the real world. METHODS: Patients receiving primary prevention single-chamber or dual-chamber ICD implantation at the Leiden University Medical Center were included in the study. Using a Markov model, lifetime cost, life years (LYs), and gained quality-adjusted life years (QALYs) were estimated for device recipients and control patients. Data on mortality, complication rates, and device longevity were retrieved from our center and entered into the Markov model. To account for model assumptions, one-way deterministic and probabilistic sensitivity analyses were performed. Importantly, calculations for the estimated incremental cost-effectiveness rate (ICER) per QALY gained are based on several numbers of assumptions, and accordingly findings may have over- or underestimated the cost-effectiveness of ICD therapy. RESULTS: Primary prevention ICD implantation adds an estimated mean of 2.07 LYs and 1.73 QALYs. Increased lifetime cost for single-chamber and dual-chamber ICD recipients were estimated at €60,788 and €64,216, respectively. This resulted for single-chamber ICD recipients, in an estimated ICER of €35,154 per QALY gained. In dual-chamber ICD recipients, an estimated ICER of €37,111 per QALY gained was calculated. According to the probabilistic sensitivity analysis, estimated cost per QALY gained are €35,837 (95% confidence interval [CI]: €28,368-€44,460) for single-chamber and €37,756 (95% CI: €29,055-€46,050) for dual-chamber ICDs. CONCLUSIONS: On the basis of data and detailed costs, derived from routine clinical practice, ICD therapy in selected patients with a reduced left ventricular ejection fraction appears to be cost-effective.

Prognostic implications of left ventricular regional function heterogeneity assessed with two-dimensional speckle tracking in patients with ST-segment elevation myocardial infarction and depressed left ventricular ejection fraction.

The aim of the current study was to evaluate the prognostic implications of myocardial tissue heterogeneity assessed with two-dimensional speckle-tracking echocardiography in patients three months after first ST-segment elevation myocardial infarction (STEMI) with left ventricular ejection fraction (LVEF) ≤35 %. For this purpose, a total of 79 patients with first STEMI and LVEF ≤35 % at three months postinfarction were evaluated. Based on left ventricular (LV) speckle-tracking longitudinal strain echocardiography, the infarct core, border zone, and remote zone at baseline and three months' follow-up were defined. Patients were followed for the occurrence of the composite end point of appropriate implantable cardioverter-defibrillator (ICD) therapy and/or cardiac mortality. During a median follow-up of 46 months, 13 patients (17 %) reached the composite end point. At baseline, patients with and without events showed comparable values of LV longitudinal strain at the infarct, border, and remote zones. However, at three months' follow-up, patients with events showed significantly more impaired longitudinal strain at the border zone (-6.8 ± 3.1 % vs. -10.5 ± 4.9 %, P = 0.002), whereas LVEF was comparable (28 ± 6 % vs. 31 ± 4 %, P = 0.09). The median three-month LV longitudinal strain at the border zone was -9.4 %. Multivariate Cox regression analysis demonstrated that three-month longitudinal strain >-9.4 % at the border zone was independently associated with the composite end point (hazard ratio 3.94, 95 % confidence interval 1.05-14.70; P = 0.04). In conclusion, regional longitudinal strain at the border zone three months post-STEMI is associated with appropriate ICD therapy and cardiac mortality.

Clinical, echocardiographic, and neurohormonal response to cardiac resynchronization therapy: are they interchangeable?

