Faculty Bibliography

BACKGROUND: There are few data characterizing temporal changes in hospitalization for recurrent acute myocardial infarction (AMI) after AMI. METHODS AND RESULTS: Using a national sample of 2 305 441 Medicare beneficiaries hospitalized for AMI from 1999 to 2010, we evaluated changes in the incidence of 1-year recurrent AMI hospitalization and mortality using Cox proportional hazards models. The observed recurrent AMI hospitalization rate declined from 12.1% (95% CI 11.9 to 12.2) in 1999 to 8.9% (95% CI 8.8 to 9.1) in 2010, a relative decline of 26.4%. The observed recurrent AMI hospitalization rate declined by a relative 27.7% in whites, from 11.9% (95% CI 11.8 to 12.1) to 8.6% (95% CI 8.5 to 8.8) versus a relative decline in blacks of 13.6% from 13.2% (95% CI 12.6 to 13.8) to 11.4% (95% CI 10.9 to 12.0). The risk-adjusted rate of annual decline in recurrent AMI hospitalizations was 4.1% (HR 0.959; 95% CI 0.958 to 0.961), and whites experienced a higher rate of decline (HR 0.957, 95% CI 0.956 to 0.959) than blacks (HR 0.974, 95% CI 0.970 to 0.979).The overall, observed 1-year mortality rate after hospitalization for recurrent AMI declined from 32.4% in 1999 to 29.7% in 2010, a relative decline of 8.3% (P<0.05). In adjusted analyses, 1-year mortality after recurrent AMI hospitalization declined 1.8% per year (HR, 0.982; 95% CI 0.980 to 0.985). CONCLUSIONS: In a national sample of Medicare beneficiaries hospitalized for AMI from 1999 to 2010, hospitalization for recurrent AMI decreased, as did subsequent mortality, albeit to a lesser extent. The risk of recurrent AMI hospitalization declined less in black patients than in whites, increasing observed racial disparities by the end of the study period.

BackgroundWhile older adults (age 75 and over) represent a large and growing proportion of patients with acute myocardial infarction (AMI), they have traditionally been under-represented in cardiovascular studies. Although chronological age confers an increased risk for adverse outcomes, our current understanding of the heterogeneity of this risk is limited. The Comprehensive Evaluation of Risk Factors in Older Patients with AMI (SILVER-AMI) study was designed to address this gap in knowledge by evaluating risk factors (including geriatric impairments, such as muscle weakness and cognitive impairments) for hospital readmission, mortality, and health status decline among older adults hospitalized for AMI.Methods/DesignSILVER-AMI is a prospective cohort study that is enrolling 3000 older adults hospitalized for AMI from a recruitment network of approximately 70 community and academic hospitals across the United States. Participants undergo a comprehensive in-hospital assessment that includes clinical characteristics, geriatric impairments, and health status measures. Detailed medical record abstraction complements the assessment with diagnostic study results, in-hospital procedures, and medications. Participants are subsequently followed for six months to determine hospital readmission, mortality, and health status decline. Multivariable regression will be used to develop risk models for these three outcomes.DiscussionSILVER-AMI will fill critical gaps in our understanding of AMI in older patients. By incorporating geriatric impairments into our understanding of post-AMI outcomes, we aim to create a more personalized assessment of risk and identify potential targets for interventions.Trial registrationTrial registration number: NCT01755052.

BACKGROUND: The epidemiology of aortic dissection (AD) has not been well described among older persons in the United States. It is not known whether advancements in AD care over the last decade have been accompanied by changes in outcomes. METHODS AND RESULTS: The Inpatient Medicare data from 2000 to 2011 were used to determine trends in hospitalization rates for AD. Mortality rates were ascertained through corresponding vital status files. A total of 32 057 initial AD hospitalizations were identified. The overall hospitalization rate for AD remained unchanged at 10 per 100 000 person-years. For 30-day and 1-year mortality associated with AD, the observed rate decreased from 31.8% to 25.4% (difference, 6.4%; 95% confidence interval [CI], 6.2-6.5; adjusted, 6.4%; 95% CI, 5.7-6.9) and from 42.6% to 37.4% (difference, 5.2%; 95% CI, 5.1-5.2; adjusted, 6.2%; 95% CI, 5.3-6.7), respectively. For patients undergoing surgical repair for type A dissections, the observed 30-day mortality decreased from 30.7% to 21.4% (difference, 9.3%; 95% CI, 8.3-10.2; adjusted, 7.3%; 95% CI, 5.8-7.8) and the observed 1-year mortality decreased from 39.9% to 31.6% (difference, 8.3%; 95% CI, 7.5-9.1%; adjusted, 8.2%; 95% CI, 6.7-9.1). The 30-day mortality decreased from 24.9% to 21% (difference, 3.9%; 95% CI, 3.5-4.2; adjusted, 2.9%; 95% CI, 0.7-4.4) and 1-year decreased from 36.4% to 32.5% (difference, 3.9%; 95% CI, 3.3-4.3; adjusted, 3.9%; 95% CI, 2.5-6.3) for surgical repair of type B dissection. CONCLUSIONS: Although AD hospitalization rates remained stable, improvement in mortality was noted, particularly in patients undergoing surgical repair.

