Merging machine learning and patient preference: a novel tool for risk prediction of percutaneous coronary interventions

BACKGROUND AND AIMS

Predicting personalized risk for adverse events following percutaneous coronary intervention (PCI) remains critical in weighing treatment options, employing risk mitigation strategies, and enhancing shared decision-making. This study aimed to employ machine learning models using pre-procedural variables to accurately predict common post-PCI complications.

METHODS

A group of 66 adults underwent a semiquantitative survey assessing a preferred list of outcomes and model display. The machine learning cohort included 107 793 patients undergoing PCI procedures performed at 48 hospitals in Michigan between 1 April 2018 and 31 December 2021 in the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2) registry separated into training and validation cohorts. External validation was conducted in the Cardiac Care Outcomes Assessment Program database of 56 583 procedures in 33 hospitals in Washington.

RESULTS

Overall rate of in-hospital mortality was 1.85% (n = 1999), acute kidney injury 2.51% (n = 2519), new-onset dialysis 0.44% (n = 462), stroke 0.41% (n = 447), major bleeding 0.89% (n = 942), and transfusion 2.41% (n = 2592). The model demonstrated robust discrimination and calibration for mortality {area under the receiver-operating characteristic curve [AUC]: 0.930 [95% confidence interval (CI) 0.920-0.940]}, acute kidney injury [AUC: 0.893 (95% CI 0.883-0.903)], dialysis [AUC: 0.951 (95% CI 0.939-0.964)], stroke [AUC: 0.751 (95%CI 0.714-0.787)], transfusion [AUC: 0.917 (95% CI 0.907-0.925)], and major bleeding [AUC: 0.887 (95% CI 0.870-0.905)]. Similar discrimination was noted in the external validation population. Survey subjects preferred a comprehensive list of individually reported post-procedure outcomes.

CONCLUSIONS

Using common pre-procedural risk factors, the BMC2 machine learning models accurately predict post-PCI outcomes. Utilizing patient feedback, the BMC2 models employ a patient-centred tool to clearly display risks to patients and providers (https://shiny.bmc2.org/pci-prediction/). Enhanced risk prediction prior to PCI could help inform treatment selection and shared decision-making discussions.

Statewide Initiative to Reduce Patient Radiation Doses During Percutaneous Coronary Intervention

BACKGROUND

Improved radiation safety practices are needed across hospitals performing percutaneous coronary intervention (PCI). This study was performed to assess the temporal trend in PCI radiation doses concurrent with the conduct of a statewide radiation safety initiative.

METHODS

A statewide initiative to reduce PCI radiation doses was conducted in Michigan between 2017 and 2021 and included focused radiation safety education, reporting of institutional radiation doses, and implementation of radiation performance metrics for hospitals. Using data from a large statewide registry, PCI discharges between July 1, 2016, and July 1, 2022, having a procedural air kerma (AK) recorded were analyzed for temporal trends. A multivariable regression analysis was performed to determine whether declines in procedural AK over time were attributable to changes in known predictors of radiation doses.

RESULTS

Among 131 619 PCI procedures performed during the study period, a reduction in procedural AK was observed over time, from a median dose of 1.46 (0.86-2.37) Gy in the first year of the study to 0.97 (0.56-1.64) Gy in the last year of the study (P<0.001). The proportion of cases with an AK ≥5 Gy declined from 4.24% to 0.86% over the same time period (P<0.0001). After adjusting for variables known to impact radiation doses, a 1-year increase in the date of PCI was associated with a 7.61% (95% CI, 7.38%-7.84%) reduction in procedural AK (P<0.0001).

CONCLUSIONS

Concurrent with the conduct of a statewide initiative to reduce procedural radiation doses, a progressive and significant decline in procedural radiation doses was observed among patients undergoing PCI in the state of Michigan.

