Impact of a dedicated center for atrial fibrillation on resource utilization and costs.

BACKGROUND: Atrial fibrillation (AF) affects millions of Americans each year and can lead to high levels of resource utilization through emergency department (ED) visits and inpatient stays. HYPOTHESIS: We hypothesized that referral of patients to a dedicated Center for AF from the ED would reduce costs of care. METHODS: The University of Pittsburgh Center for AF serves as a rapid referral center for patients with AF to avoid unnecessary inpatient admissions and provide specialized care. Patients that presented to the ED with AF and met prespecified criteria were directed to rapid outpatient follow-up instead of inpatient admission. The primary outcome of interest was 30-day total costs. Secondary outcomes included outpatient costs, inpatient costs, 90-day costs, and inpatient stay characteristics. RESULTS: We identified 96 patients (median age 65, 38% women) referred to the center for AF for a new diagnosis of AF between October 2017 and December 2019 and matched 96 control patients. After 30 days of follow-up, patients referred to the center for AF had a lower average cost ($619 vs. $1252, p < 0.001) compared to controls, driven by lower costs of ED care tempered by slightly higher outpatient costs. Thirty-day admissions and lengths of stay were also lower. These differences were persistent at 90 days. CONCLUSION: Directing patients with AF that present to the ED to follow-up at a dedicated Center for AF significantly reduced overall costs, while reducing subsequent inpatient admissions and total lengths of stay in the hospital.

Outcomes of Blacks Versus Whites with Cardiomyopathy.

Racial disparities in health outcomes have been widely documented in medicine, including in cardiovascular care. While some progress has been made, these disparities have continued to plague our healthcare system. Patients with cardiomyopathy are at an increased risk of death and cardiovascular hospitalizations. In the present analysis, we examined the baseline characteristics and outcomes of black and white men and women with cardiomyopathy. All patients with cardiomyopathy (left ventricular ejection fraction (LVEF) < 50%) cared for at University of Pittsburgh Medical Center (UPMC) between 2011 and 2017 were included in this analysis. Patients were stratified by race, and outcomes were compared between Black and White patients using Cox proportional hazard models. Of a total of 18,003 cardiomyopathy patients, 15,804 were white (88%), 1,824 were black (10%) and 375 identified as other (2%). Over a median follow-up time of 3.4 years, 7,899 patients died. Black patients were on average a decade younger (p <0.001) and demonstrated lower unadjusted all-cause mortality (hazard ratio [HR]: 0.83%; 95% CI 0.77 to 0.90; p < 0.001). However, after adjusting for age and other comorbidities, black patients had higher all-cause mortality compared to white patients (HR: 1.15, 95% CI 1.07 to 1.25; p < 0.001). These differences were seen in both men (HR:1.19, 95% CI 1.08 to 1.33; p < 0.001) and women (HR:1.12, 95% CI 0.99 to 1.25; p = 0.065). In conclusion, our data demonstrate higher all-cause mortality in black compared to white men and women with cardiomyopathy. These findings are likely explained, at least in part, by significantly higher rates of comorbidities in black patients. Earlier interventions targeting these comorbidities may mitigate the risk of progression to heart failure and improve outcomes.

A Novel Non-Invasive Assessment of Cardiac Hemodynamics in Patients With Heart Failure and Atrial Fibrillation.

BACKGROUND: Heart failure (HF) and atrial fibrillation (AF) often coexist. The hemodynamic alterations induced by AF in patients with HF are well studied; however we lack reliable and non-invasive means to study these hemodynamic alterations in ambulatory patients. We sought to evaluate the clinical utility of impedance cardiography (ICG) as a novel and non-invasive tool to evaluate cardiac hemodynamics in ambulatory patients with HF and AF. METHODS: This was a single-center observational study. A convenient sample of ambulatory patients with chronic HF underwent non-invasive electrocardiogram (ECG) and hemodynamic monitoring using BioZ Dx impedance cardiographer. Hemodynamics were automatically computed and ECG data were interpreted by an independent reviewer. RESULTS: A total of 32 patients (62 ± 14 years of age; 66% male; ejection fraction 33±13%) were enrolled. There were no baseline demographic or clinical differences between those with AF (28%) and those without AF (72%). However, patients with AF exhibited lower stroke volume (60 ± 7 vs. 89 ± 29, P = 0.008), left ventricular work (33 ± 9 vs. 45 ± 13, P = 0.016), cardiac contractility (30 ± 8 vs. 40 ± 13, P = 0.037), and arterial elasticity (13 ± 5 vs. 21 ± 5, P = 0.012), as well as higher cardiac afterload (203 ± 57 vs. 151 ± 49, P = 0.015). CONCLUSIONS: Using non-invasive ICG, we have shown that it is feasible to characterize hemodynamics in ambulatory HF patients. We show that AF compromises left ventricular function in patients with HF and is associated with excess afterload and reduced arterial elasticity.

