Reassessment of clinical variables in cardiac resynchronization defibrillator patients at the time of first replacement: Death after replacement of CRT (DARC) score.

INTRODUCTION: Cardiac resynchronization defibrillator (CRT-D) as primary prevention is known to reduce mortality. At the time of replacement, higher age and comorbidities may attenuate the benefit of implantable cardioverter-defibrillator (ICD) therapy. The purpose of this study was to evaluate the progression of comorbidities after implantation and their association with mortality following CRT-D generator replacement. In addition, a risk score was developed to identify patients at high risk for mortality after replacement. METHODS AND RESULTS: We identified patients implanted with a primary prevention CRT-D (n = 648) who subsequently underwent elective generator replacement (n = 218) from two prospective ICD registries. The cohort consisted of 218 patients (median age: 70 years, male gender: 73%, mean left ventricular ejection fraction [LVEF]: 36 ± 11% at replacement). Median follow-up after the replacement was 4.2 years during which 64 patients (29%) died and 11 patients (5%) received appropriate ICD shocks. An increase in comorbidities was observed in 77 patients (35%). The 5-year mortality rate was 41% in patients with ≥2 comorbidities at the time of replacement. A risk score incorporating age, gender, LVEF, atrial fibrillation, anemia, chronic kidney disease, and history of appropriate ICD shocks at time of replacement accurately predicted 5-year mortality (C-statistic 0.829). Patients with a risk score of greater than 2.5 had excess mortality at 5-year postreplacement compared with patients with a risk score less than 1.5 (57% vs. 6%; p < .001). CONCLUSION: A simple risk score accurately predicts 5-year mortality after replacement in CRT-D patients, as patients with a risk score of greater than 2.5 are at high risk of dying despite ICD protection.

Predicting Early Mortality Among Implantable Defibrillator Patients Treated With Cardiac Resynchronization Therapy.

BACKGROUND: The beneficial effects of a cardiac resynchronization defibrillator (CRT-D) in patients with heart failure, low left ventricular ejection fraction (LVEF), and wide QRS have clearly been established. Nevertheless, mortality remains high in some patients. The aim of this study was to develop and validate a risk score to identify patients at high risk for early mortality who are implanted with a CRT-D. METHODS AND RESULTS: For predictive modelling, 1282 consecutive patients from 5 centers (74% male; median age 66 years; median LVEF 25%; New York Heart Association class III-IV 60%; median QRS-width 160 ms) were randomly divided into a derivation and validation cohort. The primary endpoint is mortality at 3 years. Model development was performed using multivariate logistic regression by checking log likelihood, Akaike information criterion, and Bayesian information criterion. Model performance was validated using C statistics and calibration plots. The risk score included 7 independent mortality predictors, including myocardial infarction, LVEF, QRS duration, chronic obstructive pulmonary disease, chronic kidney disease, hyponatremia, and anemia. Calibration-in-the-large was suboptimal, reflected by a lower observed mortality (44%) than predicted (50%). The validated C statistic was 0.71 indicating modest performance. CONCLUSION: A risk score based on routine, readily available clinical variables can assist in identifying patients at high risk for early mortality within 3 years after CRT-D implantation.

Sex differences in outcomes of primary prevention implantable cardioverter-defibrillator therapy: combined registry data from eleven European countries.

Aims: Therapy with an implantable cardioverter defibrillator (ICD) is established for the prevention of sudden cardiac death (SCD) in high risk patients. We aimed to determine the effectiveness of primary prevention ICD therapy by analysing registry data from 14 centres in 11 European countries compiled between 2002 and 2014, with emphasis on outcomes in women who have been underrepresented in all trials. Methods and results: Retrospective data of 14 local registries of primary prevention ICD implantations between 2002 and 2014 were compiled in a central database. Predefined primary outcome measures were overall mortality and first appropriate and first inappropriate shocks. A multivariable model enforcing a common hazard ratio for sex category across the centres, but allowing for centre-specific baseline hazards and centre specific effects of other covariates, was adjusted for age, the presence of ischaemic cardiomyopathy or a CRT-D, and left ventricular ejection fraction ≤25%. Of the 5033 patients, 957 (19%) were women. During a median follow-up of 33 months (IQR 16-55 months) 129 women (13%) and 807 men (20%) died (HR 0.65; 95% CI: [0.53, 0.79], P-value < 0.0001). An appropriate ICD shock occurred in 66 women (8%) and 514 men (14%; HR 0.61; 95% CI: 0.47-0.79; P = 0.0002). Conclusion: Our retrospective analysis of 14 local registries in 11 European countries demonstrates that fewer women than men undergo ICD implantation for primary prevention. After multivariate adjustment, women have a significantly lower mortality and receive fewer appropriate ICD shocks.

