Chamberlain, Alanna M.

ABSTRACTBackgroundThe authors sought to estimate incremental economic impact of atrial fibrillation (AF) and the timing of its onset in myocardial infarction (MI) patients.HypothesisConcurrent AF and its timing are associated with higher costs in MI patients.MethodsThis retrospective cohort study included incident MI patients from Olmsted County, Minnesota, treated between November 1, 2002, and December 31, 2010. We compared inflation‐adjusted standardized costs accumulated between incident MI and end of follow‐up among 3 groups by AF status and timing: no AF, new‐onset AF (within 30 days after index MI), and prior AF. Multivariate adjustment of median costs accounted for right‐censoring in costs.ResultsThe final study cohort had 1389 patients, with 989 in no AF, 163 in new‐onset AF, and 237 in prior AF categories. Median follow‐up times were 3.98, 3.23, and 2.55 years, respectively. Mean age at index was 67 years, with significantly younger patients in the no AF group (64 years vs 76 and 77 years, respectively; P < 0.001). New‐onset and prior AF patients had more comorbid conditions (hypertension, heart failure, and chronic obstructive pulmonary disease). After accounting for differences in baseline characteristics, we found adjusted median (95% confidence interval) costs of $73 000 ($69 000‐$76 000) for no AF; $85 000 ($81 000‐$89 000) for new‐onset AF; and $97 000 ($94 000‐$100 000) for prior AF. Inpatient costs composed the largest share of total median costs (no AF, 82%; new‐onset AF, 84%; prior AF, 83%).ConclusionsAtrial fibrillation frequently coexists with MI and imposes incremental costs, mainly attributable to inpatient care. Timing of AF matters, as prior AF was found to be associated with higher costs than new‐onset AF.

Background/Aims: Depressive disorders (DEP) are often comorbid with other chronic conditions. Bidirectional associations between DEP and these conditions are poorly understood. In this study, we aimed to identify chronic conditions with the greatest influence on the DEP diagnosis. Methods: A validated electronic health record-based algorithm was applied to identify DEP patients receiving primary care at Mayo Clinic between 2000 and 2013. Cases were identified on the basis of having > 2 DEP-related ICD-9 diagnosis codes, > 1 antidepressant prescription, and > 3 mentions of in- or outpatient clinical notes for DEP. Controls were matched on birth year (± 2 years), sex and outpatient clinic visits at the same year. We ascertained 26 chronic condition categories, as defined by Chronic Conditions Data Warehouse, using the 5 years of medical records prior to the DEP diagnosis. For each age group at diagnosis (60 years), gradient boosting machine models were applied to estimate relative influence (RI) of the chronic conditions on the DEP diagnosis. Results: A total of 11,219 DEP cases were identified (median age at DEP diagnosis 44 years, 34% male and 89% white). The proportion of subjects with at least one co-occurring condition increased with older age and was higher in DEP cases compared to controls (9.5% vs. 6.9% for subjects 60 years). For subjects aged ≤ 45 years, diabetes mellitus (RI=19.6%) was identified as the most influential condition contributing to the risk of DEP, followed by asthma (RI=11.6%) and rheumatoid arthritis (RI=11.0%). For subjects aged 46–60 years, the most influential condition was rheumatoid arthritis (RI=13.2%) followed by diabetes mellitus (RI=12.9%). For subjects older than 60 years, dementia (RI=10.7%) and rheumatoid arthritis (RI=10.2%) showed similar relative contribution to the risk of DEP. Discussion: Among nonelderly adults who received primary care at Mayo Clinic (2000–2013), diabetes mellitus and rheumatoid arthritis were the strongest risk predictors for a diagnosis of depression among 26 chronic conditions considered. Our results suggest that certain chronic conditions may play a role in exacerbating, precipitating or increasing longitudinal risk of medically significant depression.

