Temporal trends in quality of care among recipients of implantable cardioverter-defibrillators: insights from the National Cardiovascular Data Registry.

BACKGROUND: The ICD Registry was established in 2006 in part to measure quality of care in patients undergoing implantation of implantable cardioverter-defibrillators (ICDs); however, whether outcomes have improved since initiation of the registry is unknown. Our objective was to examine changes over time in 3 quality metrics available from the registry. METHODS AND RESULTS: We performed an observational study of 367 153 patients who received new ICD implants from April 2006 to March 2010. Three quality metrics were selected: Adverse events (in-hospital complications or mortality), optimal medical therapy (OMT), and cardiac resynchronization therapy (CRT). OMT was defined as prescription of ß-blocker and either angiotensin-converting enzyme inhibitor or angiotensin receptor blocker in eligible patients. CRT eligibility was determined by QRS ≥120 ms, left ventricular ejection fraction ≤35%, and New York Heart Association class III/IV. Observation periods were divided into four 12-month intervals. We analyzed changes over time and used hierarchical logistic regression to adjust for potential confounders. Adverse events decreased over time (3.7% to 2.8%, P<0.001). Among eligible patients, rates of OMT and CRT increased over time (OMT: 69.0% to 74.3%, P<0.001; CRT: 80.5% to 84.2%, P<0.001). After adjustment for potential confounders, patients were significantly less likely to experience adverse events in year 4 than in year 1 (odds ratio, 0.75; 95% confidence interval, 0.71-0.79) and significantly more likely to receive OMT (odds ratio, 1.29; 95% confidence interval, 1.26-1.32) and CRT (odds ratio, 1.42; 95% confidence interval, 1.35-1.49). CONCLUSIONS: Since initiation of the ICD Registry, adverse events have been decreasing, and rates of OMT and CRT among eligible patients have been increasing, although there is still significant room for improvement.

Primary prevention implantable cardioverter defibrillators in end-stage kidney disease patients on dialysis: a matched cohort study.

BACKGROUND: Sudden cardiac death is the leading cause of death among end-stage kidney disease patients (ESKD) on dialysis, but the benefit of primary prevention implantable cardioverter defibrillators (ICDs) in this population is uncertain. We conducted this investigation to compare the mortality of dialysis patients receiving a primary prevention ICD with matched controls. METHODS: We used data from the National Cardiovascular Data Registry's ICD Registry to select dialysis patients who received a primary prevention ICD, and the Get with the Guidelines-Heart Failure Registry to select a comparator cohort. We matched ICD recipients and no-ICD patients using propensity score techniques to reduce confounding, and overall survival was compared between groups. RESULTS: We identified 108 dialysis patients receiving primary prevention ICDs and 195 comparable dialysis patients without ICDs. One year (3-year) mortality was 42.2% (68.8%) in the ICD registry cohort compared with 38.1% (75.7%) in the control cohort. There was no significant survival advantage associated with ICD [hazard ratio (HR) 0.87, 95% confidence interval (CI) 0.66-1.13, log-rank P = 0.29]. After propensity matching, our analysis included 86 ICD patients and 86 matched controls. Comparing the propensity-matched cohorts, 1 year (3 years) mortality was 43.4% (74.0%) in the ICD cohort and 39.7% (76.6%) in the control cohort; there was no significant difference in mortality outcome between groups (HR = 0.94, 95% CI: 0.67-1.31, log-rank P = 0.71). CONCLUSIONS: We did not observe a significant association between primary prevention ICDs and reduced mortality among ESKD patients receiving dialysis. Consideration of the potential risks and benefits of ICD implantation in these patients should be undertaken while awaiting the results of definitive clinical trials.

Comparative effectiveness of cardiac resynchronization therapy with an implantable cardioverter-defibrillator versus defibrillator therapy alone: a cohort study.