BACKGROUND: The relationship between changes in N-terminal pro-brain natriuretic peptide (NT-proBNP) and echocardiographic or clinical definitions of response to cardiac resynchronization therapy (CRT) has not been evaluated. The aims of the present evaluation were to assess: (1) the relationship between changes in NT-proBNP after 6 months of CRT and clinical and echocardiographic responses; (2) the association between NT-proBNP changes and long-term outcome. METHODS: In 170 patients treated with CRT (age 61 ± 11 years, 75% male), clinical and echocardiographic parameters and circulating NT-proBNP levels were assessed at baseline and 6 months after CRT. At 6 months follow-up, improvement in New York Heart Association class ≥ 1 point, decrease in left ventricular end-systolic volume ≥ 15%, and decrease in NT-proBNP ≥ 15% defined clinical, echocardiographic, and neurohormonal CRT response, respectively. All-cause mortality data were collected and related to neurohormonal response. RESULTS: Neurohormonal, echocardiographic, and clinical response rates were 54%, 58%, and 66%, respectively. The majority of patients (71%) showing echocardiographic response had NT-proBNP reduction ≥ 15%. In contrast, only 58% of patients who showed clinical response also had NT-proBNP reduction ≥ 15%. During a median follow-up of 32 months, 40 patients died. Patients with neurohormonal response demonstrated a superior long-term outcome compared to patients without neurohormonal response (log-rank P = 0.02). CONCLUSIONS: NT-proBNP reduction ≥ 15% showed better agreement with echocardiographic response compared to clinical response. Neurohormonal response was associated with superior long-term outcome compared to insufficient reduction in NT-proBNP levels.

Predictors of long-term benefit of cardiac resynchronization therapy in patients with right bundle branch block.

AIMS: The aims of this study were: (i) to characterize consecutive cardiac resynchronization therapy (CRT) recipients with right bundle branch block (RBBB) in comparison with left bundle branch block (LBBB) and (ii) to identify independent predictors of long-term outcome among CRT recipients with RBBB. The presence of RBBB has been associated with poorer prognosis after CRT compared with LBBB; however, little is known about the differences in cardiac mechanics between RBBB and LBBB patients. Furthermore, predictors of favourable outcome after CRT in patients with RBBB have not been identified. METHODS AND RESULTS: Five hundred and sixty-one consecutive CRT recipients (89 with RBBB and 472 with LBBB) underwent echocardiography before and 6 months after CRT to determine left ventricular (LV) size and function, and interventricular and LV dyssynchrony (as measured by tissue Doppler imaging). Long-term follow-up to identify a composite endpoint of all-cause mortality or heart failure hospitalization was available. Right bundle branch block patients exhibited a higher prevalence of male gender, ischaemic heart disease, atrial fibrillation, and lower exercise capacity when compared with LBBB patients, despite smaller LV volumes. In addition, the extent of both interventricular and LV dyssynchrony was less in RBBB patients. Six months after CRT, RBBB patients also showed limited LV reverse remodelling. At long-term follow-up, LV dyssynchrony and mitral regurgitation were identified as independent predictors of all-cause mortality or heart failure hospitalization among RBBB patients. CONCLUSION: Left ventricular dyssynchrony may be an important determinant of outcome following CRT in patients with RBBB and may help in the selection of CRT candidates.

Trans-venous lead removal without the use of extraction sheaths, results of >250 removal procedures.

AIMS: The number of implanted cardiac rhythm devices has rapidly increased in the past decade. Subsequently, the need for lead extraction has also increased. Several techniques of lead removal have been documented from manual traction of the lead to lead extraction assisted with mechanical or laser sheaths. The goal of this study was to review our experience with lead removal using manual traction without the assistance of extraction sheaths. METHODS AND RESULTS: In the Leiden University Medical Center all leads are removed using manual traction without the assistance of extraction sheaths. We have retrospectively reviewed all lead removal procedures performed between 2000 and 2009. Procedures were reviewed for indication, success, complication rates, and mortality. In total, 279 lead removal procedures were included. During these procedures 445 leads were removed. Time since lead implantation: 4.2 ± 4.7 years. During extraction 53(11.9%) leads fractured, of which >50% could still be completely removed using a femoral approach. A longer implantation duration [odds ratio (OR) 1.16 per year, 95% confidence interval (CI) 1.09-1.23] and passive fixation (OR 2.52, 95%CI 1.17-5.45) significantly associated with the chance of lead fracture during lead removal. Clinical success, using the primary approach of manual traction from the pectoral area, was obtained in 228 (84.8%) procedures. Major complications occurred in 2(0.7%) and minor in 13(4.7%) procedures. One patient died within 24 h after the procedure due to septic shock. There was no further mortality within the first month after the procedure. CONCLUSION: Lead removal using manual traction, without the assistance of lead extraction sheaths, is clinically successful in ~85% of the lead extraction procedures. Concomitant morbidity and mortality are low. The highest clinical success (~95%) was observed in patients with leads implanted less than 2.6 years.

