Population-average mediation analysis for zero-inflated count outcomes.

Mediation analysis is an increasingly popular statistical method for explaining causal pathways to inform intervention. While methods have increased, there is still a dearth of robust mediation methods for count outcomes with excess zeroes. Current mediation methods addressing this issue are computationally intensive, biased, or challenging to interpret. To overcome these limitations, we propose a new mediation methodology for zero-inflated count outcomes using the marginalized zero-inflated Poisson (MZIP) model and the counterfactual approach to mediation. This novel work gives population-average mediation effects whose variance can be estimated rapidly via delta method. This methodology is extended to cases with exposure-mediator interactions. We apply this novel methodology to explore if diabetes diagnosis can explain BMI differences in healthcare utilization and test model performance via simulations comparing the proposed MZIP method to existing zero-inflated and Poisson methods. We find that our proposed method minimizes bias and computation time compared to alternative approaches while allowing for straight-forward interpretations.

The Projected Impact of Population-Wide Achievement of LDL Cholesterol <70 mg/dL on the Number of Recurrent Events Among US Adults with ASCVD.

PURPOSE: Adults with atherosclerotic cardiovascular disease (ASCVD) are recommended high-intensity statins, with those at very high risk for recurrent events recommended adding ezetimibe and/or a proprotein convertase subtilisin/kexin type 9 inhibitor if their low-density lipoprotein cholesterol (LDL-C) is ≥70 mg/dL. We estimated the number of recurrent ASCVD events potentially averted if all adults in the United States (US) ≥45 years of age with ASCVD achieved an LDL-C <70 mg/dL. METHODS: The number of US adults with ASCVD and LDL-C ≥70 mg/dL was estimated from the National Health and Nutrition Examination Survey 2009-2016 (n = 596). The 10-year cumulative incidence of recurrent ASCVD events was estimated from the REasons for Geographic And Racial Differences in Stroke study (n = 5390), weighted to the US population by age, race, and sex. The ASCVD risk reduction by achieving an LDL-C <70 mg/dL was estimated from meta-analyses of lipid-lowering treatment trials. RESULTS: Overall, 14.7 (95% CI, 13.7-15.8) million US adults had ASCVD, of whom 11.6 (95% CI, 10.6-12.5) million had LDL-C ≥70 mg/dL. The 10-year cumulative incidence of ASCVD events was 24.3% (95% CI, 23.2-25.6%). We projected that 2.823 (95% CI, 2.543-3.091) million ASCVD events would occur over 10 years among US adults with ASCVD and LDL-C ≥70 mg/dL. Overall, 0.634 (95% CI, 0.542-0.737) million ASCVD events could potentially be averted if all US adults with ASCVD achieved and maintained LDL-C <70 mg/dL. CONCLUSION: A substantial number of recurrent ASCVD events could be averted over 10 years if all US adults with ASCVD achieved, and maintained, an LDL-C <70 mg/dL.

Recurrent Atherosclerotic Cardiovascular Disease Events Potentially Prevented with Guideline-Recommended Cholesterol-Lowering Therapy following Myocardial Infarction.

PURPOSE: Many adults with atherosclerotic cardiovascular disease (ASCVD) who are recommended to take a statin, ezetimibe and/or a proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i) by the 2018 American Heart Association/American College of Cardiology cholesterol guideline do not receive these medications. We estimated the percentage of recurrent ASCVD events potentially prevented with guideline-recommended cholesterol-lowering therapy following a myocardial infarction (MI) hospitalization. METHODS: We conducted simulations using data from US adults with government health insurance through Medicare or commercial health insurance in the MarketScan database. We used data from patients with an MI hospitalization in 2018-2019 to estimate the percentage receiving guideline-recommended therapy. We used data from patients with an MI hospitalization in 2013-2016 to estimate the 3-year cumulative incidence of recurrent ASCVD events (i.e., MI, coronary revascularization or ischemic stroke). The low-density lipoprotein cholesterol (LDL-C) reduction with guideline-recommended therapy was derived from trials of statins, ezetimibe and PCSK9i, and the associated ASCVD risk reduction was estimated from a meta-analysis by the Cholesterol-Lowering Treatment Trialists Collaboration. RESULTS: Among 279,395 patients with an MI hospitalization in 2018-2019 (mean age 75 years, mean LDL-C 92 mg/dL), 27.3% were receiving guideline-recommended cholesterol-lowering therapy. With current cholesterol-lowering therapy use, 25.3% (95%CI: 25.2%-25.4%) of patients had an ASCVD event over 3 years. If all patients were to receive guideline-recommended therapy, 19.8% (95%CI: 19.5%-19.9%) were estimated to have an ASCVD event over 3 years, representing a 21.6% (95%CI: 20.5%-23.6%) relative risk reduction. CONCLUSION: Implementation of guideline-recommended cholesterol-lowering therapy could prevent a substantial percentage of recurrent ASCVD events.

