Drug-induced post-repolarization refractoriness as an antiarrhythmic principle and its underlying mechanism.

AIMS: We hypothesized that amiodarone (AM), unlike d-sotalol (DS) (a 'pure' Class III agent), not only prolongs the action potential duration (APD) but also causes post-repolarization refractoriness (PRR), thereby preventing premature excitation and providing superior antiarrhythmic efficacy. METHODS AND RESULTS: We tested this hypothesis in 31 patients with inducible ventricular tachycardia (VT) during programmed stimulation with the use of the 'Franz' monophasic action potential (MAP) catheter with simultaneous pacing capability. We determined the effective refractory period (ERP) for each of three extrastimuli (S2-S4) and the corresponding MAP duration at 90% repolarization (APD90), both during baseline and on randomized therapy with either DS (n = 15) or AM (n = 16). We defined ERP > APD90 as PRR and ERP < APD90 as 'encroachment' on repolarization. A revised computer action potential model was developed to help explain the mechanisms of these in-vivo human-heart phenomena. Encroachment but not PRR was present in all patients at baseline and during DS treatment (NS vs. baseline), and VT was non-inducible in only 2 of 15 DS patients. In contrast, in 12 of 16 AM patients PRR was present (P < 0.001 vs. baseline), and VT was no longer inducible. Our model (with revised sodium channel kinetics) reproduced encroachment and drug-induced PRR. CONCLUSION: Both, AM and DS, prolonged APD90 but only AM produced PRR and prevented encroachment of premature extrastimuli. Our computer simulations suggest that PRR is due to altered kinetics of the slow inactivation of the rapid sodium current. This may contribute to the high antiarrhythmic efficacy of AM.

Efficacy and safety of implantable cardioverter-defibrillator implantation in the elderly-The I-70 Study: A randomized clinical trial.

Background: There is conflicting evidence on the efficacy of primary prevention implantable cardioverter-defibrillator (ICD) implantation in the elderly. Objective: The purpose of this study was to determine the efficacy and safety of ICD implantation in patients 70 years and older. Methods: Patients (n = 167) aged 70 years or older and eligible for ICD implantation were randomly assigned (1:1) to receive either optimal medical therapy (OMT) (n = 85) or OMT plus ICD (n = 82). Results: Of the 167 participants (mean age 76.4 years; 165 men), 144 completed the study protocol according to their assigned treatment. Average participant follow-up was 31.5 months. Mortality was similar between the 2 groups: 27 deaths in OMT vs 26 death in ICD (unadjusted hazard ratio 0.92; 95% confidence interval 0.53-1.57), but there was a trend favoring the ICD over the first 36 months of follow-up. Rates of sudden death (7 vs 5; P = .81) and all-cause hospitalization (2.65 events per participant in OMT vs 3.09 in ICD; P = .31) were not statistically significantly different. Eleven participants randomized to ICD received appropriate therapy. Five participants received an inappropriate therapy that included at least 1 ICD shock. Conclusion: The study did not recruit to target sample size, and accumulated data did not show benefit of ICD therapy in patients 70 years or older. Future studies similar in design might be feasible but will need to contend with patient treatment preference given the large number of patients who do not want an ICD implanted. Further research is needed to determine whether the ICD is effective in prolonging life among elderly device candidates.

Outcomes of Premature Ventricular Contraction-Cardiomyopathy in the Veteran Population: A Secondary Analysis of the CHF-STAT Study.

OBJECTIVES: This study sought to assess the rate and outcomes of premature ventricular contractions (PVC)-cardiomyopathy from the CHF-STAT (Survival Trial of Antiarrhythmic Therapy in Congestive Heart Failure) trial, a population with cardiomyopathy (left ventricular [LV] ejection fraction of <40%) and frequent PVCs (>10 PVCs per hour). BACKGROUND: PVCs are associated with heart failure and PVC-cardiomyopathy. The prevalence of PVC-cardiomyopathy and outcome benefits of PVC suppression are not clear. METHODS: A secondary analysis of the CHF-STAT study was performed to compare the rate of successful PVC suppression (≥80% PVC reduction), LV recovery (defined as improvement in LV ejection fraction of ≥10% points), and PVC-cardiomyopathy between amiodarone and placebo groups at 6 months. PVC-cardiomyopathy was defined if both PVC reduction of ≥80% and LV ejection fraction improvement of ≥10% were present at 6 months. Cardiac events (death or resuscitated cardiac arrest) were compared between PVC-cardiomyopathy versus non-PVC-cardiomyopathy during a 5-year follow-up. RESULTS: The rates of successful PVC suppression and LV recovery were significantly higher in the amiodarone (72% and 39%, respectively) when compared to the placebo group (12% and 16%, respectively; p < 0.001), regardless of cardiomyopathy etiology. PVC-cardiomyopathy was present in 29% and 1.8% of patients in the amiodarone and placebo groups, respectively (p < 0.001). Similar PVC-cardiomyopathy rates were found in ischemic (24% amiodarone vs. 2% placebo; p < 0.001) and nonischemic populations (41% amiodarone vs. 1.5% placebo; p < 0.001). Death and resuscitated cardiac arrest were significantly lower in patients with PVC-cardiomyopathy and those treated with amiodarone. CONCLUSIONS: The overall prevalence of PVC-cardiomyopathy in the CHF-STAT study was significant regardless of ischemic substrate (29%, overall population; 41%, nonischemic cardiomyopathy). Treatment of PVC-cardiomyopathy with amiodarone is likely to improve survival in this high-risk population.