Prophylactic implantable cardioverter-defibrillator treatment in the elderly: therapy, adverse events, and survival gain.

AIMS: In elderly patients, obscurity remains regarding the benefit of implantable cardioverter-defibrillator (ICD) treatment as primary prevention of sudden cardiac death. This study assesses implant rates, therapy, adverse events, and survival gain in the elderly primary prevention ICD patient. METHODS AND RESULTS: A total of 1395 patients treated with an ICD for primary prevention of sudden cardiac death at the Leiden University Medical Center were included and allocated to three groups according to age. Endpoints consisted of appropriate shocks and survival gain, defined as the time following first appropriate ICD shock to death. Mean follow-up was 2.9 ± 2.1 years. Fifty-one per cent of the patients were <65 years, 35% were 65-74 years, and 14% were ≥75 years. Prior to the year 2000, no ICDs were implanted in patients ≥75 years; 29% of the ICDs were implanted in patients 65-74 years. After 2005, 53% of the ICD recipients were ≥65 years at the time of implant, including 16% aged ≥75 years (P = 0.03). Five-year cumulative incidence of appropriate shocks was 19% for patients <65 years, 23% for patients 65-74 years, and 13% for patients ≥75 years (P = 0.47). At 1-year following appropriate shock, cumulative incidence for death was 35% for patients ≥75 years as compared with 7% for patients <65 years (P < 0.01). CONCLUSION: In routine clinical practice, the percentage of patients ≥75 years receiving an ICD for primary prevention is increasing. Despite experiencing comparable rates of appropriate ICD shocks, life prolongation by ICD is significantly less in elderly as compared to younger patients.

Update on small-diameter implantable cardioverter-defibrillator leads performance.

BACKGROUND: The performance of small diameter implantable cardioverter defibrillator (ICD) leads is questionable. However, data on performance during long-term follow-up are scarce. The aim of this study is to provide an update for the lead failure and cardiac perforation rate of Medtronic's Sprint Fidelis ICD lead (Medtronic Inc., Minneapolis, MN, USA) and St. Jude Medical's Riata ICD lead (St. Jude Medical Inc., St. Paul, MN, USA). METHODS: Since 1996, all ICD system implantations at the Leiden University Medical Center, the Netherlands, are registered. For this study, data up to February 2011 on 396 Sprint Fidelis leads (follow-up 3.4 ± 1.5 years), 165 8-French (F) Riata leads (follow-up 4.6 ± 2.6 years), and 30 7-F Riata leads (follow-up 2.9 ± 1.3 years) were compared with a benchmark cohort of 1,602 ICD leads (follow-up 3.4 ± 2.7 years) and assessed for the occurrence of lead failure and cardiac perforation. RESULTS: During follow-up, the yearly lead failure rate of the Sprint Fidelis lead, 7-F Riata lead, 8-F Riata lead, and the benchmark cohort was 3.54%, 2.28%, 0.78%, and 1.14%, respectively. In comparison to the benchmark cohort, the adjusted hazard ratio of lead failure was 3.7 (95% confidence interval [CI] 2.4-5.7, P < 0.001) for the Sprint Fidelis lead and 4.2 (95% CI 1.0-18.0, P < 0.05) for the 7-F Riata lead. One cardiac perforation was observed (3.3%) in the 7-F Riata group versus none in the 8-F Riata and Sprint Fidelis lead population. CONCLUSION: The current update demonstrates that the risk of lead failure during long-term follow-up is significantly increased for both the Sprint Fidelis and the 7-F Riata lead in comparison to the benchmark cohort. Only one cardiac perforation occurred.

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.

Primary prevention implantable cardioverter defibrillator recipients: the need for defibrillator back-up after an event-free first battery 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. METHODS AND RESULTS: All patients treated with an ICD for primary prevention who had a replacement because of battery depletion and who did not receive appropriate therapy before device replacement were included in this analysis. Of 154 primary prevention ICD patients needing replacement because of battery depletion, 114 (74%) patients (mean age 61 ± 11 years, 80% male) had not received appropriate ICD therapy for VA. Follow-up was 71 ± 24 months after the initial implantation and 25 ± 21 months after device replacement. Following replacement, 3-year cumulative incidence of appropriate therapy in response to ventricular tachycardia or ventricular fibrillation was 14% (95% CI 5-22%). CONCLUSION: The majority of primary prevention ICD patients do not experience VA during first battery service-life. However, a substantial part of these patients does experience appropriate ICD therapy after replacement.

