Publications

BACKGROUND: Randomized controlled trials are the "gold standard" for comparing the safety and efficacy of therapies but may be limited due to high costs, lack of feasibility, and difficulty enrolling "real-world" patient populations. The Extending Trial-Based Evaluations of Medical Therapies Using Novel Sources of Data (EXTEND) Study seeks to evaluate whether data collected within procedural registries and claims databases can reproduce trial results by substituting surrogate non-trial-based variables for exposures and outcomes.

METHODS AND RESULTS: Patient-level data from 2 clinical trial programs-the Dual Antiplatelet Therapy Study and the United States CoreValve Studies-will be linked to a combination of national registry, administrative claims, and health system data. The concordance between baseline and outcomes data collected within nontrial data sets and trial information, including adjudicated end point events, will be assessed. We will compare the study results obtained using these alternative data sources to those derived using trial-ascertained variables and end points using trial-adjudicated end points and covariates.

CONCLUSIONS: Linkage of trials to registries and claims data represents an opportunity to use alternative data sources in place of and as adjuncts to randomized clinical trial data but requires further validation. The results of this research will help determine how these data sources can be used to improve our present and future understanding of new medical treatments.

IMPORTANCE: The addition of a claims-based frailty metric to traditional comorbidity-based risk-adjustment models for acute myocardial infarction (AMI), heart failure (HF), and pneumonia improves the prediction of 30-day mortality and readmission. This may have important implications for hospitals that tend to care for frail populations and participate in Centers for Medicare & Medicaid Services value-based payment programs, which use these risk-adjusted metrics to determine reimbursement.

OBJECTIVE: To determine whether the addition of frailty measures to traditional comorbidity-based risk-adjustment models improved prediction of outcomes for patients with AMI, HF, and pneumonia.

DESIGN, SETTING, AND PARTICIPANTS: A nationwide cohort study included Medicare fee-for-service beneficiaries 65 years and older in the United States between January 1 and December 1, 2016. Analysis began August 2018.

MAIN OUTCOMES AND MEASURES: Rates of mortality within 30 days of admission and 30 days of discharge, as well as 30-day readmission rates by frailty group. We evaluated the incremental effect of adding the Hospital Frailty Risk Score (HFRS) to current comorbidity-based risk-adjustment models for 30-day outcomes across all conditions.

RESULTS: For 785 127 participants, there were 166 200 hospitalizations [21.2%] for AMI, 348 619 [44.4%] for HF, and 270 308 [34.4%] for pneumonia. The mean (SD) age at the time of hospitalization was 79.2 (8.9) years; 656 315 (83.6%) were white and 402 639 (51.3%) were women. The mean (SD) HFRS was 7.3 (7.4) for patients with AMI, 10.8 (8.3) for patients with HF, and 8.2 (5.7) for patients with pneumonia. Among patients hospitalized for AMI, an HFRS more than 15 (compared with an HFRS <5) was associated with a higher risk of 30-day postadmission mortality (adjusted odds ratio [aOR], 3.6; 95% CI, 3.4-3.8), 30-day postdischarge mortality (aOR, 4.0; 95% CI, 3.7-4.3), and 30-day readmission (aOR, 3.0; 95% CI, 2.9-3.1) after multivariable adjustment for age, sex, race, and comorbidities. Similar patterns were observed for patients hospitalized with HF (30-day postadmission mortality: aOR, 3.5; 95% CI, 3.4-3.7; 30-day postdischarge mortality: aOR, 3.5; 95% CI, 3.3-3.6; and 30-day readmission: aOR, 2.9; 95% CI, 2.8-3.0) and among patients with pneumonia (30-day postadmission mortality: aOR, 2.5; 95% CI, 2.3-2.6; 30-day postdischarge mortality: aOR, 3.0; 95% CI, 2.9-3.2; and 30-day readmission: aOR, 2.8; 95% CI, 2.7-2.9). The addition of HFRS to traditional comorbidity-based risk-prediction models improved discrimination to predict outcomes for all 3 conditions.

CONCLUSIONS AND RELEVANCE: Among Medicare fee-for-service beneficiaries, frailty as measured by the HFRS was associated with mortality and readmissions among patients hospitalized for AMI, HF, or pneumonia. The addition of HFRS to traditional comorbidity-based risk-prediction models improved the prediction of outcomes for all 3 conditions.

BACKGROUND: The role of basal septal hypertrophy (BSH) on preprocedural transthoracic echocardiography in transcatheter aortic valve replacement (TAVR) is unknown.

METHODS: Medical charts and preprocedural transthoracic echocardiograms of 378 patients who underwent TAVR were examined. The association between BSH and the primary composite outcome of valve pop-out, recapture, embolization, aborted procedure, conversion to open procedure, new conduction disturbance, or need for permanent pacemaker ≤30 days after TAVR was evaluated. Patients with preexisting pacemakers were excluded. Sensitivity analyses were performed varying the definition of BSH.

