Assessing the clinical utility of biomarkers using the intervention probability curve (IPC).

BACKGROUND: Assessing the clinical utility of biomarkers is a critical step before clinical implementation. The reclassification of patients across clinically relevant subgroups is considered one of the best methods to estimate clinical utility. However, there are important limitations with this methodology. We recently proposed the intervention probability curve (IPC) which models the likelihood that a provider will choose an intervention as a continuous function of the probability, or risk, of disease. OBJECTIVE: To assess the potential impact of a new biomarker for lung cancer using the IPC. METHODS: The IPC derived from the National Lung Screening Trial was used to assess the potential clinical utility of a biomarker for suspected lung cancer. The summary statistics of the change in likelihood of intervention over the population can be interpreted as the expected clinical impact of the added biomarker. RESULTS: The IPC analysis of the novel biomarker estimated that 8% of the benign nodules could avoid an invasive procedure while the cancer nodules would largely remain unchanged (0.1%). We showed the benefits of this approach compared to traditional reclassification methods based on thresholds. CONCLUSIONS: The IPC methodology can be a valuable tool for assessing biomarkers prior to clinical implementation.

Lifestyle Intervention and Excess Weight in Chronic Obstructive Pulmonary Disease (COPD): INSIGHT COPD Randomized Clinical Trial.

Rationale: Being overweight or obese is common among patients with chronic obstructive pulmonary disease (COPD), but whether interventions targeted at weight loss improve functional impairments is unknown. Objectives: INSIGHT (Intervention Study in Overweight Patients with COPD) tested whether a pragmatic low-intensity lifestyle intervention would lead to better physical functional status among overweight or obese participants with COPD. Methods: The trial was a 12-month, multicenter, patient-level pragmatic clinical trial. Participants were recruited from April 2017 to August 2019 from 38 sites across the United States and randomized to receive usual care or usual care plus lifestyle intervention. The intervention was a self-directed video program delivering the Diabetes Prevention Program's Group Lifestyle Balance curriculum. Results: The primary outcome was 6-minute-walk test distance at 12 months. Priority secondary outcomes were postwalk modified Borg dyspnea at 12 months and weight at 12 months. Participants (N = 684; mean age, 67.0 ± 8.0 yr [standard deviation]; 41.2% female) on average were obese (body mass index, 33.0 ± 4.6 kg/m2) with moderate COPD (forced expiratory volume in 1 second % predicted, 58.1 ± 15.7%). At 12 months, participants randomized to the intervention arm walked farther (adjusted difference, 42.3 ft [95% confidence interval (CI), 7.9-76.7 ft]; P = 0.02), had less dyspnea at the end of the 6-minute-walk test (adjusted difference, -0.36 [95% CI, -0.63 to -0.09]; P = 0.008), and had greater weight loss (adjusted difference, -1.34 kg [95% CI, -2.33 to -0.34 kg]; P = 0.008) than control participants. The intervention did not improve the odds of achieving clinically meaningful thresholds of walk distance (98.4 ft) or dyspnea (1 unit) but did achieve meaningful thresholds of weight loss (3% and 5%). Conclusions: Among participants with COPD who were overweight or obese, a self-guided low-intensity video-based lifestyle intervention led to modest weight loss but did not lead to clinically important improvements in physical functional status and dyspnea. Clinical trial registered with www.clinicaltrials.gov (NCT02634268).

Differences in VA and Non-VA Pulmonary Nodules: All Evaluations Are not Created Equal.

