Publications

Registry Assessment of Peripheral Interventional Devices (RAPID) initiated the Pathways Program to provide a transparent, collaborative forum in which to pursue insights into multiple unresolved questions on benefit-risk of paclitaxel-coated devices, including understanding the basis of the mortality signal, without a demonstrable potential biological mechanism, and whether the late mortality signal could be artifact intrinsic to multiple independent prospective randomized data sources that did not prespecify death as a long-term end point. In response to the directive, the LEAN-Case Report Form working group focused on enhancements to the RAPID Phase I Minimum Core Data set through the addition of key clinical modifiers that would be more strongly linked to longer-term mortality outcomes after peripheral arterial disease intervention in the drug-eluting device era, with the goal to have future mortality signals more accurately examined.

Whether thrombocytopenia substantively increases the risk of hemorrhage associated with anticoagulation in patients with atrial fibrillation (AF) is not established. The purpose of this study was to compare rates of bleeding in patients with AF and thrombocytopenia (platelet count < 100 000/μL) to patients with AF and normal platelet counts (>150 000/μL). We performed a propensity score-matched, retrospective cohort study of adults (n = 1070) with a new diagnosis of AF who received a prescription for an oral anticoagulant between 2015 and 2020. The thrombocytopenia cohort was defined as having at least 2 platelet counts <100 000/μL on separate days in the period spanning the 12 weeks preceding the initiation of anticoagulation to 6 weeks after the initiation of anticoagulation. The primary end point was the 1-year cumulative incidence of major bleeding; secondary end points included clinically relevant bleeding, arterial and venous thrombotic events, and all-cause mortality. Patients with AF and thrombocytopenia experienced a higher 1-year cumulative incidence of major bleeding (13.3% vs 5.7%; P < .0001) and clinically relevant bleeding (24.5% vs 16.7%; P = .005) than the controls. Thrombocytopenia was identified as an independent risk factor for major bleeding (hazard ratio, 2.20; confidence interval, 1.36-3.58; P = .001), with increasing risk based on the severity of thrombocytopenia. The cumulative incidence of arterial thrombosis at 1 year was 3.6% in the group with thrombocytopenia and 1.5% in controls (Gray test, P = .08). These findings suggest that baseline platelet counts are an important biomarker for hemorrhagic outcomes in AF and that the degree of thrombocytopenia is an important factor in determining the level of risk.

BACKGROUND: Federal programs measuring hospital quality of care for acute cardiovascular conditions are based solely on Medicare fee-for-service (FFS) beneficiaries, and exclude Medicare Advantage (MA) beneficiaries. In this study we characterize the proportion of Medicare beneficiaries enrolled in MA at the time of acute myocardial infarction (AMI), heart failure (HF), and ischemic stroke hospitalization.

METHODS: Retrospective cross-sectional study of short-term acute care hospitals using Medicare claims in 2009 and 2019.

RESULTS: There were 2,653 hospitals in 2009 and 2,732 hospitals in 2019. Across hospitals, the proportion of Medicare beneficiaries hospitalized for AMI who were enrolled in MA increased between 2009 (hospital-level median 14.4% [IQR 5.1%-26.0%]) and 2019 (33.3% [IQR 20.6%-45.2%]), with substantial variation across hospitals. Similar patterns were observed for HF (13.0% [IQR 5.3%-24.3%] to 31.0% [IQR 20.2%-42.3%]) and ischemic stroke (14.6% [IQR 5.3%-26.7%] to 33.3% [IQR 20.9%-46.0%]). Within each hospital referral region, hospital size (large 36.3% vs small 24.5%; adjusted difference 6.7%, 95% CI, 4.5%-8.8%), teaching status (teaching 34.5% vs nonteaching 28.2%; 2.8%, 1.4%-4.1%), and ownership status (private nonprofit 32.3% vs public 24.5%; 5.2%, 3.5%-6.9%) were each associated with a higher hospital MA proportion.

