Study of Antibody-Coated Fungi in Patients with Funguria and Suspected Disseminated Fungal Infections or Primary Fungal Pyelonephritis

The direct immunofluorescence method for the detection of antibody-coated bacteria in urine sediments has been used by investigators to distinguish invasive bacterial disease of the renal parenchyma from noninvasive bladder bacteriuria. The purpose of the present investigation was to test the usefulness of the demonstration of urinary fungal immunoglobulins and complement in distinguishing patients with fungal cystitis from those with suspected disseminated fungal disease. Twenty-one patients with microscopic funguria were suspected clinically of having disseminated fungal infection. Urine specimens from these patients were tested for the presence of antibody- and complement-coated fungi by direct immunofluorescence with the use of specific goat antisera to human immunoglobulins and complement. No unexpected frequencies of combinations of urinary yeast staining by specific antibody were noted. Urine specimens demonstrating funguria from 12 patients with uncomplicated illnesses were also examined for the presence of antibody- and complement-coated fungi; no unexpected frequencies of combinations of urinary yeast staining were noted in this group and no differences in frequencies of specific antibody staining were noted when compared with results in patients with suspected invasive fungal disease. Thus, no difference in the occurrence of specific antibody or complement adsorbed to urinary yeasts was observed between patients suspected of having invasive fungal disease and a small group of control patients.

FUNCTIONAL LIMITATIONS AND ADIPOKINES IN HIV-INFECTED OLDER ADULTS

BACKGROUND

There is a significant increase in the number of HIV-infected older adults (HOA). This population may experience functional decline at a much younger age. Little is known about the relationship between functional limitations and systemic adipokines in HOA.

OBJECTIVE

Our study aimed to evaluate the relationship between functional limitations and systemic adipokine levels in HOA population.

DESIGN

Cross-sectional.

SETTING

Academic hospital-based infectious disease clinic.

PARTICIPANTS

The study investigated community-dwelling HIV-infected adults >50 years old and compared this group with age, gender and BMI comparable healthy controls.

MEASUREMENTS

We measured functional status, body composition and plasma concentrations of adipokines.

RESULTS

Fifty-four HOA were studied (mean: age 57 years, BMI 29 kg/m2, CD4 604, duration of HIV 17 years) and compared with thirty-two age, gender and BMI comparable healthy controls. The HOA group showed significantly higher functional limitations compared to the age, gender and BMI comparable controls (p<0.05). Levels of adipokines were significantly different between the two groups (p<0.05). Multiple regression analyses indicated that adiponectin and visfatin were significantly correlated with several physical function measures after controlling for age, sex, and metabolic comorbidities. Adiponectin was negatively correlated with functional limitations, and this relationship was stronger in the control group compared to the HOA group. Conversely, visfatin was positively correlated with functional limitations only in the HOA group.

CONCLUSION

HOA have significant functional limitations and alteration in adipokine levels compared to controls. Adiponectin and visfatin were associated with functional limitations. Visfatin was a correlate of physical function only in the HOA group. Prospective longitudinal studies could provide further insight on the role of adipokines in HIV-related functional decline.

Survival benefit of primary prevention implantable cardioverter-defibrillator therapy after myocardial infarction: does time to implant matter? A meta-analysis using patient-level data from 4 clinical trials

BACKGROUND

Whether there is an optimal time to place an implantable cardioverter-defibrillator (ICD) more than 40 days after myocardial infarction (MI) in guideline-eligible patients is unknown.

OBJECTIVE

To evaluate the effect of time from MI to randomization on mortality, rehospitalizations, and complications.

METHODS

Individual data on patients enrolled in 9 primary prevention ICD trials were provided. Clinical trials were eligible for the current analysis if they enrolled patients with an MI more than 40 days prior to randomization to primary prevention ICD therapy vs usual care: Multicenter Automatic Defibrillator Implantation Trial I, Multicenter UnSustained Tachyardia Trial, Multicenter Automatic Defibrillator Implantation Trial II, and Sudden Cardiac Death in Heart Failure Trial.

RESULTS

ICD recipients died less frequently than nonrecipients at 5 years across all subgroups of time from MI to randomization. In unadjusted Cox proportional hazards regression, a survival benefit was evident in most subgroups. Adjusted Bayesian Weibull survival modeling yielded hazard ratio (HR) 0.50, 95% posterior credible interval (PCI) 0.20-1.25 41-180 days after MI; HR 0.98, 95% PCI 0.37-2.37 181-365 days after MI; HR 0.22, 95% PCI 0.07-0.59>1-2 years after MI; HR 0.42, 95% PCI 0.17-0.90>2-5 years after MI; HR 0.55, 95% PCI 0.25-1.15>5-10 years after MI; and HR 0.48, 95% PCI 0.20-1.02>10 years after MI. There was no evidence of an interaction between time from MI and all-cause mortality, rehospitalizations, or complications.

CONCLUSIONS

In this meta-analysis, there was scant evidence that the efficacy of primary prevention ICD therapy depends on time to implantation more than 40 days after MI. Similarly, there was no evidence that the risks of rehospitalizations or complications depend on time more than 40 days after MI.

Survival of patients receiving a primary prevention implantable cardioverter-defibrillator in clinical practice vs clinical trials

IMPORTANCE

Randomized clinical trials have shown that implantable cardioverter-defibrillator (ICD) therapy saves lives. Whether the survival of patients who received an ICD in primary prevention clinical trials differs from that of trial-eligible patients receiving a primary prevention ICD in clinical practice is unknown.

OBJECTIVE

To determine whether trial-eligible patients who received a primary prevention ICD as documented in a large national registry have a survival rate that differs from the survival rate of similar patients who received an ICD in the 2 largest primary prevention clinical trials, MADIT-II (n = 742) and SCD-HeFT (n = 829).

DESIGN, SETTING, AND PATIENTS

Retrospective analysis of data for patients enrolled in the National Cardiovascular Data Registry ICD Registry between January 1, 2006, and December 31, 2007, meeting the MADIT-II criteria (2464 propensity score-matched patients) or the SCD-HeFT criteria (3352 propensity score-matched patients). Mortality data for the registry patients were collected through December 31, 2009.

MAIN OUTCOME MEASURES

Cox proportional hazards models were used to compare mortality from any cause.

RESULTS

The median follow-up time in MADIT-II, SCD-HeFT, and the ICD Registry was 19.5, 46.1, and 35.2 months, respectively. Compared with patients enrolled in the clinical trials, patients in the ICD Registry were significantly older and had a higher burden of comorbidities. In the matched cohorts, there was no significant difference in survival between MADIT-II-like patients in the registry and MADIT-II patients randomized to receive an ICD (2-year mortality rates: 13.9% and 15.6%, respectively; adjusted ICD Registry vs trial hazard ratio, 1.06; 95% CI, 0.85-1.31; P = .62). Likewise, the survival among SCD-HeFT-like patients in the registry was not significantly different from survival among patients randomized to receive ICD therapy in SCD-HeFT (3-year mortality rates: 17.3% and 17.4%, respectively; adjusted registry vs trial hazard ratio, 1.16; 95% CI, 0.97-1.38; P = .11).

CONCLUSIONS AND RELEVANCE

There was no significant difference in survival between clinical trial patients randomized to receive an ICD and a similar group of clinical registry patients who received a primary prevention ICD. Our findings support the continued use of primary prevention ICDs in similar patients seen in clinical practice.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00000609.

Multicenter automatic defibrillator implantation trial: reduce inappropriate therapy (MADIT-RIT): background, rationale, and clinical protocol

The implantable cardioverter defibrillator (ICD) is highly effective in reducing mortality due to cardiac arrhythmias in high-risk cardiac patients. However, inappropriate therapies caused predominantly by supraventricular tachyarrhythmias (SVTs) remain a significant side effect of ICD therapy despite medical treatment, affecting 8-40% of patients. The MADIT-RIT is a global, prospective, randomized, nonblinded, three-arm, multicenter clinical investigation to be performed in the Unites States, Europe, Canada, Israel and Japan, and will utilize approximately 90 centers with plan to enroll 1500 patients programmed to three treatment arms. The objective of the MADIT-RIT trial is to determine if dual-chamber ICD or CRT-D devices with high rate cutoff (MADIT-RIT-Arm B) and/or long delay in combination with detection enhancements (MADIT-RIT-Arm C) are associated with fewer patients experiencing inappropriate therapies than standard programming (MADIT-RIT-Arm A) during postimplant follow-up of patients with indication for primary prevention device therapy. This paper describes design and analytic plan for the MADIT-RIT trial.

Reduction in inappropriate therapy and mortality through ICD programming

BACKGROUND

The implantable cardioverter-defibrillator (ICD) is highly effective in reducing mortality among patients at risk for fatal arrhythmias, but inappropriate ICD activations are frequent, with potential adverse effects.