BACKGROUND: Indeterminate pulmonary nodules present a common challenge for clinicians who must recommend surveillance or intervention based on an assessed risk of malignancy. PATIENTS AND METHODS: In this cohort study, patients presenting for indeterminate pulmonary nodule evaluation were enrolled at sites participating in the Colorado SPORE in Lung Cancer. They were followed prospectively and included for analysis if they had a definitive malignant diagnosis, benign diagnosis, or radiographic resolution or stability of their nodule for > 2 years. RESULTS: Patients evaluated at the Veterans Affairs (VA) and non-VA sites were equally as likely to have a malignant diagnosis (48%). The VA cohort represented a higher-risk group than the non-VA cohort regarding smoking history and chronic obstructive pulmonary disease (COPD). There were more squamous cell carcinoma diagnoses among VA malignant nodules (25% vs. 10%) and a later stage at diagnosis among VA patients. Discrimination and calibration of risk calculators produced estimates that were wide-ranging and different when comparing between risk score calculators as well as between VA/non-VA cohorts. Application of current American College of Chest Physicians guidelines to our groups could have resulted in inappropriate resection of 12% of benign nodules. CONCLUSION: Comparison of VA with non-VA patients shows important differences in underlying risk, histology of malignant nodules, and stage at diagnosis. This study highlights the challenge in applying risk calculators to a clinical setting, as the model discrimination and calibration were variable between calculators and between our higher-risk VA and lower-risk non-VA groups. MICROABSTRACT: Risk stratification and management of indeterminate pulmonary nodules (IPNs) is a common clinical problem. In this prospective cohort study of 282 patients with IPNs from Veterans Affairs (VA) and non-VA sites, we found differences in patient and nodule characteristics, histology and diagnostic stage, and risk calculator performance. Our findings highlight challenges and shortcomings of current IPN management guidelines and tools.

Power for balanced linear mixed models with complex missing data processes.

When designing repeated measures studies, both the amount and the pattern of missing outcome data can affect power. The chance that an observation is missing may vary across measurements, and missingness may be correlated across measurements. For example, in a physiotherapy study of patients with Parkinson's disease, increasing intermittent dropout over time yielded missing measurements of physical function. In this example, we assume data are missing completely at random, since the chance that a data point was missing appears to be unrelated to either outcomes or covariates. For data missing completely at random, we propose noncentral F power approximations for the Wald test for balanced linear mixed models with Gaussian responses. The power approximations are based on moments of missing data summary statistics. The moments were derived assuming a conditional linear missingness process. The approach provides approximate power for both complete-case analyses, which include independent sampling units where all measurements are present, and observed-case analyses, which include all independent sampling units with at least one measurement. Monte Carlo simulations demonstrate the accuracy of the method in small samples. We illustrate the utility of the method by computing power for proposed replications of the Parkinson's study.

Clinical Characteristics and Outcomes Among People Living With HIV Undergoing Percutaneous Coronary Intervention: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program.

Background Clinical characteristics and outcomes in people living with HIV (PLWH) undergoing percutaneous coronary intervention (PCI) remain poorly described. We sought to compare real-world treatment of coronary artery disease, as well as patient and procedural factors and outcomes after PCI between PLWH and uninfected controls. Methods and Results We utilized procedural registry data from the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program between January 1, 2009 and December 31, 2019 to analyze patients with obstructive coronary artery disease on angiography. In the PCI subgroup, we used inverse probability of treatment weighting and applied Cox proportional hazards to evaluate the association of HIV serostatus with outcomes, including all-cause mortality at 5 years. Among 184 310 patients with obstructive coronary artery disease, treatment strategy was similar between PLWH and controls-35.7% versus 34.2% PCI, 13.6% versus 15% coronary artery bypass grafting, and 50.7% versus 50.8% medical therapy. The PCI cohort consisted of 546 (0.9%) PLWH and 56 811 (99.1%) controls. PLWH undergoing PCI had well-controlled HIV disease, and compared with controls, were younger, more likely to be Black, had fewer traditional risk factors, more acute coronary syndrome, less extensive coronary artery disease, and similar types of stents and P2Y12 therapy. However, PLWH experienced worse survival as early as 6 months post-PCI, which persisted over time and amounted to a 21% increased mortality risk by 5 years (hazard ratio, 1.21 [95% CI, 1.03-1.42; P=0.02]). Conclusions Despite well-controlled HIV disease, a more favorable overall cardiovascular risk profile, and similar PCI procedural metrics, PLWH still have significantly worse long-term survival following PCI than controls.

Effect of a Remotely Delivered Self-directed Behavioral Intervention on Body Weight and Physical Health Status Among Adults With Obesity: The D-ELITE Randomized Clinical Trial.

