Shannon M. Dunlay

Hospitalizations After Heart Failure Diagnosis: A Community Perspective

OBJECTIVES The purpose of this study was to determine the lifetime burden and risk factors for hospitalization after heart failure (HF) diagnosis in the community. BACKGROUND Hospitalizations in patients with HF represent a major public health problem; however, the cumulative burden of hospitalizations after HF diagnosis is unknown, and no consistent risk factors for hospitalization have been identified. METHODS We validated a random sample of all incident HF cases in Olmsted County, Minnesota, from 1987 to 2006 and evaluated all hospitalizations after HF diagnosis through 2007. International Classification of Diseases-9th Revision codes were used to determine the primary reason for hospitalization. To account for repeated events, Andersen-Gill models were used to determine the predictors of hospitalization after HF diagnosis. Patients were censored at death or last follow-up. RESULTS Among 1,077 HF patients (mean age 76.8 years, 582 [54.0%] female), 4,359 hospitalizations occurred over a mean follow-up of 4.7 years. Hospitalizations were common after HF diagnosis, with 895 (83.1%) patients hospitalized at least once, and 721 (66.9%), 577 (53.6%), and 459 (42.6%) hospitalized > or =2, > or =3, and > or =4 times, respectively. The reason for hospitalization was HF in 713 (16.5%) hospitalizations and other cardiovascular in 936 (21.6%), whereas over one-half (n = 2,679, 61.9%) were noncardiovascular. Male sex, diabetes mellitus, chronic obstructive pulmonary disease, anemia, and creatinine clearance <30 ml/min were independent predictors of hospitalization (p < 0.05 for each). CONCLUSIONS Multiple hospitalizations are common after HF diagnosis, though less than one-half are due to cardiovascular causes. Comorbid conditions are strongly associated with hospitalizations, and this information could be used to define effective interventions to prevent hospitalizations in HF patients.

Trends in Incidence, Severity, and Outcome of Hospitalized Myocardial Infarction

Background— In 2000, the definition of myocardial infarction (MI) changed to rely on troponin rather than creatine kinase (CK) and its MB fraction (CK-MB). The implications of this change on trends in MI incidence and outcome are not defined. Methods and Results— This was a community study of 2816 patients hospitalized with incident MI from 1987 to 2006 in Olmsted County, Minnesota, with prospective measurements of troponin and CK-MB from August 2000 forward. Outcomes were MI incidence, severity, and survival. After troponin was introduced, 278 (25%) of 1127 incident MIs met only troponin-based criteria. When cases meeting only troponin criteria were included, incidence did not change between 1987 and 2006. When restricted to cases defined by CK/CK-MB, the incidence of MI declined by 20%. The incidence of non–ST-segment elevation MI increased markedly by relying on troponin, whereas that of ST-segment elevation MI declined regardless of troponin. The age- and sex-adjusted hazard ratio of death within 30 days for an infarction occurring in 2006 (compared with 1987) was 0.44 (95% confidence interval, 0.30 to 0.64). Among 30-day survivors, survival did not improve, but causes of death shifted from cardiovascular to noncardiovascular (P=0.001). Trends in long-term survival among 30-day survivors were similar regardless of troponin. Conclusions— Over the last 2 decades, a substantial change in the epidemiology of MI occurred that was only partially mediated by the introduction of troponin. Non–ST-segment elevation MIs now constitute the majority of MIs. Although the 30-day case fatality improved markedly, long-term survival did not change, and the cause of death shifted from cardiovascular to noncardiovascular.