CONCLUSIONS: The proportion of Medicare beneficiaries hospitalized for AMI, HF, and ischemic stroke enrolled in MA doubled between 2009 and 2019, with substantial variation across hospitals. These findings have implications for federal efforts to measure and improve quality, which currently focus only on FFS beneficiaries.

PURPOSE OF REVIEW: Peripheral artery disease (PAD) is an increasingly prevalent but frequently underdiagnosed condition that can be associated with high rates of morbidity and mortality. While an initial noninvasive approach is the cornerstone of management, revascularization is often pursued for patients with treatment-refractory claudication or chronic limb-threatening ischemia (CLTI). In this review, we discuss the current state of endovascular interventions for PAD and explore the many new emerging technologies.

RECENT FINDINGS: The last decade has resulted in numerous advances in PAD interventions including the ongoing evolution of drug-coated devices, novel approaches to complex lesions, and contemporary evidence from large clinical trials for CLTI. Advances in endovascular management have allowed for increasingly complex lesions to be tackled percutaneously. Future directions for the field include the continued evolution in device technology, continued development of state-of-the-art techniques to revascularization of complex lesions, and increased collaboration between a largely multidisciplinary field.

The noniterative conditional expectation (NICE) parametric g-formula can be used to estimate the causal effect of sustained treatment strategies. In addition to identifiability conditions, the validity of the NICE parametric g-formula generally requires the correct specification of models for time-varying outcomes, treatments, and confounders at each follow-up time point. An informal approach for evaluating model specification is to compare the observed distributions of the outcome, treatments, and confounders with their parametric g-formula estimates under the "natural course." In the presence of loss to follow-up, however, the observed and natural-course risks can differ even if the identifiability conditions of the parametric g-formula hold and there is no model misspecification. Here, we describe 2 approaches for evaluating model specification when using the parametric g-formula in the presence of censoring: 1) comparing factual risks estimated by the g-formula with nonparametric Kaplan-Meier estimates and 2) comparing natural-course risks estimated by inverse probability weighting with those estimated by the g-formula. We also describe how to correctly compute natural-course estimates of time-varying covariate means when using a computationally efficient g-formula algorithm. We evaluate the proposed methods via simulation and implement them to estimate the effects of dietary interventions in 2 cohort studies.

IMPORTANCE: Long-term acute care hospitals (LTCHs) are common sites of postacute care for patients recovering from severe respiratory failure requiring mechanical ventilation (MV). However, federal payment reform led to the closure of many LTCHs in the US, and it is unclear how closure of LTCHs may have affected upstream care patterns at short-stay hospitals and overall patient outcomes.

OBJECTIVE: To estimate the association between LTCH closures and short-stay hospital care patterns and patient outcomes.

DESIGN, SETTING, AND PARTICIPANTS: This retrospective, national, matched cohort study used difference-in-differences analysis to compare outcomes at short-stay hospitals reliant on LTCHs that closed during 2012 to 2018 with outcomes at control hospitals. Data were obtained from the Medicare Provider Analysis and Review File, 2011 to 2019. Participants included Medicare fee-for-service beneficiaries aged 66 years and older receiving MV for at least 96 hours in an intensive care unit (ie, patients at-risk for prolonged MV) and the subgroup also receiving a tracheostomy (ie, receiving prolonged MV). Data were analyzed from October 2022 to June 2023.

EXPOSURE: Admission to closure-affected hospitals, defined as those discharging at least 60% of patients receiving a tracheostomy to LTCHs that subsequently closed, vs control hospitals.

MAIN OUTCOMES AND MEASURES: Upstream hospital care pattern outcomes were short-stay hospital do-not-resuscitate orders, palliative care delivery, tracheostomy placement, and discharge disposition. Patient outcomes included hospital length of stay, days alive and institution free within 90 days, spending per days alive within 90 days, and 90-day mortality.