Atrial electrogram quality in single-pass defibrillator leads with floating atrial bipole in patients with permanent atrial fibrillation and cardiac resynchronization therapy.

Many patients receiving cardiac resynchronization therapy (CRT) suffer from permanent atrial fibrillation (AF). Knowledge of the atrial rhythm is important to direct pharmacological or interventional treatment as well as maintaining AV-synchronous biventricular pacing if sinus rhythm can be restored. A single pass single-coil defibrillator lead with a floating atrial bipole has been shown to obtain reliable information about the atrial rhythm but has never been employed in a CRT-system. The purpose of this study was to assess the feasibility of implanting a single coil right ventricular ICD lead with a floating atrial bipole and the signal quality of atrial electrograms (AEGM) in CRT-defibrillator recipients with permanent AF. METHODS AND RESULTS: Seventeen patients (16 males, mean age 73 ±â€¯6 years, mean EF 25 ±â€¯5%) with permanent AF and an indication for CRT-defibrillator placement were implanted with a designated CRT-D system comprising a single pass defibrillator lead with a atrial floating bipole. They were followed-up for 103 ±â€¯22 days using remote monitoring for AEGM transmission. All patients had at last one AEGM suitable for atrial rhythm diagnosis and of 100 AEGM 99% were suitable for visual atrial rhythm assessment. Four patients were discharged in sinus rhythm and one reverted to AF during follow-up. CONCLUSION: Atrial electrograms retrieved from a single-pass defibrillator lead with a floating atrial bipole can be reliably used for atrial rhythm diagnosis in CRT recipients with permanent AF. Hence, a single pass ventricular defibrillator lead with a floating bipole can be considered in this population.

Longevity of implantable cardioverter defibrillators: a comparison among manufacturers and over time.

AIMS: Longevity of implantable cardioverter defibrillators (ICDs) is crucial for patients and healthcare systems as replacements impact on infection rates and cost-effectiveness. Aim was to determine longevity using very large databases of two teaching hospitals with a high number of replacements and a rather homogeneous distribution among manufacturers. METHODS AND RESULTS: The study population consists of all patients in whom an ICD was inserted in. All ICD manufacturers operating in Switzerland and the Netherlands and all implanted ICDs were included. Implantable cardioverter defibrillator replacements due to normal battery depletion were considered events, and other replacements were censored. Longevity was assessed depending on manufacturers, pacing mode, implant before/after 2006, and all parameters combined. We analysed data from 3436 patients in whom 4881 ICDs [44.2% VVI-ICDs, 27.4% DDD-ICDs, 26.3% cardiac resynchronization therapy (CRT)-ICDs, 2.0% subcutaneous ICDs] were implanted. The four major manufacturers had implant shares between 18.4 and 31.5%. Replacement due to battery depletion (27.4%) was performed for 1339 ICDs. Patient survival at 5 years was 80.1%. Longevity at 5 years improved in contemporary compared with elderly ICDs [63.9-80.6% across all ICDs, of 73.7-92.1% in VVIs, 58.2-76.1% in DDDs, and of 47.1-66.3% in CRT defibrillators, all P value < 0.05]. Remarkable differences were seen among manufacturers, and those with better performance in elderly ICDs were not those with better performance in contemporary ones. CONCLUSION: Implantable cardioverter defibrillator longevity increased in contemporary models independent of manufacturer and pacing mode. Still, significant differences exist among manufacturers. These results might impact on device selection.