BACKGROUND: Trials comparing implantable cardioverter-defibrillator (ICD) therapy with cardiac resynchronization therapy with a defibrillator (CRT-D) are limited to selected patients treated at centers with extensive experience. OBJECTIVE: To compare outcomes after CRT-D versus ICD therapy in contemporary practice. DESIGN: Retrospective cohort study using the National Cardiovascular Data Registry's ICD Registry linked with Medicare claims. SETTING: 780 U.S. hospitals implanting both CRT-D and ICD devices. PATIENTS: 7090 propensity-matched patients older than 65 years with reduced left ventricular ejection fraction (<0.35) and prolonged QRS duration on electrocardiography (≥120 ms) having CRT-D or ICD implantation between 1 April 2006 and 31 December 2009. MEASUREMENTS: Risks for death, readmission, and device-related complications over 3 years. RESULTS: Compared with ICD therapy, CRT-D was associated with lower risks for mortality (cumulative incidence, 25.7% vs. 29.8%; adjusted hazard ratio [HR], 0.82 [99% CI, 0.73 to 0.93]), all-cause readmission (cumulative incidence, 68.6% vs. 72.8%; adjusted HR, 0.86 [CI, 0.81 to 0.93]), cardiovascular readmission (cumulative incidence, 45.0% vs. 52.4%; adjusted HR, 0.80 [CI, 0.73 to 0.88]), and heart failure readmission (cumulative incidence, 24.3% vs. 29.4%; adjusted HR, 0.78 [CI, 0.69 to 0.88]). It was also associated with greater risks for device-related infection (cumulative incidence, 1.9% vs. 1.0%; adjusted HR, 1.90 [CI, 1.07 to 3.37]). The lower risks for heart failure readmission associated with CRT-D compared with ICD therapy were most pronounced among patients with left bundle branch block or a QRS duration at least 150 ms and in women. LIMITATIONS: Patients were not randomly assigned to treatment groups, and few patients could be propensity-matched. The findings may not extend to younger patients or those outside of fee-for-service Medicare. CONCLUSION: In older patients with reduced left ventricular ejection fraction and prolonged QRS duration, CRT-D was associated with lower risks for death and readmission than ICD therapy alone. PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality.

Distinguishing ventricular arrhythmia originating from the right coronary cusp, peripulmonic valve area, and the right ventricular outflow tract: utility of lead I.

INTRODUCTION: Outflow tract ventricular arrhythmia (OTVA) can be complicated to target for ablation when originating from either the periaortic or pulmonary valve (PV) region. Both sites may present with a small R wave in lead V1. However, the utility of lead I in distinguishing these arrhythmia locations is unknown. METHODS AND RESULTS: Thirty-six consecutive patients (mean age 41 ± 14 years, 13 male) underwent catheter ablation for OTVA. OTVA origin was determined from intracardiac electrogram tracings and electroanatomic maps. Observers blinded to results measured QRS waveform amplitude and duration from standard 12-lead ECG tracings. Measurements with highest diagnostic performance were modeled into an algorithm. Sites of successful ablation were anterior right ventricular outflow tract (RVOT; n = 6), posterior RVOT (n = 4), PV (n = 18), and right coronary cusp (RCC; n = 8). Highest performing surface ECG discriminators were from lead I to V1 vectors: RCC, lead I R wave ≥ 1.5 mV, and V1 R wave ≥2.0 mV (sensitivity 87%, specificity 93%); PV, V1 R wave > 0 mV, and lead I R/(R+S) ≤ 0.75 (sensitivity 78%, specificity 72%); anterior RVOT, V1 R wave = 0 mV, and lead I R/(R+S) <0.4 (sensitivity 67%, specificity 97%); posterior RVOT, V1 R wave > 0 mV, and lead I R/(R+S) > 0.75 (sensitivity 75%, specificity 84%). Sequential algorithmic application of these criteria resulted in an overall accuracy of 72% in predicting site of OTVA origin. CONCLUSIONS: A relatively large R wave in lead I is seen with RCC origin but not PV origin. A sequential algorithm has limited but potentially significant value beyond assessment of lead I in approaching OTVA.

Association between prophylactic implantable cardioverter-defibrillators and survival in patients with left ventricular ejection fraction between 30% and 35%.

