Alonso, Álvaro

Background: Differences in the prevalence and duration of co-morbid conditions in atrial fibrillation (AF) patients compared to population controls have not been well documented. Methods: The prevalence and duration of 17 chronic conditions defined by the US Department of Health and Human Services, as well as anxiety, obesity, and smoking status, was obtained in a random sample of 1430 patients with incident AF from 2000-2010 and 1430 controls from Olmsted County, MN. Controls were matched to cases 1:1 on sex and age (within 5 years). Chronic conditions were ascertained electronically requiring 2 occurrences of a diagnostic code; the duration of each condition (up to 25 years) was calculated. Logistic regression determined associations of each condition with AF after adjustment for all other conditions. Results: Among the 1430 matched pairs (median age 76 years, 48.6% men), the prevalence of chronic conditions was higher in AF cases compared to controls for all conditions except asthma, dementia, depression, hepatitis, and osteoporosis (figure). However, the duration of the conditions were similar in AF compared to controls, except for hypertension (median duration 12.3 and 9.9 years in AF cases and controls, respectively; p=0.002). After adjusting for all other conditions, obesity, hypertension, congestive heart failure, coronary artery disease, chronic kidney disease, and chronic obstructive pulmonary disease remained significantly more common in AF compared to controls (figure). Conditions with the largest attributable risk of AF were hypertension (25.4%), coronary artery disease (17.7%), and congestive heart failure (12.3%). Conclusions: AF patients have a higher prevalence of many chronic conditions compared to population controls. However, besides hypertension, these comorbidities do not develop earlier in AF. Nevertheless, the excess comorbidity burden in AF is important to characterize and understand as it may partly explain the excess mortality and healthcare utilization experienced by AF patients.

Background: Differences in the impact of comorbid conditions on outcomes in atrial fibrillation (AF) patients compared to population controls have not been well documented. Methods: The prevalence of 19 chronic conditions and smoking status was obtained in 1430 patients with incident AF from 2000-2010 and 1430 controls matched 1:1 on sex and age (within 5 years) from Olmsted County, MN. Andersen-Gill models determined associations of each condition with all-cause hospitalizations in AF cases and controls after adjusting for all other conditions and accounting for the matching. Cox regression determined associations of each condition with death. Results: Among 1430 matched pairs (median age 76 years, 48.6% men), the prevalence of chronic conditions was higher in AF cases compared to controls for all conditions except asthma, dementia, depression, hepatitis, and osteoporosis. Over a mean follow-up of 6.3 years, 2678 hospitalizations and 812 deaths occurred. The rates of hospitalization were 59 and 26 per 100 person-years and the rates of death were 10 and 5 per 100 person-years in AF cases and controls, respectively. After adjusting for all other conditions, the risk of hospitalization was lower in AF patients compared to controls for those with coronary artery disease, arthritis, cancer, chronic obstructive pulmonary disease, and osteoporosis (figure). In contrast, the risk of hospitalization was higher in AF cases for those with diabetes and substance abuse. For deaths, the only comorbidity with different associations between AF cases and controls was depression. The hazard ratios (95% CI) for death were 2.02 (1.26-3.24) in AF cases and 0.90 (0.58-1.38) in controls (p-value for interaction=0.008). Conclusions: AF patients have a higher prevalence of chronic conditions compared to population controls. The associations of comorbidities with hospitalizations differed between AF cases and controls, suggesting that management of comorbidities in patients with AF may need to be tailored to this specific patient population.

Introduction: Recent studies, mainly performed in elderly whites, suggest that vitamin D, measured by 25-hydroxyvitamin D [25(OH)D], is important for cognition. Less is known about the association of 25(OH)D measured in mid-life with cognition and dementia risk in whites and blacks. Hypothesis: We hypothesized that lower concentrations of 25(OH)D would be associated cross-sectionally with lower cognitive test scores and prospectively with greater decline in cognitive test scores and with increased risk of dementia. Methods: We conducted cross-sectional (1993-1995), change (1993-1995 to 2004-2006), and prospective (follow-up through 2010) analyses of 1,652 participants in the ARIC Brain Ancillary Study with measured 25(OH)D (1993-1995). 25(OH)D was analyzed in race-specific tertiles and continuously. Cognition was measured by 3 tests: Delayed Word Recall (DWR), Digit Symbol Substitution (DSS), and Word Fluency (WF). Dementia was defined by hospitalization ICD-9 codes. Adjusted race-stratified linear regression and Cox proportional hazards models were used. Results: Mean age of participants was 62 years, 60% were female, and 48% were black. Mean 25(OH)D was higher in whites than blacks (25.5 versus 17.3 ng/ml, p<0.05). Over a median of 16.6 years, there were 145 incident hospitalized dementia cases. In prospective analyses, lower levels of 25(OH)D trended towards an association with increased dementia risk in whites and in blacks, but these results were not statistically significant (lowest versus highest tertile: whites, HR: 1.32 [95% CI: 0.69, 2.55]; blacks, HR: 1.53 [95% CI: 0.84, 2.79]) (Figure). Conclusion: In contrast to prior studies performed in elderly populations, our study did not find significant associations between lower levels of 25(OH)D in mid-life with lower cognitive test scores at baseline, change in score over time, or increased dementia risk.