Importance: The effectiveness of remotely delivered, self-directed, weight loss programs in routine clinical practice is largely unknown. Objective: To test whether a self-directed, remotely administered behavioral lifestyle intervention improves weight and self-reported general health status compared with usual care. Design, Setting, and Participants: In this randomized clinical trial, 511 adults with a body mass index (BMI) of 30 or more and less than 45 (based on electronic health record [EHR] weight and height), were enrolled from 30 Veterans Health Administration (VHA) sites between February 15, 2018, and December 18, 2018 (final follow-up February 18, 2021). Interventions: Participants were randomly assigned to the intervention group (n = 254) or the control group (n = 257). Both received usual care. Participants randomized to the intervention received Diabetes Prevention Program-based self-directed videos, handouts, and coaching messages via an online platform or US mail for 12 months. Main Outcomes and Measures: Coprimary outcomes were weight measured in primary care and recorded in the EHR and self-reported general health status using the Medical Outcomes Study 12-Item Short Form Health Survey (SF-12) physical component score (PCS; higher scores are better [range, 0-100]) at the 12-month follow-up. The between-group minimal clinically important differences are 3 kg for weight and 5 points for the SF-12 PCS. Linear mixed models used weights and SF-12 PCS measured at either time point, with participants analyzed according to randomization assignment. Statistical significance for each coprimary outcome was based on a 2-sided α level of .025. Results: Among 511 participants randomized (mean age, 57.4 [SD, 13.9] years; 231 female [45%]), 429 (84.0%) had EHR-based weights and 410 (80.2%) had SF-12 PCS data at 12 months. The unadjusted mean weight at 12 months declined from 102.7 kg to 99.8 kg in the intervention group compared with 101.9 kg to 101.0 kg in the control group (adjusted between-group mean difference, -1.93 [97.5% CI, -3.24 to -0.61]; P = .001). At 12 months, the unadjusted mean SF-12 PCS scores declined from 44.8 to 44.3 among intervention participants compared with 44.5 to 43.2 among control participants (adjusted between-group mean difference, intervention minus control, 0.69 [97.5% CI, -1.11 to 2.49]; P = .39). Cardiovascular events represented the highest percentage of serious adverse events, accounting for 25% of events in the intervention group and 35% in the control group. Conclusions and Relevance: Among adults with obesity, a remotely delivered self-directed, behavioral lifestyle intervention, compared with usual care, resulted in statistically significantly greater weight loss at 12 months, although the difference was not clinically important. There was no significant difference in self-reported general physical health status at 12 months. Trial Registration: ClinicalTrials.gov Identifier: NCT03260140.

Association of Residual Ischemic Disease With Clinical Outcomes After Percutaneous Coronary Intervention.

BACKGROUND: Anatomical scoring systems have been used to assess completeness of revascularization but are challenging to apply to large real-world datasets. OBJECTIVES: The aim of this study was to assess the prevalence of complete revascularization and its association with longitudinal clinical outcomes in the U.S. Department of Veterans Affairs (VA) health care system using an automatically computed anatomic complexity score. METHODS: Patients undergoing percutaneous coronary intervention (PCI) between October 1, 2007, and September 30, 2020, were identified, and the burden of prerevascularization and postrevascularization ischemic disease was quantified using the VA SYNTAX (Synergy Between PCI With Taxus and Cardiac Surgery) score. The association between residual VA SYNTAX score and long-term major adverse cardiovascular events (MACE; death, myocardial infarction, repeat revascularization, and stroke) was assessed. RESULTS: A total of 57,476 veterans underwent PCI during the study period. After adjustment, the highest tertile of residual VA SYNTAX score was associated with increased hazard of MACE (HR: 2.06; 95% CI: 1.98-2.15) and death (HR: 1.50; 95% CI: 1.41-1.59) at 3 years compared to complete revascularization (residual VA SYNTAX score = 0). Hazard of 1- and 3-year MACE increased as a function of residual disease, regardless of baseline disease severity or initial presentation with acute or chronic coronary syndrome. CONCLUSIONS: Residual ischemic disease was strongly associated with long-term clinical outcomes in a contemporary national cohort of PCI patients. Automatically computed anatomic complexity scores can be used to assess the longitudinal risk for residual ischemic disease after PCI and may be implemented to improve interventional quality.