Intrathoracic impedance preceding ventricular tachyarrhythmia episodes.

BACKGROUND: Heart failure is associated with ventricular tachyarrhythmias (VT/VF). Fluid accumulation during worsened heart failure may trigger VT/VF. Increased intrathoracic impedance has been correlated with fluid accumulation during heart failure. Implanted defibrillators capable of daily measures of intrathoracic impedance allow correlation of impedance with occurrence of VT/VF. We hypothesized that VT/VF episodes are preceded by decreases in intrathoracic impedance. The goal was to identify the relationship of intrathoracic impedance measured by implanted cardioverter defibrillators to the occurrence of VT/VF. METHOD: Implanted defibrillator follow-up data were obtained retrospectively. Those with Medtronic OptiVol (Medtronic Inc., Minneapolis, MN, USA), storing averaged daily and reference impedance values, were reviewed for VT/VF episodes. Impedance changes in the week leading up to VT/VF were analyzed. RESULTS: A total of 317 VT/VF episodes in a cohort of 121 patients' follow-up data were evaluated. Averaged daily intrathoracic impedance declined preceding 64% of VT/VF episodes, with an average decline of 0.46 +/- 0.35 Ohms from the day before the VT/VF episodes. However, the mean values of the averaged daily and reference impedance did not change significantly. A novel measure, DeltaTI, the sum of the daily differences between the averaged daily and reference impedance, was negative preceding 66% of VT/VF episodes (P < 0.001). The mean DeltaTI was -4.0 +/- 1.3 Ohms, which was significantly lower than the theoretically expected value of zero Ohms (P < 0.01). CONCLUSION: (1) Averaged daily impedance declined preceding 64% of VT/VF episodes, but the overall decline was of small magnitude; (2) a novel measure, DeltaTI, was negative preceding 66% of VT/VF episodes, and significantly below zero.

Prior Heart Failure Hospitalization and Outcomes in Patients with Heart Failure with Preserved and Reduced Ejection Fraction.

BACKGROUND: A prior hospitalization resulting from heart failure is associated with poor outcomes in ambulatory patients with heart failure. Less is known about this association in hospitalized patients with heart failure and whether it varies by ejection fraction. METHODS: Of the 25,345 hospitalized patients in the Medicare-linked OPTIMIZE-HF registry, 22,491 had known heart failure, of whom 7648 and 9558 had heart failure with preserved (≥50%) and reduced (≤40%) ejection fraction (HFpEF and HFrEF), respectively. Overall, 927 and 1862 patients with HFpEF and HFrEF had hospitalizations for heart failure during the 6 months before the index hospitalization, respectively. Using propensity scores for prior heart failure hospitalization, we assembled two matched cohorts of 924 pairs and 1844 pairs of patients with HFpEF and HFrEF, respectively, each balanced for 58 baseline characteristics. Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for outcomes during 6 years of follow-up. RESULTS: Among 1848 matched patients with HFpEF, HRs (95% CIs) for all-cause mortality, all-cause readmission, and heart failure readmission were 1.35 (1.21-1.50; P <0.001), 1.34 (1.21-1.47; P <0.001), and 1.90 (1.67-2.16; P <0.001), respectively. Respective HRs (95% CIs) in 3688 matched patients with HFrEF were 1.17 (1.09-1.26; P <0.001), 1.32 (1.23-1.41; P <0.001), and 1.48 (1.37-1.61; P <0.001). CONCLUSIONS: Among hospitalized patients with heart failure, a previous hospitalization for heart failure is associated with higher risks of mortality and readmission in both HFpEF and HFrEF. The relative risks of death and heart failure readmission appear to be higher in HFpEF than in HFrEF.

Early Effects of Starting Doses of Enalapril in Patients with Chronic Heart Failure in the SOLVD Treatment Trial.