Barriers to participation in cardiac rehabilitation

BACKGROUND Participation rates in cardiac rehabilitation after myocardial infarction (MI) remain low. Studies investigating the predictive value of psychosocial variables are sparse and often qualitative. We aimed to examine the demographic, clinical, and psychosocial predictors of participation in cardiac rehabilitation after MI in the community. METHODS Olmsted County, Minnesota, residents hospitalized with MI between June 2004 and May 2006 were prospectively recruited, and a 46-item questionnaire was administered before hospital dismissal. Associations between variables and cardiac rehabilitation participation were examined using logistic regression. RESULTS Among 179 survey respondents (mean age 64.8 years, 65.9% male), 115 (64.2%) attended cardiac rehabilitation. The median (25th-75th percentile) number of sessions attended within 90 days of MI was 13 (5-20). Clinical characteristics associated with rehabilitation participation included younger age (odds ratio [OR] 0.95 per 1-year increase), male sex (OR 1.93), lack of diabetes (OR 2.50), ST-elevation MI (OR 2.63), receipt of reperfusion therapy (OR 7.96), in-hospital cardiologist provider (OR 18.82), no prior MI (OR 4.17), no prior cardiac rehabilitation attendance (OR 3.85), and referral to rehabilitation in the hospital (OR 12.16). Psychosocial predictors of participation included placing a high importance on rehabilitation (OR 2.35), feeling that rehabilitation was necessary (OR 10.11), better perceived health before MI (excellent vs poor OR 7.33), the ability to drive (OR 6.25), and post-secondary education (OR 3.32). CONCLUSIONS Several clinical and psychosocial factors are associated with decreased participation in cardiac rehabilitation programs after MI in the community. As many are modifiable, addressing them may improve participation and outcomes.

Lifetime Costs of Medical Care After Heart Failure Diagnosis

Background— Heart failure (HF) care constitutes an increasing economic burden on the health care system, and has become a key focus in the health care debate. However, there are limited data on the lifetime health care costs for individuals with HF after initial diagnosis. Methods and Results— Olmsted County residents with incident HF from 1987 to 2006 were identified. Direct medical costs incurred from the time of HF diagnosis until death or last follow-up were obtained using population-based administrative data through 2007. Costs were inflated to 2008 US dollars using the general Consumer Price Index. Inpatient, outpatient, and total costs were estimated using a 2-part model with adjustment for right censoring of data. Predictors of total costs were examined using a similar model. A total of 1054 incident HF patients were identified (mean age, 76.8 years; 46.1% men). After a mean follow-up of 4.6 years, 765 (72.6%) patients had died. The estimated total lifetime costs were

Longitudinal Changes in Ejection Fraction in Heart Failure Patients with Preserved and Reduced Ejection Fraction

109 541 (95% confidence interval,

Long-term Medication Adherence after Myocardial Infarction: experience of a community

100 335 to 118 946) per person, with the majority accumulated during hospitalizations (mean,

Risk Factors for Heart Failure: A Population-Based Case-Control Study

83 980 per person). After adjustment for age, year of diagnosis, and comorbidity, diabetes mellitus and preserved ejection fraction (≥50%) were associated with 24.8% (P=0.003) and 23.6% (P=0.041) higher lifetime costs, respectively. Higher costs were observed at initial HF diagnosis and in the months immediately before death in those surviving >12 months after diagnosis. Conclusions— HF imposes a significant economic burden, primarily related to hospitalizations. Variations in cost over a lifetime can help identify strategies for efficient management of patients, particularly at the end of life.

