Positive predictive value of the diagnosis of acute myocardial infarction in an administrative database

Leveraging undecided cases in chart-reviewed phenotypes to enhance EHR-based association studies

OBJECTIVES

In electronic health record (EHR)-based association studies, phenotyping algorithms efficiently classify patient clinical outcomes into binary categories but are susceptible to misclassification errors. The gold standard, manual chart review, involves clinicians determining the true disease status based on their assessment of health records. These clinicians-labeled phenotypes are labor-intensive and typically limited to a small subset of patients, potentially introducing a third "undecided" category when phenotypes are indeterminate. We aim to effectively integrate the algorithm-derived and chart-reviewed outcomes when both are available in EHR-based association studies.

MATERIAL AND METHODS

We propose an augmented estimation method that combines the binary algorithm-derived phenotypes for the entire cohort with the trinary chart-reviewed phenotypes for a small, selected subset. Additionally, a cost-effective outcome-dependent sampling strategy is used to address the rare disease scenarios. The proposed trinary chart-reviewed phenotype integrated cost-effective augmented estimation (TriCA) was evaluated across a wide range of simulation settings and real-world applications, including using EHR data on Alzheimer's disease and related dementias (ADRD) from the OneFlorida + Clinical Research Network, and using cohort data on second breast cancer events (SBCE) from the Kaiser Permanente Washington.

RESULTS

Compared to estimation based on random sampling, our augmented method improved mean square error by up to 28.3% in simulation studies; compared to estimation using only trinary chart-reviewed phenotypes, our method improved efficiency by up to 33.3% in ADRD data and 50.8% in SBCE data.

DISCUSSION

Our simulation studies and real-world applications demonstrate that, compared to existing methods, the proposed method provides unbiased estimates with higher statistical efficiency.

CONCLUSION

The proposed method effectively combined binary algorithm-derived phenotypes for the whole cohort with trinary chart-reviewed outcomes for a limited validation set, making it applicable to a broader range of applications and enhancing risk factor identification in EHR-based association studies.

Long-Term Outcomes of Peripheral Artery Disease in Veterans: Analysis of the Peripheral Artery Disease Long-Term Survival Study (PEARLS)

BACKGROUND

Contemporary research in peripheral artery disease (PAD) remains limited due to lack of a national registry and low accuracy of diagnosis codes to identify patients with PAD.

METHODS

Leveraging a novel natural language processing system that identifies PAD with high accuracy using ankle-brachial index and toe-brachial index values, we created a registry of 103 748 patients with new-onset PAD in the Veterans Health Administration. Study end points include mortality, cardiovascular events (hospitalization for acute myocardial infarction or stroke) and limb events (hospitalization for critical limb ischemia or major amputation) and were identified using Veterans Affairs and non-Veterans Affairs encounters.

RESULTS

The mean age was 70.6 years; 97.3% were male, and 18.5% self-identified as Black. The mean ankle-brachial index value was 0.78 (SD: 0.26) and the mean toe-brachial index value was 0.51 (SD: 0.19). A majority of patients were current (27.1%) or former (30.0%) smokers. Prevalence of hypertension (86.6%), heart failure (22.7%), diabetes (54.8%), chronic kidney disease (23.6%), and chronic obstructive pulmonary disease (35.4%) was high. At 1 year, 9.4% of patients had died. The 1-year incidence of cardiovascular events was 5.6 per 100 patient-years and limb events was 7.0 per 100 patient-years.

CONCLUSIONS

We have successfully launched a registry of >100 000 patients with a new diagnosis of PAD in the Veterans Health Administration, the largest integrated health system in the United States. The incidence of death and clinical events in our cohort is high. Ongoing studies will yield important insights regarding improving care and outcomes in this high-risk group.

Antihypertensive Deprescribing and Cardiovascular Events Among Long-Term Care Residents

Importance

The practice of deprescribing antihypertensive medications is common among long-term care residents, yet the effect on cardiovascular outcomes is unclear.

Objective

To compare the incidence of hospitalization for myocardial infarction (MI) or stroke among long-term care residents who are deprescribed or continue antihypertensive therapy.

Design, Setting, and Participants

This comparative effectiveness research study used target trial emulation with observational electronic health record data from long-term care residents aged 65 years or older admitted to US Department of Veterans Affairs community living centers between October 1, 2006, and September 30, 2019, and taking at least 1 antihypertensive medication. Analyses were conducted between August 2023 and August 2024.

Exposure

A reduction in the number of antihypertensive medications or dose (by ≥30%), assessed using barcode medication administration data.

Main Outcome and Measures

Incidence of MI and stroke hospitalization up to 2 years was assessed using International Classification of Diseases, Ninth Revision and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes. A pooled logistic regression model with inverse probability of treatment weighting (IPTW) and inverse probability of censoring weighting (IPCW) was used to estimate per-protocol effects.

Results

Of 13 096 long-term care residents (97.4% men; median age, 77 years [IQR, 70-84 years]) taking antihypertensive medication, 17.8% were deprescribed antihypertensive medication over a period of 12 weeks. The estimated unadjusted cumulative incidence of stroke or MI hospitalization over 2 years was similar among residents who were and were not deprescribed antihypertensives in per-protocol analyses (11.2% vs 8.8%; difference, 2.4 percentage points [95% CI, -2.3 to 7.1 percentage points]). Participant characteristics were balanced after applying IPTW and IPCW; all standardized mean differences were less than 0.05. After full adjustment for confounding and informative censoring, the per-protocol analysis results showed no association of antihypertensive deprescribing with MI or stroke hospitalization (hazard ratio, 0.93; 95% CI, 0.70-1.26).

Conclusions and Relevance

In this comparative effectiveness research study, deprescribing antihypertensive medication was not associated with risk of hospitalization for MI or stroke in long-term care residents. These findings may be informative for long-term care residents and clinicians who are considering deprescribing antihypertensive medications.

The association of TNF inhibitor use with incident cardiovascular events in radiographic axial spondyloarthritis

BACKGROUND

Whether tumor necrosis factor inhibitor (TNFi) use is cardioprotective among individuals with radiographic axial spondyloarthritis (r-axSpA), who have heightened cardiovascular (CV) risk, is unclear. We tested the association of TNFi use with incident CV outcomes in r-axSpA.

METHODS

We identified a r-axSpA cohort within a Veterans Affairs database between 2002 and 2019 using novel phenotyping methods and secondarily using ICD codes. TNFi use was assessed as a time-varying exposure using pharmacy dispense records. The primary outcome was incident CV disease identified using ICD codes for coronary artery disease, myocardial infarction or stroke. We fit Cox models with inverse probability weights to estimate the risk of each outcome with TNFi use versus non-use. Analyses were performed in the overall cohort, and separately in two periods (2002-2010, 2011-2019) to account for secular trends.

RESULTS

Using phenotyping we identified 26,928 individuals with an r-axSpA diagnosis (mean age 63.4 years, 94 % male); at baseline 3633 were TNFi users and 23,295 were non-users. During follow-up of a mean 3.3 ± 4.2 years, 674 (18.6 %) TNFi users had incident CVD versus 11,838 (50.8 %) non-users. In adjusted analyses, TNFi use versus non-use was associated with lower risk of incident CVD (HR 0.34, 95 % CI 0.29-0.40) in the cohort overall, and in the two time periods separately.

CONCLUSION

In this r-axSpA cohort identified using phenotyping methods, TNFi use versus non-use had a lower risk of incident CVD. These findings provide reassurance regarding the CV safety of TNFi agents for r-axSpA treatment. Replication of these results in other cohorts is needed.

Long-term Outcomes of Peripheral Artery Disease In Veterans: Analysis of the PEripheral ARtery Disease Long-term Survival Study (PEARLS)

Background

Contemporary research in peripheral artery disease (PAD) remains limited due to lack of a national registry and low accuracy of diagnosis codes to identify PAD patients in electronic health records.

Methods & Results

Leveraging a novel natural language processing (NLP) system that identifies PAD with high accuracy using ankle brachial index (ABI) and toe-brachial index (TBI) values, we created a registry of 103,748 patients with new onset PAD patients in the Veterans Health Administration (VHA). Study endpoints include mortality, cardiovascular (hospitalization for acute myocardial infarction or stroke) and limb events (hospitalization for critical limb ischemia or major amputation) and were identified using VA and non-VA encounters. The mean age was 70.6 years; 97.3% were males, and 18.5% self-identified as Black race. The mean ABI value was 0.78 (SD: 0.26) and the mean TBI value was 0.51 (SD: 0.19). Nearly one-third (32.4%) patients were currently smoking and 35.4% formerly smoked. Prevalence of hypertension (86.6%), heart failure (22.7%), diabetes (54.8%), renal failure (23.6%), and chronic obstructive pulmonary disease (35.4%) was high. At 1-year, 9.4% of patients had died. The 1-year incidence of cardiovascular events was 5.6 per 100 patient-years and limb events was 4.5 per 100 patient-years.

Conclusions

We have successfully launched a registry of >100,000 patients with a new diagnosis of PAD in the VHA, the largest integrated health system in the U.S. The ncidence of death and clinical events in our cohort is high. Ongoing studies will yield important insights regarding improving care and outcomes in this high-risk group.

The clinical characteristics, managements, and outcomes of acute myocardial infarction in osteoarthritis patients; a cross-sectional analysis of 6.5 million patients

OBJECTIVES

The prevalence of osteoarthritis (OA) and cardiovascular disease are increasing and both conditions share similar risk factors. We investigated the association between OA and receipt of invasive managements and clinical outcomes in patients with acute myocardial infarction (AMI).