METHODS

We randomly assigned 1500 patients with a primary-prevention indication to receive an ICD with one of three programming configurations. The primary objective was to determine whether programmed high-rate therapy (with a 2.5-second delay before the initiation of therapy at a heart rate of ≥200 beats per minute) or delayed therapy (with a 60-second delay at 170 to 199 beats per minute, a 12-second delay at 200 to 249 beats per minute, and a 2.5-second delay at ≥250 beats per minute) was associated with a decrease in the number of patients with a first occurrence of inappropriate antitachycardia pacing or shocks, as compared with conventional programming (with a 2.5-second delay at 170 to 199 beats per minute and a 1.0-second delay at ≥200 beats per minute).

RESULTS

During an average follow-up of 1.4 years, high-rate therapy and delayed ICD therapy, as compared with conventional device programming, were associated with reductions in a first occurrence of inappropriate therapy (hazard ratio with high-rate therapy vs. conventional therapy, 0.21; 95% confidence interval [CI], 0.13 to 0.34; P<0.001; hazard ratio with delayed therapy vs. conventional therapy, 0.24; 95% CI, 0.15 to 0.40; P<0.001) and reductions in all-cause mortality (hazard ratio with high-rate therapy vs. conventional therapy, 0.45; 95% CI, 0.24 to 0.85; P=0.01; hazard ratio with delayed therapy vs. conventional therapy, 0.56; 95% CI, 0.30 to 1.02; P=0.06). There were no significant differences in procedure-related adverse events among the three treatment groups.

CONCLUSIONS

Programming of ICD therapies for tachyarrhythmias of 200 beats per minute or higher or with a prolonged delay in therapy at 170 beats per minute or higher, as compared with conventional programming, was associated with reductions in inappropriate therapy and all-cause mortality during long-term follow-up. (Funded by Boston Scientific; MADIT-RIT ClinicalTrials.gov number, NCT00947310.).

Cardiac resynchronization and quality of life in patients with minimally symptomatic heart failure

OBJECTIVES

This study compared the quality of life (QOL) of patients with cardiac resynchronization therapy (CRT) and an implantable cardioverter-defibrillator (ICD) to patients with an ICD only.

BACKGROUND

CRT with ICD is associated with a reduction in heart failure risk among minimally symptomatic patients. It is unknown whether this improves QOL.

METHODS

This study uses the MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy) data. The MADIT-CRT enrolled 1,820 patients at 110 centers across 14 countries. Patients had ischemic cardiomyopathy (New York Heart Association [NYHA] functional class I or II) or nonischemic cardiomyopathy (NYHA functional class II only), sinus rhythm, an ejection fraction of 30% or less, and prolonged intraventricular conduction with a QRS duration of 130 ms or more. QOL was evaluated on the 1,699 patients with baseline and follow-up measures using the Kansas City Cardiomyopathy Questionnaire (KCCQ). Six dimensions (Physical Limitation, Symptom Stability, Symptom Frequency, Symptom Burden, Quality of Life, and Social Limitations) and 3 summary scores (Total Symptom, Clinical Summary, and Overall Summary) were analyzed.

RESULTS

During an average follow-up of 2.4 years, the CRT-ICD group had greater improvement than the ICD-only group on all KCCQ measures (p < 0.05 on each scale). These differences were significant among patients with left bundle branch block conduction disturbance (n = 1,204, p < 0.01 on each scale), but not among patients without left bundle branch block (n = 494).

CONCLUSIONS

Compared with patients with ICD only, CRT-ICD is associated with greater improvement in QOL among relatively asymptomatic patients, specifically among those with left bundle branch conduction disturbance.

Predictors of response to cardiac resynchronization therapy in the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT)

BACKGROUND

We hypothesized that combined assessment of factors that are associated with favorable reverse remodeling after cardiac resynchronization-defibrillator therapy (CRT-D) can be used to predict clinical response to the device.

METHODS AND RESULTS

The study population comprised 1761 patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy (MADIT-CRT). Best-subset regression analysis was performed to identify factors associated with echocardiographic response (defined as percent reduction in left ventricular end-diastolic volume 1 year after CRT-D implantation) and to create a response score. Cox proportional hazards regression analysis was used to evaluate the CRT-D versus defibrillator-only reduction in the risk of heart failure or death by the response score. Seven factors were identified as associated with echocardiographic response to CRT-D and made up the response score (female sex, nonischemic origin, left bundle-branch block, QRS ≥150 milliseconds, prior hospitalization for heart failure, left ventricular end-diastolic volume ≥125 mL/m(2), and left atrial volume <40 mL/m(2)). Multivariate analysis showed a 13% (P<0.001) increase in the clinical benefit of CRT-D per 1-point increment in the response score (range, 0-14) and a significant direct correlation between risk reduction associated with CRT-D and response score quartiles: Patients in the first quartile did not derive a significant reduction in the risk of heart failure or death with CRT-D (hazard ratio=0.87; P=0.52); patients in the second and third quartiles derived 33% (P=0.04) and 36% (P=0.03) risk reductions, respectively; and patients in the upper quartile experienced a 69% (P<0.001) risk reduction (P for trend=0.005).

CONCLUSION

Combined assessment of factors associated with reverse remodeling can be used for improved selection of patients for cardiac resynchronization therapy. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00180271.

Risk of recurrent cardiac events after onset of menopause in women with congenital long-QT syndrome types 1 and 2

BACKGROUND

Women with congenital long-QT syndrome experience an increased risk for cardiac events after the onset of adolescence that is more pronounced among carriers of the LQT2 genotype. We hypothesized that the hormonal changes associated with menopause may affect clinical risk in this population.

METHODS AND RESULTS

We used a repeated-events analysis to evaluate the risk for recurrent syncope during the menopause transition and postmenopausal periods (5 years before and after the age at onset of menopause, respectively) among 282 LQT1 (n=151) and LQT2 (n=131) women enrolled in the Long-QT Syndrome Registry. Multivariate analysis showed that the risk for recurrent syncope (n=150) among LQT2 women was significantly increased during both menopause transition (hazard ratio, 3.38; P=0.005) and the postmenopausal period (hazard ratio, 8.10; P<0.001) compared with the reproductive period. The risk increase was evident among women who did or did not receive estrogen therapy. In contrast, among LQT1 women, the onset of menopause was associated with a reduction in the risk for recurrent syncope (hazard ratio, 0.19; P=0.05; P=0.02 for genotype-by-menopause interaction). Only 22 women (8%) experienced aborted cardiac arrest or sudden cardiac death during follow-up. The frequency of aborted cardiac arrest/sudden cardiac death showed a similar genotype-specific association with the onset of menopause.

CONCLUSIONS

The onset of menopause is associated with a significant increase in the risk of cardiac events (dominated by recurrent episodes of syncope) in LQT2 women, suggesting that careful follow-up and continued long-term therapy are warranted in this population.

Dyssynchrony, contractile function, and response to cardiac resynchronization therapy

BACKGROUND

Despite benefits of cardiac resynchronization therapy (CRT) in patients with severe but less symptomatic heart failure, approximately 30% of patients do not fully respond to treatment. We hypothesized that a combined assessment of left ventricular (LV) dyssynchrony and contractile function by strain-based imaging would identify patients who would most benefit from CRT.

METHODS AND RESULTS

We studied 1077 patients with New York Heart Association class I/II, LV ejection fraction ≤30% and QRS width ≥130 ms enrolled in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy trial with sufficient echocardiographic image quality for cardiac deformation analysis (implantable cardioverter-defibrillator [ICD], n=416; CRT, n=661). Patients were assigned to CRT plus an ICD or to ICD alone in 3:2 random assignment. We assessed the degree to which baseline echocardiographic assessments of dyssynchrony, measured as the standard deviation of time-to-peak transverse strain over 12 segments, contractile function, measured as global longitudinal strain, or both predicted the effect of treatment on the primary outcome of death or heart failure. With 213 primary events occurring over a mean of 2.4 years, the benefit of CRT plus an ICD relative to ICD alone was greatest in patients with mild to moderate dyssynchrony (time-to-peak transverse strain standard deviation, 142 to 230 ms) and greater baseline contractile function (global longitudinal strain ≤-8.7%). Overall, those patients with mild to moderate dyssynchrony and those with best contractile function at baseline demonstrated the greatest benefit from CRT (adjusted hazards ratio, 0.20; 95% confidence interval, 0.09 to 0.44). Dyssynchrony and global longitudinal strain predicted response to CRT independent of each other, QRS width, LV ejection fraction, and presence versus absence of left bundle-branch block, although the observed benefit remained greatest in patients with left bundle-branch block.

CONCLUSIONS

Both mechanical dyssynchrony and contractile function are important independent correlates of benefit from CRT.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00180271.

Effectiveness of Cardiac Resynchronization Therapy by QRS Morphology in the Multicenter Automatic Defibrillator Implantation Trial–Cardiac Resynchronization Therapy (MADIT-CRT)

Background—

This study aimed to determine whether QRS morphology identifies patients who benefit from cardiac resynchronization therapy with a defibrillator (CRT-D) and whether it influences the risk of primary and secondary end points in patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial–Cardiac Resynchronization Therapy (MADIT-CRT) trial.