BACKGROUND: In the Studies of Left Ventricular Dysfunction (SOLVD) treatment trial, similar clinical benefits were observed between starting doses of enalapril and the target dose achieved by postrandomization up-titration. In our current analysis, protecting the randomization, we examined the early effects of starting doses of enalapril. METHODS: There were 2569 patients with mild-to-moderate chronic heart failure with reduced ejection fraction (ejection fraction ≤35%) randomized to receive starting doses (5-10 mg/day) of placebo (n = 1284) or enalapril (n = 1285). At day 14, both study drugs were blindly up-titrated to the target dose (20 mg/day). Overall, 96% (2458/2569) of the patients returned for dose up-titration, which was achieved in 59% (1444/2458), 48% (696/1444) of whom were in the enalapril group. Hazard ratios (HRs) and 95% confidence intervals (CIs) for outcomes in the enalapril group were estimated. RESULTS: HRs (95% CIs) for all-cause mortality, heart failure hospitalization, and the combined endpoint of heart failure hospitalization or all-cause mortality at 14 days after randomization were 0.80 (0.32-2.03), 0.63 (0.35-1.12), and 0.65 (0.39-1.06), respectively. Corresponding HRs (95% CIs) at 30 days were 0.82 (0.41-1.67), 0.43 (0.27-0.68), and 0.43 (0.27-0.68), respectively. The magnitude of these early effects of starting doses of enalapril is similar to its previously reported long-term effects at the target dose. CONCLUSION: These data suggest that in stable ambulatory patients with heart failure with reduced ejection fraction, the magnitude of the early effect of starting doses of enalapril is similar to that observed during longer-term therapy with the target doses of the drug.

Digoxin Initiation and Outcomes in Patients with Heart Failure with Preserved Ejection Fraction.

BACKGROUND: Digoxin reduces the risk of heart failure hospitalization in patients with heart failure with reduced ejection fraction. Less is known about this association in patients with heart failure with preserved ejection fraction (HFpEF), the examination of which was the objective of the current study. METHODS: In the Medicare-linked OPTIMIZE-HF registry, 7374 patients hospitalized for HF had ejection fraction ≥50% and were not receiving digoxin prior to admission. Of these, 5675 had a heart rate ≥50 beats per minute, an estimated glomerular filtration rate ≥30 mL/min/1.73 m2 or did not receive inpatient dialysis, and digoxin was initiated in 524 of these patients. Using propensity scores for digoxin initiation, calculated for each of the 5675 patients, we assembled a matched cohort of 513 pairs of patients initiated and not initiated on digoxin, balanced on 58 baseline characteristics (mean age, 80 years; 66% women; 8% African American). Hazard ratios (HRs) and 95% confidence intervals (CIs) for outcomes associated with digoxin initiation were estimated in the matched cohort. RESULTS: Among the 1026 matched patients with HFpEF, 30-day heart failure readmission occurred in 6% and 9% of patients initiated and not initiated on digoxin, respectively (HR 0.70; 95% CI, 0.45-1.10; P = .124). HRs (95% CIs) for 30-day all-cause readmission and all-cause mortality associated with digoxin initiation were 0.95 (0.73-1.23; P = .689) and 0.93 (0.55-1.56; P = .773), respectively. Digoxin initiation had no association with 6-year outcomes. CONCLUSION: Digoxin initiation prior to hospital discharge was not associated with 30-day or 6-year outcomes in older hospitalized patients with HFpEF.

Systolic Blood Pressure and Outcomes in Patients With Heart Failure With Reduced Ejection Fraction.