METHODS

Using the National Inpatient Sample, adjusted binary logistic regression determined the association between OA and each outcome variable.

RESULTS

Of 6,561,940 AMI hospitalizations, 6.3% had OA. OA patients were older and more likely to be female. OA was associated with a decreased odds of coronary angiography (adjusted odds ratio 0.91; 95% confidence interval 0.90, 0.92), PCI (0.87; 0.87, 0.88), and coronary artery bypass grafting (0.98; 0.97, 1.00). OA was associated with a decreased odds of adverse outcomes (in-hospital mortality: 0.68; 0.67, 0.69; major acute cardiovascular and cerebrovascular events: 0.71; 0.70, 0.72; all-cause bleeding: 0.76; 0.74, 0.77; and stroke/TIA: 0.84; 0.82, 0.87).

CONCLUSIONS

This study of a representative sample of the US population highlights that OA patients are less likely to be offered invasive interventions following AMI. OA was also associated with better outcomes post-AMI, possibly attributed to a misclassification bias where unwell patients with OA were less likely to receive an OA code because codes for serious illness took precedence.

Benefits and Harms of Standard Versus Reduced-Dose Direct Oral Anticoagulant Therapy for Older Adults With Multiple Morbidities and Atrial Fibrillation

Background Dose reduction of direct oral anticoagulant (DOAC) medications is inconsistently applied to older adults with multiple morbidities, potentially due to perceived harms and unknown benefits of standard dosing. Methods and Results Using 2013 to 2017 US Medicare claims linked to Minimum Data Set records, we conducted a retrospective cohort study. We identified DOAC initiators (apixaban, dabigatran, rivaroxaban) aged ≥65 years with nonvalvular atrial fibrillation residing in a nursing home. We estimated inverse-probability of treatment weights for DOAC dose using propensity scores. We examined safety (hospitalization for major bleeding) and effectiveness outcomes (all-cause mortality, thrombosis [myocardial infarction, stroke, systemic embolism, venous thromboembolism]). We estimated hazard ratios (HRs) and 95% CIs using cause-specific hazard-regression models. Of 21 878 DOAC initiators, 48% received reduced dosing. The mean age of residents was 82.0 years, 66% were female, and 31% had moderate/severe cognitive impairment. After estimating inverse-probability of treatment weights, standard dosing was associated with a higher rate of bleeding (HR, 1.18 [95% CI, 1.03-1.37]; 9.4 versus 8.0 events per 100 person-years). Standard-dose therapy was associated with the highest rates of bleeding among those aged >80 years (9.1 versus 6.7 events per 100 person-years) and with a body mass index <30 kg/m2 (9.4 versus 7.4 events per 100 person-years). There was no association of dosing with mortality (HR, 0.99 [95% CI, 0.96-1.06]) or thrombotic events (HR, 1.16 [95% CI, 0.96-1.41]). Conclusions In this nationwide study of nursing home residents with nonvalvular atrial fibrillation, we found a higher rate of bleeding and little difference in effectiveness of standard versus reduced-dose DOAC treatment. Our results support the use of reduced-dose DOACs for many older adults with multiple morbidities.

Elective ascending aortic aneurysm repair outcomes in a nationwide US cohort

OBJECTIVE

To quantify contemporary outcomes following elective ascending aortic aneurysm repair, to determine risk factors for adverse events and to evaluate difference by institutional surgical volume.

METHODS

We included all elective hospitalisations of adult patients with an ascending aortic aneurysm who underwent aneurysm repair in the Nationwide Readmissions Database between 2016 and 2019. The primary outcome was a composite of in-hospital mortality, stroke (ischaemic and non-ischaemic) and myocardial infarction (MI). We identified independent predictor of adverse events and investigated outcomes by institutional volume.

RESULTS

Among 12 043 patients (mean 62.8 years of age, 28.0% female), MI, stroke or in-hospital death occurred in 598 (4.9%) patients during the index admission (acute stroke: 2.7%, MI: 0.7%, in-hospital death: 2.0%). The strongest predictors of in-hospital death, stroke or MI were chronic weight loss, pulmonary circulation disorder and concomitant descending aortic surgery. Higher procedural volume was associated with a lower incidence of in-hospital death, stroke or MI (OR comparing the highest with the lowest tertile 0.71, 95% CI 0.57 to 0.87; p=0.001) and in-hospital death (OR 0.51, 95% CI 0.37 to 0.72; p<0.001), but no difference in 30-day readmissions.

CONCLUSIONS

The overall rate of in-hospital death, stroke and MI is nearly 5% in patients undergoing elective ascending aortic aneurysm repair. Among several predictors, chronic weight loss is associated with the largest increase in the risk of poor outcomes. Higher hospital volume is associated with a lower in-hospital mortality, highlighting the importance to refer patients to high-volume centres while discussing the risks and benefits of proceeding with repair.

Development and Validation of Quality Measures for Testosterone Prescribing

Context

Accurate measures to assess appropriateness of testosterone prescribing are needed to improve prescribing practices.

Objective

This work aimed to develop and validate quality measures around the initiation and monitoring of testosterone prescribing.

Methods

This retrospective cohort study comprised a national cohort of male patients receiving care in the Veterans Health Administration who initiated testosterone during January or February 2020. Using laboratory data and diagnostic codes, we developed 9 initiation and 7 monitoring measures. These were based on the current Endocrine Society guidelines supplemented by expert opinion and prior work. We chose measures that could be operationalized using national VA electronic health record (EHR) data. We assessed criterion validity for these 16 measures by manual review of 142 charts. Main outcome measures included positive and negative predictive values (PPVs, NPVs), overall accuracy (OA), and Matthews Correlation Coefficients (MCCs).

Results

We found high PPVs (>78%), NPVs (>98%), OA (≥94%), and MCCs (>0.85) for the 10 measures based on laboratory data (5 initiation and 5 monitoring). For the 6 measures relying on diagnostic codes, we similarly found high NPVs (100%) and OAs (≥98%). However, PPVs for measures of acute conditions occurring before testosterone initiation (ie, acute myocardial infarction or stroke) or new conditions occurring after initiation (ie, prostate or breast cancer) PPVs were much lower (0% to 50%) due to few or no cases.

Conclusion

We developed several valid EHR-based quality measures for assessing testosterone-prescribing practices. Deployment of these measures in health care systems can facilitate identification of quality gaps in testosterone-prescribing and improve care of men with hypogonadism.

Racial Disparities in Hospitalization Among Patients Who Receive a Diagnosis of Acute Coronary Syndrome in the Emergency Department

Background Timely hospitalization of patients who are diagnosed with an acute coronary syndrome (ACS) at the emergency department (ED) is a crucial step to lower the risk of ACS mortality. We examined whether there are racial and ethnic differences in the risk of being discharged home among patients who received a diagnostic code of ACS at the ED and whether having health insurance plays a role. Methods and Results We examined 51 022 910 discharge records of ED visits in Florida, New York, and Utah in the years 2008, 2011, 2014, and 2016/2017 using state-specific data from the Healthcare Cost and Utilization Project. We identified ED admissions for acute myocardial infarction or unstable angina using the International Classification of Diseases, Ninth Revision (ICD-9)/International Statistical Classification of Diseases, Tenth Revision (ICD-10) diagnostic codes. We used generalized estimating equation models to compare the risk of being discharged home across racial and ethnic groups. We used Poisson marginal structural models to estimate the mediating role of health insurance status. The proportion discharged home with a diagnostic code of ACS was 12% among Black patients, 6% among White patients, 9% among Hispanic patients, and 9% among Asian/Pacific Islander patients. The incidence risk ratio for being discharged home was 1.26 (95% CI, 1.18-1.34) in Black patients, 1.23 (95% CI, 1.15-1.32) in Hispanic patients, and 1.11 (95% CI, 0.93-1.31) in Asian/Pacific Islander patients compared with White patients. Race and ethnicity were marginally associated with discharge home via pathways not mediated by health insurance. Conclusions Racial and ethnic disparities exist in the hospitalization of patients who received a diagnostic code of ACS in the ED. Possible causes need to be investigated.