IMPORTANCE: Clinical trials of prophylactic implantable cardioverter-defibrillators (ICDs) have included a minority of patients with a left ventricular ejection fraction (LVEF) between 30% and 35%. Because a large number of ICDs in the United States are implanted in such patients, it is important to study survival associated with this therapy. OBJECTIVE: To characterize patients with LVEF between 30% and 35% and compare the survival of those with and without ICDs. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study of Medicare beneficiaries in the National Cardiovascular Data Registry ICD registry (January 1, 2006, through December 31, 2007) with an LVEF between 30% and 35% who received an ICD during a heart failure hospitalization and similar patients in the Get With The Guidelines-Heart Failure (GWTG-HF) database (January 1, 2005, through December 31, 2009) with no ICD. The analysis was repeated in patients with an LVEF less than 30%. There were 3120 patients with an LVEF between 30% and 35% (816 in matched cohorts) and 4578 with an LVEF less than 30% (2176 in matched cohorts). Propensity score matching and Cox models were applied. MAIN OUTCOMES AND MEASURES: The primary outcome was all-cause mortality; data were obtained from Medicare claims through December 31, 2011. RESULTS: There were no significant differences in the baseline characteristics of the matched groups (n = 408 for both groups). Among patients with an LVEF between 30% and 35%, there were 248 deaths in the ICD Registry group, within a median follow-up of 4.4 years (interquartile range, 2.7-4.9) and 249 deaths in the GWTG HF group, within a median follow-up of 2.9 years (interquartile range, 2.1-4.4). The risk of all-cause mortality in patients with an LVEF between 30% and 35% and an ICD was significantly lower than that in matched patients without an ICD (3-year mortality rates: 51.4% vs 55.0%; hazard ratio, 0.83 [95% CI, 0.69-0.99]; P = .04). Presence of an ICD also was associated with better survival in patients with an LVEF less than 30% (3-year mortality rates: 45.0% vs 57.6%; 634 and 660 total deaths; hazard ratio, 0.72 [95% CI, 0.65-0.81]; P < .001) (P = .20 for interaction). CONCLUSIONS AND RELEVANCE: Among Medicare beneficiaries hospitalized for heart failure and with an LVEF between 30% and 35% and less than 30%, survival at 3 years was better in patients who received a prophylactic ICD than in comparable patients with no ICD. These findings support guideline recommendations to implant prophylactic ICDs in eligible patients with an LVEF of 35% or less.

Trends in use of implantable cardioverter-defibrillator therapy among patients hospitalized for heart failure: have the previously observed sex and racial disparities changed over time?

BACKGROUND: Prior studies have demonstrated low use of implantable cardioverter defibrillators (ICDs) as primary prevention, particularly among women and blacks. The degree to which the overall use of ICD therapy and disparities in use have changed is unclear. METHODS AND RESULTS: We examined 11 880 unique patients with a history of heart failure and left ventricular ejection fraction ≤35% who were ≥65 years old and enrolled in the Get With the Guidelines-Heart Failure (GWTG-HF) program from January 2005 through December 2009. We determined the rate of ICD use by year for the overall population and for sex and race groups. From 2005 to 2007, overall ICD use increased from 30.2% to 42.4% and then remained unchanged in 2008 to 2009. After adjustment for potential confounders, ICD use increased significantly in the overall study population during 2005 to 2007 (odds ratio, 1.28; 95% confidence interval, 1.11-1.48 per year; P=0.0008) and in black women (odds ratio, 1.82; 95% confidence interval, 1.28-2.58 per year; P=0.0008), white women (odds ratio, 1.30; 95% confidence interval, 1.06-1.59 per year; P=0.010), black men (odds ratio, 1.54; 95% confidence interval, 1.19-1.99 per year; P=0.0009), and white men (odds ratio, 1.25; 95% confidence interval, 1.06-1.48 per year; P=0.0072). The increase in ICD use was greatest among blacks. CONCLUSIONS: In the GWTG-HF quality improvement program, a significant increase in ICD therapy use was observed over time in all sex and race groups. The previously described racial disparities in ICD use were no longer present by the end of the study period; however, sex differences persisted.

Transitional adherence and persistence in the use of aldosterone antagonist therapy in patients with heart failure.