BACKGROUND: National guidelines recommend that systolic blood pressure (SBP) in patients with heart failure with reduced ejection fraction (HFrEF) and hypertension be maintained below 130 mm Hg. OBJECTIVES: This study sought to determine associations of SBP <130 mm Hg with outcomes in patients with HFrEF. METHODS: Of the 25,345 patients in the Medicare-linked OPTIMIZE-HF registry, 10,535 had an ejection fraction (EF) ≤40%. Of these, 5,615 had stable SBP (≤20 mm Hg admission to discharge variation), and 3,805 (68%) had a discharge SBP <130 mm Hg. Propensity scores for SBP <130 mm Hg, estimated for each of the 5,615 patients, were used to assemble a matched cohort of 1,189 pairs of patients with SBP <130 versus ≥130 mm Hg, balanced on 58 baseline characteristics (mean age 76 years; mean EF 28%, 45% women, 13% African American). This process was repeated in 3,946 patients, after excluding 1,669 patients (30% of 5,615) with a discharge SBP <110 mm Hg and assembled a second matched balanced cohort of 1,099 pairs of patients with SBP 110 to 129 mm Hg versus ≥130 mm Hg. RESULTS: Thirty-day all-cause mortality occurred in 7% and 4% of matched patients with SBP <130 mm Hg versus ≥130 mm Hg, respectively (hazard ratio [HR]: 1.76; 95% confidence interval [CI]: 1.24 to 2.48; p = 0.001). HRs (95% CIs) for all-cause mortality, all-cause readmission, and HF readmission at 1 year, associated with SBP <130 mm Hg, were 1.32 (1.15 to 1.53; p < 0.001), 1.11 (1.01 to 1.23; p = 0.030), and 1.24 (1.09 to 1.42; p = 0.001), respectively. HRs (95% CIs) for 30-day and 1-year all-cause mortality associated with SBP 110 to 129 mm Hg (vs. ≥130 mm Hg) were 1.50 (1.03 to 2.19; p = 0.035), and 1.19 (1.02 to 1.39; p = 0.029), respectively. CONCLUSIONS: Among hospitalized older patients with HFrEF, SBP <130 mm Hg is associated with poor outcomes. This association persisted when the analyses were repeated after excluding patients with SBP <110 mm Hg. There is an urgent need for randomized controlled trials to evaluate optimal SBP reduction goals in patients with HFrEF.

Amiodarone versus sotalol for atrial fibrillation.

BACKGROUND: The optimal pharmacologic means to restore and maintain sinus rhythm in patients with atrial fibrillation remains controversial. METHODS: In this double-blind, placebo-controlled trial, we randomly assigned 665 patients who were receiving anticoagulants and had persistent atrial fibrillation to receive amiodarone (267 patients), sotalol (261 patients), or placebo (137 patients) and monitored them for 1 to 4.5 years. The primary end point was the time to recurrence of atrial fibrillation beginning on day 28, determined by means of weekly transtelephonic monitoring. RESULTS: Spontaneous conversion occurred in 27.1 percent of the amiodarone group, 24.2 percent of the sotalol group, and 0.8 percent of the placebo group, and direct-current cardioversion failed in 27.7 percent, 26.5 percent, and 32.1 percent, respectively. The median times to a recurrence of atrial fibrillation were 487 days in the amiodarone group, 74 days in the sotalol group, and 6 days in the placebo group according to intention to treat and 809, 209, and 13 days, respectively, according to treatment received. Amiodarone was superior to sotalol (P<0.001) and to placebo (P<0.001), and sotalol was superior to placebo (P<0.001). In patients with ischemic heart disease, the median time to a recurrence of atrial fibrillation was 569 days with amiodarone therapy and 428 days with sotalol therapy (P=0.53). Restoration and maintenance of sinus rhythm significantly improved the quality of life and exercise capacity. There were no significant differences in major adverse events among the three groups. CONCLUSIONS: Amiodarone and sotalol are equally efficacious in converting atrial fibrillation to sinus rhythm. Amiodarone is superior for maintaining sinus rhythm, but both drugs have similar efficacy in patients with ischemic heart disease. Sustained sinus rhythm is associated with an improved quality of life and improved exercise performance.

Systolic Blood Pressure and Outcomes in Patients With Heart Failure With Preserved Ejection Fraction.

Importance: Lower systolic blood pressure (SBP) levels are associated with poor outcomes in patients with heart failure. Less is known about this association in heart failure with preserved ejection fraction (HFpEF). Objective: To determine the associations of SBP levels with mortality and other outcomes in HFpEF. Design, Setting, and Participants: A propensity score-matched observational study of the Medicare-linked Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure (OPTIMIZE-HF) registry included 25 354 patients who were discharged alive; 8873 (35.0%) had an ejection fraction of at least 50%, and of these, 3915 (44.1%) had stable SBP levels (≤20 mm Hg admission to discharge variation). Data were collected from 259 hospitals in 48 states between March 1, 2003, and December 31, 2004. Data were analyzed from March 1, 2003, to December 31, 2008. Exposure: Discharge SBP levels less than 120 mm Hg. A total of 1076 of 3915 (27.5%) had SBP levels less than 120 mm Hg, of whom 901 (83.7%) were matched by propensity scores with 901 patients with SBP levels of 120 mm Hg or greater who were balanced on 58 baseline characteristics. Main Outcomes and Measures: Thirty-day, 1-year, and overall all-cause mortality and heart failure readmission through December 31, 2008. Results: The 1802 matched patients had a mean (SD) age of 79 (10) years; 1147 (63.7%) were women, and 134 (7.4%) were African American. Thirty-day all-cause mortality occurred in 91 (10%) and 45 (5%) of matched patients with discharge SBP of less than 120 mm Hg vs 120 mm Hg or greater, respectively (hazard ratio [HR], 2.07; 95% CI, 1.45-2.95; P < .001). Systolic blood pressure level less than 120 mm Hg was also associated with a higher risk of mortality at 1 year (39% vs 31%; HR, 1.36; 95% CI, 1.16-1.59; P < .001) and during a median follow-up of 2.1 (overall 6) years (HR, 1.17; 95% CI, 1.05-1.30; P = .005). Systolic blood pressure level less than 120 mm Hg was associated with a higher risk of heart failure readmission at 30 days (HR, 1.47; 95% CI, 1.08-2.01; P = .02) but not at 1 or 6 years. Hazard ratios for the combined end point of heart failure readmission or all-cause mortality associated with SBP level less than 120 mm at 30 days, 1 year, and overall were 1.71 (95% CI, 1.34-2.18; P < .001), 1.21 (95% CI, 1.07-1.38; P = .004), and 1.12 (95% CI, 1.01-1.24; P = .03), respectively. Conclusions and Relevance: Among hospitalized patients with HFpEF, an SBP level less than 120 mm Hg is significantly associated with poor outcomes. Future studies need to prospectively evaluate optimal SBP treatment goals in patients with HFpEF.