The Dietary Approaches to Stop Hypertension (DASH) Diet Pattern and Incident Heart Failure.

BACKGROUND: The Dietary Approaches to Stop Hypertension (DASH) diet pattern has shown some promise for preventing heart failure (HF), but studies have been conflicting. OBJECTIVE: To determine whether the DASH diet pattern was associated with incident HF in a large biracial and geographically diverse population. METHODS AND RESULTS: Among participants in the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort study of adults aged ≥45 years who were free of suspected HF at baseline in 2003-2007, the DASH diet score was derived from the baseline food frequency questionnaire. The main outcome was incident HF defined as the first adjudicated HF hospitalization or HF death through December 31, 2016. We estimated hazard ratios for the associations of DASH diet score quartiles with incident HF, and incident HF with reduced ejection fraction and HF with preserved ejection fraction using the Lunn-McNeil extension to the Cox model. We tested for several prespecified interactions, including with age. Compared with the lowest quartile, individuals in the second to fourth DASH diet score quartiles had a lower risk for incident HF after adjustment for sociodemographic and health characteristics: quartile 2 hazard ratio, 0.69 (95% confidence interval [CI], 0.56-0.85); quartile 3 hazard ratio, 0.71 (95% CI, 0.58-0.87); and quartile 4 hazard ratio, 0.73 (95% CI, 0.58-0.92). When stratifying results by age, quartiles 2-4 had a lower hazard for incident HF among those age <65 years, quartiles 3-4 had a lower hazard among those age 65-74, and the quartiles had similar hazard among those age ≥75 years (Pinteraction = .003). We did not find a difference in the association of DASH diet with incident HF with reduced ejection fraction vs HF with preserved ejection fraction (P = .11). CONCLUSIONS: DASH diet adherence was inversely associated with incident HF, specifically among individuals <75 years old.

Risk for recurrent cardiovascular disease events among patients with diabetes and chronic kidney disease.

BACKGROUND: Adults who have experienced multiple cardiovascular disease (CVD) events have a very high risk for additional events. Diabetes and chronic kidney disease (CKD) are each associated with an increased risk for recurrent CVD events following a myocardial infarction (MI). METHODS: We compared the risk for recurrent CVD events among US adults with health insurance who were hospitalized for an MI between 2014 and 2017 and had (1) CVD prior to their MI but were free from diabetes or CKD (prior CVD), and those without CVD prior to their MI who had (2) diabetes only, (3) CKD only and (4) both diabetes and CKD. We followed patients from hospital discharge through December 31, 2018 for recurrent CVD events including coronary, stroke, and peripheral artery events. RESULTS: Among 162,730 patients, 55.2% had prior CVD, and 28.3%, 8.3%, and 8.2% had diabetes only, CKD only, and both diabetes and CKD, respectively. The rate for recurrent CVD events per 1000 person-years was 135 among patients with prior CVD and 110, 124 and 171 among those with diabetes only, CKD only and both diabetes and CKD, respectively. Compared to patients with prior CVD, the multivariable-adjusted hazard ratio for recurrent CVD events was 0.92 (95%CI 0.90-0.95), 0.89 (95%CI: 0.85-0.93), and 1.18 (95%CI: 1.14-1.22) among those with diabetes only, CKD only, and both diabetes and CKD, respectively. CONCLUSION: Following MI, adults with both diabetes and CKD had a higher risk for recurrent CVD events compared to those with prior CVD without diabetes or CKD.

Atrial arrhythmia related outcomes in critically ill COVID-19 patients.