Multifaceted Intervention to Improve P2Y12 Inhibitor Adherence After Percutaneous Coronary Intervention: A Stepped Wedge Trial

Background P2Y12 inhibitor medications are critical following percutaneous coronary intervention (PCI); however, adherence remains suboptimal. Our objective was to assess the effectiveness of a multifaceted intervention to improve P2Y12 inhibitor adherence following PCI. Methods and Results This was a modified stepped wedge trial of 52 eligible hospitals, of which 15 were randomly selected and agreed to participate (29 hospitals declined, and 8 eligible hospitals were not contacted). At each intervention hospital, patient recruitment occurred for 6 months and enrolled patients were followed up for 1 year after PCI. Three control groups were used: patients at intervention hospitals undergoing PCI (1) before the intervention period (preintervention); (2) after the intervention period (postintervention); or (3) at the 8 hospitals not contacted (concurrent controls). The intervention consisted of 4 components: (1) P2Y12 inhibitor delivered to patients' bedside after PCI; (2) education on importance of P2Y12 inhibitors; (3) automated reminder telephone calls to refill medication; and (4) outreach to patients if they delayed refilling P2Y12 inhibitor. The primary outcomes were as follows: (1) proportion of patients with delays filling P2Y12 inhibitor at hospital discharge and (2) proportion of patients who were adherent in the year after PCI using pharmacy refill data. Primary analysis compared intervention with preintervention control patients. There were 1377 (intent-to-treat) potentially eligible patients, of whom 803 (per protocol) were approached at intervention sites versus 5910 preintervention, 2807 postintervention, and 4736 concurrent control patients. In the intent-to-treat analysis, intervention patients were less likely to delay filling P2Y12 at hospital discharge (-3.4%; 98.3% CI, -1.2% to -5.6%) and more likely to be adherent to P2Y12 (4.1%; 98.3% CI, 1.0%-7.1%) at 1 year, but had more clinical events (3.2%; 98.3% CI, 2.3%-4.1%) driven by repeated PCI compared with preintervention patients. In post hoc analysis looking at myocardial infarction, stroke, and death, intervention patients had lower event rates compared with preintervention patients (-1.7%; 98.3% CI, -2.3% to -1.1%). Conclusions A 4-component intervention targeting P2Y12 inhibitor adherence was difficult to implement. The intervention produced mixed results. It improved P2Y12 adherence, but there was also an increase in repeat PCI. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01609842.

Event Rates and Risk Factors for Recurrent Cardiovascular Events and Mortality in a Contemporary Post Acute Coronary Syndrome Population Representing 239 234 Patients During 2005 to 2018 in the United States

Background

Patients with acute coronary syndrome (ACS) are recognized by guidelines as remaining at high risk for adverse outcomes. Evidence from contemporary, representative ACS populations in a clinical practice setting is necessary to identify subgroups and strategies for improving patient outcomes. We aimed to describe event rates and risk factors in an ACS population over prolonged follow‐up for cardiovascular end points.

Methods and Results

We identified 239 234 patients in the Optum Research Database (57.2% men; mean [standard deviation] age, 69.2 [12.2] years) with evidence of an ACS hospitalization (index ACS) during January 1, 2005 through December 30, 2018. Subgroups were based on index ACS event (myocardial infarction/unstable angina and revascularization status) and the Thrombolysis In Myocardial Infarction Risk Score for Secondary Prevention. The 5‐year event rate for the primary end point representing nonfatal myocardial infarction, nonfatal ischemic stroke, and cardiovascular death was 33.4% (95% CI, 33.1%–33.7%; P<0.001). The risk of experiencing the primary end point was ≈6‐fold higher immediately after discharge (≈40.9% annualized risk) as compared with the period 1+ years after hospitalization (≈6.4% annualized risk). Among subgroups, the 5‐year primary end point event rate was highest for myocardial infarction without revascularization and a Thrombolysis In Myocardial Infarction Risk Score for Secondary Prevention ≥4, at 47.9% (95% CI, 47.3%–48.4%; P<0.001) and 56.7% (95% CI, 55.9%–57.4%; P<0.001), respectively.

Conclusions

Patients with ACS remain at very high risk of experiencing recurrent cardiovascular events, particularly early after discharge, with identifiable subgroups at multifold higher risk of specific clinical end points.

Change in Left Ventricular Ejection Fraction With Coronary Artery Revascularization and Subsequent Risk for Adverse Cardiovascular Outcomes

BACKGROUND

Coronary revascularization is recommended to treat ischemic cardiomyopathy. However, the relations of revascularization-associated ejection fraction (EF) change to subsequent outcomes have not been elucidated.

METHODS

In 10 071 veterans (mean age 67 years; 1% women; 15% non-White) who underwent a first percutaneous coronary intervention (PCI) or coronary artery bypass grafting between January 1, 1995, and December 31, 2010, and had prerevascularization and postrevascularization EF measured, we calculated delta-EF (postprocedure EF-preprocedure EF). We related delta-EF as a continuous measure and as categories (≤-5, -5<delta-EF<0, delta-EF=0, 0<delta-EF<5, and delta-EF≥5) to death (using Cox regression) and heart failure hospitalization days (using negative binomial regression) in multivariable-adjusted models, for total sample, and PCI and coronary artery bypass grafting strata.

RESULTS

Over follow-up (mean/maximum 5/14 years) 56% died. Each 5% improvement in delta-EF was associated with statistically significant reductions in death and heart failure hospitalization days of 5% (95% CI, 3%-7%) and 10% (95% CI, 5%-15%), respectively, in the total sample and 6% (95% CI, 4%-8%) and 10% (95% CI, 5%-16%), respectively, in the PCI subgroup. Patients in the highest delta-EF category had 27% (95% CI, 19%-34%) lower mortality (30% [95% CI, 21%-37%] lower in PCI stratum) and ≈40% lower heart failure hospitalization days in total sample and PCI stratum, compared with those in the lowest category. Relations of delta-EF and outcomes in coronary artery bypass grafting subgroup did not reach statistical significance.

CONCLUSIONS

Revascularization-associated EF improvement was associated with significant reductions in mortality and heart failure hospitalization burden, particularly in the PCI subgroup.

Increased Hemoglobin A1c Time in Range Reduces Adverse Health Outcomes in Older Adults With Diabetes

OBJECTIVE

Short- and long-term glycemic variability are risk factors for diabetes complications. However, there are no validated A1C target ranges or measures of A1C stability in older adults. We evaluated the association of a patient-specific A1C variability measure, A1C time in range (A1C TIR), on major adverse outcomes.

RESEARCH DESIGN AND METHODS

We conducted a retrospective observational study using administrative data from the Department of Veterans Affairs and Medicare from 2004 to 2016. Patients were ≥65 years old, had diabetes, and had at least four A1C tests during a 3-year baseline period. A1C TIR was the percentage of days during the baseline in which A1C was in an individualized target range (6.0-7.0% up to 8.0-9.0%) on the basis of clinical characteristics and predicted life expectancy. Increasing A1C TIR was divided into categories of 20% increments and linked to mortality and cardiovascular disease (CVD) (i.e., myocardial infarction, stroke).

RESULTS

The study included 402,043 veterans (mean [SD] age 76.9 [5.7] years, 98.8% male). During an average of 5.5 years of follow-up, A1C TIR had a graded relationship with mortality and CVD. Cox proportional hazards models showed that lower A1C TIR was associated with increased mortality (A1C TIR 0 to <20%: hazard ratio [HR] 1.22 [95% CI 1.20-1.25]) and CVD (A1C TIR 0 to <20%: HR 1.14 [95% CI 1.11-1.19]) compared with A1C TIR 80-100%. Competing risk models and shorter follow-up (e.g., 24 months) showed similar results.

CONCLUSIONS

In older adults with diabetes, maintaining A1C levels within individualized target ranges is associated with lower risk of mortality and CVD.

Pregnancy-associated arterial dissections: a nationwide cohort study

AIMS

Pregnancy is a known risk factor for arterial dissection, which can result in significant morbidity and mortality in the peripartum period. However, little is known about the risk factors, timing, distribution, and outcomes of arterial dissections associated with pregnancy.

METHODS AND RESULTS

We included all women ≥12 years of age with hospitalizations associated with pregnancy and/or delivery in the Nationwide Readmissions Database between 2010 and 2015. The primary outcome was any dissection during pregnancy, delivery, or the postpartum period (42-days post-delivery). Secondary outcomes included timing of dissection, location of dissection, and in-hospital mortality. Among 18 151  897 pregnant patients, 993 (0.005%) patients were diagnosed with a pregnancy-related dissection. Risk factors included older age (32.8 vs. 28.0 years), multiple gestation (3.6% vs. 1.9%), gestational diabetes (14.3% vs. 0.2%), gestational hypertension (6.0% vs. 0.6%), and pre-eclampsia/eclampsia (2.7% vs. 0.4%), in addition to traditional cardiovascular risk factors. Of the 993 patients with dissection, 150 (15.1%) dissections occurred in the antepartum period, 232 (23.4%) were diagnosed during the admission for delivery, and 611 (61.5%) were diagnosed in the postpartum period. The most common locations for dissections were coronary (38.2%), vertebral (22.9%), aortic (19.8%), and carotid (19.5%). In-hospital mortality was 3.7% among pregnant patients with a dissection vs. <0.001% in patients without a dissection. Deaths were isolated to patients with an aortic (8.6%), coronary (4.2%), or supra-aortic (<2.5%) dissection.

CONCLUSION

Arterial dissections occurred in 5.5/100 000 hospitalized pregnant or postpartum women, most frequently in the postpartum period, and were associated with high mortality risk. The coronary arteries were most commonly involved. Pregnancy-related dissections were associated with traditional risk factors, as well as pregnancy-specific conditions.

Developing an Internally Validated Veterans Affairs Women Cardiovascular Disease Risk Score Using Veterans Affairs National Electronic Health Records

Background

The current American College of Cardiology/American Heart Association women cardiovascular disease (CVD) risk score suboptimally estimates CVD risk for young and minority women in the military. The current study developed an internally validated CVD risk score for women military service members and veterans using the Veterans Affairs (VA) national electronic health records data.