Objective: To investigate the association between low forced expiratory volume in 1 second (FEV 1 ) and incident atrial fibrillation (AF) in a population-based cohort. Background: Impaired FEV 1 , a complex measure indicating genetic, developmental, obstructive and restrictive airway disease, musculoskeletal function, and motivation, has been inconsistently associated with an increased risk of cardiovascular disease mortality. Also, extant reports do not provide separate estimates for African Americans, who surprisingly have lower AF incidence than Caucasians. Methods: We examined 15,282 middle-aged African Americans (26%) and Caucasians, men (45%) and women from four U.S. communities enrolled in the Atherosclerosis Risk in Communities (ARIC) cohort study. Lung volumes by standardized spirometry and information on covariates were collected on these participants at the baseline visit (1987-1989). Prevalent AF cases were excluded by 12-lead ECG at baseline. Incident AF was defined as the first event identified from the following: ICD codes for AF from hospital discharge records or death certificates, or ECGs performed during three triennial follow-up visits. Results: Over an average follow-up of 17.5 years, a total of 1,733 (11%) participants developed new-onset AF. The rate of incident AF increased monotonically and inversely by tertiles of FEV 1 in each of the 4 gender-race strata. The unadjusted average incidence rates of AF per 100 person years of follow up by tertiles of FEV 1 (from lowest to highest tertile) were 13.6, 8.3, and 5.7 for white men; 8.7, 4.5, and 3.4 for white women; 8.2, 5.5, and 3.8 for black men; 6.9, 4.1, and 2.4 for black women. After multivariable adjustment for traditional cardiovascular disease risk factors and height, hazard ratios (95% CI) of AF comparing the lowest with the highest tertile of FEV 1 were 1.44 (1.16,1.78) among white men, 1.45 (1.12, 1.87) among white women, 1.81 (1.09, 3.02) among black men, and 1.84(1.20, 2.82) among black women. The trend estimate for per 1 Standard-Deviation lower FEV 1 for the corresponding race and gender groups were 1.21 (1.12, 1.32), 1.38 (1.25, 1.54), 1.45 (1.18, 1.76), and 1.35 (1.12, 1.63), respectively. The above associations were observed across all smoking status categories (current, former, and never). The association between low lung function and incidence of AF was similarly unchanged after exclusion of participants with heart failure (n = 689) or CHD (n = 558) at baseline. The hazard of AF was about 50% higher among those with FEV1/FVC ratio below 0.7. Conclusions: In this large population-based cohort study with a long term follow-up, reduced FEV 1 is strongly associated with a higher AF risk, independent of race, gender, smoking, and several other CVD risk factors. These findings suggest the need for research on mechanisms underlying the observed association to seek broader opportunities for prevention of AF.

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice, causes substantial morbidity, and is associated with an excess risk of mortality. However, information on contemporary time trends in survival after AF is lacking. Thus, we aimed to determine whether survival after incident AF has changed over the last decade in a community-based cohort of 3413 individuals with incident AF between 2000 and 2010. Methods: Olmsted County, MN residents 18 years of age and older with a first-ever AF or atrial flutter event between 2000 and 2010 were identified using inpatient and outpatient diagnostic codes and electrocardiograms. Deaths from any cause were ascertained through August 31, 2012 and time trends in survival after AF were examined using Kaplan-Meier curves and Cox proportional hazards regression. Results: Among 3413 individuals with incident AF (52% men, age range 18-104) between 2000 and 2010, 1561 deaths were observed over a median follow-up of 3.4 years. Survival did not differ by year of AF diagnosis (figure). In addition, the proportion of cardiovascular disease-related deaths compared to non-cardiovascular deaths did not differ over time. After adjustment for age, sex, and Charlson comorbidity index, the hazard ratios for all-cause mortality were 1.09 (95% CI 0.97-1.23) for those diagnosed with AF in 2004-2007 vs. 2000-2003 and 1.04 (95% CI 0.90-1.12) for 2008-2010 vs. 2000-2003. Furthermore, the risk of death did not differ by sex after adjustment for age and comorbidity (HR 1.00, 95% CI 0.90-1.11 for men vs. women). Conclusions: In the community, survival after AF has remained constant over the last decade despite substantial changes in the recommendations for treatment of AF. This underscores the importance of identification of prognostic factors and continued surveillance of outcomes in AF, as well as a better understanding of how to optimize the management of AF to improve outcomes in these patients.