Comparative analysis of percutaneous revascularization practice in the United States and the United Kingdom: Insights from the BMC2 and BCIS databases

BACKGROUND

International registry comparisons provide insight into regional differences in clinical practice patterns, procedural outcomes, and general trends in population health and resource utilization in percutaneous coronary intervention (PCI). We sought to compare data from a state-wide PCI registry in the United States with a national registry from the United Kingdom (UK).

METHODS

We analyzed all PCI cases from the Blue Cross Blue Shield of Michigan Cardiovascular Consortium and the British Cardiovascular Intervention Society registries from 2010 to 2017. Procedural characteristics and in-hospital outcomes were stratified by PCI indication.

RESULTS

A total of 248,283 cases were performed in Michigan and 773,083 in the United Kingdom during the study period. The proportion of patients with a prior diagnosis of diabetes in Michigan was nearly double that in the United Kingdom (38.9% vs. 21.0%). PCI for ST-elevation myocardial infarction was more frequent in the UK (25% UK vs. 14.3% Michigan). Radial access increased in both registries, reaching 86.8% in the United Kingdom versus 45.1% in Michigan during the final study year. Mechanical support utilization was divergent, falling to 0.9% of cases in the United Kingdom and rising to 3.95% of cases in Michigan in 2017. Unadjusted crude mortality rates were similar in the two cohorts, with higher rates of post-PCI transfusion and other complications in the Michigan population.

CONCLUSIONS

In a real-world comparison using PCI registries from the US and UK, notable findings include marked differences in the prevalence of diabetes and other comorbidities, a greater proportion of primary PCI with more robust adoption of transradial PCI in the United Kingdom, and divergent trends in mechanical support with increasing use in Michigan.

Identifying potentially avoidable femoral to popliteal expanded polytetrafluoroethylene bypass for claudication using cross-site blinded peer review

OBJECTIVE

The surgical treatment of claudication can be associated with significant morbidity and costs. There are growing concerns that some patients proceed to interventions without first attempting evidence-based nonoperative management. We used a direct, cross-site, blinded expert review to evaluate the appropriateness of the surgical treatment of claudication.

METHODS

We enlisted practicing vascular surgeons to perform retrospective clinical assessments of lower extremity bypass procedures in a statewide clinical registry. Cases were limited to elective, open, infrainguinal bypasses performed for claudication using prosthetic grafts. Reviewing surgeons were randomly assigned 10 cases from a sample of 139 anonymized bypass operations and instructed to evaluate procedural appropriateness based on their expert opinion and evidence-based guidelines for preoperative treatment, namely, antiplatelet, statin, cilostazol, exercise, and smoking cessation therapy as documented in the medical record. Ninety-day episode payments were estimated from a distinct but similar cohort of patients undergoing lower extremity bypass for claudication.

RESULTS

Of 325 total reviews, surgeons stated they would not have recommended bypass in 134 reviews (41%) and deemed bypass inappropriate in 122 reviews (38%). The most common reason for inappropriateness was lack of preoperative medical and lifestyle therapy, which was present in 63% of reviews where bypass was deemed appropriate and 39% of reviews where bypass was deemed inappropriate (P < .001). Surgeons stated they would have recommended additional preoperative therapy in 65% of reviews where bypass was deemed inappropriate and 35% of reviews where bypass was deemed appropriate (P < .001). The mean total episode payments in a similar cohort of 1458 patients undergoing elective open lower extremity bypass for claudication were $31,301 ± $21,219. Extrapolating to the 325 reviews, the 134 reviews in which surgeons would not have recommended bypass were associated with potentially avoidable estimated total payments of $4,194,334, and the 122 reviews in which bypass was deemed inappropriate were associated with potentially avoidable estimated total payments of $3,818,722.

CONCLUSIONS

In this cross-site expert peer review study, 40% of lower extremity bypasses were deemed premature and, therefore, potentially avoidable, primarily owing to a lack of medical and lifestyle management before surgery. Reviews deemed inappropriate were associated with approximately $4 million in potentially avoidable costs. This approach could inform performance feedback among surgeons to help align clinical practice with evidence-based recommendations for the treatment of claudication.