RATIONALE: Coronavirus disease 2019 (COVID-19) is associated with many clinical manifestations including respiratory failure and cardiovascular compromise. OBJECTIVES: We examine outcomes in critically ill individuals with COVID-19 who develop atrial tachyarrhythmias. METHODS: We collected data from electrocardiograms and the electronic medical record of COVID-19 positive (COVID+ ) and negative (COVID- ) individuals admitted to our medical intensive care unit between February 29 and June 28, 2020. We compared clinical and demographic characteristics, new onset atrial tachyarrhythmia, hemodynamic compromise following atrial tachyarrhythmia, and in-hospital mortality in COVID+ versus COVID- . Hemodynamic compromise was defined as having a new or increased vasopressor requirement or the need for direct current cardioversion for hemodynamic instability within 1 hour of atrial tachyarrhythmia onset. RESULTS: Of 300 individuals included, 200 were COVID+ and 100 were COVID- . Mean age was 60 ± 16 years, 180 (60%) were males, and 170 (57%) were African American. New onset atrial tachyarrhythmia occurred in 16% of COVID+ and 19% of COVID- individuals (P = .51). When compared to COVID- participants without atrial tachyarrhythmia, COVID+ individuals with new onset atrial tachyarrhythmia had higher mortality after multivariable adjustment (OR 5.0, 95% CI 1.9-13.5). New onset atrial tachyarrhythmia was followed by hemodynamic compromise in 18 COVID+ but no COVID- participants (P = .0001). COVID+ individuals with hemodynamic compromise after atrial tachyarrhythmia required increased ventilatory support at the time of atrial tachyarrhythmia onset. CONCLUSIONS: Atrial tachyarrhythmia is associated with increased mortality in critically ill individuals with COVID-19, especially those mechanically ventilated. Recognition of this could assist with clinical care for individuals with COVID-19.

Contemporary Diagnosis and Management of Patients With Myocardial Infarction in the Absence of Obstructive Coronary Artery Disease: A Scientific Statement From the American Heart Association.

Myocardial infarction in the absence of obstructive coronary artery disease is found in ≈5% to 6% of all patients with acute infarction who are referred for coronary angiography. There are a variety of causes that can result in this clinical condition. As such, it is important that patients are appropriately diagnosed and an evaluation to uncover the correct cause is performed so that, when possible, specific therapies to treat the underlying cause can be prescribed. This statement provides a formal and updated definition for the broadly labelled term MINOCA (incorporating the definition of acute myocardial infarction from the newly released "Fourth Universal Definition of Myocardial Infarction") and provides a clinically useful framework and algorithms for the diagnostic evaluation and management of patients with myocardial infarction in the absence of obstructive coronary artery disease.

Home-Based Cardiac Rehabilitation: A Scientific Statement From the American Association of Cardiovascular and Pulmonary Rehabilitation, the American Heart Association, and the American College of Cardiology.

Cardiac rehabilitation (CR) is an evidence-based intervention that uses patient education, health behavior modification, and exercise training to improve secondary prevention outcomes in patients with cardiovascular disease. CR programs reduce morbidity and mortality rates in adults with ischemic heart disease, heart failure, or cardiac surgery but are significantly underused, with only a minority of eligible patients participating in CR in the United States. New delivery strategies are urgently needed to improve participation. One potential strategy is home-based CR (HBCR). In contrast to center-based CR services, which are provided in a medically supervised facility, HBCR relies on remote coaching with indirect exercise supervision and is provided mostly or entirely outside of the traditional center-based setting. Although HBCR has been successfully deployed in the United Kingdom, Canada, and other countries, most US healthcare organizations have little to no experience with such programs. The purpose of this scientific statement is to identify the core components, efficacy, strengths, limitations, evidence gaps, and research necessary to guide the future delivery of HBCR in the United States. Previous randomized trials have generated low- to moderate-strength evidence that HBCR and center-based CR can achieve similar improvements in 3- to 12-month clinical outcomes. Although HBCR appears to hold promise in expanding the use of CR to eligible patients, additional research and demonstration projects are needed to clarify, strengthen, and extend the HBCR evidence base for key subgroups, including older adults, women, underrepresented minority groups, and other higher-risk and understudied groups. In the interim, we conclude that HBCR may be a reasonable option for selected clinically stable low- to moderate-risk patients who are eligible for CR but cannot attend a traditional center-based CR program.

Risk factor control among Black and White adults with diabetes onset in older adulthood: The Reasons for Geographic and Racial Differences in Stroke (REGARDS) study.