RESULTS: Between 2011 and 2019, 99 454 patients receiving MV for at least 96 hours at 1261 hospitals were discharged to 459 LTCHs; 84 LTCHs closed. Difference-in-differences analysis included 8404 patients (mean age, 76.2 [7.2] years; 4419 [52.6%] men) admitted to 45 closure-affected hospitals and 45 matched-control hospitals. LTCH closure was associated with decreased LTCH transfer rates (difference, -5.1 [95% CI -8.2 to -2.0] percentage points) and decreased spending-per-days-alive (difference, -$8701.58 [95% CI, -$13 323.56 to -$4079.60]). In the subgroup of patients receiving a tracheostomy, there was additionally an increase in do-not-resuscitate rates (difference, 10.3 [95% CI, 4.2 to 16.3] percentage points) and transfer to skilled nursing facilities (difference, 10.0 [95% CI, 4.2 to 15.8] percentage points). There was no significant association of closure with 90-day mortality.

CONCLUSIONS AND RELEVANCE: In this cohort study, LTCH closure was associated with changes in discharge patterns in patients receiving mechanical ventilation for at least 96 hours and advanced directive decisions in the subgroup receiving a tracheostomy, without change in mortality. Further studies are needed to understand how LTCH availability may be associated with other important outcomes, including functional outcomes and patient and family satisfaction.

PURPOSE OF REVIEW: Peripheral artery disease (PAD) is an increasingly prevalent but frequently underdiagnosed condition that can be associated with high rates of morbidity and mortality. While an initial noninvasive approach is the cornerstone of management, revascularization is often pursued for patients with treatment-refractory claudication or chronic limb-threatening ischemia (CLTI). In this review, we discuss the current state of endovascular interventions for PAD and explore the many new emerging technologies.

RECENT FINDINGS: The last decade has resulted in numerous advances in PAD interventions including the ongoing evolution of drug-coated devices, novel approaches to complex lesions, and contemporary evidence from large clinical trials for CLTI. Advances in endovascular management have allowed for increasingly complex lesions to be tackled percutaneously. Future directions for the field include the continued evolution in device technology, continued development of state-of-the-art techniques to revascularization of complex lesions, and increased collaboration between a largely multidisciplinary field.

Registry Assessment of Peripheral Interventional Devices (RAPID) initiated the Pathways Program to provide a transparent, collaborative forum in which to pursue insights into multiple unresolved questions on benefit-risk of paclitaxel-coated devices, including understanding the basis of the mortality signal, without a demonstrable potential biological mechanism, and whether the late mortality signal could be artifact intrinsic to multiple independent prospective randomized data sources that did not prespecify death as a long-term end point. In response to the directive, the LEAN-Case Report Form working group focused on enhancements to the RAPID Phase I Minimum Core Data set through the addition of key clinical modifiers that would be more strongly linked to longer-term mortality outcomes after peripheral arterial disease intervention in the drug-eluting device era, with the goal to have future mortality signals more accurately examined.

BACKGROUND: Federal programs measuring hospital quality of care for acute cardiovascular conditions are based solely on Medicare fee-for-service (FFS) beneficiaries, and exclude Medicare Advantage (MA) beneficiaries. In this study we characterize the proportion of Medicare beneficiaries enrolled in MA at the time of acute myocardial infarction (AMI), heart failure (HF), and ischemic stroke hospitalization.

METHODS: Retrospective cross-sectional study of short-term acute care hospitals using Medicare claims in 2009 and 2019.