Real-World Direct Comparison of the Effectiveness and Safety of Apixaban, Dabigatran, Rivaroxaban, and Warfarin in Medicare Beneficiaries With Atrial Fibrillation.

It remains unknown whether the comparative effectiveness of direct oral anticoagulants (DOACs) and warfarin differs between atrial fibrillation patients with and without a history of stroke or transient ischemic attack (TIA). Using 2012 to 2014 Medicare claims data, we identified patients newly diagnosed with AF in 2013 to 2014 who initiated apixaban, dabigatran, rivaroxaban, or warfarin. We categorized patients based on a history of stroke or TIA. We constructed Cox proportional hazard models that included indicator variables for treatment groups, a history of stroke or TIA, and the interaction between them, and controlled for demographics and clinical characteristics. DOACs were generally more effective than warfarin in stroke prevention; however, there were important differences between subgroups defined by a history of ischemic stroke. In particular, the superiority of dabigatran compared with warfarin in ischemic stroke prevention was more pronounced in patients with a history of stroke or TIA (hazard ratio [HR] 0.64; 95% confidence interval [CI] 0.48 to 0.85) than in patients with no history of stroke or TIA (HR 0.94; 95% CI 0.75 to 1.16; p value for interaction = 0.034). There was no difference in the risk of stroke between apixaban, dabigatran, and rivaroxaban in patients with no history of stroke or TIA. However, in patients with a history of stroke or TIA, the risk of stroke was lower with dabigatran (HR 0.64; 95% CI 0.48 to 0.85) and rivaroxaban (HR 0.70; 95% CI 0.56 to 0.87), compared with apixaban (p value for both interactions <0.05). In conclusion, the comparative effectiveness of DOACs differs substantially between patients with and without a history of stroke or TIA; specifically, apixaban is less effective in patients with a history of stroke or TIA.

Adherence to Anticoagulation and Risk of Stroke Among Medicare Beneficiaries Newly Diagnosed with Atrial Fibrillation.

INTRODUCTION: The objective of this study was to compare the risk of stroke in atrial fibrillation (AF) with adherent use of oral anticoagulation (OAC), non-adherent use, and non-use of OAC. METHODS: Using 2013-2016 Medicare claims data, we identified patients newly diagnosed with AF in 2014-2015 and collected prescriptions filled for OAC in the 12 months after AF diagnosis (n = 39,272). We categorized participants each day into three time-dependent exposures: adherent use (≥ 80% of the previous 30 days covered with OAC), non-adherent use (0-80% covered with OAC), and non-use (0%). We constructed Cox proportional hazards models to estimate the association between time-dependent exposures and time to stroke, adjusting for demographics and clinical characteristics. RESULTS: The sample included 39,272 patients. Study participants spent 35.0% of the follow-up period in the adherent use exposure category, 10.9% in the non-adherent category, and 54.0% in the non-use category. OAC adherent use [hazard ratio (HR) 0.62; 95% confidence interval (CI) 0.52-0.74] and non-adherent use (HR 0.74; 95% CI 0.57-0.95) were associated with lower hazards of stroke than non-use. Adherent use of DOAC (HR 0.54; 95% CI 0.42-0.69) and warfarin (HR 0.70; 95% CI 0.56-0.89) was associated with lower risk of stroke than non-use, but the risk of stroke did not statistically differ between DOAC and warfarin adherent use (HR 0.77; 95% CI 0.56-1.04). DISCUSSION: Although adherence to OAC reduces stroke risk by nearly 40%, newly diagnosed AF patients in Medicare adhere to OAC on average only one third of the first year after AF diagnosis.

Effectiveness and Safety of Restarting Oral Anticoagulation in Patients with Atrial Fibrillation after an Intracranial Hemorrhage: Analysis of Medicare Part D Claims Data from 2010-2016.