Concurrent Cardioversion of Atrial Fibrillation during ICD Shock Testing.

BACKGROUND: Many patients receiving an implantable cardioverter-defibrillator (ICD) also have atrial fibrillation (AF). Shock testing during ICD implantation carries a potential risk of cardioversion to sinus rhythm (SR) and thrombembolic events. We aimed to analyze the recurrence of AF after cardioversion to SR during ICD shock testing. METHODS: A total of 555 consecutive patients referred to a tertiary hospital in Switzerland for ICD implantation or generator exchange between 02/2002 and 03/2010 were screened for AF. Fifty-seven patients who were in AF at the time of ICD shock testing were included. RESULTS: Forty-four patients (77%) were successfully cardioverted from AF to SR. Type of AF (persistent, not permanent 64 vs 31% of cardioverted patients) was the only predictor. Thirty-nine patients (89%) experienced a recurrence of AF/atrial flutter after a median of 54 days (interquartile range 35-251 days). The only predictor for recurrence of AF was previous AF declared as permanent. No ischemic stroke occurred during hospitalization for the procedure. CONCLUSIONS: For patients in AF undergoing shock testing at the time of ICD implant, there is a high chance of cardioversion from AF to SR, but there is also a high risk of early recurrence. Decisions regarding long-term anticoagulation should not be based on the heart rhythm immediately following shock testing.

Role of defibrillation threshold testing in the contemporary defibrillator patient population.

INTRODUCTION: Defibrillation threshold (DFT) testing has been performed to prove functionality of the implantable cardioverter defibrillator (ICD). Over the past years it has become increasingly controversial because of possible morbidity and mortality. The goal of this study was to determine unsuccessful shock testing and report strategies used to overcome these problems. METHODS AND RESULTS: A total of 314 patients with a de novo implantation of an ICD and 127 patients receiving a generator exchange were identified retrospectively. All patients underwent defibrillation threshold testing after induction of VF using a low-energy T-wave shock during the intervention, 2 shock tests after de novo implantations, 1 after generator change. A safety margin of 10 J or more was requested. Seven (2.3%) patients in the de novo group and 2 patients (1.4%) in the generator exchange group could not be defibrillated using the standard approach. All of those patients had either chronic amiodarone therapy, secondary prevention or a cardiac resynchronization therapy device (CRT). In univariate analysis, amiodarone therapy, dilated cardiomyopathy, and lower ejection fraction were predictors of failure. CONCLUSION: Our study's results as well as a review of the current literature favor shock testing, especially in patients with specific risk factors as mentioned above.

The prognosis of implantable defibrillator patients treated with cardiac resynchronization therapy: comorbidity burden as predictor of mortality.

AIMS: Comorbidity, such as myocardial infarction, diabetes, and renal failure, plays a pivotal role in the prognosis of a patient with arrhythmias. However, data on the prognostic impact of comorbiditiy in heart failure patients with cardiac resynchronization therapy and defibrillation (CRT-D) are scarce. The purpose of this study was to determine the impact of comorbidity on survival in CRT-D patients. METHODS AND RESULTS: The study population consisted of 463 heart failure patients who received a CRT-D between 1999 and 2008 in Rotterdam and Basel. The Charlson comorbidity index (CCI) is often used as an adjusting variable in prognostic models. The Cox proportional hazards analysis was performed to determine the independent effect of comorbidity on survival. During a median follow-up of 30.5 months, 85 patients died. Mortality rates at 1 and 7 years were 6.3 and 32.3%. Cumulative incidence of implantable cardioverter defibrillator (ICD) therapy at 7 years was 50%, and death without ICD therapy was observed in 9% of patients. At least three comorbid conditions were observed in 81% of patients. Patients who died had a higher CCI score compared with those who survived (3.9 ± 1.5 vs. 2.9 ± 1.5; P < 0.001). An age-adjusted CCI score ≥ 5 was a predictor of mortality (hazard ratio 3.69, 95% CI 2.06-6.60; P < 0.001) independent from indication for ICD therapy, and from ICD interventions during the clinical course. CONCLUSION: Comorbidity is often present in heart failure patients, and a high comorbidity burden was a significant predictor of mortality in CRT-D recipients. Comorbidity cannot predict appropriate ICD therapy. Death without prior ICD therapy occurs in a minor proportion of patients.