Race and outcomes after percutaneous coronary intervention: Insights from the Blue Cross Blue Shield of Michigan Cardiovascular Consortium

BACKGROUND

Current studies show similar in-hospital outcomes following percutaneous coronary intervention (PCI) between Black and White patients. Long-term outcomes and the role of individual and community-level socioeconomic factors in differential risk are less understood.

METHODS

We linked clinical registry data from PCIs performed between January, 2013 and March, 2018 at 48 Michigan hospitals to Medicare Fee-for-service claims. We analyzed patients of Black and White race. We used propensity score matching and logistic regression models to estimate the odds of 90-day readmission and Cox regression to evaluate the risk of postdischarge mortality. We used mediation analysis to evaluate the proportion of association mediated by socioeconomic factors.

RESULTS

Of the 29,317 patients included in this study, 10.28% were Black and 89.72% were White. There were minimal differences between groups regarding post-PCI in-hospital outcomes. Compared with White patients, Black patients were more likely to be readmitted within 90-days of discharge (adjusted OR 1.62, 95% CI [1.32-2.00]) and had significantly higher risk of all-cause mortality (adjusted HR 1.45, 95% CI 1.30-1.61) when adjusting for age and gender. These associations were significantly mediated by dual eligibility (proportion mediated [PM] for readmission: 11.0%; mortality: 21.1%); dual eligibility and economic well-being of the patient's community (PM for readmission: 22.3%; mortality: 43.0%); and dual eligibility, economic well-being of the community, and baseline clinical characteristics (PM for readmission: 45.0%; mortality: 87.8%).

CONCLUSIONS

Black patients had a higher risk of 90-day readmission and cumulative mortality following PCI compared with White patients. Associations were mediated by dual eligibility, community economic well-being, and traditional cardiovascular risk factors. Our study highlights the need for improved upstream care and streamlined postdischarge care pathways as potential strategies to improve health care disparities in cardiovascular disease.

Rates of Intracoronary Imaging Optimization in Contemporary Percutaneous Coronary Intervention: A Report From the BMC2 Registry

BACKGROUND

Intracoronary imaging (ICI) during percutaneous coronary intervention (PCI) improves outcomes, yet hospital- and physician-level variabilities in ICI and its impact on ICI use in contemporary PCI remain unknown. This study was performed to evaluate hospital- and physician-level use of ICI to optimize PCI.

METHODS

Using data from a large statewide registry, patients undergoing PCI between July 2019 and March 2021 were studied. The primary measure of interest was ICI (intravascular ultrasound or optical coherence tomography) optimization during PCI. A fitted hierarchical Bayesian model identified variables independently associated with ICI optimization. The performing hospital and physician were included as random effects in the model.

RESULTS

Among 48 872 PCIs, ICI optimization was performed in 8094 (16.6%). Median [interquartile range] hospital- and physician-level frequencies of ICI were 8.8% [3.1%, 16.0%] and 6.1% [1.1%, 25.0%], respectively. Bayesian modeling identified left main PCI (adjusted odds ratio [aOR], 4.41; 95% credible interval [3.82, 5.10]), proximal left anterior descending artery PCI (aOR, 2.28 [2.00, 2.59]), PCI for in-stent restenosis (aOR, 1.55 [1.40, 1.72]), and surgical consult prior to PCI (aOR, 1.21 [1.07, 1.37]) as independent predictors of ICI optimization. The hospital-level median odds ratio, an estimate of the contribution of inter-hospital variability in odds of ICI use, was 3.48 (2.64, 5.04). Physician-level median odds ratio was 3.81 (3.33, 4.45).

CONCLUSIONS

Substantial hospital- and physician-level variation in ICI was observed. Except for performance of left main PCI, the hospital and physician performing the PCI were more strongly associated with ICI optimization than any patient or procedural factors.

Trends and outcomes of percutaneous coronary intervention during the COVID-19 pandemic in Michigan

Background

The COVID-19 pandemic has severely impacted healthcare delivery and patient outcomes globally.