BACKGROUND: In patients with atrial fibrillation (AF) who survive an anticoagulant-related intracranial hemorrhage (ICH), the benefits of restarting oral anticoagulation (OAC) remain unclear. OBJECTIVE: In this study, we sought to determine the effectiveness and safety associated with resumption of OAC in atrial fibrillation patients who survive an ICH. METHODS: Using 2010-2016 Medicare claims data, we identified patients with non-valvular AF who experienced an OAC-related ICH and survived at least 6 weeks after the ICH (n = 1502). The primary outcomes included the composite of ischemic stroke and transient ischemic attack (TIA), thromboembolism (TE), a composite of ischemic stroke/TIA and TE, recurrent ICH, and all-cause mortality. We constructed Cox proportional hazard models to evaluate the association between post-ICH OAC resumption, which was measured in a time-dependent manner, and the risk of primary outcomes, while controlling for a comprehensive list of covariates. RESULTS: Among patients who survived an ICH, 69% reinitiated OAC within 6 weeks of the event, and among those who resumed OAC, 83% restarted warfarin. There was no significant difference in the risk of ischemic stroke/TIA (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.62-1.21), TE (HR 0.85, 95% CI 0.55-1.32), and ischemic stroke/TIA/TE (HR 0.81, 95% CI 0.61-1.07) between post-ICH OAC use and non-use. Post-ICH OAC use was associated with a lower risk of recurrent ICH (HR 0.62, 95% CI 0.41-0.95) and all-cause mortality (HR 0.48, 95% CI 0.37-0.62) compared with non-OAC use. CONCLUSIONS: In AF patients who survived an ICH, restarting OAC was not associated with a greater risk of recurrent ICH. Evidence from randomized controlled studies is needed to further clarify the clinical benefit of restarting OAC in this high-risk population. Further evaluation of which individuals benefit from restarting OAC is also needed to provide more clinical guidance.

Trajectories of Oral Anticoagulation Adherence Among Medicare Beneficiaries Newly Diagnosed With Atrial Fibrillation.

Background Only 50% of atrial fibrillation ( AF ) patients recommended for oral anticoagulation ( OAC ) use these medications, and less than half of them adhere to OAC . In a cohort of Medicare beneficiaries newly diagnosed with AF , we identified groups of patients with similar trajectories of OAC use and adherence, and evaluated patient characteristics affecting group membership. Methods and Results We selected continuously enrolled Medicare Part D beneficiaries with first AF diagnosis in 2014 to 2015 (n=34 898). We calculated the proportion of days covered with OAC over the first 12 months after diagnosis and identified OAC adherence trajectories using group-based trajectory models. We constructed multinomial logistic regression models to evaluate how demographics, system-level factors, and clinical characteristics were associated with group membership. We identified 4 trajectories of OAC adherence: patients who never used OAC (43.8%), late OAC initiators (7.6%), early OAC discontinuers (8.9%), and continuously adherent patients (40.1%). Predictors such as sex, black race, residence in the South, or HAS - BLED score were associated with not only OAC use, but also the timing of initiation and the likelihood of discontinuation. For example, HAS - BLED score ≥4 was associated with a higher likelihood of not using OAC (odds ratio 1.35; 95% CI , 1.14-1.62), of late initiation (1.55; 95% CI , 1.11-2.05), and of early discontinuation (odds ratio 1.35; 95% CI , 1.01-1.84). Conclusions We identified 4 distinct trajectories of OAC adherence after first AF diagnosis, with <45% of newly diagnosed AF patients belonging to the trajectory group characterized by continuous OAC adherence. Trajectories were associated not only with demographic and clinical characteristics but also with regional factors.

Cardiac resynchronization therapy using pacemakers vs defibrillators in patients with nonischemic cardiomyopathy: The United States experience from 2007 to 2014.