Exercise capacity in atrial fibrillation: a substudy of the Sotalol-Amiodarone Atrial Fibrillation Efficacy Trial (SAFE-T).

BACKGROUND: Therapy for chronic atrial fibrillation (AF) focuses on rate versus rhythm control, but little is known about the effects of common therapeutic interventions on exercise tolerance in AF. METHODS: Six hundred fifty-five patients with chronic AF underwent maximal exercise testing at baseline and 8 weeks, 6 months, and 1 year after randomization to sotalol, amiodarone, or placebo therapy and attempted direct current cardioversion. Analyses of baseline determinants of exercise capacity, predictors of change in exercise capacity at 6 months and 1 year, and the short- and long-term effects of cardioversion on exercise capacity were made. RESULTS: Age, obesity, and presence of symptoms accompanying AF were inversely associated with baseline exercise capacity, but these factors accounted for only 10% of the variance in exercise capacity. Patients most likely to benefit from cardioversion were those most limited initially, younger, not obese or hypertensive, and with an uncontrolled ventricular rate at baseline. Conversion to sinus rhythm (SR) resulted in significant reductions in resting (approximately 25 beat/min) and peak exercise (approximately 40 beat/min) heart rates at 6 months and 1 year (P < .001). Successful cardioversion improved exercise capacity by 15% at 8 weeks, and these improvements were maintained throughout the year. This improvement was observed both among those who maintained SR and those with intermittent AF. CONCLUSION: Cardioversion resulted in a sustained improvement in exercise capacity over the course of 1 year, and this improvement was similar between those in SR and those with SR and recurrent AF. Patients most likely to improve with treatment tended to be younger and nonobese and have the greatest limitations initially.

Outcomes of cardiac resynchronization therapy in patients with intermittent atrial fibrillation or atrial flutter in the COMPANION trial.

BACKGROUND: Controlled clinical trial data are lacking for cardiac resynchronization therapy (CRT) outcomes in patients with advanced heart failure (HF) from reduced left ventricular ejection fraction (HFrEF) and intermittent atrial fibrillation or flutter (IAF/AFL). OBJECTIVE: The purpose of this study was to describe CRT outcomes in patients with IAF/AFL and advanced HF. METHODS: HF outcomes in patients in the COMPANION (Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure) trial with New York Heart Association class III or IV HFrEF, left ventricular ejection fraction ≤0.35, sinus rhythm at randomization, and no history of baseline arrhythmia were compared with those with a history of IAF/AFL. RESULTS: In those with no history of baseline arrhythmia (n = 887), compared with optimal pharmacological therapy (OPT) with no CRT, the CRT + OPT arms exhibited a significant reduction in the end points of death or any hospitalization (hazard ratio [HR] 0.73 [95% Confidence Interval (CI): 0.60 to 0.89]; P = .002) and death or HF hospitalization (HR 0.53 [95% CI: 0.41 to 0.68]; P < .001). In contrast, in the IAF/AFL subgroup (n = 293), CRT did not result in improved outcomes compared with OPT (death or any hospitalization: HR 1.16 [95% CI: 0.83 to 1.63]; P = .38; death or HF hospitalization: HR 0.97 [95% CI: 0.64 to 1.46]; P = .88). The interaction between history of AF/AFL and CRT was statistically significant for both outcomes (P < .05). CONCLUSION: In the COMPANION trial, patients with moderate to severe HFrEF and a history of IAF/AFL had no benefit from CRT.