BACKGROUND: Aldosterone antagonist therapy is recommended for selected patients with heart failure and reduced ejection fraction. Adherence to therapy in the transition from hospital to home is not well understood. METHODS: We identified patients with heart failure and reduced ejection fraction who were ≥65 years old, eligible for aldosterone antagonist therapy, and discharged home from hospitals in the Get With the Guidelines-Heart Failure registry between January 1, 2005, and December 31, 2008. We used Medicare prescription drug event data to measure adherence. Main outcome measures were prescription at discharge, outpatient prescription claim within 90 days, discontinuation, and adherence as measured with the medication possession ratio. We used the cumulative incidence function to estimate rates of initiation and discontinuation. RESULTS: Among 2,086 eligible patients, 561 (26.9%) were prescribed an aldosterone antagonist at discharge. Within 90 days, 78.6% of eligible patients with a discharge prescription filled a prescription for the therapy, compared with 13.0% of eligible patients without a discharge prescription (P < .001). The median medication possession ratio was 0.63 over 1 year of follow-up. Among 634 patients who filled a prescription within 90 days of discharge, 7.9% discontinued therapy within 1 year. CONCLUSION: Most eligible patients were not prescribed aldosterone antagonist therapy at discharge from a heart failure hospitalization. Eligible patients without a discharge prescription seldom initiated therapy as outpatients. Most patients who were prescribed an aldosterone antagonist at discharge filled the prescription within 90 days and remained on therapy.

Anatomy of the coronary sinus and epicardial coronary venous system in 620 hearts: an electrophysiology perspective.

INTRODUCTION: Cannulation of the coronary sinus (CS) is a prerequisite for left ventricular (LV) pacing and certain ablation procedures. The detailed regional anatomy for the coronary veins and potential anatomic causes for difficulty with these procedures has not been established. METHODS AND RESULTS: Therefore, we performed macroscopic measurements in 620 autopsied hearts (mean age 60 ± 23 years, 44% female). The CS was preserved for analysis in 96%. Sixty-three percent had a Thebesian valve that covered the posterior aspect of the CS ostium with extension to the superior (50%) and inferior aspects (18%) and was obstructive with fenestrations in 3 specimens. Partial or near occlusive valves were present occasionally at the ostium of the great cardiac vein (Vieussens; 8%) and middle cardiac vein (5%). Ninety-three percent had left atrial branches, and 41% had at least one branch with lumen > 3 French. For CRT lead placement, the mid-lateral LV was accessible from the middle cardiac vein (20%), the left posterior vein (92%) or the anterior interventricular vein (86%). Among specimens where the left phrenic nerve was preserved it crossed the LV mid-lateral wall in 45%. CONCLUSIONS: Epicardial coronary vein anatomy is variable, and the mid-lateral LV wall can potentially be accessed through various tributaries of the epicardial veins. The orientation of the Thebesian valve favors cannulation of the CS from an anterior (ventricular) and inferior approach. Anterobasal, mid-lateral, and inferior apical LV coronary veins lie in proximity to the course of the phrenic nerve.

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.

QRS duration, bundle-branch block morphology, and outcomes among older patients with heart failure receiving cardiac resynchronization therapy.

IMPORTANCE: The benefits of cardiac resynchronization therapy (CRT) in clinical trials were greater among patients with left bundle-branch block (LBBB) or longer QRS duration. OBJECTIVE: To measure associations between QRS duration and morphology and outcomes among patients receiving a CRT defibrillator (CRT-D) in clinical practice. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study of Medicare beneficiaries in the National Cardiovascular Data Registry's ICD Registry between 2006 and 2009 who underwent CRT-D implantation. Patients were stratified according to whether they were admitted for CRT-D implantation or for another reason, then categorized as having either LBBB or no LBBB and QRS duration of either 150 ms or greater or 120 to 149 ms. MAIN OUTCOMES AND MEASURES: All-cause mortality; all-cause, cardiovascular, and heart failure readmission; and complications. Patients underwent follow-up for up to 3 years, with follow-up through December 2011. RESULTS: Among 24 169 patients admitted for CRT-D implantation, 1-year and 3-year mortality rates were 9.2% and 25.9%, respectively. All-cause readmission rates were 10.2% at 30 days and 43.3% at 1 year. Both the unadjusted rate and adjusted risk of 3-year mortality were lowest among patients with LBBB and QRS duration of 150 ms or greater (20.9%), compared with LBBB and QRS duration of 120 to 149 ms (26.5%; adjusted hazard ratio [HR], 1.30 [99% CI, 1.18-1.42]), no LBBB and QRS duration of 150 ms or greater (30.7%; HR, 1.34 [99% CI, 1.20-1.49]), and no LBBB and QRS duration of 120 to 149 ms (32.3%; HR, 1.52 [99% CI, 1.38-1.67]). The unadjusted rate and adjusted risk of 1-year all-cause readmission were also lowest among patients with LBBB and QRS duration of 150 ms or greater (38.6%), compared with LBBB and QRS duration of 120 to 149 ms (44.8%; adjusted HR, 1.18 [99% CI, 1.10-1.26]), no LBBB and QRS duration of 150 ms or greater (45.7%; HR, 1.16 [99% CI, 1.08-1.26]), and no LBBB and QRS duration of 120 to 149 ms (49.6%; HR, 1.31 [99% CI, 1.23-1.40]). There were no observed associations with complications. CONCLUSIONS AND RELEVANCE: Among fee-for-service Medicare beneficiaries undergoing CRT-D implantation in clinical practice, LBBB and QRS duration of 150 ms or greater, compared with LBBB and QRS duration less than 150 ms or no LBBB regardless of QRS duration, was associated with lower risk of all-cause mortality and of all-cause, cardiovascular, and heart failure readmissions.