Methods and Results

The study cohort included 69 574 White, Black, and Hispanic women service members and veterans aged 30 to 79 years in 2007 treated in the VA Health Care System between January 1, 2007 and December 31, 2017 (henceforth, VA women). Stratified by race and ethnicity, the new VA women CVD risk model estimated risk coefficients and 10‐year CVD risk using a time‐variant covariate Cox model. Harrell C‐statistics, calibration plots, and net classification index were used to assess accuracy and prognostic performance of the new VA women CVD risk model. The new internally validated VA women CVD risk score performed better in predicting VA women 10‐year atherosclerosis cardiovascular disease risk than the pooled cohort American College of Cardiology/American Heart Association risk score in both accuracy (White Harrell C‐statistics, 70% versus 61%; Black, 68% versus 63%) and prognostic performance (White net classification index, 0.31; 95% CI, 0.26–0.33; Black net classification index, 0.06; 95% CI, 0.03–0.09).

Conclusions

The proposed VA women CVD risk score improves accuracy of the existing American College of Cardiology/American Heart Association CVD risk assessment tool in predicting long‐term CVD risk for VA women, particularly in young and racial/ethnic minority women.

Differential Impact of Aging on Cardiovascular Risk in Women Military Service Members

Background Atherosclerotic cardiovascular disease (ASCVD) is the third leading cause of death in women service members and veterans. This study assessed 10-year ASCVD risk in women service members and veterans using their own electronic health record data extracted from Veterans Affairs (VA) national Corporate Data Warehouse database. Methods and Results We retrospectively followed 69 574 VA women, aged 30 to 79 years, from 2007 to 2017. Of these, 52% were whites (n=36 172), 42% were blacks (n=29 232), and 6% were Hispanics (n=4171). Risk factors and ASCVD events (nonfatal myocardial infarction, nonfatal stroke, and cardiac deaths) were identified using diagnostic and procedural codes from electronic health records. Then, within the same construct of the current American College of Cardiology/American Heart Association 10-year ASCVD risk assessment models for women, coefficients for risks factors were recalculated using the VA national electronic health record data, stratified by race (hereafter, VA women model). Our study found a curvilinear association of aging with increased risk of 10-year ASCVD event in VA women starting at ages as young as 30 years across all race groups. The VA women model performance in predicting ASCVD events at 10 years was mixed-moderate in discrimination (C statistics, 0.61-0.64) but good in accuracy, as demonstrated by calibration plots approximating a 45° line. Conclusions The study finding, a curvilinear association of aging with increased ASCVD risk in VA women across all races, demonstrates the need for cardiovascular risk screening of younger VA women, aged <45 years.

Composite diagnostic criteria are problematic for linking potentially distinct populations: the case of frailty

Composite diagnostic criteria are common in frailty research. We worry distinct populations may be linked to each other due to complicated criteria. We aim to investigate whether distinct populations might be considered similar based on frailty diagnostic criteria. The Functional Domains Model for frailty diagnosis included four domains: physical, nutritive, cognitive and sensory functioning. Health and Retirement Study participants with two or more deficiencies in the domains were diagnosed frail. The survival distributions were analyzed using discrete-time survival analysis. The distributions of the demographic characteristics and survival across the groups diagnosed with frailty were significantly different (p < 0.05). A deficiency in cognitive functioning was associated with the worst survival pattern compared with a deficiency in the other domains (adjusted p < 0.05). The associations of the domains with mortality were cumulative without interactions. Cognitive functioning had the largest effect size for mortality prediction (Odds ratios, OR = 2.37), larger than that of frailty status (OR = 1.92). The frailty diagnostic criteria may take distinct populations as equal and potentially assign irrelevant interventions to individuals without corresponding conditions. We think it necessary to review the adequacy of composite diagnostic criteria in frailty diagnosis.

Lower Post Myocardial Infarction Mortality Among Women Treated at Veterans Affairs Hospitals Compared to Men

BACKGROUND

There is conflicting evidence about whether mortality after myocardial infarction is higher among women than among men. This study aimed to compare sex differences in post myocardial infarction mortality in the Veterans Affairs system, a setting where the predominant subjects are men.

MATERIALS AND METHODS

The Veterans Affairs Corporate Data Warehouse inpatient and laboratory chemistry databases were used to identify patients diagnosed with acute myocardial infarction from inpatient records from January 1st, 2005 to April 25th, 2015. Mortality data was obtained through the Veterans Affairs death registry.

RESULTS

A total of 130,241 patients were identified; 127,711 men (98%) and 2,530 women (2%). Men typically had more comorbidities including congestive heart failure (54% vs. 46%, P value < 0.001), diabetes mellitus (54% vs. 48%, P value < 0.001), and chronic kidney disease (39% vs. 28%, P value < 0.001). The peak troponin-I was significantly higher among men (16.0 vs. 10.7 ng/mL, P value = 0.03). The mean follow-up time was 1490.67 ± 8 days. After adjusting for differences in demographics and comorbidities, women had a significantly lower risk of mortality (hazard ration [HR]: 0.747, P value < 0.0001) as compared to men.

CONCLUSIONS

In a health care system where the predominant subjects are men, women had better short- and long-term survival than men after an acute myocardial infarction. Further investigation is warranted to determine the reasons behind the improved outcomes in women post myocardial infarction in the veteran population.

Validation of diagnostic codes of major clinical outcomes in a National Health Insurance database

Background and objectives

The Korean National Health Insurance Service (NHIS) database has been widely used for cardiovascular research. We validated the primary diagnostic codes of major clinical outcomes, including acute myocardial infarction (AMI), gastrointestinal bleeding (GIB), stroke, and intracranial hemorrhage (ICH) used for Korea NHIS claims.

Subjects and methods

From 2016 to 2017, 800 patients with primary diagnostic codes of AMI, GIB, stroke, or ICH at discharge were randomly selected from a single tertiary medical center in Korea (200 patients per each diagnosis). The positive predictive value (PPV), sensitivity, and specificity of the primary diagnostic codes were calculated using hospital medical record review as the gold standard. Further improvement in the diagnostic validity of the codes was assessed by combining clinical information such as duration of hospitalization, blood transfusion, brain imaging studies, or prescription records of antithrombotic agents.

Results

Among 200 patients with AMI as the primary discharge diagnosis, 184 patients were clinically confirmed (PPV of 92.0%). For GIB, 184 (92.0%) patients with the primary discharge diagnosis were verified to have true GIB events, showing PPV of 92%. For stroke, 181 (90.5%) patients were clinically confirmed with true stroke events. For ICH, 143 (71.5%) patients were verified to be true ICH events. In stroke and ICH, the PPV and specificity improved after combining with the hospitalization duration, imaging studies, and prescription of antithrombotic agents.

Conclusions

For major clinical outcomes in the NHIS database, the primary diagnostic codes showed favorable reliability. For stroke and ICH, considerations of relevant clinical information could improve the accuracy of diagnosis.

Comparison of the Victorian Emergency Minimum Dataset to medical records for emergency presentations for acute cardiovascular conditions and unspecified chest pain

OBJECTIVE

The Victorian Emergency Minimum Dataset (VEMD) collects administrative and clinical data for all presentations to Victorian public ED. The present study aimed to examine the level of agreement between the VEMD data and the medical record for a sample of patients coded as having acute cardiovascular conditions (acute coronary syndrome, stroke and transient ischaemic attack [TIA]) and unspecified chest pain in the VEMD.

METHODS

Six months of data provided to the VEMD from a large metropolitan hospital was obtained, and a random sample of 10% of cases (n = 310) were selected for review. Data for eight VEMD items were compared for concordance to data recorded in the ED medical record.

RESULTS

Complete concordance between the VEMD and medical records for all eight items was observed only for 101 (33%) presentations. Overall, the least concordant variables were those with a high number of coding options: usual type of accommodation (76%), referral pattern (84%) and primary diagnosis (85%). The concordance of the VEMD primary diagnosis varied when examined as individual codes (range 75%-100%) and when combined (acute coronary syndrome = 94%, stroke or TIA = 85% and chest pain unspecified = 75%). The level of agreement for some items improved when VEMD codings were combined.

CONCLUSION

When compared to the medical record, our data suggest there is likely variation in the accuracy of some VEMD items, and suggests a larger prospective validation of the VEMD is warranted. For researchers using existing VEMD data, combining of some codes may be necessary.

Simulation of impact on cardiovascular events due to lipid-lowering therapy intensification in a population with atherosclerotic cardiovascular disease

In patients with atherosclerotic cardiovascular disease (ASCVD), guidelines recommend statins as first-line lipid-lowering therapy (LLT) with addition of nonstatin agents in those with persistently elevated low-density lipoprotein cholesterol levels.

METHODS

To estimate the cardiovascular (CV) risk reduction implications of treatment intensification, we used a previously reported simulation model with enhancements. An ASCVD cohort was developed from a US claims database. A Cox model was used to estimate baseline risk of CV events: myocardial infarction, ischemic stroke, unstable angina hospitalization, elective coronary revascularization, or cardiovascular death. Patients were sampled with replacement (bootstrapping) and entered the simulation model, which applied stepwise LLT intensification logic, with a goal of achieving low-density lipoprotein cholesterol less than 70 mg/dL at each step. CV risk reduction assumptions were based on published data. Two treatment intensification scenarios were investigated: ideal and real-world (which accounted for statin intolerance, nonadherence, and payer restrictions).

RESULTS

In a cohort of 1,000 patients with ASCVD, approximately 813 (809-818) would require treatment intensification with LLT under an ideal treatment intensification scenario. Before treatment intensification, 183 (179-187) events would be expected to occur over 5 years. With treatment intensification, 40 (34-45) of these events could be avoided. In a real-world scenario, about 818 (813-823) patients require treatment intensification with LLT, resulting in 29 (24-34) events avoided over 5 years.