Heart Rate and Outcomes in Hospitalized Patients With Heart Failure With Preserved Ejection Fraction.

BACKGROUND: A lower heart rate is associated with better outcomes in patients with heart failure (HF) with reduced ejection fraction (EF). Less is known about this association in patients with HF with preserved ejection fraction (HFpEF). OBJECTIVES: The aims of this study were to examine associations of discharge heart rate with outcomes in hospitalized patients with HFpEF. METHODS: Of the 8,873 hospitalized patients with HFpEF (EF ≥50%) in the Medicare-linked OPTIMIZE-HF (Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure) registry, 6,286 had a stable heart rate, defined as ≤20 beats/min variation between admission and discharge. Of these, 2,369 (38%) had a discharge heart rate of <70 beats/min. Propensity scores for discharge heart rate <70 beats/min, estimated for each of the 6,286 patients, were used to assemble a cohort of 2,031 pairs of patients with heart rate <70 versus ≥70 beats/min, balanced on 58 baseline characteristics. RESULTS: The 4,062 matched patients had a mean age of 79 ± 10 years, 66% were women, and 10% were African American. During 6 years (median 2.8 years) of follow-up, all-cause mortality was 65% versus 70% for matched patients with a discharge heart rate <70 versus ≥70 beats/min, respectively (hazard ratio [HR]: 0.86; 95% confidence interval [CI]: 0.80 to 0.93; p < 0.001). A heart rate <70 beats/min was also associated with a lower risk for the combined endpoint of HF readmission or all-cause mortality (HR: 0.90; 95% CI: 0.84 to 0.96; p = 0.002), but not with HF readmission (HR: 0.93; 95% CI: 0.85 to 1.01) or all-cause readmission (HR: 1.01; 95% CI: 0.95 to 1.08). Similar associations were observed regardless of heart rhythm or receipt of beta-blockers. CONCLUSIONS: Among hospitalized patients with HFpEF, a lower discharge heart rate was independently associated with a lower risk of all-cause mortality, but not readmission.

Role of amiodarone or implantable cardioverter/defibrillator in patients with atrial fibrillation and heart failure.

BACKGROUND: Heart failure complicated by atrial fibrillation (AF) is associated with excessive mortality and morbidity. The aim of the study was to determine the role of amiodarone or implantable cardioverter/defibrillator (ICD) in patients with AF and heart failure. METHODS: Patients were determined to be in sinus rhythm (SR) or AF on the baseline electrocardiogram. Mortality, ICD discharge, or change in rhythm was assessed. RESULTS: Of the 2521 patients at baseline, 2328 were in SR and 173 were in AF. Overall, after adjusting for differences in baseline variables, there was no difference in mortality between patients with SR and patients with AF (P = .98), nor within assigned groups: placebo (P) (P = .82), amiodarone (A) (P = .68), and ICD (P = .40). For patients with SR, ICD decreased mortality (P vs ICD, P = .004; A vs ICD, P = .004; P vs A, P = .75). For patients with AF, there were no differences in mortality among groups (P vs ICD, P = .99; A vs ICD, P = .88; P vs A, P = .88). Of patients with SR at baseline, 11% (264) developed AF by any electrocardiogram during follow-up (P 12%, A 8%, ICD 15%; A vs P, P = .019; A vs ICD, P = .001; P vs ICD, P = .044). Of patients with AF, 70% (121) developed SR during follow-up (P 66%, A 67%, ICD 75%, all P = not significant against each other). Any ICD shock was seen in 52% (34) of patients with AF vs 30% (222) of patients with SR (P = .001). Inappropriate shocks were seen in 37% (24) of patients with AF vs 14% (107) of patients with SR (P = .001). Appropriate shocks were more often seen in AF vs SR (P = .03). CONCLUSION: After adjustments for baseline differences, patients with AF and patients with SR have similar overall mortality rates. Compared to P or A, ICD improves survival in patients with SR, but may not in patients with AF. Amiodarone is effective in reducing new AF, but not in converting AF to SR. Implantable cardioverter/defibrillator, inappropriate, and appropriate shocks were more often seen in AF than in SR.

The efficacy of azimilide in the treatment of atrial fibrillation in the presence of left ventricular systolic dysfunction: results from the Azimilide Postinfarct Survival Evaluation (ALIVE) trial.