OBJECTIVE: To characterise the trends in the left ventricular assist device (LVAD) implantation rates and outcomes between 2004 and 2011 in the Medicare population. Since the approval of the HeartMate II in 2008, the use of LVADs has steadily climbed. Given the increase in LVAD use, issues around discharge disposition, post-implant hospitalisations and costs require further understanding. METHODS: We examined LVAD implantation rates and short-term and long-term outcomes among Medicare fee-for-service beneficiaries hospitalised for LVAD implantation. We also conducted analyses among survivors 1-year post-discharge to examine rehospitalisation rates. Lastly, we reported Centers for Medicare & Medicaid Services (CMS) payments for both index hospitalisation and rehospitalisations 1 year post-discharge. RESULTS: A total of 2152 LVAD implantations were performed with numbers increasing from 107 in 2004 to 612 in 2011. The 30-day mortality rate decreased from 52% to 9%, and 1-year mortality rate decreased from 69% to 31%. We observed no change in overall length of stay, but post-procedure length of stay increased. We also found an increase in home discharge dispositions from 26% to 53%. Between 2004 and 2010, the rehospitalisation rate increased and the number of hospital days decreased. The adjusted CMS payment for the index hospitalisation increased from $188 789 to $225 697 over time but decreased for rehospitalisation from $60 647 to $53 630. CONCLUSIONS: LVAD implantations increased over time. We found decreasing 30-day and 1-year mortality rates and increasing home discharge disposition. The proportion of patients rehospitalised among 1-year survivors remained high with increasing index hospitalisation cost, but decreasing post-implantation costs over time.

BACKGROUND: Elevated resting pulse rate (RPR) is a well-recognized risk factor for adverse outcomes. Epidemiological evidence supports the beneficial effects of regular exercise for lowering RPR, but studies are mainly confined to persons younger than 65 years. We set out to evaluate the utility of a physical activity (PA) intervention for slowing RPR among older adults. METHODS: A total of 424 seniors (ages 70-89 years) were randomized to a moderate intensity PA intervention or an education-based "successful aging" health program. Resting pulse rate was assessed at baseline, 6 months, and 12 months. Longitudinal differences in RPR were evaluated between treatment groups using generalized estimating equation models, reporting unstandardized beta coefficients with robust SEs. RESULTS: Increased frequency and duration of aerobic training were observed for the PA group at 6 and 12 months as compared with the successful aging group (P < .001). In both groups, RPR remained unchanged over the course of the 12-month study period (P = .67). No significant improvement was observed (beta [SE] = 0.58 [0.88]; P = .51) for RPR when treatment groups were compared using the generalized estimating equation method. Comparable results were found after omitting participants with a pacemaker, cardiac arrhythmia, or who were receiving beta-blockers. CONCLUSIONS: Twelve months of moderate intensity aerobic training did not improve RPR among older adults. Additional studies are needed to determine whether PA of longer duration and/or greater intensity can slow RPR in older persons.