Predictive power of T-wave alternans and of ventricular gradient hysteresis for the occurrence of ventricular arrhythmias in primary prevention cardioverter-defibrillator patients.

BACKGROUND AND PURPOSE: Left ventricular ejection fraction lacks specificity to predict sudden cardiac death in heart failure. T-wave alternans (TWA; beat-to-beat T-wave instability, often measured during exercise) is deemed a promising noninvasive predictor of major cardiac arrhythmic event. Recently, it was demonstrated that TWA during recovery from exercise has additional predictive value. Another mechanism that potentially contributes to arrhythmogeneity is exercise-recovery hysteresis in action potential morphology distribution, which becomes apparent in the spatial ventricular gradient (SVG). In the current study, we investigated the performance of TWA amplitude (TWAA) during a complete exercise test and of exercise-recovery SVG hysteresis (SVGH) as predictors for lethal arrhythmias in a population of heart failure patients with cardioverter-defibrillators (ICDs) implanted for primary prevention. METHODS: We performed a case-control study with 34 primary prevention ICD patients, wherein 17 patients (cases) and 17 patients (controls) had no ventricular arrhythmia during follow-up. We computed, in electrocardiograms recorded during exercise tests, TWAA (maximum over the complete test) and the exercise-recovery hysteresis in the SVG. Statistical analyses were done by using the Student t test, Spearman rank correlation analysis, receiver operating characteristics analysis, and Kaplan-Meier analysis. Significant level was set at 5%. RESULTS: Both SVGH and TWAA differed significantly (P < .05) between cases (mean ± SD, SVGH: -18% ± 26%, TWAA: 80 ± 46 µV) and controls (SVGH: 5% ± 26%, TWAA: 49 ± 20 µV). Values of TWAA and SVGH showed no significant correlation in cases (r = -0.16, P = .56) and in controls (r = -0.28, P = .27). Receiver operating characteristics of SVGH (area under the curve = 0.734, P = .020) revealed that SVGH less than 14.8% discriminated cases and controls with 94.1% sensitivity and 41.2% specificity; hazard ratio was 3.34 (1.17-9.55). Receiver operating characteristics of TWA (area under the curve = 0.699, P = .048) revealed that TWAA greater than 32.5 µV discriminated cases and controls with 93.8% sensitivity and 23.5% specificity; hazard ratio was 2.07 (0.54-7.91). DISCUSSION AND CONCLUSION: Spatial ventricular gradient hysteresis bears predictive potential for arrhythmias in heart failure patients with an ICD for primary prevention, whereas TWA analysis seems to have lesser predictive value in our pilot group. Spatial ventricular gradient hysteresis is relatively robust for noise, and, as it rests on different electrophysiologic properties than TWA, it may convey additional information. Hence, joint analysis of TWA and SVGH may, possibly, improve the noninvasive identification of high-risk patients. Further research, in a large group of patients, is required and currently carried out by our group.

Longitudinal mechanics of the periinfarct zone and ventricular tachycardia inducibility in patients with chronic ischemic cardiomyopathy.