OBJECTIVES: The purpose of this study was to assess the effect of oral azimilide dihydrochloride (AZ) 100 mg versus placebo on the onset, termination, and prevalence of atrial fibrillation (AF) in a subpopulation of patients in the Azimilide Postinfarct Survival Evaluation (ALIVE) trial. BACKGROUND: Previous clinical trials have demonstrated the antiarrhythmic effects of AZ in patients with AF. Azimilide was investigated for its effects on mortality in patients with depressed left ventricular (LV) function after recent myocardial infarction (MI) and in a subpopulation of patients with AF. METHODS: A total of 3,381 post-MI patients with depressed LV function were enrolled in this randomized, placebo-controlled, double-blind study of AZ 100 mg on all-cause mortality. A total of 93 patients had AF on the baseline 12-lead electrocardiogram (ECG). An additional 27 patients developed AF after initially being in sinus rhythm at randomization. These patients were identified through 12-lead ECGs obtained during routine visits at week 2, months 1, 4, 8, and 12. RESULTS: Patients with AF at baseline had a higher mortality than those without AF (p = 0.0006). Among AF patients, there was no difference in mortality between AZ patients and placebo patients (p = 0.82). Fewer AZ patients developed AF than placebo patients (p = 0.04). More AZ patients than placebo patients converted to sinus rhythm, but this difference did not achieve statistical significance (p = 0.076). Over one-year follow-up, more AZ patients were in sinus rhythm than placebo patients (p = 0.04). CONCLUSIONS: Azimilide was safe and effective AF therapy in patients with depressed LV function after an MI.

Vasopeptidase inhibition with omapatrilat in chronic heart failure: acute and long-term hemodynamic and neurohumoral effects.

OBJECTIVES: We investigated the acute and long-term hemodynamic and neurohumoral effects of the vasopeptidase inhibitor omapatrilat in human heart failure. BACKGROUND: Angiotensin-converting enzyme (ACE) inhibition constitutes a major advance in the treatment of chronic heart failure (CHF). Simultaneous inhibition of both neutral endopeptidase and ACE with omapatrilat may represent a new treatment strategy in CHF. METHODS: Three hundred and sixty-nine patients with symptomatic heart failure were randomized to double-blind treatment with omapatrilat (first 190 patients: 2.5 mg, 5 mg or 10 mg; last 179 patients: 2.5 mg, 20 mg or 40 mg once daily) for 12 weeks. RESULTS: Acutely, the 10 mg, 20 mg and 40 mg doses of omapatrilat produced greater reductions in pulmonary capillary wedge pressure (PCWP), systolic blood pressure (SBP) and systemic vascular resistance compared with 2.5 mg. Higher doses were associated with greater increases in vasodilator and natriuretic peptides, in addition to ACE inhibition. After 12 weeks, omapatrilat 20 mg and 40 mg showed greater falls from baseline in PCWP (40 mg: 0 h to 12 h average change -7.3 +/- 0.8 mm Hg) and SBP (40 mg: -11.7 +/- 1.7 mm Hg) than 2.5 mg (both p < 0.01 vs. 2.5 mg). The incidence of adverse experiences and patient withdrawal were similar in all groups. CONCLUSIONS: In CHF, the acute hemodynamic benefit seen with higher doses of omapatrilat was associated with increases in plasma vasodilator and natriuretic peptide levels in addition to ACE inhibition. After 12 weeks, the hemodynamic benefit was maintained. Omapatrilat may be a promising new agent in CHF.

Valsartan reduces the incidence of atrial fibrillation in patients with heart failure: results from the Valsartan Heart Failure Trial (Val-HeFT).

BACKGROUND: Atrial fibrillation (AF) in heart failure (HF) is generally considered a negative prognostic factor. Recent studies indicate that the incidence of AF might be decreased by renin angiotensin aldosterone system inhibitors. The identification of a treatment to prevent its occurrence is likely to improve patients outcome. The aims of these subanalyses of Val-HeFT were to assess (a) the effects of valsartan in the prevention of AF, (b) the independent predictors of this event, and (c) the prognostic role of AF occurrence. METHODS AND RESULTS: The occurrence of AF was evaluated based on adverse event reports in the patients with HF enrolled in Val-HeFT. Patients were randomized to valsartan or placebo on top of their prescribed treatments for HF. During the mean 23 months of follow-up, AF was reported in 287/4395 patients (6.53%) in sinus rhythm at baseline, of whom 113/2205 (5.12%) were allocated to valsartan and 174/2190 (7.95%) to placebo (P = .0002). Multivariable analysis showed that brain natriuretic peptide (BNP) levels at baseline above the median value (HR 2.28, 95% CI 1.75-2.98), age over 70 years (HR 1.51, 95% CI 1.17-1.95), male sex (HR 1.53, 95% CI 1.07-2.18), and the valsartan treatment (HR 0.63, 95% CI 0.49-0.81) were independently associated with AF occurrence. Cox multivariable regression analysis showed that occurrence of AF was independently associated with a worse prognosis, with the adjusted hazard risks for all-cause mortality and combined mortality/morbidity of 1.40 (95% CI 1.16-1.58) and 1.38 (95% CI 1.12-1.70), respectively. CONCLUSIONS: The results of the present study demonstrate that (a) adding valsartan to prescribed therapy for HF significantly reduces the incidence of AF by 37%; (b) BNP level and advanced age were the strongest independent predictors for AF occurrence; and (c) AF occurrence further worsens the outcome in patients with HF.