Risk for incident atrial fibrillation in patients who receive antihypertensive drugs: a nested case-control study.

BACKGROUND: Different antihypertensive drug classes may alter risk for atrial fibrillation. Some studies suggest that drugs that interfere with the renin-angiotensin system may be favorable because of their effect on atrial remodeling. OBJECTIVE: To assess and compare the relative risk for incident atrial fibrillation among hypertensive patients who receive antihypertensive drugs from different classes. DESIGN: Nested case-control analysis. SETTING: The United Kingdom-based General Practice Research Database, a well-validated primary care database comprising approximately 5 million patient records. PATIENTS: 4661 patients with atrial fibrillation and 18,642 matched control participants from a population of 682,993 patients treated for hypertension. MEASUREMENTS: A comparison of the risk for atrial fibrillation among hypertensive users of angiotensin-converting enzyme (ACE) inhibitors, angiotensin II-receptor blockers (ARBs), or beta-blockers with the reference group of users of calcium-channel blockers. Patients with clinical risk factors for atrial fibrillation were excluded. RESULTS: Current exclusive long-term therapy with ACE inhibitors (odds ratio [OR], 0.75 [95% CI, 0.65 to 0.87]), ARBs (OR, 0.71 [CI, 0.57 to 0.89]), or beta-blockers (OR, 0.78 [CI, 0.67 to 0.92]) was associated with a lower risk for atrial fibrillation than current exclusive therapy with calcium-channel blockers. LIMITATION: Blood pressure changes during treatment courses could not be evaluated, and risk for bias by indication cannot be fully excluded in an observational study. CONCLUSION: In hypertensive patients, long-term receipt of ACE inhibitors, ARBs, or beta-blockers reduces the risk for atrial fibrillation compared with receipt of calcium-channel blockers. PRIMARY FUNDING SOURCE: None.

[Device therapy in chronic heart failure]. / Device-Therapie der chronischen Herzinsuffizienz.

Besides optimal drug therapy, cardiac resynchronisation therapy offers a further therapy option for selected patients. Additional ICD implantation should be evaluated as well to prevent sudden cardiac death.

Application of the heart failure meta-score to predict prognosis in patients with cardiac resynchronization defibrillators.

BACKGROUND: The Heart Failure (HF) Meta-score may be useful in predicting prognosis in patients with primary prevention cardiac resynchronization defibrillators (CRT-D) considering the competing risk of appropriate defibrillator shock versus mortality. METHODS: Data from 648 consecutive patients from two centers were used for the evaluation of the performance of the HF Meta-score. The primary endpoint was mortality and the secondary endpoint was time to first appropriate implantable cardioverter-defibrillator (ICD) shock or death without prior appropriate ICD shock. Fine-Gray model was used for competing risk regression analysis. RESULTS: In the entire cohort, 237 patients died over a median follow-up of 5.2 years. Five-year cumulative incidence of mortality ranged from 12% to 53%, for quintiles 1 through 5 of the HF Meta-score, respectively (log-rank P < 0.001). Compared with the lowest quintile, mortality risk was higher in the highest quintile (HR 6.9; 95%CI 3.7-12.8). The HF Meta-score had excellent calibration, accuracy, and good discrimination in predicting mortality (C-statistic 0.76 at 1-year and 0.71 at 5-year). The risk of death without appropriate ICD shock was higher in risk quintile 5 compared to quintile 1 (sub HR 5.8; 95%CI 3.1-11.0, P < 0.001). CONCLUSIONS: Our study demonstrated a good ability of the HF Meta-score to predict survival in HF patients treated with CRT-D as primary prevention. The HF Meta-score proved to be useful in identifying a subgroup with a significantly poor prognosis despite a CRT-D.