The objective of this study was to determine whether attainment of clinical and lifestyle targets varied by race and sex among adults with diabetes onset in older adulthood. This study included 1420 black and white adults from the REGARDS study without diabetes at baseline (2003-07) but with diabetes onset at the follow-up exam (2013-16). Attainment of clinical targets (A1c <8%; blood pressure < 140/90 mmHg; and statin use) and lifestyle targets (not smoking; physical activity≥ 4 times/week; and moderate/no alcohol use) was assessed at the follow-up exam. Modified Poisson regression was used to obtain prevalence ratios (PR) for meeting clinical and lifestyle targets stratified by race and sex, separately. The mean age was 71.5 years, 53.6% were female, and 46.1% were black. The majority were aware of their diabetes status (85.7%) and used oral or injectable hypoglycemic medications (64.8%). Overall, 39.4% met all 3 clinical targets and 18.8% met all 3 lifestyle targets. Meeting A1c and blood pressure targets were similar by race and sex. Statin use was more prevalent for men than women among white adults (PR = 1.13; 95% CI = 0.99-1.29) and black adults (PR = 1.23; 95% CI = 1.06-1.43). For lifestyle factors, the non-smoking prevalence was similar by race and sex, while white men were more likely than white women to be physically active. Although the attainment of each clinical and lifestyle target separately was generally high among adults with diabetes onset in older adulthood, race and sex differences were apparent. Comprehensive management of clinical and lifestyle factors in people with diabetes remains suboptimal.

PCSK9 loss-of-function variants and Lp(a) phenotypes among black US adults.

The pharmacologic inhibition of proprotein convertase subtilisin-kexin type 9 (PCSK9) lowers lipoprotein (a) [Lp(a)] concentrations. However, the impact of genetic PCSK9 loss-of-function variants (LOFVs) on Lp(a) is uncertain. We determined the association of PCSK9 LOFVs with Lp(a) measures among black adults. Genotyping for PCSK9 LOFVs was conducted in 10,196 black Reasons for Geographic and Racial Differences in Stroke study participants. Among 241 participants with and 723 randomly selected participants without PCSK9 LOFVs, Lp(a) concentations, apo(a) kringle IV (KIV) repeats (a proxy for isoform size), and oxidized phospholipid (OxPL) apoB levels were measured using validated methods. Median Lp(a) concentrations among participants with and without PCSK9 LOFVs were 63.2 and 80.4 nmol/l, respectively (P = 0.016). After adjusting for age, sex, estimated glomerular filtration rate, LDL cholesterol, and statin use, participants with versus without a PCSK9 LOFV had a lower median Lp(a) concentration [Δ = -18.8 nmol/l (95% CI: -34.2, -3.3)]. Median apo(a) isoform sizes were 24 and 23 KIV repeats (P = 0.12) among participants with and without PCSK9 LOFVs, respectively [Δ = 1.1 (95% CI: 0.2, 2.0) after adjustment]. Median OxPL-apoB levels among participants with and without PCSK9 LOFVs were 3.4 and 4.1 nM (P = 0.20), respectively [Δ = -1.2 nM (95% CI -2.4, -0.04) after adjustment]. Among black adults, PCSK9 LOFVs were associated with lower Lp(a) concentration and OxPL-apoB levels.

Low Utilization of Beta-Blockers Among Medicare Beneficiaries Hospitalized for Heart Failure With Reduced Ejection Fraction.

BACKGROUND: The evidence-based beta-blockers carvedilol, bisoprolol, and metoprolol succinate reduce mortality and hospitalizations among patients with heart failure with reduced ejection fraction (HFrEF). Use of these medications is not well described in the general population of patients with HFrEF, especially among patients with potential contraindications. OBJECTIVES: Our goal was to describe the patterns of prescription fills for carvedilol, bisoprolol, and metoprolol succinate among Medicare beneficiaries hospitalized for HFrEF, as well as to estimate the associations between specific contraindications for beta-blocker therapy and those patterns. METHODS AND RESULTS: With the use of the cohort of 15,205 Medicare beneficiaries hospitalized for HFrEF from 2007 to 2013 in the 5% Medicare random sample, we described prescription fills (30 days after discharge) and dosage patterns (1 year after discharge) for beta-blockers. By means of of Fine and Gray competing risk models, we estimated the associations between potential contraindications (hypotension, chronic obstructive pulmonary disease [COPD], asthma, and syncope) and prescription fill and dosing patterns while adjusting for demographics, comorbidities, and health care utilization. For beneficiaries who did not die or readmitted to the hospital, 38% of hospitalizations were followed by a prescription fill for an evidence-based beta-blocker within 30 days, 12% were followed by prescription fills for at least 50% of the recommended dose of an evidence-based beta-blocker within 1 year, and 9% were followed by a prescription fill for an up-titrated dose of an evidence-based beta-blocker within 1 year. The prevalence of the contraindications were 21% for hypotension, 48% for COPD, 15% for asthma, and 12% for syncope. Among beneficiaries who did not fill a prescription for an evidence-based beta-blocker within 30 days, 67% had at least 1 of these contraindications. Hypotension, COPD, and syncope were each associated with a ∼10% lower risk of filling a prescription for an evidence-based beta-blocker. CONCLUSIONS: Prescription fill and up-titration rates for evidence-based beta-blockers are low among Medicare beneficiaries with HFrEF, but contraindications explain only a minor part of these low rates.