RESULTS: Of 296 TAVR patients (78.3%) with interpretable images, 55 (18.6%) had BSH at a median of 40 days (interquartile range, 19-62 days) before TAVR. Age and sex were similar among those with and without BSH. BSH patients received postdilation more frequently (BSH+ vs BSH-: 41.8% vs 29.9%, P = .04). A total of 50 individuals (16.9%) received pacemakers within 30 days, and 128 (43.2%) developed conduction disturbances (with left bundle branch block most common), without differences between groups. BSH was unrelated to the primary outcome on multivariate analysis (adjusted odds ratio BSH+ vs BSH-, 0.94; 95% CI, 0.42-2.11; P = .88).

CONCLUSIONS: In this convenience sample of TAVR recipients at a large academic medical center, patients with BSH were more likely to receive postdilation. BSH was not associated with procedural or conduction outcomes after TAVR in patients without preexisting pacemakers.

BACKGROUND: Cerebrovascular events (CVEs) are devastating complications after aortic valve replacement. We assessed whether billing claims accurately identify CVEs in place of clinical event adjudication in structural heart disease trials.

METHODS: Adult participants in the US CoreValve High Risk and SURTAVI trials (Surgical or Transcatheter Aortic-Valve Replacement in Intermediate-Risk Patients) were linked to Medicare inpatient claims from January 1, 2006 to December 31, 2016. Claims consistent with CVEs within 14 days of a similar trial-adjudicated CVE were considered a match. The sensitivity, specificity, and positive and negative predictive values of International Classification of Diseases,Ninth andTenthRevisions, Clinical Modification billing codes for cerebrovascular disease were determined against trial-defined CVEs as the criterion standard. Kaplan-Meier estimates of claims-defined versus trial-defined CVEs were compared.

RESULTS: Among 4230 linked trial participants (linkage rate 79.8%), 550 (13.0%) sustained 630 adjudicated CVEs over a 5-year follow-up period. Linked and nonlinked individuals were similar. An algorithm using 4 International Classification of Diseases, Ninth Revision, Clinical Modification codes (434.91, 434.11, 433.11, and 997.02) had a sensitivity of 60.9%, specificity of 99.0%, positive predictive value of 86.5%, and negative predictive value of 95.8% for identifying a trial-adjudicated ischemic stroke. An algorithm using 3 International Classification of Diseases, Tenth Revision, Clinical Modification codes (I63.9, I63.40, I63.49) had a sensitivity of 66.7%, specificity of 99.4%, positive predictive value of 88.9%, and negative predictive value of 97.6%.

CONCLUSIONS: In linked clinical trial and Medicare claims data, 4 International Classification of Diseases, Ninth Revision, Clinical Modification and 3 International Classification of Diseases, Tenth Revision, Clinical Modification billing codes identified half of trial-adjudicated CVEs during follow-up with high specificity and predictive value, but imperfect sensitivity. Although low sensitivity may limit the use of claims to substitute for traditional trial outcomes to identify CVEs, high specificity suggests claims could be used to trigger evaluation of neurological events, potentially improving the efficiency of the evaluation of techniques and devices designed to reduce such events.

AIMS: Despite rising rates of cardiogenic shock (CS), data on trends and in-hospital outcomes of short-term non-durable mechanical circulatory support (MCS) are limited. Thus, we aimed to identify recent national trends in MCS utilisation in the USA, patient-level predictors of MCS use, and in-hospital outcomes in CS inclusive of extracorporeal membrane oxygenation (ECMO).

METHODS AND RESULTS: Hospitalisations of US adults with a discharge diagnosis of CS, from January 2004 to December 2014, in the National Inpatient Sample were included. Rates of MCS were stratified by device type and clinical presentation. Outcomes included in-hospital mortality, hospitalisation costs, and number of procedures. A total of 183,516 hospitalisations with CS (47,636 [25.9%] involving MCS) were included. MCS recipients were younger, less frequently female, received more procedures, had higher costs, and more frequently presented with MI (MCS vs. non-MCS: 71.6% vs. 42.9%; p<0.0001). Growth in CS hospitalisations (214.4%) outpaced annual MCS use (160.0%), with relative declines in intra-aortic balloon pump use starting in 2008. Right heart catheterisation rates for both groups remained low (MCS vs. non-MCS: 5.9% vs. 3.3%; p<0.0001). In-hospital mortality declined but remained high in both groups (MCS vs. non-MCS [2014]: 32.7% vs. 41.5%; p<0.0001).

CONCLUSIONS: In-hospital mortality for CS has declined but remains high. Rates of CS have outpaced MCS utilisation which remains uncommon in non-MI hospitalisations with shock. MCS is associated with utilisation of other procedures during hospitalisation.

OBJECTIVES: Factors associated with performing urgent coronary angiography (UCA) in patients with out-of-hospital cardiac arrest (OHCA) were identified.

BACKGROUND: Current guidelines for resuscitated OHCA patients recommend UCA if there is ST-elevation on post-arrest electrocardiogram or high suspicion of acute myocardial infarction. Some have advocated for UCA in all OHCA regardless of suspected etiology. The reasons for variations in performing UCA are not well understood.