Methods and Results—

Baseline 12-lead ECGs were evaluated with regard to QRS morphology. Heart failure event or death was the primary end point of the trial. Death, heart failure event, ventricular tachycardia, and ventricular fibrillation were secondary end points. Among 1817 patients with available sinus rhythm ECGs at baseline, there were 1281 (70%) with left bundle-branch block (LBBB), 228 (13%) with right bundle-branch block, and 308 (17%) with nonspecific intraventricular conduction disturbances. The latter 2 groups were defined as non-LBBB groups. Hazard ratios for the primary end point for comparisons of CRT-D patients versus patients who only received an implantable cardioverter defibrillator (ICD) were significantly ( P <0.001) lower in LBBB patients (0.47; P <0.001) than in non-LBBB patients (1.24; P =0.257). The risk of ventricular tachycardia, ventricular fibrillation, or death was decreased significantly in CRT-D patients with LBBB but not in non-LBBB patients. Echocardiographic parameters showed significantly ( P <0.001) greater reduction in left ventricular volumes and increase in ejection fraction with CRT-D in LBBB than in non-LBBB patients.

Conclusions—

Heart failure patients with New York Heart Association class I or II and ejection fraction ≤30% and LBBB derive substantial clinical benefit from CRT-D: a reduction in heart failure progression and a reduction in the risk of ventricular tachyarrhythmias. No clinical benefit was observed in patients with a non-LBBB QRS pattern (right bundle-branch block or intraventricular conduction disturbances).

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00180271.

Time-dependent benefit of preventive cardiac resynchronization therapy after myocardial infarction

AIMS

Cardiac remodelling is a progressive process after myocardial infarction (MI). However, currently there are no data regarding the effect of s:elapsed time from MI on the benefit of cardiac resynchronization therapy with defibrillator (CRT-D). The present study was designed to evaluate the relationship between elapsed time from MI and the benefit of preventive CRT-D therapy in patients with ischaemic cardiomyopathy (ICM).

METHODS AND RESULTS

The risk of heart failure (HF) or death as a function of elapsed time from MI to enrolment, by treatment with CRT-D vs. implantable cardioverter defibrillator (ICD)-only therapy, was assessed among 704 ICM patients with a documented MI enrolled in MADIT-CRT, and separately in a subset of ICM patients without a documented prior MI (n = 237). In ICD patients, the adjusted risk of HF or death increased by 4% (P = 0.01) for each year elapsed from MI. Multivariate analysis demonstrated that patients with remote MI [categorized at the median value (≥8 years)] derived a significantly greater benefit from CRT-D [HR = 0.42 (P < 0.001)] than those with a more recent MI [HR = 1.26 (P = 0.35); P-value for interaction <0.001]. Consistently, the benefit of CRT-D was directly related to increasing quartiles of elapsed time from MI [Q(1) (<3 years): HR = 1.67; P = 0.20, Q(2) (3-8 years): HR = 1.12; P = 0.71, Q(3) (8-15 years): HR = 0.47; P = 0.02, and Q(4) (≥15 years): HR = 0.38; P = 0.001]. The ICM subgroup with no documented MI also derived enhanced benefit from CRT-D (HR = 0.43; P = 0.003).

CONCLUSION

In patients with ischaemic cardiomyopathy, the risk of HF or death and the magnitude of CRT-D benefit are directly related to elapsed time from MI.

Long-Term Benefit of Primary Prevention With an Implantable Cardioverter-Defibrillator

Background—

The Multicenter Automatic Defibrillator Implantation Trial II (MADIT-II) showed a significant 31 reduction in the risk of death with primary implantable cardioverter-defibrillator (ICD) therapy during a median follow-up of 1.5 years. However, currently there are no data on the long-term efficacy of primary defibrillator therapy.

Methods and Results—

MADIT-II enrolled 1232 patients with ischemic left ventricular dysfunction who were randomized to ICD and non-ICD medical therapy and were followed up through November 2001. For the present long-term study, we acquired posttrial mortality data through March 2009 for all study participants (median follow-up, 7.6 years). Multivariate Cox proportional hazards regression modeling was performed to calculate the hazard ratio for ICD versus non-ICD therapy during long-term follow-up. At 8 years of follow-up, the cumulative probability of all-cause mortality was 49 among patients treated with an ICD compared with 62 among non-ICD patients ( P <0.001). Multivariate analysis demonstrated that ICD therapy was associated with a significant long-term survival benefit (hazard ratio for 0- through 8-year mortality=0.66 [95 confidence interval, 0.56 to 0.78]; P <0.001). Treatment with an ICD was shown to be associated with a significant reduction in the risk of death during the early phase of the extended follow-up period (0 through 4 years: hazard ratio=0.61 [95 confidence interval, 0.50 to 0.76]; P <0.001) and with continued life-saving benefit during the late phase of follow-up (5 through 8 years: hazard ratio=0.74 [95 confidence interval, 0.57 to 0.96]; P =0.02).

Conclusions—

Our findings demonstrate a sustained 8-year survival benefit with primary ICD therapy in the MADIT-II population.

Effect of Cardiac Resynchronization Therapy on Reverse Remodeling and Relation to Outcome

Background— Cardiac resynchronization therapy (CRT) plus implantation of an implantable cardioverter defibrillator (ICD) reduced the risk of death or heart failure event in patients with mildly symptomatic heart failure, left ventricular dysfunction, and wide QRS complex compared with an ICD only. We assessed echocardiographic changes in patients enrolled in the MADIT-CRT trial (Multicenter Automatic Defibrillator Implantation Trial: Cardiac Resynchronization Therapy) to evaluate whether the improvement in outcomes with CRT plus an ICD was associated with favorable alterations in cardiac size and function.

Methods and Results— A total of 1820 patients were randomly assigned to CRT plus an ICD or to an ICD only in a 3:2 ratio. Echocardiographic studies were obtained at baseline and 12 months later in 1372 patients. We compared changes in cardiac size and performance between treatment groups and assessed the relationship between these changes over the first year, as well as subsequent outcomes. Compared with the ICD-only group, the CRT-plus-ICD group had greater improvement in left ventricular end-diastolic volume index (−26.2 versus −7.4 mL/m 2 ), left ventricular end-systolic volume index (−28.7 versus −9.1 mL/m 2 ), left ventricular ejection fraction (11% versus 3%), left atrial volume index (−11.9 versus −4.7 mL/m 2 ), and right ventricular fractional area change (8% versus 5%; P <0.001 for all). Improvement in end-diastolic volume at 1 year was predictive of subsequent death or heart failure, with adjustment for baseline covariates and treatment group; each 10% decrease in end-diastolic volume was associated with a 40% reduction in risk ( P <0.001).

Conclusions— CRT resulted in significant improvement in cardiac size and performance compared with an ICD-only strategy in patients with mildly symptomatic heart failure. Improvement in these measures accounted for the outcomes benefit.

Clinical Trial Registration Information— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00180271.

Cardiac-resynchronization therapy for the prevention of heart-failure events

BACKGROUND

This trial was designed to determine whether cardiac-resynchronization therapy (CRT) with biventricular pacing would reduce the risk of death or heart-failure events in patients with mild cardiac symptoms, a reduced ejection fraction, and a wide QRS complex.

METHODS

During a 4.5-year period, we enrolled and followed 1820 patients with ischemic or nonischemic cardiomyopathy, an ejection fraction of 30% or less, a QRS duration of 130 msec or more, and New York Heart Association class I or II symptoms. Patients were randomly assigned in a 3:2 ratio to receive CRT plus an implantable cardioverter-defibrillator (ICD) (1089 patients) or an ICD alone (731 patients). The primary end point was death from any cause or a nonfatal heart-failure event (whichever came first). Heart-failure events were diagnosed by physicians who were aware of the treatment assignments, but they were adjudicated by a committee that was unaware of assignments.

RESULTS

During an average follow-up of 2.4 years, the primary end point occurred in 187 of 1089 patients in the CRT-ICD group (17.2%) and 185 of 731 patients in the ICD-only group (25.3%) (hazard ratio in the CRT-ICD group, 0.66; 95% confidence interval [CI], 0.52 to 0.84; P=0.001). The benefit did not differ significantly between patients with ischemic cardiomyopathy and those with nonischemic cardiomyopathy. The superiority of CRT was driven by a 41% reduction in the risk of heart-failure events, a finding that was evident primarily in a prespecified subgroup of patients with a QRS duration of 150 msec or more. CRT was associated with a significant reduction in left ventricular volumes and improvement in the ejection fraction. There was no significant difference between the two groups in the overall risk of death, with a 3% annual mortality rate in each treatment group. Serious adverse events were infrequent in the two groups.

CONCLUSIONS

CRT combined with ICD decreased the risk of heart-failure events in relatively asymptomatic patients with a low ejection fraction and wide QRS complex. (ClinicalTrials.gov number, NCT00180271.)