Characteristics and Cardiovascular Disease Event Rates among African Americans and Whites Who Meet the Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk (FOURIER) Trial Inclusion Criteria.

PURPOSE: Determine the risk for cardiovascular disease (CVD) events among adults with clinically evident CVD who meet the inclusion criteria for the FOURIER clinical trial on PCSK9 inhibition in a real-world database. METHODS: We analyzed data from 2072 African American and 2972 white REasons for Geographic And Racial Differences in Stroke (REGARDS) study participants 45-85 years of age with clinically evident CVD. Study participants meeting the FOURIER inclusion criteria (one major or two minor cardiovascular risk factors, fasting LDL cholesterol ≥ 70 mg/dL or non-HDL cholesterol ≥ 100 mg/dL, triglycerides ≤ 400 mg/dL, and taking statin) were followed for CVD events (myocardial infarction, stroke, coronary revascularization, and CVD death) from baseline in 2003-2007 through 2014. RESULTS: Overall, 771 (37.2%) African Americans and 1200 (40.4%) whites met the FOURIER inclusion criteria. The CVD event rate per 1000 person years was 60.6 (95% CI 53.6-67.6) among African Americans and 63.5 (95% CI 57.7-69.3) among whites. The risk for CVD events among adults meeting the FOURIER inclusion criteria was higher for those with a history of multiple cardiovascular events (hazard ratios among African Americans and whites 1.34 [95% CI 1.05-1.71] and 1.34 [1.10-1.63], respectively), a prior coronary revascularization (1.44 [1.13-1.84] and 1.23 [1.00-1.52], respectively), diabetes (1.38 [1.08-1.76] and 1.41 [1.15-1.72], respectively), reduced glomerular filtration rate (1.63 [1.26-2.11] and 1.29 [1.03-1.62], respectively), and albuminuria (1.77 [1.37-2.27] and 1.33 [1.07-1.65], respectively). CONCLUSIONS: The CVD event rate is high among African Americans and whites meeting the FOURIER inclusion criteria. Characteristics associated with a higher CVD risk may inform the decision to initiate PCSK9 inhibition.

Titration to High-Intensity Statin Therapy Following Acute Myocardial Infarction in Patients With and Without Diabetes Mellitus.

BACKGROUND: Patients with diabetes mellitus (DM) have a high risk for cardiovascular disease (CVD) events after an acute myocardial infarction (AMI). High-intensity statins reduce CVD risk following AMI among patients with and without DM. METHODS: We determined the proportion of Medicare beneficiaries 66 to 75 years of age taking a low/moderate-intensity statin with (n = 6718) and without (n = 6414) DM who titrated to a high-intensity statin dosage (i.e., atorvastatin 40 or 80 mg, or rosuvastatin 20 or 40 mg) following an AMI hospitalization in 2014-2015. All patients had a pharmacy claim for a statin fill within 365 days prior to, and within 30 days after their AMI hospitalization. We excluded beneficiaries without Medicare fee-for-service coverage including pharmacy benefits during the study period and those with a pharmacy claim for a high-intensity statin prior to their AMI. RESULTS: The first statin fill following hospital discharge was for a high-intensity dosage among 37.7% and 44.4% of patients with and without DM, respectively. After multivariable adjustment, the risk ratio (RR) for titrating to a high-intensity statin comparing patients with versus without DM was 1.01 (95% CI 0.96, 1.06). Among patients whose first statin fill post-AMI was for a low/moderate-intensity dosage, 7.5% of those with DM titrated to a high-intensity statin within 182 days, compared with 9.2% of those without DM (multivariable-adjusted RR 0.90 [95% CI 0.75, 1.08]). CONCLUSIONS: Most patients taking a low/moderate-intensity statin were not titrated to a high-intensity dosage following AMI irrespective of their diabetes status, potentially leaving substantial residual risk for recurrent CVD events.