OBJECTIVES: This study tested whether myocardial extracellular volume (ECV) is increased in patients with hypertension and atrial fibrillation (AF) undergoing pulmonary vein isolation and whether there is an association between ECV and post-procedural recurrence of AF. BACKGROUND: Hypertension is associated with myocardial fibrosis, an increase in ECV, and AF. Data linking these findings are limited. T1 measurements pre-contrast and post-contrast in a cardiac magnetic resonance (CMR) study provide a method for quantification of ECV. METHODS: Consecutive patients with hypertension and recurrent AF referred for pulmonary vein isolation underwent a contrast CMR study with measurement of ECV and were followed up prospectively for a median of 18 months. The endpoint of interest was late recurrence of AF. RESULTS: Patients had elevated left ventricular (LV) volumes, LV mass, left atrial volumes, and increased ECV (patients with AF, 0.34 +/- 0.03; healthy control patients, 0.29 +/- 0.03; p < 0.001). There were positive associations between ECV and left atrial volume (r = 0.46, p < 0.01) and LV mass and a negative association between ECV and diastolic function (early mitral annular relaxation [E'], r = -0.55, p < 0.001). In the best overall multivariable model, ECV was the strongest predictor of the primary outcome of recurrent AF (hazard ratio: 1.29; 95% confidence interval: 1.15 to 1.44; p < 0.0001) and the secondary composite outcome of recurrent AF, heart failure admission, and death (hazard ratio: 1.35; 95% confidence interval: 1.21 to 1.51; p < 0.0001). Each 10% increase in ECV was associated with a 29% increased risk of recurrent AF. CONCLUSIONS: In patients with AF and hypertension, expansion of ECV is associated with diastolic function and left atrial remodeling and is a strong independent predictor of recurrent AF post-pulmonary vein isolation.

BACKGROUND: Although pulmonary vein isolation has become a mainstream therapy for selected patients with atrial fibrillation (AF), late recurrent AF is common and its risk factors remain poorly defined. The purpose of our study was to test the hypothesis that reduced left atrial passive emptying function (LAPEF) as determined by cardiac magnetic resonance has a strong association with late recurrent AF after pulmonary vein isolation. METHODS AND RESULTS: Three hundred forty-six patients with AF referred for cardiac magnetic resonance pulmonary vein mapping before pulmonary vein isolation were included. Maximum LA volumes (VOLmax) and volumes before atrial contraction (VOLbac) were measured; LAPEF was calculated as (VOLmax-VOLbac)/VOLmaxx100. Kaplan-Meier curves were constructed to determine late recurrent AF stratified by LAPEF quintile. Cox proportional hazards regression was used to adjust for known markers of recurrence. During a median follow-up of 27 months, 124 patients (35.8%) experienced late recurrent AF. Patients with recurrence were more likely to have nonparoxysmal AF (75.8% versus 51.4%; P<0.01), higher mean VOLmax (60.2 versus 52.8 mL/m(2); P<0.01), and lower mean LAPEF (19.1% versus 26.0%; P<0.01). Patients in the lowest LAPEF quintile were at highest risk of developing recurrent AF (2-year recurrence for lowest versus highest: 60.5% versus 17.3%; P<0.01). After adjusting for known predictors of recurrence, patients with low LAPEF remained significantly more likely to recur (hazard ratio for lowest versus highest quintile, 3.92; 95% confidence interval, 2.01-7.65). CONCLUSIONS: We found a strong association between LAPEF and recurrent AF after pulmonary vein isolation that persisted after multivariable adjustment.

AIMS: Obesity is associated with the development of atrial fibrillation (AF), and both obesity and AF are independently associated with the development of heart failure with preserved ejection fraction. We tested the hypothesis that sleep apnea (SA) would have a body mass index (BMI) independent association with adverse left ventricular (LV) remodeling and clinical outcomes in patients with AF and preserved LV function. METHODS AND RESULTS: From 720 consecutive patients with AF, 403 patients without myocardial disease (preserved LV function) were identified and followed up for 3.3 +/- 1.5 years. The primary outcome was a combination of all-cause mortality/heart failure hospitalization. Left ventricular mass and LV mass-to-volume ratio were higher in patients with SA and obesity (P < .0001 for all). Body mass index (beta per log = .47; P < .0001) and SA (beta = .05; P = .045) were independently associated with LV mass index. Patients with treated SA had a lower LV mass index (but not LV mass-to-volume ratio) compared with untreated (P = .002). In a best overall multivariable model, SA therapy (beta = -.129; P = .001) and BMI (beta per log = .373; P = .0007) had opposing associations with LV mass index. Sleep apnea (hazard ratio [HR] = 2.94; P = .0004) and BMI (HR per 1 kg/m(2) = 1.08; P = .004) were associated with clinical outcome in unadjusted analysis. Only SA was associated with clinical outcome in a best overall multivariable model (HR = 2.14; P = .02). CONCLUSION: Sleep apnea and obesity are independently associated with adverse LV remodeling and clinical outcomes in patients with preserved LV function, whereas continuous positive airway pressure therapy is associated with a beneficial effect on LV remodeling. Research investigating SA therapies in patients at high risk for LV remodeling and heart failure is warranted.