Tumor Necrosis Factor-α and Mortality in Heart Failure A Community Study

Background—Heart failure (HF) can occur in patients with preserved (HFpEF, EF≥50%) or reduced (HFrEF, EF<50%) ejection fraction (EF), but changes in EF after HF diagnosis are not well described. Methods and Results—Among a community cohort of incident HF patients diagnosed from 1984 to 2009 in Olmsted County, Minnesota, we obtained all EFs assessed by echocardiography from initial HF diagnosis until death or last follow-up through March 2010. Mixed effects models fit a unique linear regression line for each person using serial EF data. Compiled results allowed estimates of the change in EF over time in HFpEF and HFrEF. Among 1233 HF patients (48.3% male, mean age 75.0 years, mean follow-up 5.1 years), 559 (45.3%) had HFpEF at diagnosis. In HFpEF, on average, EF decreased by 5.8% over 5 years (P<0.001) with greater declines in older individuals and those with coronary disease. Conversely, EF increased in HFrEF (average increase 6.9% over 5 years, P<0.001). Greater increases were noted in women, younger patients, individuals without coronary disease, and those treated with evidence-based medications. Overall, 39% of HFpEF patients had an EF<50% and 39% of HFrEF patients had an EF≥50% at some point after diagnosis. Decreases in EF over time were associated with reduced survival whereas increases in EF were associated with improved survival. Conclusions—These data suggest that progressive contractile dysfunction may contribute to the pathophysiology of HFpEF. Prospective longitudinal studies are needed to confirm these observations and establish the mechanism and clinical relevance of decline in EF over time in HFpEF.

Bilateral Internal Thoracic Artery Harvest and Deep Sternal Wound Infection in Diabetic Patients

BACKGROUND Adherence to evidence-based medications after myocardial infarction is associated with improved outcomes. However, long-term data on factors affecting medication adherence after myocardial infarction are lacking. METHODS Olmsted County residents hospitalized with myocardial infarction from 1997-2006 were identified. Adherence to HMG-CoA reductase inhibitors (statins), beta blockers, angiotensin-converting enzyme inhibitors, and angiotensin II receptor blockers, were examined. Cox proportional hazard regression was used to determine the factors associated with medication adherence over time. RESULTS Among 292 subjects with incident myocardial infarction (63% men, mean age 65 years), patients were followed for an average of 52+/-31 months. Adherence to guideline-recommended medications decreased over time, with 3-year medication continuation rates of 44%, 48%, and 43% for statins, beta-blockers, and angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers, respectively. Enrollment in a cardiac rehabilitation program was associated with an improved likelihood of continuing medications, with adjusted hazard ratio (95% confidence interval) for discontinuation of statins and beta-blockers among cardiac rehabilitation participants of 0.66 (0.45-0.92) and 0.70 (0.49-0.98), respectively. Smoking at the time of myocardial infarction was associated with a decreased likelihood of continuing medications, although results did not reach statistical significance. There were no observed associations between demographic characteristics, clinical characteristics of the myocardial infarction, and medication adherence. CONCLUSIONS After myocardial infarction, a large proportion of patients discontinue use of medications over time. Enrollment in cardiac rehabilitation after myocardial infarction is associated with improved medication adherence.

Identifying patients hospitalized with heart failure at risk for unfavorable future quality of life

BACKGROUND The relative contribution of risk factors to the development of heart failure remains controversial. Further, whether these contributions have changed over time or differ by sex is unclear. Few population-based studies have been performed. We aimed to estimate the population attributable risk (PAR) associated with key risk factors for heart failure in the community. METHODS Between 1979 and 2002, 962 incident heart failure cases in Olmsted County were age and sex-matched to population-based controls using Rochester Epidemiology Project resources. We determined the frequency of risk factors (coronary heart disease, hypertension, diabetes mellitus, obesity, and smoking), odds ratios, and PAR of each risk factor for heart failure. RESULTS The mean number of risk factors for heart failure per case was 1.9 + or - 1.1 and increased over time (P<.001). Hypertension was the most common (66%), followed by smoking (51%). The prevalence of hypertension, obesity, and smoking increased over time. The risk of heart failure was particularly high for coronary disease and diabetes with odds ratios (95% confidence intervals) of 3.05 (2.36-3.95) and 2.65 (1.98-3.54), respectively. However, the PAR was highest for coronary disease and hypertension; each accounted for 20% of heart failure cases in the population, although coronary disease accounted for the greatest proportion of cases in men (PAR 23%) and hypertension was of greatest importance in women (PAR 28%). CONCLUSION Preventing coronary disease and hypertension will have the greatest population impact in preventing heart failure. Sex-targeted prevention strategies might confer additional benefit. However, these relationships can change, underscoring the importance of continued surveillance of heart failure.