Automated electrocardiographic quantification of myocardial scar in patients undergoing primary prevention implantable cardioverter-defibrillator implantation: Association with mortality and subsequent appropriate and inappropriate therapies.

BACKGROUND: Myocardial scarring from infarction or nonischemic fibrosis forms an arrhythmogenic substrate. The Selvester QRS score has been developed to estimate myocardial scar from the 12-lead electrocardiogram. OBJECTIVE: We aimed to assess the value of an automated version of the Selvester QRS score for the prediction of implantable cardioverter-defibrillator (ICD) therapy and death in patients undergoing primary prevention ICD implantation. METHODS: Unselected patients undergoing primary prevention ICD implantation were included in this retrospective, observational, multicenter study. The QRS score was calculated automatically from a digital standard preimplantation 12-lead electrocardiogram and was correlated to the occurrence of death and appropriate and inappropriate shocks during follow-up. Analyses were performed in groups defined by QRS duration < 130 ms vs ≥ 130 ms. RESULTS: Overall, 1047 patients (872 [83%] men; median age 64 years IQR [55-71]) with ischemic (648, 62%) or nonischemic (399, 38%) cardiomyopathy were included. The median QRS duration was 123 ms (interquartile range [IQR] 111-157 ms), and the median QRS score was 5 (IQR 2-8). The QRS duration was <130 ms in 59% and ≥130 ms in 41%. During a median follow-up of 45 months (IQR 24-72 months), a QRS score of ≥5 was independently associated with a significantly higher risk of mortality (hazard ratio [HR] 1.67; 95% confidence interval [CI] 1.05-2.66; P = .031) and appropriate (HR 1.83; 95% CI 1.07-3.14; P = .028) and inappropriate (HR 2.32; 95% CI 1.04-5.17; P = .039) shocks in patients with QRS duration ≥ 130 ms. No association of the QRS score and outcome was observed in patients with QRS duration < 130 ms (P > .05). CONCLUSION: The automatically calculated Selvester QRS score, an indicator of myocardial scar burden, predicts mortality and appropriate and inappropriate shocks in patients undergoing primary prevention ICD implantation with a prolonged QRS duration.

Necessity for surgical revision of defibrillator leads implanted long-term: causes and management.

BACKGROUND: Defibrillator lead malfunction is a potential long-term complication in patients with an implantable cardioverter-defibrillator (ICD). The aim of this study was to determine the incidence and causes of lead malfunction necessitating surgical revision and to evaluate 2 approaches to treat lead malfunction. METHODS AND RESULTS: We included 1317 consecutive patients with an ICD implanted at 3 European centers between 1993 and 2004. The types and causes of lead malfunction were recorded. If the integrity of the high-voltage part of the lead could be ascertained, an additional pace/sense lead was implanted. Otherwise, the patients received a new ICD lead. Of the 1317 patients, 38 experienced lead malfunction requiring surgical revision and 315 died during a median follow-up of 6.4 years. At 5 years, the cumulative incidence was 2.5% (95% confidence interval, 1.5 to 3.6). Lead malfunction resulted in inappropriate ICD therapies in 76% of the cases. Implantation of a pace/sense lead was feasible in 63%. Both lead revision strategies were similar with regard to lead malfunction recurrence (P=0.8). However, the cumulative incidence of recurrence was high (20% at 5 years; 95% confidence interval, 1.7 to 37.7). CONCLUSIONS: ICD lead malfunction necessitating surgical revision becomes a clinically relevant problem in 2.5% of ICD recipients within 5 years. In selected cases, simple implantation of an additional pace/sense lead is feasible. Regardless of the chosen approach, the incidence of recurrent ICD lead-related problems after lead revision is 8-fold higher in this population.

Comparison of Multivariate Risk Estimation Models to Predict Prognosis in Patients With Implantable Cardioverter Defibrillators With or Without Cardiac Resynchronization Therapy.