Background— Chronic disease can contribute to functional disability, which can degrade quality of life. However, the prevalence of functional disability and its association with outcomes among patients with heart failure requires further study. Methods and Results— Southeastern Minnesota residents with heart failure were enrolled from September 2003 through January 2012 into a cohort study with follow-up through December 2012. Difficulty with 9 activities of daily living (ADLs) was assessed by a questionnaire. Patients were divided into 3 categories of ADL difficulty (no/minimal, moderate, severe). The associations of ADL difficulty with mortality and hospitalization were assessed using Cox and Andersen-Gill models. Among 1128 patients (mean age, 74.7 years; 49.2% female), a majority (59.4%) reported difficulty with one or more ADLs at enrollment, with 272 (24.1%) and 146 (12.9%) experiencing moderate and severe difficulty, respectively. After a mean (SD) follow-up of 3.2 (2.4) years, 614 patients (54.4%) had died. Mortality increased with increasing ADL difficulty; the hazard ratio (95% confidence interval) for death was 1.49 (1.22–1.82) and 2.26 (1.79–2.86) for those with moderate and severe difficulty, respectively, compared to those with no/minimal difficulty ( P trend <0.001). Patients with moderate and severe difficulty were at an increased risk for all-cause and noncardiovascular hospitalization. In a second assessment, 17.7% of survivors reported more difficulty with ADLs and patients with persistently severe or worsening difficulty were at an increased risk for death (hazard ratio, 2.10; 95% confidence interval, 1.71–2.58; P <0.001) and hospitalization (hazard ratio, 1.51; 95% confidence interval, 1.31–1.74; P <0.001). Conclusions— Functional disability is common in patients with heart failure, can progress over time, and is associated with adverse prognosis.

Early treatment-seeking for symptoms of atrial fibrillation (AF) is critical to avert AF-related stroke and heart failure, but early treatment is hindered if symptoms are not accurately interpreted. The purpose of this research was to describe symptom representation and treatment-seeking responses prior to diagnosis of AF. For this descriptive study, 150 participants were surveyed to describe the type and temporality of symptoms, perceptions regarding the cause, seriousness, controllability of symptoms, and responses to symptoms prior to diagnosis. Participants’ mean age was 66.5 years, and 51% were female. Participants perceived symptoms as having nondisease-based causes, as not very serious, and as amenable to self-management. The majority took a wait and see response with 69% waiting more than 1 week after symptom onset to seek treatment. Lack of recognition of the seriousness of symptoms of AF and delayed treatment put patients at risk of poorer outcomes.

Background Atrial fibrillation ( AF ) is associated with increased risk of hospitalization. Little is known about the impact of AF on utilization of noninpatient health care or about sex or race differences in AF ‐related utilization. We examined rates of inpatient and outpatient utilization by AF status in the Atherosclerosis Risk in Communities study. Methods and Results Participants with incident AF enrolled in fee‐for‐service Medicare for at least 12 continuous months between 1991 and 2009 (n=932) were matched on age, sex, race and field center with up to 3 participants without AF (n=2729). Healthcare utilization was ascertained from Medicare claims and classified by primary International Classification of Diseases, ninth revision code. The average annual numbers of days hospitalized were 13.2 (95% CI 11.6 to 15.0) and 2.8 (95% CI 2.5 to 3.1) for those with and without AF , respectively. The corresponding numbers of annual outpatient claims were 53.3 (95% CI 50.5 to 56.3) and 22.9 (95% CI 22.1 to 23.8) for those with and without AF , respectively. Most utilization among AF patients was attributable to non‐ AF conditions. The adjusted rate ratio for annual days hospitalized for other cardiovascular disease–related reasons was 4.58 (95% CI : 3.41 to 6.16) for those with AF versus those without AF . The association between AF and healthcare utilization was similar among men and women and among white and black participants. Conclusions Participants with AF had considerably greater healthcare utilization, and the difference in utilization for other cardiovascular disease –related reasons was substantial. In addition to rate or rhythm treatment, AF management should focus on the accompanying cardiovascular comorbidities.