The Effect of Intrathoracic Lesion Location on Initial Tyrosine Kinase Inhibitor Response in Advanced Oncogene-Addicted Non-Small Cell Lung Cancer: A Comparison Between RECIST 1.1 and a Novel Method of Response Assessment (MAX).

INTRODUCTION: Different subtypes of non-small cell lung cancer (NSCLC) are associated with different patterns of metastatic spread. Anatomic location of lesions in the chest may influence patterns of cancer growth and the shrinkage to therapy. Consequently, lesion location could affect apparent response rates per RECIST. We sought to explore this and develop, as needed, treatment response assessments less affected by the location. METHODS: Cases of advanced oncogene-addicted NSCLC (EGFR, ALK, and ROS1) with pre- and on-therapy imaging during initial targeted therapy were identified. Lesions located in the lung parenchyma, pleural space or intra-thoracic lymph nodes were identified and analyzed separately from each other by RECIST 1.1 (unidimensional measurements) and by a novel MAX methodology (bidimensional measurements) which takes the axis with the greatest absolute percentage change on therapy in each location as the representative measurement. RESULTS: Three hundred three patients with 446 unidimensional measured lesions were included for RECIST analysis. Two hundred forty nine patients with 386 bidimensional measured lesions were included for MAX analysis, as well as the analysis comparing RECIST and MAX. Intrathoracic location significantly impacted percentage shrinkage and the response rate per RECIST. The response rates for pleural, intra-parenchymal and nodal lesions were 34.1%, 49.6%, and 68.3%, respectively (P = .0002). The MAX methodology both increased the apparent treatment effect and made it consistent between intrathoracic locations. For pleural, parenchymal and nodal lesions, the MAX calculated response rate were 83.7%, 72.2%, and 75.4%, respectively (P-value = .24). CONCLUSION: Intrathoracic lesion location affects RECIST-based treatment effectiveness estimations. The MAX methodology neutralizes location effect when examining impact of treatment and should be explored further.

The Intervention Probability Curve: Modeling the Practical Application of Threshold-Guided Decision-Making, Evaluated in Lung, Prostate, and Ovarian Cancers.

BACKGROUND: Diagnostic prediction models are useful guides when considering lesions suspicious for cancer, as they provide a quantitative estimate of the probability that a lesion is malignant. However, the decision to intervene ultimately rests on patient and physician preferences. The appropriate intervention in many clinical situations is typically defined by clinically relevant, actionable subgroups based upon the probability of malignancy. However, the "all-or-nothing" approach of threshold-based decisions is in practice incorrect. METHODS: Here, we present a novel approach to understanding clinical decision-making, the intervention probability curve (IPC). The IPC models the likelihood that an intervention will be chosen as a continuous function of the probability of disease. We propose the cumulative distribution function as a suitable model. The IPC is explored using the National Lung Screening Trial and the Prostate Lung Colorectal and Ovarian Screening Trial datasets. RESULTS: Fitting the IPC results in a continuous curve as a function of pretest probability of cancer with high correlation (R2 > 0.97 for each) with fitted parameters closely aligned with professional society guidelines. CONCLUSIONS: The IPC allows analysis of intervention decisions in a continuous, rather than threshold-based, approach to further understand the role of biomarkers and risk models in clinical practice. IMPACT: We propose that consideration of IPCs will yield significant insights into the practical relevance of threshold-based management strategies and could provide a novel method to estimate the actual clinical utility of novel biomarkers.

Potential Reduction in Adverse Events and Cost with Novel Anticoagulants among Patients with Acute Limb Ischemia.

Background: Acute limb ischemia (ALI) is associated with significant morbidity and mortality. Novel anticoagulants reduce adverse events among patients with peripheral artery disease, though the potential effect of these therapies is unclear in patients with ALI. The present study thus sought to evaluate the potential clinical benefit of universal application of novel anticoagulants to a high-risk population of patients with ALI. Methods: In this retrospective cohort study, we identified patients diagnosed with ALI in the Veterans Affairs Healthcare System between 2015 and 2016. We then calculated the incidence of adverse cardiovascular events (death/stroke/myocardial infarction/amputation/repeat intervention) as if they were treated with rivaroxaban using published data. Further, we calculated the cost to treat a Veteran diagnosed with one of these outcomes, and the potential savings had patients been universally treated with novel anticoagulants. Results: We identified 286 patients that presented with lower extremity ALI and were not treated with anticoagulation. Potential treatment of these patients with rivaroxaban resulted in significantly fewer adverse events, with an 11.9% reduction in cases at 21 months (95% CI: 5.5-17.8%) and a 13.4% reduction in cases at 47 months (95% CI: 5.6-20.5%). This corresponded to significant decreases in healthcare spending for patients with ALI who were treated with rivaroxaban. Conclusions: Among patients with ALI, treatment with rivaroxaban could result in a significant reduction in adverse cardiovascular events. The reduction in events would in turn lead to significant decreases in healthcare spending for this population.