CONCLUSIONS

Intensification of LLT in an ASCVD population translates into a substantial number of CV events avoided. This simulation-based model could assist in assessing the potential benefits of various types of population-level LLT interventions.

Site Variation and Outcomes for Antithrombotic Therapy in Atrial Fibrillation Patients After Percutaneous Coronary Intervention

Background:

Patients with atrial fibrillation (AF) treated with percutaneous coronary intervention (PCI) require multiple antithrombotic therapies. The optimal strategy is debated suggesting increased treatment variation. This study sought to characterize site-level variation in antithrombotic therapies in AF patients after PCI and determine the association with outcomes.

Methods:

Using the retrospective TREAT-AF study (The Retrospective Evaluation and Assessment of Therapies in AF) from the Veterans Health Administration, patients with newly diagnosed, nonvalvular AF between 2004 and 2015 followed by a PCI with a P2Y 12 -antagonist prescription were identified. Patients were grouped according to the therapy dispensed 7 days before until 30 days after the PCI: oral anticoagulation plus platelet inhibition (OAC+PI) or platelet inhibition only. A combined outcome of death, myocardial infarction, stroke, or major bleeding was assessed 1 year after PCI and Cox regression was performed to estimate hazard ratios.

Results:

Of 230 762 patients with newly diagnosed AF, 4042 (1.8%) underwent PCI and received a P2Y 12 -antagonist during the observation period (age, 67±9 years; CHA 2 DS 2 -VASc, 2.7±1.7; HAS-BLED, 2.6±1.2). Among these, 47% were prescribed OAC+PI, and 53% platelet inhibition only 7 days before until 30 days after the PCI. Across 63 sites, the use of OAC+PI ranged from 19% to 66%. Prescription of OAC+PI was independently associated with a reduction in the combined outcome of death, myocardial infarction, stroke, or major bleeding compared with platelet inhibition only (adjusted hazard ratio, 0.85; 95% CI, 0.73–0.99; P =0.033).

Conclusions:

In patients with established AF undergoing PCI, the use of OAC+PI varied substantially across sites in the 30 days post-PCI. Anticoagulation appeared to be underutilized but was associated with improved outcomes. Strategies to promote OAC+PI and minimize site variation may be useful, particularly in light of recent randomized trials.

Intensive Glucose Control in Patients with Type 2 Diabetes - 15-Year Follow-up

BACKGROUND

We previously reported that a median of 5.6 years of intensive as compared with standard glucose lowering in 1791 military veterans with type 2 diabetes resulted in a risk of major cardiovascular events that was significantly lower (by 17%) after a total of 10 years of combined intervention and observational follow-up. We now report the full 15-year follow-up.

METHODS

We observationally followed enrolled participants (complete cohort) after the conclusion of the original clinical trial by using central databases to identify cardiovascular events, hospitalizations, and deaths. Participants were asked whether they would be willing to provide additional data by means of surveys and chart reviews (survey cohort). The prespecified primary outcome was a composite of major cardiovascular events, including nonfatal myocardial infarction, nonfatal stroke, new or worsening congestive heart failure, amputation for ischemic gangrene, and death from cardiovascular causes. Death from any cause was a prespecified secondary outcome.

RESULTS

There were 1655 participants in the complete cohort and 1391 in the survey cohort. During the trial (which originally enrolled 1791 participants), the separation of the glycated hemoglobin curves between the intensive-therapy group (892 participants) and the standard-therapy group (899 participants) averaged 1.5 percentage points, and this difference declined to 0.2 to 0.3 percentage points by 3 years after the trial ended. Over a period of 15 years of follow-up (active treatment plus post-trial observation), the risks of major cardiovascular events or death were not lower in the intensive-therapy group than in the standard-therapy group (hazard ratio for primary outcome, 0.91; 95% confidence interval [CI], 0.78 to 1.06; P = 0.23; hazard ratio for death, 1.02; 95% CI, 0.88 to 1.18). The risk of major cardiovascular disease outcomes was reduced, however, during an extended interval of separation of the glycated hemoglobin curves (hazard ratio, 0.83; 95% CI, 0.70 to 0.99), but this benefit did not continue after equalization of the glycated hemoglobin levels (hazard ratio, 1.26; 95% CI, 0.90 to 1.75).

CONCLUSIONS

Participants with type 2 diabetes who had been randomly assigned to intensive glucose control for 5.6 years had a lower risk of cardiovascular events than those who received standard therapy only during the prolonged period in which the glycated hemoglobin curves were separated. There was no evidence of a legacy effect or a mortality benefit with intensive glucose control. (Funded by the VA Cooperative Studies Program; VADT ClinicalTrials.gov number, NCT00032487.).

Simulation of Lipid-Lowering Therapy Intensification in a Population With Atherosclerotic Cardiovascular Disease

Importance

In patients with atherosclerotic cardiovascular disease (ASCVD), guidelines recommend optimizing statin treatment, and consensus pathways suggest use of ezetimibe and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors in patients with persistently elevated low-density lipoprotein cholesterol (LDL-C) levels despite use of statins. Recent trials have provided evidence of benefit in reduction of cardiovascular events with these agents.

Objective

To estimate the percentage of patients with ASCVD who would require a PCSK9 inhibitor when oral lipid-lowering therapy (LLT) is intensified first.

Design, Setting, and Participants

This simulation model study used a large administrative database of US medical and pharmacy claims to identify a cohort of 105 269 patients with ASCVD enrolled from January 1, 2012, through December 31, 2013, who met the inclusion criteria (database cohort). Patients were sampled with replacement (bootstrapping) to match the US epidemiologic distribution and entered into a Monte Carlo simulation (simulation cohort) that applied stepwise treatment intensification algorithms in those with LDL-C levels of at least 70 mg/dL. All patients not initially receiving a statin were given atorvastatin, 20 mg, and the following LLT intensification steps were applied: uptitration to atorvastatin, 80 mg; add-on ezetimibe therapy; add-on alirocumab therapy, 75 mg (a PCSK9 inhibitor); and uptitration to alirocumab, 150 mg. Sensitivity analyses included evolocumab as a PCSK9 inhibitor. Efficacy was estimated from published studies and incorporated patient-level variation. Data were analyzed from December 2015 to May 2017.

Exposures

Treatment intensification strategies with LLT.

Main Outcomes and Measures

Use of LLT among the population with ASCVD and distributions of LDL-C levels under various treatment intensification scenarios.

Results

Inclusion criteria were met by 105 269 individuals in the database cohort (57.2% male and 42.8% female; mean [SD] age, 65.1 [12.1] years). In the simulation cohort (1 million patients; 54.8% male and 45.2% female; mean [SD] age, 66.4 [12.2] years), before treatment intensification, 51.5% used statin monotherapy and 1.7% used statins plus ezetimibe. Only 25.2% achieved an LDL-C level of less than 70 mg/dL. After treatment intensification, 99.3% could achieve an LDL-C level of less than 70 mg/dL, including 67.3% with statin monotherapy, 18.7% with statins plus ezetimibe, and 14% with add-on PCSK9 inhibitor.

Conclusions and Relevance

Large gaps exist between recommendations and current practice regarding LLT in the population with ASCVD. In our model that assumes no LLT intolerance and full adherence, intensification of oral LLT could achieve an LDL-C level of less than 70 mg/dL in most patients, with only a modest percentage requiring a PCSK9 inhibitor.

Relation Between Statewide Hospital Performance Reports on Myocardial Infarction and Cardiovascular Outcomes

Healthcare systems may be judged on quality of care and access to health services. Studies on the association of hospital quality of care scores and clinical outcomes have yielded mixed results. With the help of a richer and more representative database, the aim of our study was to shed light on these inconsistencies. We examined the association of 4 process of care scores (prescription of aspirin, β blocker, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker used for left ventricular systolic dysfunction, and an overall composite score) for acute myocardial infarction (AMI), reported in the Hospital Performance Reports, with 30-day and 1-year rates of readmission for AMI and cardiovascular (CV) death. Clinical outcomes were from the Myocardial Infarction Data Acquisition System, an administrative database that comprises all patient CV disease admissions to acute care hospitals in New Jersey. CV death was related with overall score (adjusted odds ratio [OR] 0.821, 95% confidence interval [CI] 0.726 to 0.930, p = 0.002) at 30 days and with all 4 scores at 1 year (OR ranging from 0.829 to 0.997, p <0.01). Readmission due to AMI was associated with the overall score (OR 0.789, 95% CI 0.691 to 0.902, p <0.0001) and the aspirin score (OR 0.995, 95% CI 0.990 to 1, p = 0.046) at 30 days. Low hospital performance scores for AMI were associated with increased CV death and readmission for AMI. In conclusion, healthcare providers should allocate their resources to improving hospital performance to decrease AMI case fatality, AMI readmissions, and CV-related healthcare spending.

Depression and all-cause mortality risk in HIV-infected and HIV-uninfected US veterans: a cohort study

OBJECTIVES

The contribution of depression to mortality in adults with and without HIV infection is unclear. We hypothesized that depression increases mortality risk and that this association is stronger among those with HIV infection.

METHODS

Veterans Aging Cohort Study (VACS) data were analysed from the first clinic visit on or after 1 April 2003 (baseline) to 30 September 2015. Depression definitions were: (1) major depressive disorder defined using International Classification of Diseases, Ninth Revision (ICD-9) codes; (2) depressive symptoms defined as Patient Health Questionnaire (PHQ)-9 scores ≥ 10. The outcome was all-cause mortality. Covariates were demographics, comorbid conditions and health behaviours.