BACKGROUND: Quantification of segmental left ventricular (LV) strain by speckle-tracking echocardiography can identify transmural infarcts in patients with chronic ischemic cardiomyopathy. The aim of the study was to explore the relationship between the LV longitudinal peak systolic strain (LPSS) of the infarct, periinfarct, and remote zones and monomorphic ventricular tachycardia (VT) inducibility on electrophysiologic (EP) study. METHODS: A total of 134 patients with chronic ischemic cardiomyopathy scheduled for EP study were included. The protocol consisted of clinical, electrocardiographic, and echocardiographic evaluation, including LV longitudinal strain analysis using speckle-tracking echocardiography, immediately before EP study. An infarct segment was defined as a longitudinal strain value of greater than -5%, and a periinfarct segment was defined as immediately adjacent to an infarct segment. RESULTS: The infarct zone had the most impaired longitudinal strain (-0.5% ± 3.0%), whereas the periinfarct and remote zones had more preserved longitudinal strain (-10.8% ± 1.9% and -14.5% ± 3.0%, respectively; analysis of variance, P < .001). Seventy-two (54%) patients had inducible monomorphic VT on EP study. There was no significant difference in LV ejection fraction (31% ± 9% vs 32% ± 11%, P = .29) between inducible and noninducible patients. Longitudinal peak systolic strain of the periinfarct zone was more impaired in inducible patients (-9.8% ± 1.5% vs -11.0% ± 2.1%, P = .001), but no differences in LPSS of the infarct (-0.5% ± 3.2% vs -0.4% ± 2.7%, P = .75) and remote (-14.6% ± 2.8% vs -14.5% ± 3.4%, P = .92) zones were observed. Only LPSS of the periinfarct zone (OR 1.43, 95% CI 1.15-1.78, P = .001) was independently related to monomorphic VT inducibility on multiple logistic regression. CONCLUSIONS: Longitudinal strain analysis may be a useful imaging tool to risk stratify ischemic patients for malignant ventricular arrhythmia.

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.

Long-Term Echocardiographic Outcome in Super-Responders to Cardiac Resynchronization Therapy and the Association With Mortality and Defibrillator Therapy.

Super-response to cardiac resynchronization therapy (CRT) is associated with significant left ventricular (LV) reverse remodeling and improved clinical outcome. The study aimed to: (1) evaluate whether LV reverse remodeling remains sustained during long-term follow-up in super-responders and (2) analyze the association between the course of LV reverse remodeling and ventricular arrhythmias. Of all, primary prevention super-responders to CRT were selected. Super-response was defined as LV end-systolic volume reduction of ≥30% 6 months after device implantation. Cox regression analysis was performed to investigate the association of LV ejection fraction (LVEF) as time-dependent variable with implantable-cardioverter defibrillator (ICD) therapy and mortality. A total of 171 super-responders to CRT-defibrillator were included (mean age 67 ± 9 years; 66% men; 37% ischemic heart disease). Here of 129 patients received at least 1 echocardiographic evaluation after a median follow-up of 62 months (25th to 75th percentile, 38 to 87). LV end-diastolic volume, LV end-systolic volume, and LVEF after 6-month follow-up were comparable with those after 62-month follow-up (p = 0.90, p = 0.37, and p = 0.55, respectively). Changes in LVEF during follow-up in super-responders were independently associated with appropriate ICD therapy (hazard ratio 0.94, 95% CI 0.90 to 0.98; p = 0.005) and all-cause mortality (hazard ratio 0.95, 95% CI 0.91 to 1.00; p = 0.04). A 5% increase in LVEF was associated with a 1.37 times lower risk of appropriate ICD therapy and a 1.30 times lower risk of mortality. In conclusion, LV reverse remodeling in super-responders to CRT remains sustained during long-term follow-up. Changes in LVEF during follow-up were associated with mortality and ICD therapy.

The relationship between time from myocardial infarction, left ventricular dyssynchrony, and the risk for ventricular arrhythmia: speckle-tracking echocardiographic analysis.

BACKGROUND: Differences in arrhythmogenic substrate may explain the variable efficacy of implantable cardioverter-defibrillators (ICDs) in primary sudden cardiac death prevention over time after myocardial infarction (MI). Speckle-tracking echocardiography allows the assessment left ventricular (LV) dyssynchrony, which may reflect the electromechanical heterogeneity of myocardial tissue. The aim of the present study was to evaluate the relationship among LV dyssynchrony, age of MI, and their association with the risk for ventricular tachycardia (VT) after MI. METHODS: A total of 206 patients (median age, 67 years; 87% men) with prior MIs (median MI age, 6.2 years; interquartile range, 0.66-15 years) who underwent programmed electrical stimulation, speckle-tracking echocardiography, and ICD implantation were retrospectively evaluated. LV dyssynchrony was defined as the standard deviation of time to peak longitudinal systolic strain values using speckle-tracking strain echocardiography. LV scar burden was evaluated by the percentage of segments exhibiting scar (defined as an absolute longitudinal strain of magnitude < 4.5%). Patients were followed up for the occurrence of first monomorphic VT requiring ICD therapy (antitachycardia pacing or shock) for a median of 24 months. RESULTS: In total, 75 individuals experienced the primary end point of monomorphic VT. LV dyssynchrony was independently associated with the occurrence of VT at follow-up (hazard ratio per 10-msec increase, 1.12; 95% confidence interval, 1.07-1.18; P < .001), together with nonrevascularization of the infarct-related artery and VT inducibility. Patients with older (>180 months) MIs had a higher likelihood of VT inducibility (88% vs 63%, P = .003) and greater scar burden (14.7 ± 15.8% vs 10.7 ± 11.4%, P = .03) compared with patients with recent (<8 months) MIs. CONCLUSIONS: LV dyssynchrony is independently associated with the occurrence of VT after MI.