Aims

We aimed to evaluate the influence of the COVID-19 pandemic on the temporal trends and outcomes of patients undergoing percutaneous coronary intervention (PCI) in Michigan.

Methods

We compared all patients undergoing PCI in the BMC2 Registry between March and December 2020 (“pandemic cohort”) with those undergoing PCI between March and December 2019 (“pre-pandemic cohort”). A risk-adjusted analysis of in-hospital outcomes was performed between the pre-pandemic and pandemic cohort. A subgroup analysis was performed comparing COVID-19 positive vs. negative patients during the pandemic.

Results

There was a 15.2% reduction in overall PCI volume from the pre-pandemic (n = 25,737) to the pandemic cohort (n = 21,822), which was more pronounced for stable angina and non-ST-elevation acute coronary syndromes (ACS) presentations, and between February and May 2020. Patients in the two cohorts had similar clinical and procedural characteristics. Monthly mortality rates for primary PCI were generally higher in the pandemic period. There were no significant system delays in care between the cohorts. Risk-adjusted mortality was higher in the pandemic cohort (aOR 1.26, 95% CI 1.07–1.47, p = 0.005), a finding that was only partially explained by worse outcomes in COVID-19 patients and was more pronounced in subjects with ACS. During the pandemic, COVID-19 positive patients suffered higher risk-adjusted mortality (aOR 5.69, 95% CI 2.54–12.74, p<0.001) compared with COVID negative patients.

Conclusions

During the COVID-19 pandemic, we observed a reduction in PCI volumes and higher risk-adjusted mortality. COVID-19 positive patients experienced significantly worse outcomes.

Hospital and Operator Variation in Cardiac Rehabilitation Referral and Participation After Percutaneous Coronary Intervention: Insights From Blue Cross Blue Shield of Michigan Cardiovascular Consortium

BACKGROUND

Despite its established benefit and strong endorsement in international guidelines, cardiac rehabilitation (CR) use remains low. Identifying determinants of CR referral and use may help develop targeted policies and quality improvement efforts. We evaluated the variation in CR referral and use across percutaneous coronary intervention (PCI) hospitals and operators.

METHODS

We performed a retrospective observational cohort study of all patients who underwent PCI at 48 nonfederal Michigan hospitals between January 1, 2012 and March 31, 2018 and who had their PCI clinical registry record linked to administrative claims data. The primary outcomes included in-hospital CR referral and CR participation, defined as at least one outpatient CR visit within 90 days of discharge. Bayesian hierarchical regression models were fit to evaluate the association between PCI hospital and operator with CR referral and use after adjusting for patient characteristics.

RESULTS

Among 54 217 patients who underwent PCI, 76.3% received an in-hospital referral for CR, and 27.1% attended CR within 90 days after discharge. There was significant hospital and operator level variation in in-hospital CR referral with median odds ratios of 3.88 (95% credible interval [CI], 3.06-5.42) and 1.64 (95% CI, 1.55-1.75), respectively, and in CR participation with median odds ratios of 1.83 (95% CI, 1.63-2.15) and 1.40 (95% CI, 1.35-1.47), respectively. In-hospital CR referral was significantly associated with an increased likelihood of CR participation (adjusted odds ratio, 1.75 [95% CI, 1.52-2.01]), and this association varied by treating PCI hospital (odds ratio range, 0.92-3.75) and operator (odds ratio range, 1.26-2.82).

CONCLUSIONS

In-hospital CR referral and 90-day CR use after PCI varied significantly by hospital and operator. The association of in-hospital CR referral with downstream CR use also varied across hospitals and less so across operators suggesting that specific hospitals and operators may more effectively translate CR referrals into downstream use. Understanding the factors that explain this variation will be critical to developing strategies to improve CR participation overall.