Transitions of Care Among Patients Undergoing Percutaneous Coronary Intervention for Stable Angina: Insights From the Veterans Affairs Clinical Assessment Reporting and Tracking Program.

Background Effective transitions from the procedural to outpatient setting are essential to ensure high-quality cardiovascular care across health care systems, particularly among patients undergoing invasive cardiac procedures. We evaluated the association of postprocedural follow-up visits and antiplatelet prescriptions with clinical outcomes among patients undergoing percutaneous coronary intervention for stable angina at community or Veterans Affairs (VA) hospitals. Methods and Results Patients who actively received care within the VA Healthcare System and underwent percutaneous coronary intervention for stable angina at a community or VA hospital between October 1, 2015, and September 30, 2019, were identified. We compared mortality for patients receiving community or VA care, and among subgroups of community-treated patients by the presence of a postprocedural follow-up visit within 30 days or prescription for antiplatelet (P2Y12) medication within 120 days of the procedure. Among 12 837 patients who survived the first 30 days, 5133 were treated at community hospitals, and 7704 were treated in the VA. Prescriptions for antiplatelet therapy were less common for those treated in the community (85%) compared with the VA at 1 year (95%; hazard ratio [HR], 0.46; 95% CI, 0.44-47). Compared with VA-treated patients, the hazards for death were similar for patients treated in the community with a follow-up visit (HR, 1.17; 95% CI, 0.97-1.40) or with a fill for an antiplatelet therapy (HR, 1.08; 95% CI, 0.90-1.30). However, patients treated in the community without a follow-up visit had an 86% (HR, 1.86; 95% CI, 1.40-2.48) increased hazard of death, and those without antiplatelet prescription fill had a 144% increased hazard of death (HR, 2.44; 95% CI, 1.85-3.21) compared with all VA-treated patients. Conclusions Patients treated at community facilities have a decreased chance of receiving antiplatelet prescriptions after percutaneous coronary intervention with a concordant increased hazard of mortality, emphasizing the importance of transitions of care across health care systems when assessing cardiovascular quality.

Clinical Characteristics and Outcomes Among Patients Undergoing High-Risk Percutaneous Coronary Interventions by Single or Multiple Operators: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program.

Background High-risk percutaneous coronary intervention (HR-PCI) is increasingly common among contemporary patients with coronary artery disease. Experts have advocated for a collaborative 2-operator approach to support intraprocedural decision-making for these complex interventions. The impact of a second operator on patient and procedural outcomes is unknown. Methods and Results Patients who underwent HR-PCI from 2015 to 2018 within the Veterans Affairs Healthcare System were identified. Propensity-matched cohorts were generated to compare the outcomes following HR-PCI performed by a single or multiple (≥2) operators. The primary end point was the 12-month rate of major adverse cardiovascular events. We identified 6672 patients who underwent HR-PCI during the study period; 6211 (93%) were treated by a single operator, and 461 (7%) were treated by multiple operators, with a nonsignificant trend toward increased multioperator procedures over time. A higher proportion of patients treated by multiple operators underwent left main (10% versus 7%, P=0.045) or chronic total occlusion intervention (11% versus 5%, P<0.001). Lead interventionalists participating in multioperator procedures practiced at centers with higher annual HR-PCI volumes (124±71.3 versus 111±69.2; standardized mean difference, 0.197; P<0.001) but otherwise performed a similar number of HR-PCI procedures per year (34.4±35.3 versus 34.7±30.7; standardized mean difference, 0.388; P=0.841) compared with their peers performing single-operator interventions. In a propensity-matched cohort, there was no significant difference in major adverse cardiovascular events (32% versus 30%, P=0.444) between patients who underwent single-operator versus multioperator HR-PCI. Adjusted analyses accounting for site-level variance showed no significant differences in outcomes. Conclusions Patients who underwent multioperator HR-PCI had similar outcomes compared with single-operator procedures. Further studies are needed to determine if the addition of a second operator offers clinical benefits to a subset of HR-PCI patients undergoing left main or chronic total occlusion intervention.