BACKGROUND: The impact of implantable defibrillator therapy on outcomes of patients with nonischemic cardiomyopathy (NICM) who receive a cardiac resynchronization therapy (CRT) device is controversial. OBJECTIVE: The purpose of this study was to examine the outcomes of NICM patients who receive a CRT-pacemaker (CRT-P) vs CRT-defibrillator (CRT-D). METHODS: Using 2007-2014 claims data for a 5% random sample of Medicare beneficiaries, we followed patients with NICM who received a CRT device (1236 CRT-P, 4359 CRT-D), excluding those with a prior history of ventricular arrhythmias with a primary outcome of all-cause mortality and secondary outcomes including time to first cardiac hospitalization and total medical costs. Propensity score matching and Cox proportional hazard models were used to balance patient characteristics between treatment groups. RESULTS: At 5 years, 2007 patients (36%) died and 3809 (68%) were hospitalized for any reason, whereas 2504 (45%) were hospitalized for cardiac causes. In the propensity score matched sample, the time to all-cause mortality (hazard ratio [HR] 0.90; 95% confidence interval [CI] 0.74-1.09), any hospitalization (HR 1.13; 95% CI 0.98-1.30), and cardiac hospitalization (HR 0.98; 95% CI 0.83-1.17) did not differ between matched CRT-P and CRT-D recipients. However, CRT-P recipients had significantly lower medical costs (difference ∼$20,000) and cardiac-related medical costs at 12 and 24 months. CONCLUSION: Although more expensive, defibrillator therapy is not associated with prolonged survival or decreased risk of hospitalization in CRT recipients with NICM. These results suggest that in patients with NICM and no previous history of ventricular arrhythmias, CRT-P devices should be considered. These findings have important clinical and economic implications.

Outcomes of Patients With Atrial Fibrillation Newly Recommended for Oral Anticoagulation Under the 2014 American Heart Association/American College of Cardiology/Heart Rhythm Society Guideline.

BACKGROUND: In March 2014, the American Heart Association updated their guidelines for the management of oral anticoagulation (OAC) in atrial fibrillation, recommending OAC for all patients with CHA2DS2-VASc ≥2. Previously, only patients with CHADS2 ≥2 were recommended for anticoagulation. This study compared effectiveness and safety outcomes of OAC among patients who would receive OAC using the 2014 guidelines but not the 2011 guidelines. METHODS AND RESULTS: Using claims data from a 5% sample of 2013-2014 Medicare beneficiaries, we identified patients with initially diagnosed atrial fibrillation between 2013 and 2014 and selected those who would receive OAC under the 2014 guidelines but not the 2011 guidelines (those with CHA2DS2-VASc score ≥2 or CHADS2 score <2). Patients were categorized according to their use of OAC after first atrial fibrillation diagnosis (2937 users and 2914 nonusers). Primary outcomes included the composite of ischemic stroke, systemic embolism and death, and any bleeding event. Cox proportional hazard models were constructed to compare the risk of primary outcomes between the 2 groups, while controlling for patient demographic and clinical characteristics. There was no difference in the combined risk of stroke, systemic embolism, and death between the treatment groups (hazard ratio, 1.00; 95% confidence interval, 0.84-1.20). The risk of bleeding was higher for patients receiving OAC than for patients not receiving OAC (hazard ratio, 1.70, 95% confidence interval, 1.46-1.97). CONCLUSIONS: The benefit of OAC is not well defined in this patient population, and new studies that minimize residual confounding are needed to fully understand the risk/benefit of OAC in patients with atrial fibrillation and low to moderate stroke risk.

Impact of Race on Outcome of Patients Undergoing Rhythm Control of Atrial Fibrillation.

Racial disparities between African American (AA) and White patients have been documented in cardiovascular disease. We investigated whether these disparities exist in patients undergoing rhythm control for atrial fibrillation (AF). 5873 AF patients (241 AA) were followed to the endpoint of death, stroke, or AF recurrence. Invasive procedures for AF rhythm control were examined in both racial groups. Over a mean follow-up time of 40 months, AA patients had a higher adjusted risk of death [HR 1.39, 95% CI 1.00-1.92, p = 0.043] and stroke [HR 1.90, 95% CI 1.13-3.15, p = 0.013] but a lower risk of AF recurrence [HR 0.79, 95% CI 0.63-0.97, p = 0.026]. In addition, AA patients were less likely to undergo AF ablation (p = 0.006) or surgical maze (p = 0.032) procedures compared to White patients, possibly due to the lower rates of AF recurrence. Significant racial disparities exist in the management and outcomes of AA and White patients undergoing rhythm control management for AF.

Geographic Variation in the Use of Oral Anticoagulation Therapy in Stroke Prevention in Atrial Fibrillation.