RESULTS

Among 129 140 eligible participants, 30% had HIV infection, 16% had a major depressive disorder diagnosis, and 24% died over a median follow-up time of 11 years. The death rate was 25.3 [95% confidence interval (CI) 25.0-25.6] deaths per 1000 person-years. Major depressive disorder was associated with mortality [hazard ratio (HR) 1.04; 95% CI 1.01, 1.07]. This association was modified by HIV status (interaction P-value = 0.02). In HIV-stratified analyses, depression was significantly associated with mortality among HIV-uninfected veterans but not among those with HIV infection. Among those with PHQ-9 data (n = 7372), 50% had HIV infection, 22% had PHQ-9 scores ≥ 10, and 28% died over a median follow-up time of 12 years. The death rate was 27.3 (95% CI 26.1-28.5) per 1000 person-years. Depressive symptoms were associated with mortality (HR 1.16; 95% CI 1.04, 1.28). This association was modified by HIV status (interaction P-value = 0.05). In HIV-stratified analyses, depressive symptoms were significantly associated with mortality among veterans with HIV infection but not among those without HIV infection.

CONCLUSIONS

Depression was associated with all-cause mortality. This association was modified by HIV status and method of depression ascertainment.

Incidence of myocardial infarction in pregnancy: a systematic review and meta-analysis of population-based studies

Aims

Cardiac disease is one of the leading causes of indirect maternal death, and myocardial infarction (MI) is one of its most common aetiologies. The objectives of this systematic review and meta-analysis were to characterize the incidence of pregnancy-associated MI (PAMI), as well as the maternal mortality and the case-fatality rates due to PAMI.

Methods and results

Articles were obtained by searching electronic databases, bibliographies and conference proceedings with no language or date restrictions. Two reviewers independently selected population-based cohort and case-control studies reporting on incidence, mortality and case-fatality rates for pregnancy-associated MI. Meta-analysis was performed to estimate pooled maternal incidence, mortality and case-fatality rates. Meta-regression was performed to explore heterogeneity. Based on 17 included studies, the pooled incidence of PAMI and maternal mortality from PAMI were 3.34 (2.09–4.58) and 0.20 (0.10–0.29) per 100 000 pregnancies, respectively. The case-fatality rate was 5.03% (3.78–6.27%). Country/region (meta-regression P = 0.006) and years of study (meta-regression P = 0.04) were potential explanations for the observed heterogeneity in the pooled incidence estimates of maternal MI and its associated mortality, with more recent studies and those conducted in the USA revealing the highest rates.

Conclusion

This article provides a global estimate of the incidence, mortality rate, and case fatality rate of pregnancy-associated MI. We identified higher rates of PAMI in the USA (relative to Canada and European countries) and rising rates over time. Further research regarding this population is needed, especially given rising maternal age and the increasing prevalence of cardiovascular risk factors.

Modafinil and the risk of cardiovascular events: Findings from three US claims databases

PURPOSE

This study examined the potential risk of cardiovascular (CV) events associated with modafinil and the consistency of the risk estimates across databases.

METHODS

A retrospective, inception cohort design of patients who initiated treatment with modafinil between 2006 and 2008 was used in three US health care claims databases. Modafinil users were matched with nonusers. Patients were further divided into two cohorts of obstructive sleep apnea (OSA) and non-OSA (NOSA) cohorts. Endpoints of interest, including myocardial infarction (MI), stroke, CV hospitalizations, and all-cause death, were assessed using incidence rates and Cox proportional hazard ratios (HRs), adjusted for potential confounding factors.

RESULTS

The cohorts included a total of 175 524 patients in MarketScan CM; 77 266-in IMS LifeLink; and 8174-in MarketScan Medicaid. No increased risk for MI in the OSA and NOSA cohorts was observed across all three databases. The risks of CV hospitalization in the OSA and NOSA cohorts were not different between the modafinil users and nonusers, except for IMS LifeLink database where the HR was lower than one in the modafinil users compared with the nonusers (HR, 0.69; 95% confidence interval [CI], 0.54 to 0.87). For OSA patients with prior stroke, an adjusted HR of 1.96 (95% CI, 1.02 to 3.76) was observed for stroke among modafinil users compared with nonusers. Among the NOSA, the HRs for all-cause death in the OSA were inconsistent across databases.

CONCLUSIONS

Except for few CV outcomes, applying one common protocol generated consistent risk estimates of CV events following modafinil use across cohorts and databases.

Advances in Electronic Phenotyping: From Rule-Based Definitions to Machine Learning Models

With the widespread adoption of electronic health records (EHRs), large repositories of structured and unstructured patient data are becoming available to conduct observational studies. Finding patients with specific conditions or outcomes, known as phenotyping, is one of the most fundamental research problems encountered when using these new EHR data. Phenotyping forms the basis of translational research, comparative effectiveness studies, clinical decision support, and population health analyses using routinely collected EHR data. We review the evolution of electronic phenotyping, from the early rule-based methods to the cutting edge of supervised and unsupervised machine learning models. We aim to cover the most influential papers in commensurate detail, with a focus on both methodology and implementation. Finally, future research directions are explored.

Development and validation of novel algorithms to identify patients with inflammatory bowel diseases in Israel: an epi-IIRN group study

Background

Before embarking on administrative research, validated case ascertainment algorithms must be developed. We aimed at developing algorithms for identifying inflammatory bowel disease (IBD) patients, date of disease onset, and IBD type (Crohn's disease [CD] vs ulcerative colitis [UC]) in the databases of the four Israeli Health Maintenance Organizations (HMOs) covering 98% of the population.

Methods

Algorithms were developed on 5,131 IBD patients and 2,072 controls, following independent chart review (60% CD and 39% UC). We reviewed 942 different combinations of clinical parameters aided by mathematical modeling. The algorithms were validated on an independent cohort of 160,000 random subjects.

Results

The combination of the following variables achieved the highest diagnostic accuracy: IBD-related codes, alone if more than five to six codes or combined with purchases of IBD-related medications (at least three purchases or ≥3 months from the first to last purchase) (sensitivity 89%, specificity 99%, positive predictive value [PPV] 92%, negative predictive value [NPV] 99%). A look-back period of 2-5 years (depending on the HMO) without IBD-related codes or medications best determined the date of diagnosis (sensitivity 83%, specificity 68%, PPV 82%, NPV 70%). IBD type was determined by the majority of CD/UC codes of the three recent contacts or the most recent when less than three contacts were recorded (sensitivity 92%, specificity 97%, PPV 97%, NPV 92%). Applying these algorithms, a total of 38,291 IBD patients were residing in Israel, corresponding to a prevalence rate of 459/100,000 (0.46%).

Conclusion

The application of the validated algorithms to Israel's administrative databases will now create a large and accurate ongoing population-based cohort of IBD patients for future administrative studies.

Risk of Acute Myocardial Infarction Among Hepatitis C Virus (HCV)-Positive and HCV-Negative Men at Various Lipid Levels: Results From ERCHIVES

Background

Risk of acute myocardial infarction (AMI) among hepatitis C virus (HCV)-positive versus HCV-negative persons with similar lipid levels is unknown. We determined incident AMI rates among HCV-positive and HCV-negative men among various lipid strata.

Methods

We created a propensity score matched (PSM) cohort and a low cardiovascular disease (CVD) risk cohort. Primary outcome was incident AMI rates by HCV status in each lipid strata using National Cholesterol Program guidelines for lipid strata.

Results

We identified 85863 HCV-positive and HCV-negative men in the PSM population. The incidence rates/1000 patient-years (95% confidence interval [CI]) for AMI among total cholesterol (TC) 200-239 stratum were 5.3 (4.89, 5.71) for HCV-positive versus 4.71 (4.42, 5) for HCV-negative men (P = .02) and for TC >240 mg/dL were 7.38 (6.49, 8.26) versus 6.17 (5.64, 6.71) (P = .02). For low-density lipoprotein cholesterol (LDL) of 130-159 mg/dL, AMI rates were 5.44 (4.97, 5.91) for HCV-positive and 4.81 (4.48, 5.14) for HCV-negative men (P = .03). The rise in risk with increasing lipid levels was greater in younger HCV-positive than in HCV-negative men (e.g., TC > 240 mg/dL: age >50 HR 1.38 [HCV-positive] and 1.12 [HCV-negative]; age ≤50 HR 1.6 [HCV-positive] and 1.29 [HCV-negative]), and more profoundly altered in HCV-positive men by lipid lowering therapy (change in HR with lipid-lowering therapy for TC >240 mg/dL from 1.82 to 1.19 [HCV-positive] from 1.48 to 1.03 [HCV-negative]).

Conclusions

HCV-positive men have a higher risk of AMI than HCV-negative men at higher TC/LDL levels; this risk is more pronounced at a younger age. Lipid lowering therapy significantly reduces this risk, with more profound reduction among HCV-positive versus HCV-negative men at similar lipid levels.

Chart validation of inpatient ICD-9-CM administrative diagnosis codes for acute myocardial infarction (AMI) among intravenous immune globulin (IGIV) users in the Sentinel Distributed Database

BACKGROUND

The Sentinel Distributed Database (SDD) is a large database of patient-level administrative health care records, primarily derived from insurance claims and electronic health records, and is sponsored by the US Food and Drug Administration for medical product safety evaluations. Acute myocardial infarction (AMI) is a common study endpoint for drug safety studies that rely on health records from the SDD and other administrative databases.