RESULTS: There were 2,653 hospitals in 2009 and 2,732 hospitals in 2019. Across hospitals, the proportion of Medicare beneficiaries hospitalized for AMI who were enrolled in MA increased between 2009 (hospital-level median 14.4% [IQR 5.1%-26.0%]) and 2019 (33.3% [IQR 20.6%-45.2%]), with substantial variation across hospitals. Similar patterns were observed for HF (13.0% [IQR 5.3%-24.3%] to 31.0% [IQR 20.2%-42.3%]) and ischemic stroke (14.6% [IQR 5.3%-26.7%] to 33.3% [IQR 20.9%-46.0%]). Within each hospital referral region, hospital size (large 36.3% vs small 24.5%; adjusted difference 6.7%, 95% CI, 4.5%-8.8%), teaching status (teaching 34.5% vs nonteaching 28.2%; 2.8%, 1.4%-4.1%), and ownership status (private nonprofit 32.3% vs public 24.5%; 5.2%, 3.5%-6.9%) were each associated with a higher hospital MA proportion.

CONCLUSIONS: The proportion of Medicare beneficiaries hospitalized for AMI, HF, and ischemic stroke enrolled in MA doubled between 2009 and 2019, with substantial variation across hospitals. These findings have implications for federal efforts to measure and improve quality, which currently focus only on FFS beneficiaries.

IMPORTANCE: Long-term acute care hospitals (LTCHs) are common sites of postacute care for patients recovering from severe respiratory failure requiring mechanical ventilation (MV). However, federal payment reform led to the closure of many LTCHs in the US, and it is unclear how closure of LTCHs may have affected upstream care patterns at short-stay hospitals and overall patient outcomes.

OBJECTIVE: To estimate the association between LTCH closures and short-stay hospital care patterns and patient outcomes.

DESIGN, SETTING, AND PARTICIPANTS: This retrospective, national, matched cohort study used difference-in-differences analysis to compare outcomes at short-stay hospitals reliant on LTCHs that closed during 2012 to 2018 with outcomes at control hospitals. Data were obtained from the Medicare Provider Analysis and Review File, 2011 to 2019. Participants included Medicare fee-for-service beneficiaries aged 66 years and older receiving MV for at least 96 hours in an intensive care unit (ie, patients at-risk for prolonged MV) and the subgroup also receiving a tracheostomy (ie, receiving prolonged MV). Data were analyzed from October 2022 to June 2023.

EXPOSURE: Admission to closure-affected hospitals, defined as those discharging at least 60% of patients receiving a tracheostomy to LTCHs that subsequently closed, vs control hospitals.

MAIN OUTCOMES AND MEASURES: Upstream hospital care pattern outcomes were short-stay hospital do-not-resuscitate orders, palliative care delivery, tracheostomy placement, and discharge disposition. Patient outcomes included hospital length of stay, days alive and institution free within 90 days, spending per days alive within 90 days, and 90-day mortality.

RESULTS: Between 2011 and 2019, 99 454 patients receiving MV for at least 96 hours at 1261 hospitals were discharged to 459 LTCHs; 84 LTCHs closed. Difference-in-differences analysis included 8404 patients (mean age, 76.2 [7.2] years; 4419 [52.6%] men) admitted to 45 closure-affected hospitals and 45 matched-control hospitals. LTCH closure was associated with decreased LTCH transfer rates (difference, -5.1 [95% CI -8.2 to -2.0] percentage points) and decreased spending-per-days-alive (difference, -$8701.58 [95% CI, -$13 323.56 to -$4079.60]). In the subgroup of patients receiving a tracheostomy, there was additionally an increase in do-not-resuscitate rates (difference, 10.3 [95% CI, 4.2 to 16.3] percentage points) and transfer to skilled nursing facilities (difference, 10.0 [95% CI, 4.2 to 15.8] percentage points). There was no significant association of closure with 90-day mortality.

CONCLUSIONS AND RELEVANCE: In this cohort study, LTCH closure was associated with changes in discharge patterns in patients receiving mechanical ventilation for at least 96 hours and advanced directive decisions in the subgroup receiving a tracheostomy, without change in mortality. Further studies are needed to understand how LTCH availability may be associated with other important outcomes, including functional outcomes and patient and family satisfaction.