The effect of ketamine and saffan on the beta-endorphin and ACTH response to hemorrhage in the minipig

The endocrine response is an important component of the physiological response to blood loss. There is some variability in reported levels of certain hormones during hemorrhage such as the stress hormone adrenocorticotrophic hormone (ACTH). Therefore, the effect of two anesthetic agents, ketamine and saffan, on ACTH and beta-endorphin levels during hemorrhage was assessed in 12 minipigs. The animals were divided into two groups, group I saffan and group II ketamine (n=6). Pigs were subjected to a continuous fixed volume hemorrhage under one of the above anesthetics while spontaneously breathing. Blood pressure and heart rate responses were recorded together with beta-endorphin and ACTH levels both before and at 10, 20, 30, 40 min after the onset of bleeding. ACTH levels were higher in the ketamine-anesthetized pigs and rose significantly faster with falling blood pressure than ACTH measured in pigs under saffan anesthesia. In contrast, the hemorrhage induced beta-endorphin increase was not significantly different between the two anesthetic groups. These results indicate that choice of anesthetic agent is important when investigating the hormone response to hemorrhage and may account for the variable hormone levels in the published literature to date.

Mechanisms of ventricular fibrillation initiation in MADIT II patients with implantable cardioverter defibrillators

BACKGROUND

The availability of stored intracardiac electrograms from implantable defibrillators (ICDs) has facilitated the study of the mechanisms of ventricular tachyarrhythmia onset. This study aimed to determine the patterns of initiation of ventricular fibrillation (VF) in Multicenter Automatic Defibrillator Implantation Trial (MADIT) II patients along with associated electrocardiogram (ECG) parameters and clinical characteristics.

METHODS

Examination of stored electrograms enabled us to evaluate the rhythm preceding each episode of VF and to calculate (intracardiac) ECG parameters including QT, QT peak (QTp), coupling interval, and prematurity index.

RESULTS

Sixty episodes of VF among 29 patients (mean age 64.4 +/- 2.5 years) were identified. A single ventricular premature complex (VPC) initiated 46 (77%) episodes whereas a short-long-short (SLS) sequence accounted for 14 (23%) episodes. Of the 29 patients studied, 23 patients had VF episodes preceded by a VPC only, two patients with SLS only, and four patients with both VPC and SLS-initiated episodes. There were no significant differences between initiation patterns in regards to the measured ECG parameters; a faster heart rate with SLS initiation (mean RR prior to VF of 655 +/- 104 ms for SLS and 744 +/- 222 ms for VPC) approached significance (P = 0.06). The two patients with SLS only were not on beta-blockers compared to 83% of the VPC patients.

CONCLUSION

Ventricular fibrillation is more commonly initiated by a VPC than by a SLS sequence among the MADIT II population. Current pacing modes designed to prevent bradycardia and pause-dependent arrhythmias are unlikely to decrease the incidence of VPC-initiated episodes of VF.

Inappropriate implantable cardioverter-defibrillator shocks in MADIT II: frequency, mechanisms, predictors, and survival impact

OBJECTIVES

This study sought to identify the incidence and outcome related to inappropriate implantable cardioverter-defibrillator (ICD) shocks, that is, those for nonventricular arrhythmias.

BACKGROUND

The MADIT (Multicenter Automatic Defibrillator Implantation Trial) II showed that prophylactic ICD implantation improves survival in post-myocardial infarction patients with reduced ejection fraction. Inappropriate ICD shocks are common adverse consequences that may impair quality of life.

METHODS

Stored ICD electrograms from all shock episodes were adjudicated centrally. An inappropriate shock episode was defined as an episode during which 1 or more inappropriate shocks occurred; another inappropriate ICD episode occurring within 5 min was not counted. Programmed parameters for patients with and without inappropriate shocks were compared.

RESULTS

One or more inappropriate shocks occurred in 83 (11.5%) of the 719 MADIT II ICD patients. Inappropriate shock episodes constituted 184 of the 590 total shock episodes (31.2%). Smoking, prior atrial fibrillation, diastolic hypertension, and antecedent appropriate shock predicted inappropriate shock occurrence. Atrial fibrillation was the most common trigger for inappropriate shock (44%), followed by supraventricular tachycardia (36%), and then abnormal sensing (20%). The stability detection algorithm was programmed less frequently in patients receiving inappropriate shocks (17% vs. 36%, p = 0.030), whereas other programming parameters did not differ significantly from those without inappropriate shocks. Importantly, patients with inappropriate shocks had a greater likelihood of all-cause mortality in follow-up (hazard ratio 2.29, p = 0.025).

CONCLUSIONS

Inappropriate ICD shocks occurred commonly in the MADIT II study, and were associated with increased risk of all-cause mortality.

Risk stratification for primary implantation of a cardioverter-defibrillator in patients with ischemic left ventricular dysfunction

OBJECTIVES

The study was designed to develop a simple risk stratification score for primary therapy with an implantable cardioverter-defibrillator (ICD).

BACKGROUND

Current guidelines recommend primary ICD therapy in patients with a low ejection fraction (EF). However, the benefit of the ICD in the low EF population may not be uniform.

METHODS

Best-subset proportional-hazards regression analysis was used to develop a simple clinical risk score for the end point of all-cause mortality in patients allocated to the conventional therapy arm of MADIT (Multicenter Automatic Defibrillator Implantation Trial)-II after excluding a pre-specified subgroup of very high-risk (VHR) patients (defined by blood urea nitrogen [BUN] >or=50 mg/dl and/or serum creatinine >or=2.5 mg/dl). The benefit of the ICD was then assessed within risk score categories and separately in VHR patients.

RESULTS

The selected risk score model comprised 5 clinical factors (New York Heart Association functional class >II, age >70 years, BUN >26 mg/dl, QRS duration >0.12 s, and atrial fibrillation). Crude mortality rates in the conventional group were 8% and 28% in patients with 0 and >or=1 risk factors, respectively, and 43% in VHR patients. Defibrillator therapy was associated with a 49% reduction in the risk of death (p < 0.001) among patients with >or=1 risk factors (n = 786), whereas no ICD benefit was identified in patients with 0 risk factors (n = 345; hazard ratio 0.96; p = 0.91) and in VHR patients (n = 60; hazard ratio 1.00; p > 0.99).

CONCLUSIONS

Our data suggest a U-shaped pattern for ICD efficacy in the low-EF population, with pronounced benefit in intermediate-risk patients and attenuated efficacy in lower- and higher-risk subsets.

Pyrolysis of waste electrical and electronic equipment: effect of antinomy trioxide on the pyrolysis of styrenic polymers

This work has investigated the effect that antimony trioxide has on the pyrolysis of styrenic polymers and the effect that different types of brominated flame retardants used in plastics have on the composition of the pyrolysis products. Brominated high impact polystyrene (Br-HIPS) which contained either 5% or 0% antimony trioxide and either decabromodiphenyl oxide (DDO) or decabromodiphenyl ethane (DDE) was pyrolysed in a fixed bed reactor at 430 degrees C. Some experiments on the fixed bed reactor involved mixing the Br-HIPS with polystyrene. The gaseous products were analysed by GC-FID and GC-TCD and it was found that antimony trioxide caused an increase in the proportion of ethane and ethene and suppressed the proportion of butane and butene. When DDE was the flame retardant increased proportions of ethane and ethene were found in the pyrolysis gas compared to when DDO used. When polystyrene was mixed with the Br-HIPS it suppressed the trends observed in the gas composition during the pyrolysis of Br-HIPS. The pyrolysis oils were characterised using FT-IR, GC-MS, GC-FID, and GC-ECD. It was found that the plastic which did not contain antimony trioxide pyrolysed to form mainly toluene, ethylbenzene, styrene, cumene, and alpha-methylstyrene. The oils produced from the pyrolysis of the plastic that contained antimony trioxide did not contain any styrene or alpha-methylstyrene, but instead contained greater concentrations of ethylbenzene and cumene. The absence of styrene and alpha-methylstyrene from the pyrolysis oil occurred even when the Br-HIPS was mixed with polystyrene. GC-ECD analysis of the oils showed that the plastics which did not contain antimony trioxide pyrolysed to form (1-bromoethyl)benzene, which was totally absent from the pyrolysis oils when antimony trioxide was present in the plastic.

Improved Survival Associated with Prophylactic Implantable Defibrillators in Elderly Patients with Prior Myocardial Infarction and Depressed Ventricular Function: A MADIT-II Substudy

INTRODUCTION

We aim to evaluate the mortality benefit from defibrillator therapy in eligible elderly patients. Effective primary prevention of sudden cardiac death with implantable cardioverter defibrillators is well demonstrated in patients with coronary disease and depressed ventricular function.

METHODS AND RESULTS

Among 1,232 patients enrolled with prior infarct and left ventricular ejection fraction < or = 0.30, 204 were > or = 75 years old. Of these 204 patients, 121 underwent defibrillator implant. Relative to the younger patients, those > or = 75 years had a higher incidence of atrial fibrillation, elevated blood urea nitrogen (BUN), widened QRS, and lower use of beta-blockers and HMG-CoA reductase inhibitors. Relevant clinical covariates were similar in elderly patients randomized to conventional and defibrillator therapy. The hazard ratio for the mortality risk in patients > or = 75 years assigned to defibrillator implant compared with those in conventional therapy was 0.56 (95 confidence interval 0.29-1.08; P = 0.08) after a mean follow-up of 17.2 months. Comparatively, the hazard ratio in patients < 75 years assigned to defibrillator implant was 0.63 (0.45-0.88; P = 0.01) after 20.8 months. Elderly patients had similar reductions in quality of life (QoL) regardless of treatment randomization. Scores through Health Utilities Index Mark III (HUI) Questionnaire changes from baseline to 1 year were -0.22 for patients with conventional therapy versus -0.20 for patients with ICD, and -0.36 versus -0.27 at 2 years, respectively (P = NS).