Several multivariate risk score models were developed to predict prognosis of patients with heart failure (HF). We compared 3 models with regard to prediction of mortality in patients with HF who received an implantable defibrillator (ICD) or a cardiac resynchronization therapy defibrillator (CRT-D), as primary prevention of sudden death. The study cohort consisted of 823 patients (ICD = 410; CRT-D = 413). The evaluated models were the Seattle Heart Failure Model (SHFM), the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) score, and an adjusted Charlson Comorbidity Index (aCCI). End point was the performance of the models to predict all-cause mortality at 5 years. This was determined by c-statistics, for both subgroups. Multivariate analysis was used to analyze the relations between the risk score models, their individual components and mortality, and its applicability to the entire population. Cumulative mortality was 4.9% at 1 year and 21.1% at 5 years. Discriminatory power for 5-year mortality was highest for the SHFM (0.73; p <0.001) compared with the MADIT II score and the aCCI for the entire population. SHFM performed better than the MADIT II score for CRT-D group. In the entire population, the SHFM and the aCCI were significant predictors of mortality in multivariate analysis (hazard ratio 1.90, 95% confidence interval 1.49 to 2.43 vs hazard ratio 1.11, 95% confidence interval 1.01 to 1.22). The strongest individual components were age, HF, impaired renal function, and cancer, whereas CRT-D use was no predictor. In conclusion, the SHFM has the best discriminatory power for 5-year mortality in patients with HF with an ICD or CRT-D. The aCCI and MADIT II scores are less powerful but viable alternatives.

Prophylactic implantable cardioverter defibrillator therapy in dilated cardiomyopathy: impact of left ventricular function.

BACKGROUND: The value of an implantable cardioverter defibrillator (ICD) for primary prevention in dilated cardiomyopathy (DCM) is unclear, as randomized trials could not show a survival benefit compared to drug therapy. It has not been investigated if patients with a very poor left ventricular function (LVEF) could profit from an ICD. METHODS: Consecutive patients with DCM who received an ICD between December 1996 and November 2003 were included in this analysis. Patients were divided in group A (secondary prevention) and group B (primary prevention). Both groups were stratified in subgroups with left ventricular ejection fraction (LVEF) below and above 20%. RESULTS: Fifty eight patients were included (male 50, age 56.4+/-12.7 years). Follow-up was 34+/-19 months. There was no difference regarding death (18% vs. 11%), but significant differences (p value <0.05) regarding any adverse events (55% vs. 22%), any ICD intervention (48% vs. 17%) and ICD interventions for life-threatening arrhythmias (27% vs. 0%) between group A and B. LVEF was not predictive for events in group A, whereas in group B only patients with a LVEF <20% had events (p value 0.02). Over time there was an increase of the LVEF of more than 15% determined by echocardiography in 36% of patients, significantly more often in group B. CONCLUSIONS: Indication for primary prevention with an ICD in DCM should be made with caution. Larger studies are needed to determine if patients with LVEF of <20% might benefit from an ICD.

Atrial fibrillation: estimated excess rate of stroke due to lacking adherence to guidelines.

QUESTIONS UNDER STUDY: Many patients with atrial fibrillation (AF), risk factors for stroke and no obvious contraindications do not receive oral anticoagulation. Estimations of the increased rate of stroke due to neglected anticoagulation, particularly in an elderly, non-selected population, are unknown. METHODS: Consecutive patients with paroxysmal or permanent atrial fibrillation admitted to the medical or surgical department of our hospital for any reason were studied. Risk factors for stroke and contraindications for anticoagulation were recorded. Estimations of the increased rate of cerebrovascular events due to neglected anticoagulation were based on data of a large meta-analysis. Patients were further stratified into different age and risk groups. RESULTS: 484 patients with a mean age of 75 (12) years were studied, 45% were female. 237 patients had no oral anticoagulation at hospital discharge, despite guideline recommendations. Contraindications for anticoagulation were found in 85 (36%) of these patients, resulting in 152 patients with neglected anticoagulation (31% of all patients with AF). We estimated that, if all those patients would have been treated according to guidelines, 7.4 strokes per year could be prevented in the study population. The estimated rate of preventable events was 4.9%/year (7.4/152). CONCLUSIONS: With better adherence to guidelines for oral anticoagulation in patients with atrial fibrillation and risk factors for stroke, a significant number of strokes could be prevented.