METHODS: A retrospective analysis of subjects presenting with resuscitated OHCA to a single academic medical center from 12/15/2007 to 8/31/2014 was conducted. Demographic and clinical characteristics of patients undergoing UCA, defined as angiography within 6 hr of presentation, were compared with those not undergoing UCA. Logistic regression was used to determine predictors of UCA.

RESULTS: A total of 323 resuscitated OHCA patients (mean age, 64 years; women, 35%) were included in the analysis; 107 (33.1%) underwent coronary angiography during their hospitalization and 66 (20.4%) underwent UCA. Multivariable adjusted factors associated with UCA were ST-elevation [odds ratio (OR) 14.66, 95% confidence interval (CI) 6.28-34.24, P < 0.001], initial shockable rhythm (OR 3.69, 95% CI 1.52-8.97, P = 0.004), and history of coronary artery disease (CAD) (OR 3.37, 95% CI 1.43-7.95, P = 0.005). Higher age (OR 0.71 per decade, 95% CI 0.55-0.92, P = 0.01) and obvious non-cardiac cause of arrest (OR 0.08, 95% CI 0.02-0.38, P = 0.001) were negatively associated with UCA.

CONCLUSIONS: In resuscitated out-of-hospital cardiac arrest patients, ST-elevation, shockable rhythm, and history of CAD were associated with performing urgent coronary angiography; older patients and those with obvious non-cardiac causes of arrest were negatively associated.

BACKGROUND: Readmission rates after hospitalizations for heart failure (HF), acute myocardial infarction (AMI), and pneumonia among Medicare beneficiaries are used to assess quality and determine reimbursement. Whether these measures reflect readmission rates for other conditions or insurance groups is unknown.

OBJECTIVE: To investigate whether hospital-level 30-day readmission measures for publicly reported conditions (HF, AMI, and pneumonia) among Medicare patients reflect those for Medicare patients hospitalized for unreported conditions or non-Medicare patients hospitalized with HF, AMI, or pneumonia.

DESIGN: Cross-sectional.

SETTING: Population-based.

PARTICIPANTS: Hospitals in the all-payer Nationwide Readmissions Database in 2013 and 2014.

MEASUREMENTS: Hospital-level 30-day all-cause risk-standardized excess readmission ratios (ERRs) were compared for 3 groups of patients: Medicare beneficiaries admitted for HF, AMI, or pneumonia (Medicare reported group); Medicare beneficiaries admitted for other conditions (Medicare unreported group); and non-Medicare beneficiaries admitted for HF, AMI, or pneumonia (non-Medicare group).

RESULTS: Within-hospital differences in ERRs varied widely among groups. Medicare reported ratios differed from Medicare unreported ratios by more than 0.1 for 29% of hospitals and from non-Medicare ratios by more than 0.1 for 46% of hospitals. Among hospitals with higher readmission ratios, ERRs for the Medicare reported group tended to overestimate ERRs for the non-Medicare group but underestimate those for the Medicare unreported group.

LIMITATION: Medicare groups and risk adjustment differed slightly from those used by the Centers for Medicare & Medicaid Services.

CONCLUSION: Hospital ERRs, as estimated by Medicare to determine financial penalties, have poor agreement with corresponding measures for populations and conditions not tied to financial penalties. Current publicly reported measures may not be good surrogates for overall hospital quality related to 30-day readmissions.

PRIMARY FUNDING SOURCE: Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology.

BACKGROUND: Apparent increase in mortality associated with being admitted to hospital on a weekend compared to weekdays has led to controversial policy changes to weekend staffing in the United Kingdom. Studies in the United States have been inconclusive and diagnosis specific, and whether to implement such changes is subject to ongoing debate.

OBJECTIVE: To compare mortality, length of stay, and cost between patients admitted on weekdays and weekends.

DESIGN: Retrospective cohort study.

SETTING: National Inpatient Sample, an administrative claims database of a 20% stratified sample of discharges from all hospitals participating in the Healthcare Cost and Utilization Project.

PATIENTS: Adult patients who were emergently admitted from 2012 to 2014.

INTERVENTION: The primary predictor was whether the admission was on a weekday or weekend.

MEASUREMENTS: The primary outcome was in-hospital mortality and secondary outcomes were length of stay and cost.

RESULTS: We included 13,505,396 patients in our study. After adjusting for demographics and disease severity, we found a small difference in inpatient mortality rates on weekends versus weekdays (odds ratio [OR] 1.029; 95% confidence interval [CI], 1.020-1.039; P < .001). There was a statistically significant but clinically small decrease in length of stay (2.24%; 95% CI, 2.16-2.33; P < .001) and cost (1.14%; 95% CI, 1.05-1.24; P < .001) of weekend admissions. A subgroup analysis of the most common weekend diagnoses showed substantial heterogeneity between diagnoses.

CONCLUSIONS: Differences in mortality of weekend admissions may be attributed to underlying differences in patient characteristics and severity of illness and is subject to large between-diagnoses heterogeneity. Increasing weekend services may not result in desired reduction in inpatient mortality rate.