Percutaneous Coronary Intervention in Patients With a History of Gastrointestinal Bleeding (From the Blue Cross Blue Shield of Michigan Cardiovascular Consortium)

Potent antithrombotic agents are routinely prescribed after percutaneous coronary intervention (PCI) to reduce ischemic complications. However, in patients who are at an increased bleeding risk, this may pose significant risks. We sought to evaluate the association between a history of gastrointestinal bleeding (GIB) and outcomes after PCI. We linked clinical registry data from PCIs performed at 48 Michigan hospitals between 1/2013 and 3/2018 to Medicare claims. We used 1:5 propensity score matching to adjust for patient characteristics. In-hospital outcomes included bleeding, transfusion, stroke or death. Post-discharge outcomes included 90-day all-cause readmission and long-term mortality. Of 30,206 patients, 1.1% had a history of GIB. Patients with a history of GIB were more likely to be older, female, and have more cardiovascular comorbidities. After matching, those with a history of GIB (n = 312) had increased post-procedural transfusions (15.7% vs 8.4%; p < 0.001), bleeding (11.9% vs 5.2%; p < 0.001), and major bleeding (2.8% vs 0.6%; p = 0.004). Ninety-day readmission rates were similar among those with and without a history of GIB (34.3% vs 31.3%; p = 0.318). There was no significant difference in post-discharge survival (1 year: 78% vs 80%; p = 0.217; 5 years: 54% vs 51%; p = 0.189). In conclusion, after adjusting for baseline characteristics, patients with a history of GIB had increased risk of post-PCI in-hospital bleeding complications. However, a history of GIB was not significantly associated with 90-day readmission or long-term survival.

Marijuana Use and In-Hospital Outcomes After Percutaneous Coronary Intervention in Michigan, United States

OBJECTIVES

The aim of this study was to evaluate the association between reported marijuana use and post-percutaneous coronary intervention (PCI) in-hospital outcomes.

BACKGROUND

Marijuana use is increasing as more states in the United States legalize its use for recreational and medicinal purposes. Little is known about the frequency of use and relative safety of marijuana among patients presenting for PCI.

METHODS

The authors analyzed Blue Cross Blue Shield of Michigan Cardiovascular Consortium PCI registry data between January 1, 2013, and September 30, 2016. One-to-one propensity matching and multivariable logistic regression were used to adjust for differences between patients with or without reported marijuana use, and rates of post-PCI complications were compared.

RESULTS

Among 113,477 patients, 3,970 reported marijuana use. Compared with those without reported marijuana use, patients with reported marijuana use were likely to be younger (53.9 years vs 65.8 years), to use tobacco (73.0% vs 26.8%), to present with ST-segment elevation myocardial infarction (27.3% vs 15.9%), and to have fewer cardiovascular comorbidities. After matching, compared with patients without reported marijuana use, those with reported marijuana use experienced significantly higher risks for bleeding (adjusted odds ratio [aOR]: 1.54; 95% confidence interval [CI]: 1.20-1.97; P < 0.001) and cerebrovascular accident (aOR: 11.01; 95% CI: 1.32-91.67; P = 0.026) and a lower risk for acute kidney injury (aOR: 0.61; 95% CI: 0.42-0.87; P = 0.007). There were no significant differences in risks for transfusion and death.

CONCLUSIONS

A modest fraction of patients undergoing PCI used marijuana. Reported marijuana use was associated with higher risks for cerebrovascular accident and bleeding and a lower risk for acute kidney injury after PCI. Clinicians and patients should be aware of the higher risk for post-PCI complications in these patients.

Prevalence of coronary risk factors in contemporary practice among patients undergoing their first percutaneous coronary intervention: Implications for primary prevention

Background

Cigarette smoking, hypertension, dyslipidemia, diabetes, and obesity are conventional risk factors (RFs) for coronary artery disease (CAD). Population trends for these RFs have varied in recent decades. Consequently, the risk factor profile for patients presenting with a new diagnosis of CAD in contemporary practice remains unknown.

Objectives

To examine the prevalence of RFs and their temporal trends among patients without a history of myocardial infarction or revascularization who underwent their first percutaneous coronary intervention (PCI).