N-terminal pro-B-type natriuretic peptide and microsize myocardial infarction risk in the reasons for geographic and racial differences in stroke study.

BACKGROUND: N-terminal pro B-type peptide (NT-proBNP) has been associated with risk of myocardial infarction (MI), but less is known about the relationship between NT-proBNP and very small non ST-elevation MI, also known as microsize MI. These events are now routinely detectable with modern troponin assays and are emerging as a large proportion of all MI. Here, we sought to compare the association of NT-proBNP with risk of incident typical MI and microsize MI in the REasons for Geographic and Racial Differences in Stroke (REGARDS) Study. METHODS: The REGARDS Study is a national cohort of 30,239 US community-dwelling black and white adults aged ≥ 45 years recruited from 2003 to 2007. Expert-adjudicated outcomes included incident typical MI (definite/probable MI with peak troponin ≥ 0.5 µg/L), incident microsize MI (definite/probable MI with peak troponin < 0.5 µg/L), and incident fatal CHD. Using a case-cohort design, we estimated the hazard ratio of the outcomes as a function of baseline NT-proBNP. Competing risk analyses tested whether the associations of NT-proBNP differed between the risk of incident microsize MI and incident typical MI as well as if the association of NT-proBNP differed between incident non-fatal microsize MI and incident non-fatal typical MI, while accounting for incident fatal coronary heart disease (CHD) as well as heart failure (HF). RESULTS: Over a median of 5 years of follow-up, there were 315 typical MI, 139 microsize MI, and 195 incident fatal CHD. NT-proBNP was independently and strongly associated with all CHD endpoints, with significantly greater risk observed for incident microsize MI, even after removing individuals with suspected HF prior to or coincident with their incident CHD event. CONCLUSION: NT-proBNP is associated with all MIs, but is a more powerful risk factor for microsize than typical MI.

Quality of anticoagulation control and hemorrhage risk among African American and European American warfarin users.

OBJECTIVE: We evaluated whether percent time in target range (PTTR), risk of over-anticoagulation [international normalized ratio (INR)>4], and risk of hemorrhage differ by race. As PTTR is a strong predictor of hemorrhage risk, we also determined the influence of PTTR on the risk of hemorrhage by race. PARTICIPANTS AND METHODS: Among 1326 warfarin users, PTTR was calculated as the percentage of interpolated INR values within the target range of 2.0-3.0. PTTR was also categorized as poor (PTTR<60%), good (60≤PTTR<70%), or excellent (PTTR≥70%) anticoagulation control. Over-anticoagulation was defined as INR more than 4 and major hemorrhages included serious, life-threatening, and fatal bleeding episodes. Logistic regression and survival analyses were carried out to evaluate the association of race with PTTR (≥60 vs. <60) and major hemorrhages, respectively. RESULTS: Compared with African Americans, European Americans had higher PTTR (57.6 vs. 49.1%; P<0.0001) and were more likely to attain 60≤PTTR<70% (22.9 vs. 13.1%; P<0.001) or PTTR of at least 70% (26.9 vs. 18.2%; P=0.001). Older (>65 years) patients without venous thromboembolism indication and chronic kidney disease were more likely to attain PTTR of at least 60%. After accounting for clinical and genetic factors, and PTTR, African Americans had a higher risk of hemorrhage [hazard ratio (HR)=1.58; 95% confidence interval (CI): 1.04-2.41; P=0.034]. Patients with 60≤PTTR<70% (HR=0.62; 95% CI: 0.38-1.02; P=0.058) and PTTR of at least 70% (HR=0.27; 95% CI: 0.15-0.49; P<0.001) had a lower risk of hemorrhage compared with those with PTTR less than 60%. CONCLUSION: Despite the provision of warfarin management through anticoagulation clinics, African Americans achieve a lower overall PTTR and have a significantly higher risk of hemorrhage. Personalized medicine interventions tailored to African American warfarin users need to be developed.