Integrated Biomarkers for the Management of Indeterminate Pulmonary Nodules.

Rationale: Patients with indeterminate pulmonary nodules (IPNs) at risk of cancer undergo high rates of invasive, costly, and morbid procedures. Objectives: To train and externally validate a risk prediction model that combined clinical, blood, and imaging biomarkers to improve the noninvasive management of IPNs. Methods: In this prospectively collected, retrospective blinded evaluation study, probability of cancer was calculated for 456 patient nodules using the Mayo Clinic model, and patients were categorized into low-, intermediate-, and high-risk groups. A combined biomarker model (CBM) including clinical variables, serum high sensitivity CYFRA 21-1 level, and a radiomic signature was trained in cohort 1 (n = 170) and validated in cohorts 2-4 (total n = 286). All patients were pooled to recalibrate the model for clinical implementation. The clinical utility of the CBM compared with current clinical care was evaluated in 2 cohorts. Measurements and Main Results: The CBM provided improved diagnostic accuracy over the Mayo Clinic model with an improvement in area under the curve of 0.124 (95% bootstrap confidence interval, 0.091-0.156; P < 2 × 10-16). Applying 10% and 70% risk thresholds resulted in a bias-corrected clinical reclassification index for cases and control subjects of 0.15 and 0.12, respectively. A clinical utility analysis of patient medical records estimated that a CBM-guided strategy would have reduced invasive procedures from 62.9% to 50.6% in the intermediate-risk benign population and shortened the median time to diagnosis of cancer from 60 to 21 days in intermediate-risk cancers. Conclusions: Integration of clinical, blood, and image biomarkers improves noninvasive diagnosis of patients with IPNs, potentially reducing the rate of unnecessary invasive procedures while shortening the time to diagnosis.

Determinants Associated With Longitudinal Adherence to Annual Lung Cancer Screening: A Retrospective Analysis of Claims Data.

OBJECTIVE: Lung cancer screening (LCS) efficacy is highly dependent on adherence to annual screening, but little is known about real-world adherence determinants. We used insurance claims data to examine associations between LCS annual adherence and demographic, comorbidity, health care usage, and geographic factors. MATERIALS AND METHODS: Insurance claims data for all individuals with an LCS low-dose CT scan were obtained from the Colorado All Payer Claims Dataset. Adherence was defined as a second claim for a screening CT 10 to 18 months after the index claim. Cox proportional hazards regression was used to define the relationship between annual adherence and age, gender, insurance type, residence location, outpatient health care usage, and comorbidity burden. RESULTS: After exclusions, the final data set consisted of 9,056 records with 3,072 adherent, 3,570 nonadherent, and 2,414 censored (unclassifiable) individuals. Less adherence was associated with ages 55 to 59 (hazard ratio [HR] = 0.80, 99% confidence interval [CI] = 0.67-0.94), 60 to 64 (HR = 0.83, 99% CI = 0.71-0.97), and 75 to 79 (HR = 0.79, 99% CI = 0.65-0.97); rural residence (HR = 0.56, 99% CI = 0.43-0.73); Medicare fee-for-service (HR = 0.45, 99% CI = 0.39-0.51), and Medicaid (HR = 0.50, 99% CI = 0.40-0.62). A significant interaction between outpatient health care usage and comorbidity was also observed. Increased outpatient usage was associated with increased adherence and was most pronounced for individuals without comorbidities. CONCLUSIONS: This population-based description of LCS adherence determinants provides insight into populations that might benefit from specific interventions targeted toward improving adherence and maximizing LCS benefit. Quantifying population-based adherence rates and understanding factors associated with annual adherence are critical to improving screening adherence and reducing lung cancer death.