Early clinical experience with CardioCard - a credit card-sized electronic patient record.

QUESTIONS UNDER STUDY: CardioCard is a CDROM of credit card size containing medical information on cardiac patients. Patient data acquired during hospital stay are stored in PDF format and secured by a password known to patients only. In a consecutive series of patients, we assessed acceptance and utility of this new information medium. METHODS AND RESULTS: A questionnaire was sent to all patients who had received CardioCard over a one-year period. The questionnaire was returned by 392 patients (73%). 44% of patients had the card with them all the time. The majority of patients (73%) considered the CardioCard useful (8% not useful, 19% no statement) and most (78%) would even agree to bear additional costs. Only 5% worried about data security. In contrast, 44% would be concerned of data transmission via internet. During an observation period of 6 (SD 3) months, data were accessed by 27% of patients and 12% of their physicians. The proportion of card users was lower among older patients: < or = 50 years (y), 39%; 51.60 y, 38%; 61.70 y, 26%; >70 y, 16% and particularly among older women: 61.70 y, 9%; >70 y, 5%. Technical problems during data access occurred in 34%, mostly due to incorrect handling. CONCLUSIONS: A majority of patients considered CardioCard as useful and safe. Lack of hardware equipment or insufficient computer knowledge, but not safety issues were the most important limitations. As patients expressed concerns regarding protection of privacy if data were accessible via internet, this would remain a strong limiting factor for online use.

Methadone-induced Torsade de pointes tachycardias.

Methadone is a synthetic opioid frequently used in drug maintenance programs for heroin addicts. It prolongs the QT-interval and is mainly metabolized by the isoenzyme CYP3A4 of the hepatic cytochrome-P450-system, which is used by numerous other QT-prolonging agents. Its most severe side effect is the development of life-threatening Torsade de pointes ventricular tachycardia in the setting of a prolonged QT-interval. Since drug addicts are prone to concomitant medical conditions requiring additional medication as well as to continued abuse of cocaine, they are at higher risk for developing this major complication of methadone therapy. Before subjecting patients on methadone to other drugs, the QT-interval should be determined and it should be ascertained whether the new agent has the property to prolong the QT-interval or is metabolised by the cytochrome-P450 system.

Application of a mortality risk score in a general population of patients with an implantable cardioverter defibrillator (ICD).

OBJECTIVE: The implantable cardioverter defibrillator (ICD) is very effective in the prevention of sudden cardiac death, but its benefit is impaired by competing risks. A simple risk model to predict mortality was designed for patients with primary prevention and ischaemic cardiomyopathy. We aimed to apply this score to a general ICD population. METHODS: This retrospective registry study included all patients in whom an ICD was implanted at a tertiary referral hospital. Risk factors were age >70 years, QRS width >120 ms, atrial fibrillation, New York Heart Association Functional Classification class >2 and glomerular filtration rate <60 mL/min/1.73 m(2). Kaplan-Meier curves were constructed according to the presence of 0, 1, 2 and >2 risk factors. RESULTS: The cohort consists of 1032 patients, 881 (86%) were men, mean age was 61±14 years and mean follow-up 66±46 months. 256 patients (25%) died 58±41 months after implant. The setting was secondary prevention in 498 patients (48%). No risk factors was present in 32% of patients, 1 in 27%, 2 in 20% and >2 in 21%, respectively. There was a significant and comprehensible relation between risk score and mortality. Cumulative survival was 82% in patients with 0 risk factors, 63% in those with 1, 41% in those with 2 and 23% in those with >2 risk factors (p < 0.0001). ICD therapies were documented in 421 patients (41%) without correlation to risk factors. CONCLUSIONS: In a mixed population of primary and secondary preventive ICD carriers, application of a simple risk score predicts long-term mortality but not appropriate use of the ICD.