Significant Discrepancy Between Estimated and Actual Longevity in St. Jude Medical Implantable Cardioverter-Defibrillators.

BACKGROUND: Real-time estimated longevity has been reported in pacemakers for several years, and was recently introduced in implantable cardioverter-defibrillators (ICDs). OBJECTIVE: We sought to evaluate the accuracy of this longevity estimate in St. Jude Medical (SJM) ICDs, especially as the device battery approaches depletion. METHODS: Among patients with SJM ICDs who underwent generator replacements due to reaching elective replacement indicator (ERI) at our institution, we identified those with devices that provided longevity estimates and reviewed their device interrogations in the 18 months prior to ERI. Significant discrepancy was defined as a difference of more than 12 months between estimated and actual longevity at any point during this period. RESULTS: Forty-six patients with Current/Promote devices formed the study group (40 cardiac resynchronization therapy [CRT] and 6 single/dual chamber). Of these, 34 (74%) had significant discrepancy between estimated and actual longevity (28 CRT and all single/dual). Longevity was significantly overestimated by the device algorithm (mean maximum discrepancy of 18.8 months), more in single/dual than CRT devices (30.5 vs. 17.1 months). Marked discrepancy was seen at voltages ≥2.57 volts, with maximum discrepancy at 2.57 volts (23 months). The overall longevity was higher in the discrepant group of CRT devices than in the nondiscrepant group (67 vs. 61 months, log-rank P = 0.03). CONCLUSIONS: There was significant overestimation of longevity in nearly three-fourths of Current/Promote SJM ICDs in the last 18 months prior to ERI. Longevity estimates of SJM ICDs may not be reliable for making clinical decisions on frequency of follow-up, as the battery approaches depletion.

Race influences warfarin dose changes associated with genetic factors.

Warfarin dosing algorithms adjust for race, assigning a fixed effect size to each predictor, thereby attenuating the differential effect by race. Attenuation likely occurs in both race groups but may be more pronounced in the less-represented race group. Therefore, we evaluated whether the effect of clinical (age, body surface area [BSA], chronic kidney disease [CKD], and amiodarone use) and genetic factors (CYP2C9*2, *3, *5, *6, *11, rs12777823, VKORC1, and CYP4F2) on warfarin dose differs by race using regression analyses among 1357 patients enrolled in a prospective cohort study and compared predictive ability of race-combined vs race-stratified models. Differential effect of predictors by race was assessed using predictor-race interactions in race-combined analyses. Warfarin dose was influenced by age, BSA, CKD, amiodarone use, and CYP2C9*3 and VKORC1 variants in both races, by CYP2C9*2 and CYP4F2 variants in European Americans, and by rs12777823 in African Americans. CYP2C9*2 was associated with a lower dose only among European Americans (20.6% vs 3.0%, P < .001) and rs12777823 only among African Americans (12.3% vs 2.3%, P = .006). Although VKORC1 was associated with dose decrease in both races, the proportional decrease was higher among European Americans (28.9% vs 19.9%, P = .003) compared with African Americans. Race-stratified analysis improved dose prediction in both race groups compared with race-combined analysis. We demonstrate that the effect of predictors on warfarin dose differs by race, which may explain divergent findings reported by recent warfarin pharmacogenetic trials. We recommend that warfarin dosing algorithms should be stratified by race rather than adjusted for race.

Medical therapy following hospitalization for heart failure with reduced ejection fraction and association with discharge to long-term care: a cross-sectional analysis of the REasons for Geographic And Racial Differences in Stroke (REGARDS) population.

