Hammill, Bradley G.

ImportanceAtrial fibrillation (AF) is the most common, chronic, cardiac arrythmia in older US adults. It is not known whether AF is independently associated with increased risk of retinal stroke (central retinal artery occlusion), a subtype of ischemic stroke that causes severely disabling visual loss in most cases and is a harbinger of further vascular events.ObjectiveTo determine whether there is an association between AF and retinal stroke.Design, Setting, and ParticipantsThis retrospective cohort study was performed between July 2023 and May 2024 using computerized inpatient, outpatient, emergency department, and skilled nursing facility claims files for a 5% sample of US fee-for-service Medicare beneficiaries aged 66 years and older between 2000 and 2020. Follow-up ended at death, conclusion of fee-for-service Medicare coverage, end of the study period, or loss to follow-up of 85% of the study cohort.ExposureAF, based on validated International Classification of Diseases, Ninth Revision, Clinical Modification and International Statistical Classification of Diseases, Tenth Revision, Clinical Modification diagnosis codes.Main Outcomes and MeasuresThe primary end point was incident retinal stroke in the primary diagnostic position of a single claim in any venue of care. Secondary end points included retinal stroke in any position of a single claim, 1 positive control end point (cerebral ischemic stroke), and 4 negative control end points (central retinal vein occlusion, urinary tract infection, humeral fracture, and cataract). Unadjusted and adjusted hazard ratios (HRs) and rate differences were computed across matched and overlap-weighted cohorts with and without AF (defined as 1 inpatient claim or 2 outpatient claims within a 365-day period).ResultsIn total, 1 090 144 patients (591 400 female [54.3%]; mean [SD] age, 76.92 [7.09] years) were included in the study; 545 072 patients had AF and 545 072 were matched controls. The median (IQR) follow-up was 45 (18 to 90) months. In total, 1333 patients with AF (rate, 0.55 per 1000 person-years) and 1082 AF-free matched controls (rate, 0.50 per 1000 person-years) experienced retinal stroke. The cause-specific, adjusted HR of retinal stroke after overlap weighting was 1.14 (95% CI, 1.02 to 1.28; adjusted rate difference, 0.05 [95% CI, −0.01 to 0.11]). AF was associated with cerebral ischemic stroke (adjusted HR, 1.73 [95% CI, 1.69 to 1.76]; adjusted rate difference, 10.11 [95% CI, 9.72 to 10.49]). Of 4 prespecified negative control end points, AF was not associated with central retinal vein occlusion but was associated with urinary tract infection, cataract, and humeral fracture.Conclusions and RelevanceIn this cohort study of Medicare beneficiaries aged 66 years and older, AF was independently associated with retinal stroke. The magnitude of the association was small, and a contribution from residual, unmeasured confounding could not be excluded.

Abstract Whether initiation of statins could increase survival free of dementia and disability in adults aged ≥75 years is unknown. PREVENTABLE, a double‐blind, placebo‐controlled randomized pragmatic clinical trial, will compare high‐intensity statin therapy (atorvastatin 40 mg) with placebo in 20,000 community‐dwelling adults aged ≥75 years without cardiovascular disease, disability, or dementia at baseline. Exclusion criteria include statin use in the prior year or for >5 years and inability to take a statin. Potential participants are identified using computable phenotypes derived from the electronic health record and local referrals from the community. Participants will undergo baseline cognitive testing, with physical testing and a blinded lipid panel if feasible. Cognitive testing and disability screening will be conducted annually. Multiple data sources will be queried for cardiovascular events, dementia, and disability; survival is site‐reported and supplemented by a National Death Index search. The primary outcome is survival free of new dementia or persisting disability. Co‐secondary outcomes are a composite of cardiovascular death, hospitalization for unstable angina or myocardial infarction, heart failure, stroke, or coronary revascularization; and a composite of mild cognitive impairment or dementia. Ancillary studies will offer mechanistic insights into the effects of statins on key outcomes. Biorepository samples are obtained and stored for future study. These results will inform the benefit of statins for increasing survival free of dementia and disability among older adults. This is a pioneering pragmatic study testing important questions with low participant burden to align with the needs of the growing population of older adults.