BACKGROUND AND PURPOSE: Underuse of oral anticoagulation in stroke prevention in atrial fibrillation is common; however, it remains unknown how it varies geographically. The objective of this study was to evaluate geographic variation in oral anticoagulation use and in the initiation of new oral anticoagulants (NOACs). METHODS: Using 2013 to 2014 claims data from a 5% random sample of Medicare beneficiaries, we identified patients newly diagnosed with atrial fibrillation who initiated NOACs (n=8659), warfarin (n=11 771) or no oral anticoagulation therapy (n=18 226) in 2013 to 2014. Each patient was assigned to 1 of the 306 Dartmouth hospital-referral regions based on his/her zip code. We constructed logistic regressions to calculate the mean adjusted probability of initiating oral anticoagulation and the mean adjusted probability of initiating an NOAC among patients on oral anticoagulation in each hospital-referral region, after adjustment for demographic, clinical, and provider characteristics and type of insurance. Finally, we computed the correlation between 2 probabilities. RESULTS: Higher in the Midwest (0.54) and Northeast (0.54) and lowest in the South (0.47), the mean adjusted probability of initiating oral anticoagulation was 0.51, ranging from 0.32 to 0.72. The mean adjusted probability of being prescribed an NOAC among those on oral anticoagulation was 0.42 and was highest in the South (0.50) and lowest in the Midwest (0.36) and Northeast (0.39). In areas with the lower use of oral anticoagulation, patients on any oral anticoagulation therapy had a higher likelihood of being prescribed an NOAC (correlation coefficient, -0.16; P=0.006). CONCLUSIONS: Large geographic variation exists in oral anticoagulation use in atrial fibrillation. The use of oral anticoagulation is lower in the South, where the rates of stroke are unusually high. In the future, it will be important to analyze whether the high rates of stroke in the South can be partially attributed to the underuse of oral anticoagulation in this region.

Anticoagulation Use and Clinical Outcomes After Major Bleeding on Dabigatran or Warfarin in Atrial Fibrillation.

BACKGROUND AND PURPOSE: Little is known about the clinical outcomes associated with posthemorrhage anticoagulation resumption for atrial fibrillation. This study had 2 objectives: first, to evaluate anticoagulation use after a first major bleed on warfarin or dabigatran and, second, to compare effectiveness and safety outcomes between patients discontinuing anticoagulation after a major bleed and patients restarting warfarin or dabigatran. METHODS: Using 2010 to 2012 Medicare Part D data, we identified atrial fibrillation patients who experienced a major bleeding event while using warfarin (n=1135) or dabigatran (n=404) and categorized them by their posthemorrhage use of anticoagulation. We followed them until an ischemic stroke, recurrent hemorrhage, or death through December 31, 2012. We constructed logistic regression models to evaluate factors affecting anticoagulation resumption and Cox proportional hazard models to compare the combined risk of ischemic stroke and all-cause mortality and the risk of recurrent bleeding between treatment groups. RESULTS: Resumption of anticoagulation with warfarin (hazard ratio [HR] 0.76; 95% confidence interval [CI] 0.59-0.97) or dabigatran (HR 0.66; 95% CI 0.44-0.99) was associated with lower combined risk of ischemic stroke and all-cause mortality than anticoagulation discontinuation. The incidence of recurrent major bleeding was higher for patients prescribed warfarin after the event than for those prescribed dabigatran (HR 2.31; 95% CI 1.19-4.76) or whose anticoagulation ceased (HR 1.56; 95% CI 1.10-2.22), but did not differ between patients restarting dabigatran and those discontinuing anticoagulation (HR 0.65; 95% CI 0.32-1.33). CONCLUSIONS: Dabigatran was associated with a superior benefit/risk ratio than warfarin and anticoagulation discontinuation in the treatment of atrial fibrillation patients who have survived a major bleed.

Health and Economic Outcomes Associated with Use of an Antimicrobial Envelope as a Standard of Care for Cardiac Implantable Electronic Device Implantation.