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.

Super-responders to cardiac resynchronization therapy remain at risk for ventricular arrhythmias and benefit from defibrillator treatment.

AIMS: Mortality and ventricular arrhythmias are reduced in patients responding to cardiac resynchronization therapy (CRT). This response is accompanied by improvement in LVEF, and some patients even outgrow original eligibility criteria for implantable cardioverter-defibrillator (ICD) implantation. It is however unclear if these patients still benefit from ICD treatment. The current study aimed to evaluate if the incidence of ICD therapy is related to the extent of CRT response. METHODS AND RESULTS: All patients who underwent primary prevention CRT-defibrillator implantation were included. They were divided into subgroups according to the reduction in LV end-systolic volume (LVESV) 6 months after implantation. Pre-defined subgroups were: negative responders (increased LVESV), non-responders (decreased LVESV 0-14%), responders (decreased LVESV 15-29%), and super-responders (decreased LVESV ≥30%). During a median follow-up of 57 months (25th-75th percentile 39-84), 512 patients were studied [101 (20%) negative responders, 101 (20%) non-responders, 149 (29%) responders, and 161 (31%) super-responders]. In the first year of follow-up super-responders received significantly less appropriate ICD therapy (3% vs. 12%; P < 0.001). The 5-year cumulative incidence of appropriate ICD therapy was 31% [95% confidence interval (CI) 19-43] in negative responders, 39% (95% CI 25-53) in non-responders, 34% (95% CI 25-43) in responders, and 27% (95% CI 18-35) in super-responders, respectively (p = 0.13). CONCLUSIONS: The extent of CRT response was associated with a parallel reduction of appropriate device therapy during the first year of follow-up. Thereafter, no association was observed. Furthermore, 23% of super-responders were treated for potentially life-threatening arrhythmias and benefit from ICD treatment.

Significant lead-induced tricuspid regurgitation is associated with poor prognosis at long-term follow-up.

BACKGROUND: Although the presence of an RV lead is a potential cause of tricuspid regurgitation (TR), the clinical impact of significant lead-induced TR is unknown. OBJECTIVE: To evaluate the effect of significant lead-induced TR on cardiac performance and long-term outcome after cardioverter-defibrillator (ICD) or pacemaker implantation. METHODS: A retrospective cohort of 239 ICD (n=191) or pacemaker (n=48) recipients (age 60±14 years, 77% male) from a tertiary care university hospital, with an echocardiographic evaluation before and within 1-1.5 years after device implantation were included. Significant lead-induced TR was defined as TR worsening, reaching a grade ≥2 at follow-up echocardiography. During long-term follow-up (median 58, IQR 35-76 months), all-cause mortality and heart failure related events were recorded. RESULTS: Before device implantation, most patients had TR grade 1 or 2 (64.0%) or no TR (33.9%), but after lead placement, significant TR was seen in 91 patients (38%). Changes in cardiac volumes and function at follow-up were similar between patients with and without significant lead-induced TR, except for larger RV diastolic area (17±6mm(2) vs 16±5mm(2), p=0.009), larger right atrial diameter (39±10 mm vs 36±8 mm, p<0.001) and higher pulmonary arterial pressures (41±15 mm Hg vs 33±10 mm Hg, p<0.001) in patients with significant lead-induced TR. Patients with significant lead-induced TR had worse long-term survival (HR=1.687, p=0.040) and/or more heart failure related events (HR=1.641, p=0.019). At multivariate analysis, significant lead-induced TR was independently associated with all-cause mortality (HR=1.749, p=0.047) together with age, LVEF and percentage RV pacing. CONCLUSIONS: Significant lead-induced TR is associated with poor long-term prognosis.