Renin-Angiotensin-Aldosterone System Inhibitor Use and Mortality in Pulmonary Hypertension: Insights From the Veterans Affairs Clinical Assessment Reporting and Tracking Database.

BACKGROUND: The renin-angiotensin-aldosterone system (RAAS) contributes to pulmonary hypertension (PH) pathogenesis. Although animal data suggest that RAAS inhibition attenuates PH, it is unknown if RAAS inhibition is beneficial in PH patients. RESEARCH QUESTION: Is RAAS inhibitor use associated with lower mortality in a large cohort of patients with hemodynamically confirmed PH? STUDY DESIGN AND METHODS: We used the Department of Veterans Affairs Clinical Assessment Reporting and Tracking Database to study retrospectively relationships between RAAS inhibitors (angiotensin converting enzyme inhibitors [ACEIs], angiotensin receptor blockers [ARBs], and aldosterone antagonists [AAs]) and mortality in 24,221 patients with hemodynamically confirmed PH. We evaluated relationships in the full and in propensity-matched cohorts. Analyses were adjusted for demographics, socioeconomic status, comorbidities, disease severity, and comedication use in staged models. RESULTS: ACEI and ARB use was associated with improved survival in unadjusted Kaplan-Meier survival analyses in the full cohort and the propensity-matched cohort. This relationship was insensitive to adjustment, independent of pulmonary artery wedge pressure, and also was observed in a cohort restricted to individuals with precapillary PH. AA use was associated with worse survival in unadjusted Kaplan-Meier survival analyses in the full cohort; however, AA use was associated less robustly with mortality in the propensity-matched cohort and was not associated with worse survival after adjustment for disease severity, indicating that AAs in real-world practice are used preferentially in sicker patients and that the unadjusted association with increased mortality may be an artifice of confounding by indication of severity. INTERPRETATION: ACEI and ARB use is associated with lower mortality in veterans with PH. AA use is a marker of disease severity in PH. ACEIs and ARBs may represent a novel treatment strategy for diverse PH phenotypes.

Long-term predictive value of stroke volume index obtained from right heart catheterization: Insights from the veterans affairs clinical assessment, reporting, and tracking program.

BACKGROUND: Right heart catheterization-derived hemodynamic parameters have been associated with short-term prognosis. HYPOTHESIS: Hemodynamic parameters will be associated with long-term prognosis. METHODS: Retrospective cohort study from the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program included patients who underwent an index right heart catheterization between 2008 and 2016. Cox proportional hazard models were used to examine the association between stroke volume index and all-cause mortality. RESULTS: For the final cohort of 37 209 patients, mean follow-up was 3.7 ± 2.5 years. All-cause mortality was 42.0% in the low (<35 cc/beat/m2 ) compared with 33.2% in the normal stroke volume index group (≥35 cc/beat/m2 ). In adjusted analysis, low stroke volume was significantly associated with higher mortality risk (HR (95% CI) 1.14 (1.10-1.18); P < .001) independent of clinical parameters. The area under the curve (AUC) for continuous measures of stroke volume index at predicting mortality in a Cox proportional hazard model was 0.56 at 3 years. When stroke volume index was combined with 14 clinical covariates, the AUC was 0.70 at 3 years. The addition of stroke volume index to these clinical covariates did not increase the discriminatory ability of the model at 1 year in a clinically meaningful way (integrated discrimination improvement index = 0.0021, 95% CI: 0.0010-0.0034). CONCLUSIONS: The long-term prognostic value of right heart catheterization-derived stroke volume index appears to be marginal. While there was a weak association of low stroke volume index and excess mortality, inclusion of this parameter to a set of clinical covariates did not improve prognostic discrimination.

Pulmonary vascular resistance and clinical outcomes in patients with pulmonary hypertension: a retrospective cohort study.