CONCLUSION

The implantable defibrillator is associated with an equivalent reduction of mortality in elderly and younger patients, with no compromise in the QoL in the older age subjects.

Health-Related Quality of Life Consequences of Implantable Cardioverter Defibrillators

BACKGROUND

Implantable cardioverter defibrillators (ICDs) improve survival and extend lives of patients with severe heart disease.

OBJECTIVE

We sought to evaluate the impact of ICDs on health-related quality of life (HRQOL) during the first 3 years after implantation.

SUBJECTS

A total of 1089 patients from the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) were randomized to an ICD or medical treatment only.

MEASURES

Health Utility Index (HUI3) at baseline, 3, 12, 24, and 36 months following randomization; survival data.

RESEARCH DESIGN

We constructed mean profiles of HRQOL for living patients, estimated overall quality-adjusted life years (QALYs), separately by treatment arm, and calculated cumulative QALY gains/losses as the difference between the areas under the treatment specific HRQOL profiles. Multivariate fixed effect regression models were developed to impute the missing HRQOL data using baseline patient characteristics (age, gender, treatment, HUI3 score, diabetes, diuretics use, and NYHA class). Bootstrapped standard errors were calculated for the estimated differences in HRQOL gains/losses between treatment arms. Similarly, we performed subgroup analyses (by gender, age, and baseline NYHA class, blood urine nitrogen, ejection fraction, and QRS).

RESULTS

There were no differences in QALYs loss for living patients by treatment group (-0.037, P = 0.64) or in overall QALYs loss by treatment group (0.043, P = 0.37) over 3 years. In subgroup analysis, female subjects demonstrated a trend towards greater survival benefit (0.298, P = 0.07) and overall QALYs (0.261, P = 0.14).

CONCLUSIONS

Adverse effects of the ICD on HRQOL together with lower HRQOL among survivors may offset the 3-year survival benefits of ICDs.

Inverse Relationship of Blood Pressure Levels to Sudden Cardiac Mortality and Benefit of the Implantable Cardioverter-Defibrillator in Patients With Ischemic Left Ventricular Dysfunction

OBJECTIVES

This study was designed to evaluate the relationship among blood pressure (BP) levels, risk of sudden cardiac death (SCD), and benefit of the implantable cardioverter-defibrillator (ICD) in patients with ischemic left ventricular (LV) dysfunction.

BACKGROUND

Low BP has been shown to be associated with increased mortality in patients with LV dysfunction and heart failure. We hypothesized that increasing BP levels are associated with a reduction in the risk of SCD in this population, thereby limiting ICD efficacy in a lower-risk subset.

METHODS

The independent contribution of systolic blood pressure (SBP) and diastolic blood pressure (DBP) to outcome was analyzed in 1,231 patients enrolled in the prospective MADIT-II (Multicenter Automatic Defibrillator Implantation Trial II).

RESULTS

Multivariate analysis showed that in the conventional therapy arm of the trial, 10-mm Hg increments in systolic BP were independently associated with a respective 14% (p = 0.01) and 16% (p = 0.04) reduction in the risk of cardiac mortality and SCD; similar trends were shown for DBP. Defibrillator therapy provided the least survival benefit to patients in the lower-risk, upper SBP (>130 mm Hg) and DBP (>/=80 mm Hg) quartiles (hazard ratio 1.04 [p = 0.89] and 1.05 [p = 0.88], respectively), whereas a respective 39% and 38% (p = 0.002) reduction in the risk of death with ICD therapy was observed among patients with lower BP values.

CONCLUSIONS

In patients with ischemic LV dysfunction, SBP and DBP levels show an inverse correlation with sudden cardiac mortality. These noninvasive hemodynamic parameters may be useful for identifying lower-risk patients, in whom the benefit of primary defibrillator implantation is more limited.

Prognostic value of location and type of myocardial infarction in the setting of advanced left ventricular dysfunction

Location (anterior) and type (Q wave) of myocardial infarction (MI) might be considered of prognostic significance when predicting mortality. However, there are limited data regarding the prognostic significance of type and location of MI in patients with severely depressed left ventricular function. In 1,221 patients in the MADIT II, Q-wave MI was observed in 763 patients (62%), 115 (10%) had non-Q-wave MI, and 343 (28%) had conduction abnormalities. In patients with Q-wave MI, anterior MI was present in 430 (57%), inferior in 155 (20%), and combined in 178 (23%) patients. Study end points included all-cause mortality, hospitalization or death due to worsening congestive heart failure, and episodes of ventricular tachycardia or ventricular fibrillation requiring implantable cardioverter-defibrillator therapy. In a multivariate Cox proportional hazard model predicting mortality, the following clinical variables entered the predictive model at a p value <0.10: treatment (implantable cardioverter-defibrillator vs conventional therapy), age dichotomized at 65 years, angina pectoris, ejection fraction dichotomized at 25%, serum urea nitrogen dichotomized at 25 mg/dl, and beta-blocker use. After adjustment for these covariates, risk of mortality was not significantly different in non-Q-wave MI versus Q-wave MI. However, when analyzing location of MI, inferior wall MI was associated with a significantly (hazard ratio 1.58, p = 0.048) higher risk of mortality than anterior wall MI. In addition, patients with conduction abnormalities had a higher risk of mortality (hazard ratio 1.36, p = 0.088) than patients with anterior wall MI. In conclusion, in the setting of severely depressed ejection fraction (< or =30%), inferior wall MI was associated with a significantly higher risk of mortality than anterior wall MI.

Long QT syndrome in adults

OBJECTIVES

The aims of this study were: 1) to evaluate risk factors influencing the clinical course of mutation-confirmed adult patients with long QT syndrome (LQTS), 2) to study life-threatening cardiac events as a specific end point in adults, and 3) to examine the protective effect of beta-blocker therapy on cardiac events in adult LQTS patients with known cardiac channel mutations.

BACKGROUND

The clinical course and risk factors for cardiac events in genotype-confirmed adult patients with LQTS have not been previously investigated.

METHODS

The clinical characteristics of 812 mutation-confirmed LQTS patients age 18 years or older were studied with both univariate and multivariate analyses to determine the genotype-phenotype factors that influence the clinical course of adult patients with this disorder.

RESULTS

Female gender, corrected QT (QTc) interval, LQT2 genotype, and frequency of cardiac events before age 18 years were associated with increased risk of having any cardiac events between the ages of 18 and 40 years. Female gender, QTc interval > or =500 ms, and interim syncopal events during follow-up after age 18 years were associated with significantly increased risk of life-threatening cardiac events in adulthood. Beta-blockers provided a 60% reduction in risk of any cardiac event and life-threatening events, with somewhat greater effect in higher-risk subjects.

CONCLUSIONS

The severity of LQTS in adulthood can be risk stratified with information regarding genotype, gender, QTc duration, and history of cardiac events. Beta-blockers effectively reduce but do not eliminate the risk of both syncopal and life-threatening cardiac events in adult patients with mutation-confirmed LQTS.

Physical functioning and mental well-being in association with health outcome in patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial II

AIMS

The association of psychosocial and physical factors with health outcome in patients with congestive heart failure (CHF) has not been fully explored. The aim of this study was to assess the physical and mental health in relationship to health outcome in post-infarction patients with advanced left ventricular dysfunction.

METHODS AND RESULTS

A total of 1058 patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) completed the Medical Outcome Trust Short Form (SF-12) at baseline. Physical component summary (PCS) and mental component summary (MCS) of SF-12 were analysed in relationship to survival, hospitalization due to CHF, and implantable cardioverter-defibrillator (ICD) therapy. Both baseline PCS and MCS were significantly associated with death (P < 0.001 and P < 0.016, respectively) and hospitalization due to CHF (P <or= 0.001). After adjustment for significant clinical covariates and treatment group, low PCS and low MCS groups remained significant predictors of mortality and CHF hospitalization. Neither PCS nor MCS was associated with appropriate ICD therapy for ventricular tachyarrhythmias. Patients who experienced appropriate ICD shocks had a statistically significant deterioration of PCS but not MCS from baseline to 12 months.

CONCLUSION

Lower baseline PCS and MCS are associated with unfavourable health outcome in MADIT II patients, but not with appropriate ICD therapy for ventricular tachyarrhythmias. Patients who experience ICD shock reported a decrease in PCS, but little or no changes in MCS.

Cigarette Smoking and the Risk of Supraventricular and Ventricular Tachyarrhythmias in High-Risk Cardiac Patients with Implantable Cardioverter Defibrillators

INTRODUCTION

Nicotine elevates serum catecholamine concentration and is therefore potentially arrhythmogenic. However, the effect of cigarette smoking on arrhythmic risk in coronary heart disease patients is not well established.