Background: Current guidelines recommend oral anticoagulation for the prevention of stroke in most patients with atrial fibrillation (AF). Direct oral anticoagulants (DOACs) are associated with lower risk of ischemic stroke and intracranial bleeding than warfarin and, therefore, may reduce risk of dementia among patients with AF. Hypothesis: AF patients initiating DOACs for stroke prevention will have lower risk of dementia than patients initiating warfarin. Methods: We used data from two US healthcare claim databases, MarketScan (2007-2015) and Optum Clinformatics (2009-2015). Using validated algorithms, we identified patients with AF who initiated oral anticoagulation. Dementia was defined as having an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code of 290.xx, 294.xx, or 331.0. Comorbidities and use of other medications were defined based on inpatient, outpatient, and pharmacy claims. We performed a series of head-to-head comparisons of different oral anticoagulants (warfarin, dabigatran, rivaroxaban, and apixaban) in propensity score-matched cohorts. In each database, multivariable-adjusted Cox regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident dementia for each comparison of propensity score-matched cohorts, adjusting for age, sex, comorbidities, use of other medications, and markers of socioeconomic status (in the Optum database only). We meta-analyzed database-specific results using a random-effects model. Results: The analysis included 307,099 AF patients from the MarketScan database and 161,346 from the Optum database, of which 6,572 and 4,391 respectively had a diagnosis of incident dementia. Mean follow up ranged between 0.7 to 2.3 years and incident of diagnosed dementia between 7 to 14 cases per 1000 person-years across different oral anticoagulant initiator groups. Patients initiating DOACs had a lower risk of incident dementia than those initiating warfarin (dabigatran: HR 0.85, 95%CI 0.71, 1.01; rivaroxaban: HR 0.85, 95%CI 0.76, 0.94; apixaban: HR 0.80, 95%CI 0.65, 0.97). There were no differences in risk of incident dementia comparing DOAC user groups (dabigatran vs. rivaroxaban: HR 1.02, 95%CI 0.79, 1.32; dabigatran vs. apixaban: HR 0.92, 95%CI 0.63, 1.36; apixaban vs. rivaroxaban: HR 1.01, 95%CI 0.86, 1.19). Conclusions: Patients with AF initiating DOACs experienced lower rates of incident dementia than warfarin users. No obvious benefit was observed for any particular DOAC in relation to dementia rates.

Background: Oral anticoagulants (OACs) are recommended for AF patients for the prevention of thromboembolic events, including stroke. Stroke risk stratification scores (e.g., CHA 2 DS 2 -VASc) are used to tailor therapeutic recommendations for patients in different risk groups. However, these were derived before the advent of direct OACs. At present, there is no tool that estimates a patient’s stroke risk, given their individual characteristics, by type of OAC. Methods: We used healthcare utilization data from two independent US databases (MarketScan and Optum) to construct and validate a predictive model of ischemic stroke in patients with AF initiating OACs. Patients with non-valvular AF initiating OACs were identified from the MarketScan data for years 2007-2015. Using bootstrapping methods and backward selection of 44 candidate variables, we developed a model which selected variables predicting stroke. The final model was validated in patients with non-valvular AF in the Optum Clinformatics database in the period 2009-2015. Results: Among 135,523 patients with AF initiating OAC in the MarketScan dataset, 2,028 experienced an ischemic stroke after anticoagulant initiation. The stepwise model identified 15 variables (including type of OAC) associated with ischemic stroke (Table). The discrimination (c-statistic) of the model was adequate [0.68, 95% confidence interval (CI) 0.66-0.70], showing excellent calibration (χ 2 = 7.7 p=0.57). The model was then applied to the 84,549 AF patients in the Optum data set (1408 stroke events). The model showed similar discrimination (c-statistic 0.67, 95%CI 0.65-0.70) and calibration (χ 2 = 12.8 p=0.17). However, previously-developed predicted models had similar discriminative ability (CHA 2 DS 2 -VASc 0.67, 95%CI 0.65-0.68; ATRIA 0.67, 95%CI 0.65-0.68) Conclusion: A novel model using extensive administrative healthcare data for the identification of patients at higher risk of ischemic stroke by type of anticoagulant did not perform better than established simple models.