BACKGROUND: In pulmonary hypertension subgroups, elevated pulmonary vascular resistance (PVR) of 3·0 Wood units or more is associated with poor prognosis. However, the spectrum of PVR risk in pulmonary hypertension is not known. To address this area of uncertainty, we aimed to analyse the relationship between PVR and adverse clinical outcomes in pulmonary hypertension. METHODS: We did a retrospective cohort study of all patients undergoing right heart catheterisation (RHC) in the US Veterans Affairs health-care system (Oct 1, 2007-Sep 30, 2016). Patients were included in the analyses if data from a complete RHC and at least 1 year of follow-up were available. Both inpatients and outpatients were included, but individuals with missing mean pulmonary artery pressure (mPAP), pulmonary artery wedge pressure, or cardiac output were excluded. The primary outcome measure was time to all-cause mortality assessed by the Veteran Affairs vital status file. Cox proportional hazards models were used to assess the association between PVR and outcomes, and the mortality hazard ratio was validated in a RHC cohort from Vanderbilt University Medical Center (Sept 24, 1998-June 1, 2016). FINDINGS: The primary cohort (N=40 082; 38 751 [96·7%] male; median age 66·5 years [IQR 61·1-73·5]; median follow-up 1153 days [IQR 570-1971]), included patients with a history of heart failure (23 201 [57·9%]) and chronic obstructive pulmonary disease (13 348 [33·3%]). We focused on patients at risk for pulmonary hypertension based on a mPAP of at least 19 mm Hg (32 725 [81·6%] of 40 082). When modelled as a continuous variable, the all-cause mortality hazard for PVR was increased at around 2·2 Wood units compared with PVR of 1·0 Wood unit. Among patients with a mPAP of at least 19 mm Hg and pulmonary artery wedge pressure of 15 mm Hg or less, the adjusted hazard ratio (HR) for mortality was 1·71 (95% CI 1·59-1·84; p<0·0001) and for heart failure hospitalisation was 1·27 (1·13-1·43; p=0·0001), when comparing PVR of 2·2 Wood units or more to less than 2·2 Wood units. The validation cohort (N=3699, 1860 [50·3%] male, median age 60·4 years [49·5-69·2]; median follow-up 1752 days [IQR 1281-2999]) included 2870 patients [77·6%] with mPAP of at least 19 mm Hg (1418 [49·4%] male). The adjusted mortality HR for patients in the mPAP of 19 mm Hg or more group and with PVR of 2·2 Wood units or more and pulmonary artery wedge pressure of 15 mm or less Hg (1221 [42·5%] of 2870) was 1·81 (95% CI 1·33-2·47; p=0·0002). INTERPRETATION: These data widen the continuum of clinical risk for mortality and heart failure in patients referred for RHC with elevated pulmonary artery pressure to include PVR of around 2.2 Wood units and higher. Testing the generalisability of these findings in at-risk populations with fewer cardiopulmonary comorbidities is warranted. FUNDING: None.

Impact of a Hybrid Lung Cancer Screening Model on Patient Outcomes and Provider Behavior.

BACKGROUND: Lung cancer screening (LCS) implementation is complicated by the Centers for Medicare and Medicaid Services reimbursement requirements of shared decision-making and tobacco cessation counseling. LCS programs can utilize different structures to meet these requirements, but the impact of programmatic structure on provider behavior and screening outcomes is poorly described. PATIENTS AND METHODS: In a retrospective chart review of 624 patients in a hybrid structure, academic LCS program, we compared characteristics and outcomes of primary care provider (PCP)- and specialist-screened patients. We also assessed the impact of the availability of an LCS specialty clinic and best practice advisory (BPA) on PCP ordering patterns using electronic medical record generated reports. RESULTS: During the study period of July 1, 2014 through June 30, 2018, 48% of patients were specialist-screened and 52% were PCP-screened; there were no clinically relevant differences in patient characteristics or screening outcomes between these populations. PCPs demonstrate distinct practice patterns when offered the choice of specialist-driven or PCP-driven screening. Increased exposure to a LCS BPA is associated with increased PCP screening orders. The addition of a nurse navigator into the LCS program increased documentation of shared decision-making and tobacco cessation counseling to > 95% and virtually eliminated screening of ineligible patients. CONCLUSIONS: Systematic interventions including a BPA and nurse navigator are associated with increased screening and improved program quality, as evidenced by reduced screening of ineligible patients, increased lung cancer risk of the screened population, and improved compliance with LCS guidelines. Individual PCPs demonstrate clear preferences regarding LCS that should be considered in program design.