Design and rationale of a retrospective clinical effectiveness study of aldosterone antagonist therapy in patients with heart failure.

BACKGROUND: Despite demonstrated efficacy in randomized trials, aldosterone antagonist therapy is not used in many eligible patients with heart failure. Questions remain about its clinical effectiveness and safety for patients who are underrepresented in randomized trials and those at risk for hyperkalemia. METHODS: The proposed study will evaluate the effectiveness of aldosterone antagonist therapy in eligible Medicare beneficiaries ≥ 65 years old hospitalized for heart failure between 2005 and 2008. Data are from the GWTG-HF registry linked with Medicare inpatient and prescription drug event files. We will use inverse probability-weighted estimators to assess differences in mortality, cardiovascular readmission, and readmission for hyperkalemia between patients who receive or do not receive aldosterone antagonist therapy. RESULTS: The initial data set included 33,652 patients; 5,463 (16.2%) met all inclusion criteria. Compared with patients who did not meet the inclusion criteria, patients in the final cohort were more likely to be younger (77.3 vs 80.3 years) and male (63.8% vs 41.3%) and to have ischemic heart failure (74.2% vs 59.5%) (all P < .001). Mortality rates were 24.7% at 1 year and 50.7% at 3 years; cardiovascular readmission rates were 50.1% at 1 year and 65.2% at 3 years. CONCLUSIONS: The proposed study will evaluate the clinical effectiveness of aldosterone antagonist therapy in Medicare beneficiaries hospitalized for heart failure with reduced ejection fraction, an underrepresented population in clinical trials. By addressing this evidence gap, the study has the potential to inform clinical decision making and improve patient outcomes.

Myocardium of the superior vena cava, coronary sinus, vein of Marshall, and the pulmonary vein ostia: gross anatomic studies in 620 hearts.

INTRODUCTION: Radiofrequency ablation for atrial fibrillation (AF) frequently involves energy delivery at the ostia of the thoracic veins. Detailed evaluation of the myocardium extending into the caval veins, vein of Marshall, as well as at the pulmonary vein ostia has not been completely evaluated. METHODS AND RESULTS: Post-mortem assessment of 620 formalin-fixed hearts (mean age 60 ± 23 years, 44% female) was performed. The hearts were examined for integrity of venous structures and their atrial connections. Systematic gross anatomic evaluation including measurements on myocardial extensions in these veins was performed. Macroscopic myocardial extensions into pulmonary veins were noted in 99% of specimens evaluated and were circumferentially symmetric (99.6%). Myocardial extensions into the superior vena cava (SVC) occurred in 78% with the majority being circumferentially asymmetric (61%). Occasionally, myocardium extended into the azygos vein (6%). There were no myocardial extensions in the inferior vena cava (IVC). In some cases, the right atrial pectinate muscle extended into the coronary sinus (7%). The vein of Marshall was consistently located anterior to the left-sided pulmonary veins and posterior to the left atrial appendage, overlying the left atrial endocardial ridge. CONCLUSIONS: Myocardial extensions into the pulmonary veins are usually circumferential at the ostia validating the necessity for wide area rather than segmental ablation to isolate these veins during AF ablation. Myocardial extensions into the SVC are common and less likely to be circumferential, whereas extensions into the IVC are not present. The left atrial ridge is a reliable endocardial target for radiofrequency ablation of the vein of Marshall.