PURPOSE

In this chart validation study, we report on the positive predictive value (PPV) of inpatient International Classification of Diseases, Ninth Revision, Clinical Modification AMI administrative diagnosis codes (410.x1 and 410.x0) in the SDD.

METHODS

As part of an assessment of thromboembolic adverse event risk following treatment with intravenous immune globulin, charts were obtained for 103 potential post-intravenous immune globulin AMI cases. Charts were abstracted by trained nurses and physician-adjudicated based on prespecified diagnostic criteria.

RESULTS

Acute myocardial infarction status could be determined for 89 potential cases. The PPVs for the inpatient AMI diagnoses recorded in the SDD were 75% overall (95% CI, 65-84%), 93% (95% CI, 78-99%) for principal-position diagnoses, 88% (95% CI, 72-97%) for secondary diagnoses, and 38% (95% CI, 20-59%) for position-unspecified diagnoses (eg, diagnoses originating from separate physician claims associated with an inpatient stay). Of the confirmed AMI cases, demand ischemia was the suspected etiology more often for those coded in secondary or unspecified positions (72% and 40%, respectively) than for principal-position AMI diagnoses (21%).

CONCLUSIONS

The PPVs for principal and secondary AMI diagnoses were high and similar to estimates from prior chart validation studies. Position-unspecified diagnosis codes were less likely to represent true AMI cases.

No Increase in Risk of Acute Myocardial Infarction in Privately Insured Adults Prescribed Proton Pump Inhibitors vs Histamine-2 Receptor Antagonists (2002-2014)

BACKGROUND & AIMS

Proton pump inhibitors (PPIs) are commonly used medications. Recent studies reported an increased risk of acute myocardial infarction (MI) in PPI users vs non-users. We evaluated MI risk associated with PPIs compared with histamine-2 receptor antagonists (H2RAs) in privately insured adults in the United States.

METHODS

Using administrative claims from commercial and Medicare Supplemental plans (2001-2014), we compared risk of MI in patients who started a new prescription for PPIs vs H2RAs. Enrollees were followed from their first prescription until MI, medication discontinuation, plan disenrollment, or December 31, 2014. MI was defined using hospital diagnosis codes. Risk differences (RD), risk ratios, and 95% confidence intervals (CIs) were estimated using Kaplan-Meier methods at 3, 12, and 36 months after treatment initiation. Standardized morbidity ratio weights were used to control measured confounding. Analyses were stratified by plan type (commercial vs Medicare Supplemental).

RESULTS

We identified more than 5 million new users of prescription PPIs and H2RAs. Median follow-up time was 60 days for patients with commercial insurance and 96 days in patients with Medicare Supplemental insurance. The 12-month weighted risk of MI was low overall (approximately 2 cases per 1000 among patients in commercial plans; 8 per 1000 among patients in Medicare Supplemental plans). In the RD analysis, we found no significant differences in MI risk between patients who started PPIs vs H2RAs for the first 12 months, either in the commercial population (weighted RD per 1000, -0.08; 95% CI, -0.51 to 0.36) or the Medicare Supplemental population (weighted RD per 1000, -0.45; 95% CI, -1.53 to 0.58).

CONCLUSION

In an analysis of administrative claims from commercial and Medicare Supplemental plans, we found no evidence that prescription PPIs increase risk of MI compared with prescription H2RAs. Physicians and patients should not avoid starting a PPI because of concerns related to MI risk.

Sustained Posttransplantation Diabetes Is Associated With Long-Term Major Cardiovascular Events Following Liver Transplantation

Cardiovascular disease is a leading cause of death among liver transplant (LT) recipients. With a rising burden of posttransplantation metabolic disease, increases in cardiovascular-related morbidity and mortality may reduce life expectancy after LT. It is unknown if the risk of long-term major cardiovascular events (MCEs) differs among LT recipients with varying diabetic states. We performed a retrospective cohort study of LT recipients from 2003 through 2013 to compare the incidence of MCEs among patients (1) without diabetes, (2) with pretransplantation diabetes, (3) with de novo transient posttransplantation diabetes, and (4) with de novo sustained posttransplantation diabetes. We analyzed 994 eligible patients (39% without diabetes, 24% with pretransplantation diabetes, 16% with transient posttransplantation diabetes, and 20% with sustained posttransplantation diabetes). Median follow-up was 54.7 months. Overall, 12% of patients experienced a MCE. After adjustment for demographic and clinical variables, sustained posttransplantation diabetes was the only state associated with a significantly increased risk of MCEs (subdistribution hazard ratio 1.95, 95% confidence interval 1.20-3.18). Patients with sustained posttransplantation diabetes mellitus had a 13% and 27% cumulative incidence of MCEs at 5 and 10 years, respectively. While pretransplantation diabetes has traditionally been associated with cardiovascular disease, the long-term risk of MCEs is greatest in LT recipients with sustained posttransplantation diabetes mellitus.

A comparison of in-hospital acute myocardial infarction management between Portugal and the United States: 2000-2010

Objective

To compare healthcare in acute myocardial infarction (AMI) treatment between contrasting health systems using comparable representative data from Europe and USA.

Design

Repeated cross-sectional retrospective cohort study.

Setting

Acute care hospitals in Portugal and USA during 2000-2010.

Participants

Adults discharged with AMI.

Interventions

Coronary revascularizations procedures (percutaneous coronary intervention (PCI), coronary artery bypass graft (CABG) surgery).

Main Outcome Measures

In-hospital mortality and length of stay.

Results

We identified 1 566 601 AMI hospitalizations. Relative to the USA, more hospitalizations in Portugal presented with elevated ST-segment, and fewer had documented comorbidities. Age-sex-adjusted AMI hospitalization rates decreased in USA but increased in Portugal. Crude procedure rates were generally lower in Portugal (PCI: 44% vs. 47%; CABG: 2% vs. 9%, 2010) but only CABG rates differed significantly after standardization. PCI use increased annually in both countries but CABG decreased only in the USA (USA: 0.95 [0.94, 0.95], Portugal: 1.04 [1.02, 1.07], odds ratios). Both countries observed annual decreases in risk-adjusted mortality (USA: 0.97 [0.965, 0.969]; Portugal: 0.99 [0.979, 0.991], hazard ratios). While between-hospital variability in procedure use was larger in USA, the risk of dying in a high relative to a low mortality hospital (hospitals in percentiles 95 and 5) was 2.65 in Portugal when in USA was only 1.03.

Conclusions

Although in-hospital mortality due to an AMI improved in both countries, patient management in USA seems more effective and alarming disparities in quality of care across hospitals are more likely to exist in Portugal.

FIB-4 stage of liver fibrosis predicts incident heart failure among HIV-infected and uninfected patients

Liver fibrosis is common, particularly in individuals who are infected with human immunodeficiency virus (HIV). HIV-infected individuals have excess congestive heart failure (CHF) risk compared with uninfected people. It remains unknown whether liver fibrosis stage influences the CHF risk or if HIV or hepatitis C virus (HCV) infection modifies this association. Our objectives were to assess whether 1) stage of liver fibrosis is independently associated with incident CHF and 2) the association between stage of liver fibrosis and incident CHF is modified by HIV/HCV status. Participants alive on or after April 1, 2003, in the Veterans Aging Cohort Study were included. Those without prevalent cardiovascular disease were followed until their first CHF event, death, last follow-up date, or December 31, 2011. Liver fibrosis was measured using the fibrosis 4 index (FIB-4), which is calculated using age, aminotransferases, and platelets. Cox proportional hazards regression models were adjusted for cardiovascular disease risk factors. Among 96,373 participants over 6.9 years, 3844 incident CHF events occurred. FIB-4 between 1.45 and 3.25 (moderate fibrosis) and FIB-4 > 3.25 (advanced fibrosis/cirrhosis) were associated with CHF (hazard ratio [95% confidence interval], 1.17 [1.07-1.27] and 1.65 [1.43-1.92], respectively). The association of advanced fibrosis/cirrhosis and incident CHF persisted regardless of HIV/HCV status.

CONCLUSION

Moderate and advanced liver fibrosis/cirrhosis are associated with an increased risk of CHF. The association for advanced fibrosis/cirrhosis persists even among participants without hepatitis C and/or HIV infection. Assessing liver health may be important for reducing the risk of future CHF events, particularly among HIV and hepatitis C infected people among whom cardiovascular disease risk is elevated and liver disease is common. (Hepatology 2017;66:1286-1295).