METHODS AND RESULTS

The risk of appropriate and inappropriate defibrillator therapy by smoking status was analyzed in 717 patients who received an implantable cardioverter defibrillator (ICD) in the Multicenter Automatic Defibrillator Implantation Trial-II. Compared with patients who had quit smoking before study entry (past smokers) and patients who had never smoked (never smokers), patients who continued smoking (current smokers) were significantly younger and generally had more favorable baseline clinical characteristics. Despite this, the adjusted hazard ratio (HR) for appropriate ICD therapy for fast ventricular tachycardia (at heart rates >or=180 b.p.m) or ventricular fibrillation was highest among current smokers (HR = 2.11 [95% CI 1.11-3.99]) and intermediate among past smokers (HR = 1.57 [95% CI 0.95-2.58]), as compared with never smokers (P for trend = 0.02). Current smokers also exhibited a higher risk of inappropriate ICD shocks (HR = 2.93 [95% CI 1.30-6.63]) than past (HR = 1.91 [95% CI 0.97-3.77]) and never smokers (P for trend = 0.008).

CONCLUSIONS

In patients with ischemic left ventricular dysfunction, continued cigarette smoking is associated with a significant increase in the risk of life-threatening ventricular tachyarrhythmias and inappropriate ICD shocks induced by rapid supraventricular arrhythmias. Our findings stress the importance of complete smoking cessation in this high-risk population.

Relations among renal function, risk of sudden cardiac death, and benefit of the implanted cardiac defibrillator in patients with ischemic left ventricular dysfunction

Implanted cardioverter defibrillator therapy has been shown to be associated with a significant reduction in the risk of sudden cardiac death (SCD) in patients with ischemic left ventricular dysfunction. However, data on the relation between renal function and SCD in this population are limited, and the effect of renal dysfunction on the implanted cardioverter defibrillator benefit has not been determined. We performed a retrospective analysis of the outcome associated with renal dysfunction, as determined by the estimated glomerular filtration rate (eGFR), in patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial-II. Multivariate analysis in conventionally treated patients showed that for each 10-U reduction in eGFR, the risk of all-cause mortality and SCD increased by 16% (p = 0.005) and 17% (p = 0.03), respectively. Defibrillator therapy was associated with a survival benefit in each eGFR category of > or = 35 ml/min/1.73 m2 (overall risk reduction for all-cause mortality 32%, p = 0.01 and for SCD 66%, p < 0.001). However, no implanted cardioverter defibrillator benefit was shown among patients with an eGFR < 35 ml/min/1.73 m2 (all-cause mortality hazard ratio 1.09, p = 0.84; SCD hazard ratio 0.95, p = 0.95). In conclusion, in patients with high-risk cardiac disease enrolled in the Multicenter Automatic Defibrillator Implantation Trial-II, a significant increase was found in the risk of SCD with declining renal function. Defibrillator therapy was associated with a significant survival benefit among the study patients with mild to moderate or no renal disease, but no benefit was shown among patients with more advanced renal dysfunction.

Causes and consequences of heart failure after prophylactic implantation of a defibrillator in the multicenter automatic defibrillator implantation trial II

BACKGROUND

Implantable cardioverter-defibrillator (ICD) therapy may be associated with an increased risk for heart failure (HF). The present study evaluated the frequency, causes, and consequences of HF after ICD implantation.

METHODS AND RESULTS

We performed a retrospective analysis of the clinical factors and outcomes associated with postenrollment HF events in 1218 patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial II. The adjusted hazard ratios (HRs) of ICD:conventional therapy for first and recurrent HF events were 1.39 (P=0.02) and 1.58 (P<0.001), respectively. The risk was increased among patients who received single-chamber or dual-chamber ICDs. Development of HF was associated with an increased mortality risk (HR, 3.80; P<0.001). Among patients who received a single-chamber ICD, there was a similar survival benefit before and after the development of HF (HR, 0.59 and 0.61, respectively; P=0.92 for difference), whereas among patients with dual-chamber devices, there was a significant reduction in survival benefit after HF (HR, 0.26 and 0.83, respectively; P=0.01 for difference). Within the defibrillator arm of the trial, patients who received life-prolonging therapy from the ICD had an increased risk for first and recurrent HF events (HR, 1.90; P=0.01 and 1.74; P<0.001, respectively).

CONCLUSIONS

Patients with chronic ischemic heart disease who are treated with either single-chamber or dual-chamber ICDs have improved survival but an increased risk of HF. The present data suggest that ICD therapy transforms sudden death risk to a subsequent HF risk. These findings should direct more attention to the prevention of HF in patients who receive an ICD.

The Cost Effectiveness of Implantable Cardioverter-Defibrillators

OBJECTIVES

We sought to evaluate the cost implications of the implantable cardioverter-defibrillator (ICD), using utilization, cost, and survival data from the Multicenter Automatic Defibrillator Implantation Trial (MADIT)-II.

BACKGROUND

This trial showed that prophylactic implantation of a defibrillator reduces the rate of mortality in patients who experienced a previous myocardial infarction and low left ventricular ejection fraction. Given the size of the eligible population, the cost effectiveness of the ICD has substantial implications.

METHODS

Our research comprises the cost-effectiveness component of the randomized controlled trial, MADIT-II, based on utilization, cost, and survival information from 1,095 U.S. patients who were assigned randomly to receive an ICD or conventional medical care. Utilization data were converted to costs using a variety of national and hospital-specific data. The incremental cost-effectiveness ratio (iCER) was calculated as the difference in discounted costs divided by the difference in discounted life expectancy within 3.5 years. Secondary analyses included projections of survival (using three alternative assumptions), corresponding cost assumptions, and the resulting cost-effectiveness ratios until 12 years after randomization.

RESULTS

During the 3.5-year period of the study, the average survival gain for the defibrillator arm was 0.167 years (2 months), the additional costs were 39,200 dollars, and the iCER was 235,000 dollars per year-of-life saved. In three alternative projections to 12 years, this ratio ranged from 78,600 dollars to 114,000 dollars.

CONCLUSIONS

The estimated cost per life-year saved by the ICD in the MADIT-II study is relatively high at 3.5 years but is projected to be substantially lower over the course of longer time horizons.

Time Dependence of Defibrillator Benefit After Coronary Revascularization in the Multicenter Automatic Defibrillator Implantation Trial (MADIT)-II

OBJECTIVES

The study was designed to assess the effect of elapsed time from coronary revascularization (CR) on the benefit of the implantable cardioverter-defibrillator (ICD) and the risk of sudden cardiac death (SCD) in patients with ischemic left ventricular dysfunction.

BACKGROUND

The ICD improves survival in appropriately selected high-risk cardiac patients by 30% to 54%. However, in the Coronary Artery Bypass Graft (CABG)-Patch trial no evidence of improved survival was shown among a similar population of patients in whom an ICD was implanted prophylactically at the time of elective CABG.

METHODS

The outcome by time from CR was analyzed in 951 patients in whom a revascularization procedure was performed before enrollment in the Multicenter Automatic Defibrillator Implantation Trial (MADIT)-II.

RESULTS

The adjusted hazard ratio (HR) of ICD versus conventional therapy was 0.64 (p = 0.01) among patients enrolled more than six months after CR, whereas no survival benefit with ICD therapy was shown among patients enrolled six months or earlier after CR (HR = 1.19; p = 0.76). In the conventional therapy group, the risk of cardiac death increased significantly with increasing time from CR (p for trend = 0.009), corresponding mainly to a six-fold increase in the risk of SCD among patients enrolled more than six months after CR.

CONCLUSIONS

In patients with ischemic left ventricular dysfunction, the efficacy of ICD therapy after CR is time dependent, with a significant life-saving benefit in patients receiving device implantation more than six months after CR. The lack of ICD benefit when implanted early after CR may be related to a relatively low risk of SCD during this time period.

Reduction in Ventricular Tachyarrhythmias With Statins in the Multicenter Automatic Defibrillator Implantation Trial (MADIT)-II

OBJECTIVES

We evaluated whether statins have anti-arrhythmic effects by exploring the association of statin use with appropriate implantable cardioverter-defibrillator (ICD) therapy for ventricular tachycardia/ventricular fibrillation (VT/VF) in the Multicenter Automatic Defibrillator Implantation Trial (MADIT)-II.

BACKGROUND

A few studies have suggested that lipid-lowering drugs may have anti-arrhythmic effects in patients with coronary artery disease.

METHODS

Patients receiving an ICD (n = 654; U.S. centers only) in the MADIT-II study were categorized by the percentage of days each patient received statins during follow-up (90% to 100%, n = 386; 11% to 89%, n = 116; and 0% to 10%, n = 152). The Kaplan-Meier method with significance testing by the log-rank statistic and time-dependent proportional hazards regression analysis were used to evaluate the effect of statin use on the probability of ICD therapy for the combined end point VT/VF or cardiac death and for the end point VT/VF.

RESULTS

The cumulative rate of ICD therapy for VT/VF or cardiac death, whichever occurred first, was significantly reduced in those with > or =90% statin usage compared to those with lower statin usage (p = 0.01). The time-dependent statin:no statin therapy hazard ratio was 0.65 (p < 0.01) for the end point of VT/VF or cardiac death and 0.72 (p = 0.046) for VT/VF after adjusting for relevant covariates.