Background Heart failure ( HF ) patients experience impaired functional status, diminished quality of life, high utilization of healthcare resources, and poor survival. Yet, the identification of patient‐centered factors that influence prognosis is lacking. Methods and Results We determined the association of 2 measures of self‐rated health with healthcare utilization and skilled nursing facility ( SNF ) admission in a community cohort of 417 HF patients prospectively enrolled between October 2007 and December 2010 from Olmsted County, MN . Patients completed a 12‐item Short Form Health Survey ( SF ‐12). Low self‐reported physical functioning was defined as a score ≤25 on the SF ‐12 physical component. The first question of the SF ‐12 was used as a measure of self‐rated general health. After 2 years, 1033 hospitalizations, 1407 emergency department ( ED ) visits, and 19,780 outpatient office visits were observed; 87 patients were admitted to a SNF . After adjustment for confounding factors, an increased risk of hospitalizations (1.52 [1.17 to 1.99]) and ED visits (1.48 [1.04 to 2.11]) was observed for those with low versus moderate‐high self‐reported physical functioning. Patients with poor and fair self‐rated general health also experienced an increased risk of hospitalizations (poor: 1.73 [1.29 to 2.32]; fair: 1.46 [1.14 to 1.87]) and ED visits (poor: 1.73 [1.16 to 2.56]; fair: 1.48 [1.13 to 1.93]) compared with good‐excellent self‐rated general health. No association between self‐reported physical functioning or self‐rated general health with outpatient visits and SNF admission was observed. Conclusion In community HF patients, self‐reported measures of physical functioning predict hospitalizations and ED visits, indicating that these patient‐reported measures may be useful in risk stratification and management in HF .

Background— Reduced low forced expiratory volume in 1 second (FEV 1 ) is reportedly associated with an increased risk of atrial fibrillation (AF). Extant reports do not provide separate estimates for never smokers or for blacks, who incongruously have lower AF incidence than whites. Methods and Results— We examined 15 004 middle-aged blacks and whites enrolled in the Atherosclerosis Risk in Communities (ARIC) cohort study. Standardized spirometry data were collected at the baseline examination. Incident AF was identified from the first among the following: International Classification of Diseases codes for AF on hospital discharge records or death certificates or 12-lead ECGs performed during 3 triennial follow-up visits. Over an average follow-up of 17.5 years, a total of 1691 participants (11%) developed new-onset AF. The rate of incident AF was inversely associated with FEV 1 in each of the 4 race and sex groups. After multivariable adjustment for traditional cardiovascular disease risk factors and height, hazard ratios of AF comparing the lowest with the highest quartile of FEV 1 were 1.37 (95% confidence interval, 1.02–1.83) for white women, 1.49 (95% confidence interval, 1.16–1.91) for white men, 1.63 (95% confidence interval, 1.00–2.66) for black women, and 2.36 (95% confidence interval, 1.30–4.29) for black men. The above associations were observed across all smoking status categories. Moderate/severe airflow obstruction (FEV 1 /forced vital capacity <0.70 and FEV 1 < 80% of predicted value) was also associated with higher AF incidence. Conclusions— In this large population-based study with a long-term follow-up, reduced FEV 1 and obstructive respiratory disease were associated with a higher AF incidence after adjustment for measured confounders.

Background— In patients with heart failure and preserved ejection fraction (HFpEF), atrial fibrillation (AF) may predate, concur with, or develop after HFpEF diagnosis. We sought to define the temporal relationship between AF and HFpEF, to identify factors associated with AF, and to determine the prognostic impact of prevalent and incident AF in HFpEF. Method and Results— From 1983 to 2010, 939 Olmsted County, Minnesota, residents (age, 77±12 years; 61% female) newly diagnosed with HFpEF (EF ≥0.50) were evaluated. Baseline rhythm classification included prior AF (>3 months before HFpEF diagnosis), concurrent AF (±3 months), or sinus rhythm. Incident AF (>3 months after HFpEF diagnosis) and all-cause mortality were ascertained through February 2012. Prior AF (29%) and concurrent AF (23%) were associated with older age, higher brain-type natriuretic peptide, and larger left atrial volume index at HFpEF diagnosis compared with sinus rhythm. Of HFpEF patients in sinus rhythm at diagnosis, 32% developed AF over a median follow-up of 3.7 years (interquartile range, 1.5–6.7 years; 69 events per 1000 person-years). Age and diastolic dysfunction were positively and statin use was inversely associated with incident AF. With no AF used as the referent, prior or concurrent AF (combined hazard ratio, 1.3; 95% confidence interval, 1.0–1.6; P =0.03) and incident AF, modeled as a time-dependent covariate (hazard ratio, 2.1; 95% confidence interval, 1.4–3.0; P <0.001), were independently associated with death after adjustment for pertinent covariates. Conclusions— AF occurs in two thirds of HFpEF patients at some point in the natural history and confers a poor prognosis. Further study is required to determine whether intervention for AF may improve outcomes or if statin use can prevent AF in HFpEF.