Associations between aldosterone antagonist therapy and risks of mortality and readmission among patients with heart failure and reduced ejection fraction.

CONTEXT: Aldosterone antagonist therapy for heart failure and reduced ejection fraction has been highly efficacious in randomized trials. However, questions remain regarding the effectiveness and safety of the therapy in clinical practice. OBJECTIVE: To examine the clinical effectiveness of newly initiated aldosterone antagonist therapy among older patients hospitalized with heart failure and reduced ejection fraction. DESIGN, SETTING, AND PARTICIPANTS: Using clinical registry data linked to Medicare claims from 2005 through 2010, we examined outcomes of eligible patients hospitalized with heart failure and reduced ejection fraction. We used Cox proportional hazards models and inverse-weighted estimates of the probability of treatment to adjust for treatment selection bias. MAIN OUTCOME MEASURES: All-cause mortality, cardiovascular readmission, and heart failure readmission at 3 years, and hyperkalemia readmission at 30 days and 1 year. RESULTS: Among 5887 patients who met the inclusion criteria, the mean age was 77.6 years; of those 1070 (18.2%) started aldosterone antagonist therapy at discharge. Cumulative incidence rates among treated and untreated patients were 49.9% vs 51.2% (P = .62) for mortality; 63.8% vs 63.9% (P = .65) for cardiovascular readmission; and 38.7% vs 44.9% (P < .001) for heart failure readmission at 3 years; and 2.9% vs 1.2% (P < .001) for hyperkalemia readmission within 30 days and 8.9% vs 6.3% (P = .002) within 1 year. After inverse weighting for the probability of treatment, there were no significant differences in mortality (hazard ratio [HR], 1.04; 95% CI, 0.96-1.14; P = .32) and cardiovascular readmission (HR, 1.00; 95% CI, 0.91-1.09; P = .94). Heart failure readmission was lower among treated patients at 3 years (HR, 0.87; 95% CI, 0.77-0.98; P = .02). Readmission associated with hyperkalemia was higher with aldosterone antagonist therapy at 30 days (HR, 2.54; 95% CI, 1.51-4.29; P < .001) and 1 year (HR, 1.50; 95% CI, 1.23-1.84; P < .001). CONCLUSIONS: Initiation of aldosterone antagonist therapy at hospital discharge was not independently associated with improved mortality or cardiovascular readmission but was associated with improved heart failure readmission among eligible older patients with heart failure and reduced ejection fraction. There was a significant increase in the risk of readmission with hyperkalemia, predominantly within 30 days after discharge.

Characteristics of premature ventricular complexes as correlates of reduced left ventricular systolic function: study of the burden, duration, coupling interval, morphology and site of origin of PVCs.

BACKGROUND: Frequent premature ventricular complexes (PVCs) can cause a decline in left ventricular ejection fraction (LVEF). We investigated whether the site of origin and other PVC characteristics are associated with LVEF. METHODS: We retrospectively studied 70 consecutive patients (mean age 42 ± 17 years, 40 [57%] female) with no other cause of cardiomyopathy undergoing ablation of PVCs. We analyzed the association of a reduced LVEF, defined by LVEF <50% on echocardiography, with features of PVCs obtained from electrocardiography, 24- or 48-hour Holter monitor and electrophysiology study. RESULTS: Patients with reduced LVEF (n = 17) as compared to normal LVEF (n = 53) had an increased burden of PVCs (29.3 ± 14.6% vs 16.7 ± 13.7%, P = 0.004), higher prevalence of nonsustained ventricular tachycardia (VT) [13 (76%) vs 21 (40%), P = 0.01], longer PVC duration (154.3 ± 22.9 vs 145.6 ± 20.8 ms, P = 0.03) and higher prevalence of multiform PVCs [15 (88%) vs 31 (58%), P = 0.04]. There was no significant difference in prevalence of sustained VT, QRS duration of normally conducted complexes, PVC coupling interval, or delay in PVC intrinsicoid deflection. Patients with fascicular PVCs (n = 5) had higher mean LVEF compared to others (66.2 ± 4.0% vs 53.0 ± 10.0%, P = 0.002). There was no association of LVEF with other PVC foci or with left-bundle versus right-bundle branch block morphologies. The threshold burden of PVCs associated with reduced LVEF was lower for right as compared to left ventricular PVCs. CONCLUSION: In addition to the PVC burden, other characteristics like a longer PVC duration, presence of nonsustained VT, multiform PVCs and right ventricular PVCs might be associated with cardiomyopathy.