Global longitudinal strain and left atrial volume index improve prediction of appropriate implantable cardioverter defibrillator therapy in hypertrophic cardiomyopathy patients.

Accurate predictors of appropriate implantable cardioverter defibrillator (ICD) therapy in hypertrophic cardiomyopathy (HCM) patients are lacking. Both left atrial volume index (LAVI) and global longitudinal strain (GLS) have been proposed as prognostic markers in HCM patients. The specific value of LAVI and GLS to predict appropriate ICD therapy in high-risk HCM patients was studied. LAVI and 2-dimensional speckle tracking-derived GLS were assessed in 92 HCM patients undergoing ICD implantation (69 % men, mean age 50 ± 14 years). During long-term follow-up, appropriate ICD therapies, defined as antitachycardia pacing and/or shock for ventricular arrhythmia, were recorded. Appropriate ICD therapy occurred in 21 patients (23 %) during a median follow-up of 4.7 (2.2-8.2) years. Multivariate analysis revealed LAVI (p = 0.03) and GLS (p = 0.04) to be independent predictors of appropriate ICD therapy. Both LAVI and GLS showed higher accuracy to predict appropriate ICD therapy compared to presence of ≥1 conventional sudden cardiac death (SCD) risk factor(s) [area under the curve 0.76 (95 % CI 0.65-0.87) and 0.65 (95 % CI 0.54-0.77) versus 0.52 (95 % CI 0.43-0.58) respectively, p < 0.001]. No patient with both LAVI <34 mL/m(2) and GLS <-14 % experienced appropriate ICD therapy. Assessment of both LAVI and GLS on top of conventional SCD risk factors provided incremental clinical predictive value for appropriate ICD therapy, as shown by likelihood ratio test (p < 0.001) and integrated discrimination improvement index (0.17, p < 0.001). LAVI and GLS provide high negative predictive value for appropriate ICD therapy in high-risk HCM patients. Additionally to conventional SCD risk factors, both parameters may be useful to optimize criteria and timing for ICD implantation in these patients.

Effect of cardiac resynchronization therapy on the sequence of mechanical activation assessed by two-dimensional radial strain imaging.

Cardiac resynchronization therapy (CRT) induces left ventricular (LV) reverse remodeling by synchronizing LV mechanical activation. We evaluated changes in segmental LV activation after CRT and related them to CRT response. A total of 292 patients with heart failure (65 ± 10 years, 77% men) treated with CRT underwent baseline echocardiographic assessment of LV volumes and ejection fraction. Time-to-peak radial strain was measured for 6 midventricular LV segments with speckle-tracking strain imaging. Moreover, the time difference between the peak radial strain of the anteroseptal and the posterior segments was calculated to obtain LV dyssynchrony. After 6 months, LV volumes, segmental LV mechanical activation timings, and LV dyssynchrony were reassessed. Response to CRT was defined as ≥15% decrease in LV end-systolic volume at 6-month follow-up. Responders (n = 177) showed LV resynchronization 6 months after CRT (LV dyssynchrony from 200 ± 127 to 85 ± 86 ms; p <0.001) by earlier activation of the posterior segment (from 438 ± 141 to 394 ± 132 ms; p = 0.001) and delayed activation of the anteroseptal segment (from 295 ± 155 to 407 ± 138 ms; p <0.001). In contrast, nonresponders (n = 115) experienced an increase in LV dyssynchrony 6 months after CRT (from 106 ± 86 to 155 ± 112 ms; p = 0.001) with an earlier activation of posterior wall (from 391 ± 139 to 355 ± 136 ms; p = 0.039) that did not match the delayed anteroseptal activation (from 360 ± 148 to 415 ± 122 ms; p = 0.001). In conclusion, responders to CRT showed LV resynchronization through balanced lateral and anteroseptal activations. In nonresponders, LV dyssynchrony remains, by posterior wall preactivation and noncompensatory delayed septal wall activation.

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.