QRS duration and mortality in patients with congestive heart failure.

BACKGROUND AND OBJECTIVES: It has been suggested that prolongation of the QRS duration (>120 ms) is an independent risk factor for mortality in patients with cardiomyopathy. The purpose of this study was to examine the association between QRS duration and survival in patients with heart failure. METHODS: We performed a retrospective analysis to examine the association between QRS prolongation (> or =120 ms) and mortality. The study population included 669 patients with heart failure. Two groups, on the basis of baseline QRS duration <120 milliseconds or > or =120 milliseconds, were identified. The groups were compared with respect to total mortality and sudden death. Subgroups were also stratified by right bundle branch block and left bundle branch block, ejection fraction (EF) <30% and > or =30% to 40%, ischemic and nonischemic cardiomyopathy, amiodarone and placebo. RESULTS: Prolonged QRS was associated with a significant increase in mortality (49.3% vs 34.0%, P =.0001) and sudden death (24.8% vs 17.4%, P =.0004). Left bundle branch block was associated with worse survival (P =.006) but not sudden death. In patients with an EF <30%, QRS prolongation continued to be associated with a significant increase in mortality (51.6% vs 41.1%, P =.01) and sudden death (28.8% vs 21.1%, P =.02). In those with an EF of 30% to 40%, QRS prolongation was associated with a significant increase in mortality (42.7% vs 23.3%, P =.0036) but not in sudden death (13.3% vs 12.0%, P =.625). After adjustment for baseline variables, independent predictors of mortality were found to be prolongation of QRS (P =.0028, risk ratio 1.46) and depressed EF (P =.0001, risk ratio 0.965). Age, type of cardiomyopathy, and drug treatment group were not predictive of mortality. CONCLUSION: QRS prolongation is an independent predictor of both increased total mortality and sudden death in patients with heart failure.

Prognostic value of heart rate variability in chronic congestive heart failure (Veterans Affairs' Survival Trial of Antiarrhythmic Therapy in Congestive Heart Failure).

Although the value of heart rate variability (HRV) for risk stratification after acute myocardial infarction has been demonstrated, the value of low HRV as a predictor of sudden cardiac death in patients with ischemic cardiomyopathy has not been shown convincingly to date. We retrospectively analyzed electrocardiographic data from 179 patients in the Veterans Affairs' Survival Trial of Antiarrhythmic Therapy in Congestive Heart Failure to determine if HRV (expressed as the SD of the normal-to-normal RR intervals [SDNN]) would be useful as a predictor of overall mortality and sudden death. Because our goal was to identify high-risk patients, we compared patients in the lowest quartile of HRV with the remaining patients. Among the 127 patients meeting inclusion criteria, SDNN <65.3 ms (the lowest quartile) was the sole independent factor predictive of survival in a multivariate model (p = 0.0001). A Cox proportional-hazards model revealed that each increase of 10 ms in SDNN conferred a 20% decrease in risk of mortality (p = 0.0001). Furthermore, patients with SDNN <65.3 ms had a significantly increased risk of sudden death (p = 0.016). Thus, HRV was the sole independent predictor of overall mortality and was significantly associated with sudden death in this population.

Comparison of sotalol versus amiodarone in maintaining stability of sinus rhythm in patients with atrial fibrillation (Sotalol-Amiodarone Fibrillation Efficacy Trial [Safe-T]).

The Sotalol-Amiodarone Fibrillation Efficacy Trial (SAFE-T) is a randomized, double-blind, multicenter, placebo-controlled trial in which the effects of sotalol and amiodarone in maintaining stability of sinus rhythm are being examined in patients with persistent atrial fibrillation at 20 Veterans Affairs medical centers. The time to the occurrence of atrial fibrillation or flutter in patients with atrial fibrillation converted to sinus rhythm is the primary outcome measure, with a number of parameters as secondary end points. SAFE-T had randomized 665 patients when enrollment terminated on October 31, 2001. Follow-up of patients continued until October 31, 2002, for a maximum period of 54 months and a minimum period of 12 months for all patients.