Non-evidence-based ICD implantations in the United States.

CONTEXT: Practice guidelines do not recommend use of an implantable cardioverter-defibrillator (ICD) for primary prevention in patients recovering from a myocardial infarction or coronary artery bypass graft surgery and those with severe heart failure symptoms or a recent diagnosis of heart failure. OBJECTIVE: To determine the number, characteristics, and in-hospital outcomes of patients who receive a non-evidence-based ICD and examine the distribution of these implants by site, physician specialty, and year of procedure. DESIGN, SETTING, AND PATIENTS: Retrospective cohort study of cases submitted to the National Cardiovascular Data Registry-ICD Registry between January 1, 2006, and June 30, 2009. MAIN OUTCOME MEASURE: In-hospital outcomes. RESULTS: Of 111,707 patients, 25,145 received non-evidence-based ICD implants (22.5%). Patients who received a non-evidence-based ICD compared with those who received an evidence-based ICD had a significantly higher risk of in-hospital death (0.57% [95% confidence interval {CI}, 0.48%-0.66%] vs 0.18% [95% CI, 0.15%-0.20%]; P <.001) and any postprocedure complication (3.23% [95% CI, 3.01%-3.45%] vs 2.41% [95% CI, 2.31%-2.51%]; P <.001). There was substantial variation in non-evidence-based ICDs by site. The rate of non-evidence-based ICD implants was significantly lower for electrophysiologists (20.8%; 95% CI, 20.5%-21.1%) than nonelectrophysiologists (24.8% [95% CI, 24.2%-25.3%] for nonelectrophysiologist cardiologists; 36.1% [95% CI, 34.3%-38.0%] for thoracic surgeons; and 24.9% [95% CI, 23.8%-25.9%] for other specialties) (P<.001 for all comparisons). There was no clear decrease in the rate of non-evidence-based ICDs over time (24.5% [6908/28,233] in 2006, 21.8% [7395/33,965] in 2007, 22.0% [7245/32,960] in 2008, and 21.7% [3597/16,549] in 2009; P <.001 for trend from 2006-2009 and P = .94 for trend from 2007-2009). CONCLUSION: Among patients with ICD implants in this registry, 22.5% did not meet evidence-based criteria for implantation.

Syncope while driving: clinical characteristics, causes, and prognosis.

BACKGROUND: The risk of syncope occurring while driving has obvious implications for personal and public safety. We aimed to define the clinical characteristics, causes, and prognosis of syncope while driving. METHODS AND RESULTS: In this case-control study of consecutive patients evaluated for syncope from 1996 through 1998 at an academic medical center, we documented causes, clinical characteristics, and recurrence of syncope while driving. Of 3877 patients identified, 381 (9.8%) had syncope while driving (driving group). Compared with the 3496 patients (90.2%) who did not have syncope while driving, the driving group was younger (P=0.01) and had higher percentages of male patients (P<0.001) and patients with a history of any cardiovascular disease (P=0.01) and stroke (P=0.02). Syncope while driving was commonly caused by neurally mediated syncope (37.3%) and cardiac arrhythmias (11.8%). Long-term survival in the driving group was comparable to that of an age- and sex-matched cohort from the Minnesota population (P=0.15). Among the driving group, syncope recurred in 72 patients, 35 of whom (48.6%) had recurrence >6 months after the initial evaluation. Recurrences during driving happened in 10 patients in the driving group, 7 of which (70%) were >12 months after the initial evaluation. CONCLUSIONS: In our study, neurally mediated syncope was the most common type of syncope while driving. The causes of syncope, the late recurrences of syncope (during > or =6 months of follow-up), and the overall low incidence of recurrent syncope while driving provide useful information to supplement current recommendations on driving for these patients.