CONCLUSIONS

Statin use in patients with an ICD was associated with a reduction in the risk of cardiac death or VT/VF, whichever occurred first, and was associated with a reduction in VT/VF episodes. These findings suggest that statins have anti-arrhythmic properties.

Differences in outcomes between patients treated with single- versus dual-chamber implantable cardioverter defibrillators: a substudy of the Multicenter Automatic Defibrillator Implantation Trial II

OBJECTIVES

We sought to evaluate the influence of single- versus dual-chamber implantable cardioverter defibrillators (ICDs) on the occurrence of heart failure and mortality as well as appropriate and inappropriate ICD therapy in the Multicenter Automatic Defibrillator Implantation Trial II (MADIT-II).

BACKGROUND

In MADIT-II, ICD therapy in patients with a prior myocardial infarction and ejection fraction < or =0.30 was associated with a 31% reduction in risk of mortality when compared to conventionally treated patients. An unexpected finding was an increased occurrence of hospitalization for heart failure in the ICD group.

METHODS

Data from 717 patients randomized to ICD therapy with single- or dual-chamber pacing devices in MADIT-II were retrospectively analyzed. Endpoints selected for analysis included death from any cause, new or worsening heart failure requiring hospitalization, death or heart failure, appropriate therapy for ventricular tachycardia (VT) or ventricular fibrillation (VF), and inappropriate ICD therapy for atrial fibrillation or supraventricular tachycardia.

RESULTS

A total of 404 single-chamber ICDs (S-ICDs) and 313 dual-chamber ICDs (D-ICDs) were implanted. Patients receiving D-ICDs were at a higher risk at baseline than those receiving S-ICDs, with older age, higher NYHA class, more frequent prior CABG, wider QRS complex, more LBBB, higher BUN level, a history of more atrial arrhythmias requiring treatment, and a longer time interval from their index myocardial infarction to enrollment. While there was a trend toward an increase in adverse outcomes in the D-ICD group, no statistically significant differences in heart failure or mortality were observed between S-ICD versus D-ICD groups.

CONCLUSIONS

Patients with D-ICDs had a nonsignificant trend toward higher mortality and heart failure rates than patients with S-ICDs.

Multicenter automatic defibrillator implantation trial-cardiac resynchronization therapy (MADIT-CRT): design and clinical protocol

The planned MADIT-CRT trial is designed to determine if CRT-D will reduce the risk of mortality and HF events by approximately 25% in subjects with ischemic (NYHA class I-II) and non-ischemic (NYHA class II) cardiomyopathy, left ventricular dysfunction (EF<or=0.30), and prolonged intraventricular conduction (QRS duration>or=130 ms).

Safety and efficacy of flecainide in subjects with Long QT-3 syndrome (DeltaKPQ mutation): a randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

We conducted a study of chronic therapy with flecainide versus placebo in a small group of LQT-3 patients with the DeltaKPQ deletion to evaluate the safety and efficacy of flecainide in this genetic disorder. In vitro studies have shown that flecainide provides correction of the impaired inactivation associated with the DeltaKPQ deletion.

METHODS

A randomized, double-blind, placebo-controlled clinical trial was conducted with flecainide and placebo in six male LQT-3 subjects with the DeltaKPQ deletion.

RESULTS

The lowest possible dose of flecainide associated with at least a 40 ms reduction in the QTc interval was determined in an initial open-label, dose-ranging investigation using one-fourth or half of the recommended maximal antiarrhythmic flecainide dose. QTc reduction was achieved with a flecainide dose of 1.5 mg/kg per day in 4 subjects and with 3.0 mg/kg per day in 2 subjects. Subjects were randomized to four 6-month alternating periods of flecainide and placebo therapy based on the open-label dose findings. Average QTc values during placebo and flecainide therapies were 534 ms and 503 ms, respectively, with an adjusted reduction in QTc of -27.1 ms (95% confidence interval: -36.8 ms to -17.4 ms; P<0.001) at a mean flecainide blood level of 0.11+/-0.05 microg/ml. Minimal prolongation in QRS occurred (mean: +2.5 ms), and there were no major adverse cardiac effects.

CONCLUSIONS

Chronic low-dose flecainide significantly shortens the QTc interval in LQT-3 subjects with the DeltaKPQ mutation. No major adverse drug effects were observed with flecainide during this trial, but the sample size is not large enough to evaluate the safety of flecainide therapy in patients with this mutation.

Predictive Value of Ventricular Arrhythmia Inducibility for Subsequent Ventricular Tachycardia or Ventricular Fibrillation in Multicenter Automatic Defibrillator Implantation Trial (MADIT) II Patients

In the Multicenter Automatic Defibrillator Implantation Trial (MADIT) II, implantable cardioverter-defibrillator (ICD)-randomized patients underwent electrophysiologic testing. Both inducible and noninducible patients received an ICD. We correlated inducibility with the occurrence of subsequent ventricular tachycardia (VT) or ventricular fibrillation (VF). Intracardiac ICD electrograms for subsequent events were analyzed to categorize the spontaneous arrhythmia as VT or VF. The two-year Kaplan-Meier event rate for VT in inducible patients was 29.0% versus 19.3% in noninducible patients. However, ICD therapy for spontaneous VF was less common at two years in inducible patients (3.2%) than in noninducible patients (8.6%). In the MADIT II study, inducibility predicted an increased likelihood of VT but decreased VF.

OBJECTIVES

We correlated electrophysiologic inducibility with spontaneous ventricular tachycardia (VT) or ventricular fibrillation (VF) in the Multicenter Automatic Defibrillator Implantation Trial (MADIT) II.

BACKGROUND

In the MADIT II study, 593 (82%) of 720 implantable cardioverter-defibrillator (ICD) randomized patients underwent electrophysiologic testing. Patients received an ICD whether they were inducible or not.

METHODS

A "standard" inducibility definition included sustained monomorphic or polymorphic VT induced with three or fewer extrastimuli or VF induced with two or fewer extrastimuli. We compared a narrow inducibility definition (only monomorphic VT) and a broad definition (standard definition plus VF with three extrastimuli). We used ICD-stored electrograms to categorize spontaneous VT or VF.

RESULTS

Inducible patients (standard definition) had a greater likelihood of experiencing ICD therapy for VT than noninducible patients (p = 0.023). Unexpectedly, ICD therapy for spontaneous VF was less common (p = 0.021) in inducible patients than in noninducible patients. The two-year Kaplan-Meier event rate for VT or VF was 29.4% for inducible patients and 25.5% for noninducible patients. Standard inducibility did not predict the combined end point of VT or VF (p = 0.280, by log-rank analysis). The narrow inducibility definition outperformed the standard definition, whereas the broad definition appeared inferior to the standard definition.

CONCLUSIONS

In the MADIT II study patients, inducibility was associated with an increased likelihood of VT. Noninducible MADIT II study subjects using this electrophysiologic protocol had a considerable VT event rate and a higher VF event rate than inducible patients. Induction of polymorphic VT or VF, even with double extrastimuli, appears less relevant than induction of monomorphic VT.

Clinical Course and Implantable Cardioverter Defibrillator Therapy in Postinfarction Women with Severe Left Ventricular Dysfunction

BACKGROUND

There are limited data regarding implantable cardioverter defibrillator (ICD) therapy in postinfarction women with severe left ventricular dysfunction. The aim of this study was to evaluate the risk of cardiac events and effects of ICD therapy in women as compared to men enrolled in the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II).

METHODS AND RESULTS

Among 1,232 patients enrolled in MADIT II, there were 192 (16%) women and 1,040 (84%) men. When compared to men, women had an increased frequency of NYHA class > or =II (70 vs 63%; P = 0.067), hypertension (60% vs 52%; P = 0.047), diabetes (42% vs 34%; P = 0.027), and LBBB (25% vs 17%; P = 0.011), and less frequent CABG surgery (42% vs 60%; P < 0.001). The 2-year cumulative mortality in patients randomized to conventional therapy was not significantly different in women and men (30% and 20%, respectively; P = 0.19). Adjusting for relevant clinical covariates, the hazard ratios for ICD effectiveness were similar in women (0.57; 95% CI = 0.28-1.18; P = 0.132) and men (0.66; 95% CI = 0.48-0.91; P = 0.011). The risk of appropriate ICD therapy for VT/VF was lower in women than in men (hazard ratio = 0.60 for female vs male gender; 95% CI = 0.37-0.98; P = 0.039).

CONCLUSIONS

MADIT II women had similar mortality and similar ICD effectiveness when compared to men. MADIT II women with ICDs had a lower risk of arrhythmic events with fewer episodes of ventricular tachycardia than men.

Factors Influencing Appropriate Firing of the Implanted Defibrillator for Ventricular Tachycardia/Fibrillation

OBJECTIVES

The purpose of this study was to prospectively examine the role of clinical, laboratory, echocardiographic, and electrophysiological variables as predictors of appropriate initial implantable cardioverter-defibrillator (ICD) therapy for ventricular tachycardia (VT) or ventricular fibrillation (VF) or death in the Multicenter Automatic Defibrillator Implantation Trial II (MADIT-II) population.