Background: Elevated carotid intima-media thickness (cIMT) and presence of carotid plaque are markers of atherosclerosis, which may be linked to structural brain injury. Using data from the ARIC-NCS cohort, we tested the hypotheses that greater cIMT and presence of carotid plaque at late midlife were each associated with presence of infarcts (lacunar and cortical) and cerebral microbleeds (lobar and subcortical), greater white matter hyperintensity (WMH) volume, and smaller regional brain volumes in late life. Methods: We included 1,795 ARIC participants who had carotid ultrasounds in 1990-92 and brain MRI scans in 2011-13. Weighted linear regression was used for continuous (brain volume) outcomes, and weighted logistic regression for dichotomous outcomes (infarcts and cerebral microbleeds). Results: Participants were aged 57±6 years at baseline, 57% were female, and 23% were Black. Mean ± SD follow-up was 21±1 years. After multivariable adjustments, the highest quintile of cIMT in late midlife was associated with smaller deep grey matter volume (β [95% CI]: -0.11 [-0.22, -0.01]) and cortical volume in a temporal-parietal meta region of interest (ROI) (β [95% CI]: -0.10 [-0.20, -0.01]) in late life (Table). At baseline, 473 (26%) participants had carotid plaque present on their carotid ultrasound. Similar to cIMT, those with carotid plaque had smaller regional brain volumes than those without carotid plaque present (βs [95% CIs]: -0.05 [-0.12, 0.03] and -0.06 [-0.13, 0.01] for deep grey matter and temporal-parietal meta ROI volumes, respectively). No significant relations were observed with WMH volume, or the presence of any infarcts or cerebral microbleeds. Conclusion: Greater midlife cIMT and presence of carotid plaque were associated with smaller deep grey matter volume and cortical volume in a temporal-parietal meta ROI in later life. Contrary to our hypothesis, associations between midlife subclinical atherosclerosis and markers of vascular brain injury in later life were null.

Background: Multimorbidity is common in patients with atrial fibrillation (AF), yet comorbidity patterns are not well documented. Methods: The prevalence of 18 chronic conditions was obtained in patients with AF from 2013-2017 from a 27-county region in the Midwest. All patients had AF documented on an electrocardiogram or Holter monitor. To compare comorbidity patterns between patients with and without AF, controls were matched 1:1 on age (± 5 years) and sex. For AF patients and controls separately, the Somers’ D statistic was used to quantify the non-random concordance of each pair of chronic conditions beyond chance (ranging from -1 [perfect disagreement] to 1 [perfect agreement]; 0 indicating coincidental agreement by chance alone). Significance of the Somers’ D statistic was evaluated using a permutation approach with the Benjamini-Hochberg procedure for controlling the false discovery rate at 0.1%. Results: Among the 16,543 patients with AF (median age 76 years, 57% men), the most common conditions were hypertension (70%), hyperlipidemia (61%), arthritis (41%), and diabetes (40%). Many pairs of chronic conditions co-occurred more frequently than expected. However, no material differences were observed in the co-occurrence of conditions in patients with AF compared to controls (data not shown). Among patients with AF, the co-occurrence of conditions differed by age (Figure). In those ≤65 years, the strongest co-occurrence of conditions was depression/anxiety, although several condition pairs had Somers’ D statistics of >0.4. In those aged 65-74 years, hypertension/hyperlipidemia and depression/anxiety had the strongest co-occurrence, whereas hypertension/hyperlipidemia was strongest for those aged ≥75 years. Conclusion: Although differences in the co-occurrence of conditions did not exist between AF and community controls, among the patients with AF, the patterns of co-existing conditions differed by age. A better understanding of the clinical consequences of multimorbidity in AF patients is needed.

Introduction: We recently reported that abnormal P-wave indices (PWI)—ECG markers of atrial cardiomyopathy (AC)—are associated with an increased risk of dementia, independent of atrial fibrillation (AF) and clinical ischemic stroke. The mechanisms, however, remain unclear, but may include silent ischemia. Hypothesis: Abnormal PWI are associated with higher prevalence of cortical infarcts on MRI, suggesting cardioembolism as a potential mechanism. Methods: ARIC-NCS participants (mean age, 72.2±5.3 years; 60% women; 29% black) who underwent 3T brain MRI scans in 2011-2013 were included. Abnormal PWI included P-wave terminal force in lead V1 [(PTFV1) defined as ≥4000 μV*ms] and P-wave duration [(PWD) defined as >120 ms], which were measured from standard 12-lead ECGs. Brain MRI outcomes included cortical infarcts, cerebral microbleeds (CMB), and markers of small vessel disease [white matter hyperintensities (WMH) and lacunar infarcts]. We used weighted multivariable logistic and linear regression analyses. Results: Of the 1,850 participants, 464 had abnormal PTFV1 and 415 had prolonged PWD. After multivariable adjustment including AF, abnormal PTFV1 and PWD were significantly associated with 26-44% increased odds of cortical and lacunar infarcts (Table) . Although PWD was associated with CMB in Model 1, the association was no longer significant after multivariable adjustment. Finally, abnormal PWIs were not associated with WMH after adjusting for stroke and AF (P >0.5). Conclusions: Abnormal PWI are associated with higher prevalence of cortical infarcts, suggesting cardioembolism with silent ischemia as a possible mechanism underlying the association of AC with dementia. More research is needed to evaluate other mechanisms such as cerebral small vessel disease.