Relationship of Kidney Injury Biomarkers with Long-Term Cardiovascular Outcomes after Cardiac Surgery

Clinical AKI, measured by serum creatinine elevation, is associated with long-term risks of adverse cardiovascular (CV) events and mortality in patients after cardiac surgery. To evaluate the relative contributions of urine kidney injury biomarkers and plasma cardiac injury biomarkers in adverse events, we conducted a multicenter prospective cohort study of 968 adults undergoing cardiac surgery. On postoperative days 1-3, we measured five urine biomarkers of kidney injury (IL-18, NGAL, KIM-1, L-FABP, and albumin) and five plasma biomarkers of cardiac injury (NT-proBNP, H-FABP, hs-cTnT, cTnI, and CK-MB). The primary outcome was a composite of long-term CV events or death, which was assessed via national health care databases. During a median 3.8 years of follow-up, 219 (22.6%) patients experienced the primary outcome (136 CV events and 83 additional deaths). Compared with patients without postsurgical AKI, patients who experienced AKI Network stage 2 or 3 had an adjusted hazard ratio for the primary composite outcome of 3.52 (95% confidence interval, 2.17 to 5.71). However, none of the five urinary kidney injury biomarkers were significantly associated with the primary outcome. In contrast, four out of five postoperative cardiac injury biomarkers (NT-proBNP, H-FABP, hs-cTnT, and cTnI) strongly associated with the primary outcome. Mediation analyses demonstrated that cardiac biomarkers explained 49% (95% confidence interval, 1% to 97%) of the association between AKI and the primary outcome. These results suggest that clinical AKI at the time of cardiac surgery is indicative of concurrent CV stress rather than an independent renal pathway for long-term adverse CV outcomes.

Does the association between adherence to statin medications and mortality depend on measurement approach? A retrospective cohort study

BACKGROUND

The aim of this study was to examine the relationship between mortality and statin adherence using two different approaches to adherence measurement (summary versus repeated-measures).

METHODS

A retrospective cohort study was conducted using administrative data from Saskatchewan, Canada between 1994 and 2008. Eligible individuals received a prescription for a statin following hospitalization for acute coronary syndrome (ACS). Adherence was measured using proportion of days covered (PDC) expressed either as: 1) a fixed summary measure, or 2) as a repeatedly measured covariate. Multivariable Cox-proportional hazards models were used to estimate the association between adherence and mortality.

RESULTS

Among 9,051 individuals, optimal adherence (≥80%) modeled with a fixed summary measure was not associated with mortality benefits (adjusted HR 0.97, 95% CI 0.86 to 1.09, p = 0.60). In contrast, repeated-measures approach resulted in a significant 25% reduction in the risk of death (adjusted HR 0.75, 95% CI 0.67 to 0.85, p < 0.01).

CONCLUSIONS

Unlike the summary measure, the repeated measures approach produces a significant reduction of all-cause mortality with optimal adherence. This effect may be a result of the repeated measures approach being more sensitive, or more prone to survival bias. Our findings clearly demonstrate the need to undertake (and report) multiple approaches when assessing the benefits of medication adherence.

Prasugrel Use Following PCI and Associated Patient Outcomes: Insights From the National VA CART Program

BACKGROUND

Prasugrel is more effective than clopidogrel in preventing thrombotic complications after percutaneous coronary intervention (PCI) among patients with acute coronary syndromes (ACS), but it increases the risk of bleeding in subgroups of patients. There is limited data on whether prasugrel use in routine practice is targeted to clinical settings with greatest anticipated patient benefit.

METHODS

In a national cohort of 11 617 veterans who underwent PCI between 2010 and 2013 at Veterans Administration hospitals nationwide, we assessed overall trends in the use of prasugrel and the frequency of prasugrel use in patients with contraindications (prior transient ischemic attack or cerebrovascular accident), higher bleeding risk (age ≥75 or weight <60 kg), and nonindicated settings (non-acute coronary syndrome [non-ACS]). We then evaluated the association between prasugrel use and 1-year risk-adjusted mortality, myocardial infarction, and major bleeding rates.

RESULTS

Overall, 1040 (9.0%) patients who received prasugrel after PCI were included. Prasugrel was infrequently used in contraindicated (2.4%) or higher-bleeding-risk (1.8%) settings. Additionally, 35.8% of patients received prasugrel in settings that lack evidence of clinical benefit (ie, non-ACS). Compared with clopidogrel, there were no significant differences in risk-adjusted mortality, myocardial infarction, or major bleeding outcomes with prasugrel therapy at 1-year follow-up.

CONCLUSIONS

Prasugrel use after PCI in the Veterans Administration is low and prasugrel was rarely used in contraindicated or high-bleeding-risk settings. However, a third of patients received prasugrel for off-label non-ACS indications that lack efficacy data.

Dual-System Use: Are There Implications for Risk Adjustment and Quality Assessment?

The authors examined the implications of dual-system use for risk adjustment and quality assessment. The sample (n = 34 151) included all veterans dually enrolled in the Veterans Health Administration (VA) and the private sector in 1998 with (1) an inpatient discharge from either a VA or Medicare setting for 1 of 6 conditions/procedures and (2) inpatient and/or outpatient use in both the VA and private sector. The authors used the Diagnostic Cost Groups risk-adjustment system to obtain concurrent and prospective health status (relative risk scores) using veterans' Medicare diagnoses only, VA diagnoses only, and diagnoses from both systems. Both concurrent and prospective relative risk scores increased when diagnoses from both systems were used; the population's disease profile also was affected. The authors conclude that it is important to capture the true disease burden of the population by obtaining diagnoses from all health care systems providing care to facilitate meaningful comparisons of performance.

TESTING POPULATION-SPECIFIC QUANTITATIVE TRAIT ASSOCIATIONS FOR CLINICAL OUTCOME RELEVANCE IN A BIOREPOSITORY LINKED TO ELECTRONIC HEALTH RECORDS: LPA AND MYOCARDIAL INFARCTION IN AFRICAN AMERICANS

Previous candidate gene and genome-wide association studies have identified common genetic variants in LPA associated with the quantitative trait Lp(a), an emerging risk factor for cardiovascular disease. These associations are population-specific and many have not yet been tested for association with the clinical outcome of interest. To fill this gap in knowledge, we accessed the epidemiologic Third National Health and Nutrition Examination Surveys (NHANES III) and BioVU, the Vanderbilt University Medical Center biorepository linked to de-identified electronic health records (EHRs), including billing codes (ICD-9-CM) and clinical notes, to test population-specific Lp(a)-associated variants for an association with myocardial infarction (MI) among African Americans. We performed electronic phenotyping among African Americans in BioVU≥40 years of age using billing codes. At total of 93 cases and 522 controls were identified in NHANES III and 265 cases and 363 controls were identified in BioVU. We tested five known Lp(a)-associated genetic variants (rs1367211, rs41271028, rs6907156, rs10945682, and rs1652507) in both NHANES III and BioVU for association with myocardial infarction. We also tested LPA rs3798220 (I4399M), previously associated with increased levels of Lp(a), MI, and coronary artery disease in European Americans, in BioVU. After meta-analysis, tests of association using logistic regression assuming an additive genetic model revealed no significant associations (p<0.05) for any of the five LPA variants previously associated with Lp(a) levels in African Americans. Also, I4399M rs3798220 was not associated with MI in African Americans (odds ratio = 0.51; 95% confidence interval: 0.16 - 1.65; p=0.26) despite strong, replicated associations with MI and coronary artery disease in European American genome-wide association studies. These data highlight the challenges in translating quantitative trait associations to clinical outcomes in diverse populations using large epidemiologic and clinic-based collections as envisioned for the Precision Medicine Initiative.

Geographic Variation in Treatment and Outcomes Among Patients With AMI: Investigating Urban-Rural Differences Among Hospitalized Patients

BACKGROUND

The value of early invasive revascularization for patients suffering acute myocardial infarction (AMI) is well known. However, access to revascularization services varies geographically and demographically. Previous studies have not examined the influence of rural residence on revascularization rates and outcomes among patients hospitalized with AMI.

METHODS

Our retrospective cohort study included patients hospitalized in Washington State with a primary diagnosis of AMI from 2009 to 2012. Urban or rural residence was determined using rural-urban commuting area (RUCA) codes. Multivariable models were used to evaluate geographic variation in rates of invasive versus medical management, in-hospital mortality, rehospitalization, and subsequent revascularization procedures.

RESULTS

Our study included 25,156 urban dwellers and 2,770 rural residents. Adjusted models found rural patients to be at increased odds of undergoing invasive revascularization during the initial episode of AMI care (OR = 1.11; 95% CI: 1.01-1.21; P = .02) compared to urban dwelling patients. Rural patients were more likely to be transferred for care (OR = 4.28; 95% CI: 3.93-4.66; P < .001) and more likely to undergo coronary artery bypass grafting (CABG) (OR = 1.55; 95% CI: 1.35-1.78; P < .001) compared to the urban cohort. We found no significant geographic cohort differences in in-hospital mortality or subsequent revascularization rates.

CONCLUSION

Our findings suggest that despite limited access to cardiac care facilities, rural patients are accessing revascularization services. However, rural residents are more likely to undergo CABG during their index admission. High transfer rates suggest that rural regions rely on effective transfer networks to access invasive cardiac services.

Falsification Testing of Instrumental Variables Methods for Comparative Effectiveness Research

OBJECTIVES

To demonstrate how falsification tests can be used to evaluate instrumental variables methods applicable to a wide variety of comparative effectiveness research questions.

STUDY DESIGN

Brief conceptual review of instrumental variables and falsification testing principles and techniques accompanied by an empirical application. Sample STATA code related to the empirical application is provided in the Appendix.

EMPIRICAL APPLICATION

Comparative long-term risks of sulfonylureas and thiazolidinediones for management of type 2 diabetes. Outcomes include mortality and hospitalization for an ambulatory care-sensitive condition. Prescribing pattern variations are used as instrumental variables.

CONCLUSIONS

Falsification testing is an easily computed and powerful way to evaluate the validity of the key assumption underlying instrumental variables analysis. If falsification tests are used, instrumental variables techniques can help answer a multitude of important clinical questions.