Background— Cardiac resynchronization therapy with defibrillator (CRT-D) reduces morbidity and mortality among selected patients with heart failure in clinical trials. The effectiveness of this therapy in clinical practice has not been well studied. Methods and Results— We compared a cohort of 4471 patients from the National Cardiovascular Data Registry’s Implantable Cardioverter-Defibrillator (ICD) Registry hospitalized primarily for heart failure and who received CRT-D between April 1, 2006, and December 31, 2009, to a historical control cohort of 4888 patients with heart failure without CRT-D from the Acute Decompensated Heart Failure National Registry (ADHERE) hospitalized between January 1, 2002, and March 31, 2006. Both registries were linked with Medicare claims to evaluate longitudinal outcomes. We included patients from the ICD Registry with left ventricular ejection fraction ≤35% and QRS duration ≥120 ms who were admitted for heart failure. We used Cox proportional hazards models to compare outcomes with and without CRT-D after adjustment for important covariates. After multivariable adjustment, CRT-D was associated with lower 3-year risks of death (hazard ratio, 0.52; 95% confidence interval, 0.48–0.56; P <0.001), all-cause readmission (hazard ratio, 0.69; 95% confidence interval, 0.65–0.73; P <0.001), and cardiovascular readmission (hazard ratio, 0.60; 95% confidence interval, 0.56–0.64; P <0.001). The association of CRT-D with mortality did not vary significantly among subgroups defined by age, sex, race, QRS duration, and optimal medical therapy. Conclusions— CRT-D was associated with lower risks of mortality, all-cause readmission, and cardiovascular readmission than medical therapy alone among patients with heart failure in community practice.

Background— Patients with heart failure and atrial fibrillation are at higher risk of thromboembolic events than patients with heart failure alone. Yet, the use of anticoagulation therapy varies in clinical practice, especially among older patients, for whom its effectiveness is poorly understood. Methods and Results— Using clinical registry data linked to Medicare claims from 2005 to 2011, we examined outcomes of older patients hospitalized with heart failure and atrial fibrillation who newly initiated anticoagulation therapy at discharge. We used Cox proportional hazards models and inverse probability-weighted treatment estimates to adjust for selection bias. Main outcomes were mortality and readmission at 1 and 3 years. Among 5105 patients in 195 hospitals, 1623 (31.8%) started anticoagulation therapy at discharge. Treated patients had lower unadjusted rates of all-cause mortality (26.4% versus 42.8%; P <0.001) and all-cause readmission (58.4% versus 63.7%; P <0.001) at 1 year. After inverse weighting for the probability of treatment and adjustment for other discharge medications, anticoagulation therapy was associated with significantly lower 1-year mortality (hazard ratio, 0.70; 99% confidence interval, 0.59–0.82), but there was no statistically significant difference in the risk of all-cause readmission (hazard ratio, 0.89; 99% confidence interval, 0.78–1.01) or other readmission outcomes. Results were similar at 3 years. Conclusions— Initiation of anticoagulation therapy at hospital discharge was associated with improved mortality at 1 and 3 years but was not associated with improved cardiovascular readmission among older patients with heart failure and atrial fibrillation.

Background— Guidelines recommend that implantable cardioverter-defibrillator (ICD) candidates have an estimated longevity of ≥1 year. Longevity can be affected by chronic kidney disease (CKD). Methods and Results— Using the National Cardiovascular Data Registry ICD registry linked with the Social Security Death Master File, we assessed the rate of death after primary prevention ICD placement between January 1, 2006, and December 31, 2007, according to CKD stage. Using Cox models, we identified factors associated with death among patients with CKD. Compared with patients without CKD (n=26 056), those with CKD (n=21 226) were older, less commonly men, more often white, and more frequently had comorbid illness. Compared with patients without CKD, patients with a glomerular filtration rate 30 to 60, glomerular filtration rate <30, and end-stage renal disease on dialysis had a higher risk of death after ICD placement (hazard ratio, 2.08; 95% confidence interval, 1.99–2.18; P <0.0001; hazard ratio, 4.20; 95% confidence interval, 3.92–4.50; P <0.0001; and hazard ratio, 4.80; 95% confidence interval, 4.46–5.17; P <0.0001, respectively). Corresponding 1-year death rates were 4.4%, 9.1%, 20.2%, and 22.4%. Among patients with CKD, factors associated with increased risk of death included CKD severity, age >65 years, heart failure symptoms, diabetes mellitus, lung disease, serum sodium <140 mEq/L, atrial fibrillation or flutter, and a lower ejection fraction. Conclusions— The risk of death after primary prevention ICD placement is proportional to CKD severity. Among patients with CKD, several factors are prognostically significant and could inform clinical decision making on primary prevention ICD candidacy.