BACKGROUND: Less intensive treatment for heart failure with reduced ejection fraction (HFrEF) may be appropriate for patients in long-term care settings because of limited life expectancy, frailty, comorbidities, and emphasis on quality of life. METHODS: We compared treatment patterns between REasons for Geographic And Racial Differences in Stroke (REGARDS) study participants discharged to long-term care versus home following HFrEF hospitalizations. We examined medical records and Medicare pharmacy claims for 147 HFrEF hospitalizations among 80 participants to obtain information about discharge disposition and medication prescriptions and fills. RESULTS: Discharge to long-term care followed 22 of 147 HFrEF hospitalizations (15%). Participants discharged to long-term care were more likely to be prescribed beta-blockers and less likely to be prescribed aldosterone receptor antagonists and hydralazine/isosorbide dinitrate (96%, 14%, and 5%, respectively) compared to participants discharged home (81%, 22%, and 23%, respectively). The percentages of participants discharged to long-term care and home who had claims for filled prescriptions were similar for beta-blockers (68% versus 66%) and angiotensin converting enzyme inhibitors or angiotensin receptor blockers (ACEI/ARBs) (45% versus 47%) after 1 year. Smaller percentages of participants discharged to long-term care had claims for filled prescriptions of other medications compared to participants discharged home (diuretics: long-term care-50%, home-72%; hydralazine/isosorbide dinitrate: long-term care-5%, home-23%; aldosterone receptor antagonists: long-term care-5%, home-23%). CONCLUSIONS: Differences in medication prescriptions and fills among individuals with HFrEF discharged to long-term care versus home may reflect prioritization of some medical therapies over others for patients in long-term care.

Southern Dietary Pattern is Associated With Hazard of Acute Coronary Heart Disease in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study.

BACKGROUND: The association of overall diet, as characterized by dietary patterns, with risk of incident acute coronary heart disease (CHD) has not been studied extensively in samples including sociodemographic and regional diversity. METHODS AND RESULTS: We used data from 17 418 participants in Reasons for Geographic and Racial Differences in Stroke (REGARDS), a national, population-based, longitudinal study of white and black adults aged ≥45 years, enrolled from 2003 to 2007. We derived dietary patterns with factor analysis and used Cox proportional hazards regression to examine hazard of incident acute CHD events - nonfatal myocardial infarction and acute CHD death - associated with quartiles of consumption of each pattern, adjusted for various levels of covariates. Five primary dietary patterns emerged: Convenience, Plant-based, Sweets, Southern, and Alcohol and Salad. A total of 536 acute CHD events occurred over a median (interquartile range) 5.8 (2.1) years of follow-up. After adjustment for sociodemographics, lifestyle factors, and energy intake, highest consumers of the Southern pattern (characterized by added fats, fried food, eggs, organ and processed meats, and sugar-sweetened beverages) experienced a 56% higher hazard of acute CHD (comparing quartile 4 with quartile 1: hazard ratio, 1.56; 95% confidence interval, 1.17-2.08; P for trend across quartiles=0.003). Adding anthropometric and medical history variables to the model attenuated the association somewhat (hazard ratio, 1.37; 95% confidence interval, 1.01-1.85; P=0.036). CONCLUSIONS: A dietary pattern characteristic of the southern United States was associated with greater hazard of CHD in this sample of white and black adults in diverse regions of the United States.

Diabetes, diabetes severity, and coronary heart disease risk equivalence: REasons for Geographic and Racial Differences in Stroke (REGARDS).

BACKGROUND: Evidence is mixed regarding whether diabetes confers equivalent risk of coronary heart disease (CHD) as prevalent CHD. We investigated whether diabetes and severe diabetes are CHD risk equivalents. METHODS: At baseline, participants in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study (black and white US adults ≥45 years old recruited in 2003-2007) were categorized as having prevalent CHD only (self-reported or electrocardiogram evidence; n = 3,043), diabetes only (self-reported or elevated glucose; n = 4,012), diabetes and prevalent CHD (n = 1,529), and neither diabetes nor prevalent CHD (n = 17,155). Participants with diabetes using insulin and/or with albuminuria (urinary albumin-to-creatinine ratio ≥30 mg/g) were categorized as having severe diabetes. Participants were followed up through 2011 for CHD events (myocardial infarction or fatal CHD). RESULTS: During a mean follow-up of 5 years, 1,385 CHD events occurred. The hazard ratios of CHD events comparing participants with diabetes only, diabetes, and prevalent CHD and neither diabetes nor prevalent CHD with those with prevalent CHD were 0.65 (95% CI 0.54-0.77), 1.54 (95% CI 1.30-1.83), and 0.41 (95% CI 0.35-0.47), respectively, after adjustment for demographics and risk factors. Compared with participants with prevalent CHD, the hazard ratio of CHD events for participants with severe diabetes was 0.88 (95% CI 0.72-1.09). CONCLUSIONS: Participants with diabetes had lower risk of CHD events than did those with prevalent CHD. However, participants with severe diabetes had similar risk to those with prevalent CHD. Diabetes severity may need consideration when deciding whether diabetes is a CHD risk equivalent.