INTRODUCTION: Infection of cardiac implanted electrical devices (CIED) is a problem. In selected patients, use of an "antibacterial envelope" (AIGISRx®) is associated with low CIED infection rates. The value of this device when used as a standard of care is unclear. METHODS AND RESULTS: Retrospective analysis of all patients (N = 1,476) who underwent CIED implantation at a single hospital. During the study period, some implanters used the AIGISRx as a standard of care (Yes-AIGISRx Group, N = 365), whereas others did not use it at all (No-AIGISRx Group, N = 1,111). A risk score based on preoperative factors was calculated for each patient. Rates of CIED infection within 6 months were measured, and associated costs were estimated. The Yes-AIGISRx and No-AIGISRx groups had similar preoperative infection risk. In the No-AIGISRx group, 19 infections were observed (1.7%), versus 0 in the Yes-AIGISRx group (P = 0.006). The 6-month mortality rate among patients with infection was significantly greater than among those without infection (15.7% vs. 4.5%, P = 0.021). The average hospital duration for infection care was 13 days. By extrapolating the infection rate and costs observed in the No-AIGISRx group to the Yes-AIGISRx group, we estimated that there would have been 6.2 additional infections costing approximately $340,000. This cost was similar to the actual cost of the devices in the Yes-AIGISRx group, estimated at $320,000. CONCLUSIONS: Standard of care use of an antibacterial envelope as a standard of care was associated with a significantly lower rate of CIED infection, and appeared to be economically reasonable. Prospective trials to address these findings may be worthwhile.

Sudden cardiac death risk stratification and assessment: primary prevention based on ejection fraction criteria.

Sudden cardiac death (SCD) is the prime cause of death in the United States. The trials that focus on identifying and protecting patients at risk of SCD have identified the left ventricular ejection fraction (EF) as the single clinical marker that is most useful for risk assessment and stratification in primary prevention. This article reviews the data from major randomized clinical trials of implantable cardioverter-defibrillator implantation in patients with low EF for the primary prevention of SCD and exposes some of the shortcomings of the EF as a stratifier of mortality risk.

Role of cardiac resynchronization in end-stage heart failure patients requiring inotrope therapy.

BACKGROUND: Outcomes among inotrope-treated heart failure (HF) patients receiving cardiac resynchronization therapy (CRT) have not been well characterized, particularly in those requiring intravenous inotropes at the time of implant. METHODS: We analyzed 759 consecutive CRT-defibrillator recipients who were categorized as never on inotropes (NI; n = 585), weaned from inotropes before implant (PI; n = 124), or on inotropes at implant (II; n = 50). Survival free from heart transplant or ventricular assist device and overall survival were compared using the Social Security Death Index. A patient cohort who underwent unsuccessful CRT implantation and received a standard defibrillator (SD; n = 94) comprised a comparison group. Propensity score analysis was used to control for intergroup baseline differences. RESULTS: Compared with the other cohorts, II patients had more comorbidities. Both survival endpoints differed significantly (P < .001) among the 4 cohorts; II patients demonstrated shorter survival than NI patients, with the PI and SD groups having intermediate survival. After adjusting for propensity scores, overall differences and patterns in survival endpoints persisted (P < .01), but the only statistically significant pairwise difference was overall survival between the NI and II groups at 12 months (hazard ratio 2.95, 95% confidence interval 1.05-8.35). CRT recipients ever on inotropes (PI and II) and SD patients ever requiring inotropes (n = 17) experienced similar survival endpoints. Among II patients, predictors of hospital discharge free from inotropes after CRT included male gender, older age, and ability to tolerate ß-blockade. CONCLUSIONS: Inotrope-dependent HF patients show significantly worse survival despite CRT than inotrope-naïve patients, in part because of more comorbid conditions at baseline. CRT may not provide a survival advantage over a standard defibrillator among patients who have received inotropes before CRT. Weaning from inotropes and initiating neurohormonal antagonists before CRT should be an important goal among inotrope-dependent HF patients.

Usefulness of baseline electrocardiographic QRS complex pattern to predict response to cardiac resynchronization.