BACKGROUND

There is limited information regarding the determinants of appropriate ICD therapy in patients with reduced ventricular function after a myocardial infarction.

METHODS

We used secondary analysis in one arm of a multicenter randomized clinical trial in patients with a previous myocardial infarction and reduced left ventricular function.

RESULTS

We analyzed baseline and follow-up data on 719 patients enrolled in the ICD arm of the MADIT-II study. Appropriate ICD therapy was observed in 169 subjects. Clinical, laboratory, echocardiographic, and electrophysiological variables, along with measures of clinical instability such as interim hospitalization for congestive heart failure (IH-CHF) and interim hospitalization for coronary events (IH-CE), were examined with proportional hazards models and Kaplan-Meier time-to-event curves before and after first interim hospitalization. Interim hospitalization-CHF, IH-CE, no beta-blockers, digitalis use, blood urea nitrogen (BUN) >25, body mass index (BMI) > or =30 kg/m2, and New York Heart Association functional class >II were associated with increased risk for appropriate ICD therapy for VT, VF, or death. In a multivariate (stepwise selection) analysis, IH-CHF was associated with an increased risk for the end point of either VT or VF (hazard ratio [HR] 2.52, 95% confidence interval [CI] 1.69 to 3.74, p < 0.001) and for the combined end point of VT, VF, or death (HR 2.97, 95% CI 2.15 to 4.09, p < 0.001). Interim hospitalization-CE was associated with an increased risk for VT, VF, or death (HR 1.66, 95% CI 1.09 to 2.52, p = 0.02).

CONCLUSIONS

These results provide important mechanistic information, suggesting that worsening clinical condition and cardiac instability, as reflected by an IH-CHF or IH-CE, are subsequently associated with a significant increase in the risk for appropriate ICD therapy (for VT/VF) and death.

Effects of beta-blockers on implantable cardioverter defibrillator therapy and survival in the patients with ischemic cardiomyopathy (from the Multicenter Automatic Defibrillator Implantation Trial-II)

This study examined the effects of beta blockers on (1) appropriate implantable cardioverter defibrillator (ICD) therapy for ventricular tachycardia (VT) or ventricular fibrillation (VF), (2) inappropriate ICD therapy for atrial fibrillation or supraventricular tachycardia, and (3) survival in 691 patients who received ICDs in the Multicenter Automatic Defibrillator Implantation Trial-II. The study population involved 258 patients who were not receiving beta blockers and 433 who were receiving metoprolol (n = 192), atenolol (n = 58), or carvedilol (n = 182). Patients receiving beta blockers were divided into the upper quartile and lower 3 quartiles of the drug doses they were taking. Patients receiving the higher doses of beta blockers (those in the top quartile of doses) had a significant reduction in the risk for VT or VF requiring ICD therapy compared with patients not receiving beta blockers (hazard ratio 0.48, p = 0.02). The frequency of inappropriate ICD therapy for supraventricular tachyarrhythmias was not significantly different among the 3 treatment groups (p = 0.32). Beta-blocker use at the 2 dosage levels was associated with significant improvement in survival compared with the nonuse of beta blockers (hazard ratios 0.42 to 0.44, p <0.01). In conclusion, beta blockers reduce the risk for VT or VF and improve survival in ICD-treated patients with ischemic cardiomyopathy.

Comparison of efficacy of implanted cardioverter-defibrillator in patients with versus without diabetes mellitus

In the second Multicenter Automatic Defibrillator Implantation Trial, patients with a previous myocardial infarction and left ventricular ejection fraction < or =0.30 benefited significantly from prophylactic implantable cardioverter-defibrillator (ICD) placement. Diabetic patients who had a myocardial infarction had a worse prognosis compared with nondiabetics. The present study used data from the second Multicenter Automatic Defibrillator Implantation Trial to assess the efficacy of ICD placement on survival in diabetic patients. Of the 1,232 patients in the second Multicenter Automatic Defibrillator Implantation Trial, 489 were characterized as diabetic. They were more likely to be New York Heart Association class II to IV, be hypertensive, have renal dysfunction, have an increased body mass index, and to take diuretic drugs. Diabetic patients had a 24% greater adjusted risk of death than nondiabetic patients. The hazard ratio (HR) for the risk of death in patients treated with the ICD compared with conventional therapy was similar in diabetics (HR 0.61; 95% confidence interval [CI] 0.38 to 0.98) and nondiabetics (HR 0.71; 95% CI 0.49 to 1.05), with no evidence of interaction. Thus, diabetic patients derive a similar benefit from ICD therapy despite being sicker and having a higher mortality rate overall.

The clinical implications of cumulative right ventricular pacing in the multicenter automatic defibrillator trial II

INTRODUCTION

This study was designed to assess whether right ventricular pacing in the implantable cardioverter defibrillator (ICD) arm of the Multicenter Automatic Defibrillator Implantation Trial (MADIT) II was associated with an unfavorable outcome.

METHODS AND RESULTS

Data on the number of ventricular paced beats were available in 567 (76%) of 742 MADIT II patients with ICDs. The number of ventricular paced beats over the total number of beats showed a bimodal distribution with patients being predominantly paced or nonpaced. Therefore, patients were dichotomized at 0-50% and 51-100% of cumulative pacing with median pacing rate 0.2% and 95.6%, respectively. Endpoints included new or worsening heart failure, appropriate ICD therapy for VT/VF, and the combined endpoint of heart failure or death. Clinical features associated with frequent ventricular pacing included age >or=65 years, advanced NYHA heart failure class, LVEF < 0.25, first degree AV and bundle branch block, and amiodarone use. During follow-up, 119 patients (21%) had new or worsened heart failure, 130 (23%) had new or worsened heart failure or death, and 142 (25%) had appropriate therapy for VT/VF. In comparison to patients with infrequent pacing, those with frequent pacing had significantly higher risk of new or worsened heart failure (hazard ratio = 1.93; P = 0.002) and VT/VF requiring ICD therapy (HR = 1.50; P = 0.02).

CONCLUSIONS

Patients in MADIT II who were predominantly paced had a higher rate of new or worsened heart failure and were more likely to receive therapy for VT/VF. These results suggest the deleterious consequences of RV pacing, particularly in the setting of severe LV dysfunction.

Long-term clinical course of patients after termination of ventricular tachyarrhythmia by an implanted defibrillator

BACKGROUND

The implanted cardioverter defibrillator (ICD) improves survival in high-risk cardiac patients. This analysis from the MADIT-II trial database examines the long-term clinical course and subsequent mortality risk of patients after termination of life-threatening ventricular tachyarrhythmias by an ICD.

METHODS AND RESULTS

Life-table survival analysis was performed, and proportional hazards regression analysis was used to evaluate the contribution of baseline clinical factors and time-dependent defibrillator therapy to mortality during long-term follow-up. Of 720 patients with an ICD (average follow-up 21 months), 169 patients received 701 antiarrhythmic device therapies for ventricular tachyarrhythmias. Few baseline characteristics distinguished patients who received appropriate ICD therapy for their first ventricular tachyarrhythmic episode. The probability of survival for at least 1 year after first therapy for ventricular tachycardia (VT) or ventricular fibrillation (VF) was 80%. The hazard ratios for the risk of death due to any cause in those who survived appropriate therapy for termination of VT and VF were 3.4 (P<0.001) and 3.3 (P=0.01), respectively, compared with those who survived without receiving ICD therapy, with a high frequency of heart failure and late nonsudden cardiac death after first successful ICD therapy for VF.

CONCLUSIONS

Successful appropriate therapy by an ICD for VT or VF is associated with 80% survival at 1 year after arrhythmia termination. These patients are at increased risk for heart failure and nonsudden cardiac death after device termination of VT or VF and should receive special attention for the prevention and management of progressive left ventricular dysfunction during long-term follow-up.

Temporal aspects of improved survival with the implanted defibrillator (MADIT-II)

The present study retrospectively explored the reasons for delay in the onset of survival benefit from the implanted cardioverter defibrillator (ICD) in the Second Multicenter Automatic Defibrillator Implantation Trial. The cumulative probability of cause-specific death over time was estimated by the Kaplan-Meier method and by proportional hazards regression analysis. Early cardiac death survival curves were similar by treatment assignment in the 0- to 12-month period (p = 0.76). Late cardiac death survival curves by treatment assignment in the >12- to 52-month follow-up period were divergent with a lower probability of late cardiac death in the ICD arm compared with conventional therapy group (p <0.001). The time-specific hazard ratios of ICD to conventional therapy for cardiac death in the early and late periods were significantly different from each other (nominal p = 0.004). There was a significant decrease in sudden cardiac death with ICD therapy in the early (p = 0.012) and late (p <0.001) groups. In the early period, the rate of nonsudden cardiac death was significantly higher in the ICD group than in the conventional therapy group (p = 0.003). Rates of late nonsudden cardiac death were similar in the 2 treatment arms (p = 0.11).