Cardiac resynchronization therapy (CRT) improves morbidity and mortality in patients with heart failure with QRS>120 ms, yet most patients studied in clinical trials manifested baseline left branch bundle block (LBBB). It is unclear whether benefits of CRT extend to patients with right branch bundle block (RBBB) or a paced QRS at baseline despite QRS>120 ms. Orthotopic heart transplantation- and ventricular assist device-free survival, symptomatic response, and echocardiographic response were evaluated in the 636 patients who underwent CRT at our institution from 2000 to 2007 in whom the baseline electrocardiogram showed LBBB (n=412; 65%), paced QRS (n=162; 26%), or RBBB (n=62; 10%). Mortality was assessed using the Social Security Death Index, and the medical record was analyzed for clinical data. A decrease in New York Heart Association class>or=0.5 after >or=6 months of CRT defined symptomatic response. Echocardiographic evidence of improved left ventricular function and reverse remodeling was evaluated after >or=6 months of CRT. Survival free from orthotopic heart transplantation and ventricular assist device placement was best in patients with LBBB and worst in those with RBBB, whereas patients with paced QRS had an intermediate prognosis (p=0.003). This finding remained significant after controlling for baseline differences among the 3 groups. Symptomatic response was observed most often in patients with LBBB (60%), occurred least often in patients with RBBB (14%), and was intermediate in patients with paced QRS (46%; p<0.001). Echocardiographic improvement showed a similar stepwise trend. In conclusion, patients with RBBB undergoing CRT had low rates of symptomatic and echocardiographic response, and their survival free from orthotopic heart transplantation or ventricular assist device placement was significantly worse than in patients with LBBB. Patients with conventionally paced QRS experienced an intermediate response.

Predictors of mortality amongst recipients of implantable cardioverter defibrillators for secondary prevention of cardiac arrest.

BACKGROUND: Implantable Cardioverter-defibrillators (ICD) reduce mortality in survivors of cardiac arrest (CA). We investigated the predictors of mortality after ICD implantation in survivors of CA. METHODS: Retrospective review of clinical records and social security death index of all patients who received an ICD in a preexisting database of survivors of CA at the University of Pittsburgh Medical Center was performed. Multivariate analyses using the Cox proportional hazard model were performed with backward elimination to identify independent predictors of the time to death, and Kaplan-Meier curves were plotted. RESULTS: Eighty patients (64 men) with a mean age of 64.4+/-12.5 years were followed for 4.7+/-2.3 years after ICD implantation. Survival rates were 93.8%, 65% and 50% at 1, 5, and 10 years, respectively. Independent predictors of time to death were determined to include age (hazard ratio (HR) = 1.91 per 10-year increase, p = 0.003), serum creatinine > or = 1.3 mg/dL (HR = 2.56, p = 0.004), and QRS width >120 ms (HR = 5.14, p = 0.012). CONCLUSIONS: In this sample of ICD recipients secondary to CA, older age, elevated serum creatinine, and wider QRS duration were independent predictors of mortality. The presence of more than one risk factor in the same patient was associated with higher mortality rates. Whether interventions such as biventricular pacing can offset this increase risk of death warrants further investigation.

Utilization of implantable cardioverter-defibrillators in survivors of cardiac arrest in the United States from 1996 to 2001.

OBJECTIVES: We analyzed the incidence of implantable cardioverter-defibrillator (ICD) therapy in survivors of cardiac arrest (CA) in the U.S. from 1996 through 2001. BACKGROUND: Cardiac arrest is a class I indication for ICD therapy. The current patterns of ICD utilization in survivors of CA have not been fully examined. METHODS: We searched a representative sample of all hospital discharges for patients admitted with the primary diagnosis of CA who survived to hospital discharge. Patients with a concomitant diagnosis of acute myocardial infarction or previous ICD in situ were excluded. RESULTS: From 1996 to 2001, 113,262 patients were admitted for CA. Of those, 63,745 (56.3%) did not survive to hospital discharge. Of the remaining 49,517 patients, 30.7% received an ICD before discharge, with a gradual increase in implantation rates from 1996 (23.6%) to 2001 (46.3%). Using logistic regression for the years 2000 and 2001, patients who were discharged without an ICD were older (odds ratio [OR] 0.93 for every 10-year increase in age, p < 0.001), more likely to be African American (OR 0.19, p < 0.001), and more likely to be admitted to a smaller hospital (OR 2.24 for each additional 100 beds, p < 0.001). These predictors were independent of other co-morbid illnesses. CONCLUSIONS: Although they are increasing, the rates of ICD therapy after CA remain very low. There are gross discrepancies by race. At a time when newer indications for ICD implantation are emerging, efforts should be focused on identifying the causes of this underutilization and discrepancies in survivors of CA.

Effects of race and health insurance on the rates of pacemaker implantation for complete heart block in the United States.

Although indicated for adults with complete heart block, pacemaker implantation is not always practiced. There are gross discrepancies by race, type of health insurance coverage, and size of hospital of admission in the utilization of pacemakers.