Methods

We examined the prevalence and temporal trends of RFs among patients without a history of prior myocardial infarction, PCI, or coronary artery bypass graft surgery who underwent PCI at 47 non-federal hospitals in Michigan between 1/1/2010 and 3/31/2018.

Results

Of 69,571 men and 38,930 women in the study cohort, 95.5% of patients had 1 or more RFs and nearly half (55.2% of women and 48.7% of men) had ≥3 RFs. The gap in the mean age at the time of presentation between men and women narrowed as the number of RFs increased with a gap of 6 years among those with 2 RFs to <1 year among those with 5 RFs. Compared with patients without a current/recent history of smoking, those with a current/recent history of smoking presented a decade earlier (age 56.8 versus 66.9 years; p <0.0001). Compared with patients without obesity, patients with obesity presented 4.0 years earlier (age 61.4 years versus 65.4 years; p <0.0001).

Conclusions

Modifiable RFs are widely prevalent among patients undergoing their first PCI. Smoking and obesity are associated with an earlier age of presentation. Population-level interventions aimed at preventing obesity and smoking could significantly delay the onset of CAD and the need for PCI.

The DISCO study-Does Interventionalists' Sex impact Coronary Outcomes?

OBJECTIVES

To examine the association of operator sex with appropriateness and outcomes of percutaneous coronary intervention (PCI).

BACKGROUND

Recent studies suggest that physician sex may impact outcomes for specific patient cohorts. There are no data evaluating the impact of operator sex on PCI outcomes.

METHODS

We studied the impact of operator sex on PCI outcome and appropriateness among all patients undergoing PCI between January 2010 and December 2017 at 48 non-federal hospitals in Michigan. We used logistic regression models to adjust for baseline risk among patients treated by male versus female operators in the primary analysis.

RESULTS

During this time, 18 female interventionalists and 385 male interventionalists had performed at least one PCI. Female interventionalists performed 6362 (2.7%) of 239,420 cases. There were no differences in the odds of mortality (1.48% vs. 1.56%, adjusted OR [aOR] 1.138, 95% CI: 0.891-1.452), acute kidney injury (3.42% vs. 3.28%, aOR 1.027, 95% CI: 0.819-1.288), transfusion (2.59% vs. 2.85%, aOR 1.168, 95% CI: 0.980-1.390) or major bleeding (0.95% vs. 1.07%, aOR 1.083, 95% CI: 0.825-1.420) between patients treated by female versus male interventionalist. While the absolute differences were small, PCIs performed by female interventional cardiologists were more frequently rated as appropriate (86.64% vs. 84.45%, p-value <0.0001). Female interventional cardiologists more frequently prescribed guideline-directed medical therapy.

CONCLUSIONS

We found no significant differences in risk-adjusted in-hospital outcomes between PCIs performed by female versus male interventional cardiologists in Michigan. Female interventional cardiologists more frequently performed PCI rated as appropriate and had a higher likelihood of prescribing guideline-directed medical therapy.

Comparative Safety of Bioabsorbable Polymer Everolimus-Eluting, Durable Polymer Everolimus-Eluting, and Durable Polymer Zotarolimus-Eluting Stents in Contemporary Clinical Practice

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Leptin and obesity

An imbalance between calorie intake and energy expenditure produces obesity. It has been a major problem in societies of the developing and developed world. In obesity an excessive amount of fat accumulates in adipose tissue cells as well as in other vital organs like liver, muscles, and pancreas. The adipocytes contain ob genes and express leptin, a 16 kDa protein. In the present communication, we reviewed the molecular basis of the etiopathophysiology of leptin in obesity. Special emphasis has been given to the use of leptin as a drug target for obesity treatment, the role of diet in the modulation of leptin secretion, and reduction of obesity at diminished level of blood leptin induced by physical exercise.

Effect Of Transtibial Prosthesis Mass On Gait Asymmetries

BACKGROUND

Individuals with transtibial amputation (TTA) typically walk with an asymmetrical gait pattern, which may predispose them to secondary complications and increase risk of fall. Gait asymmetry may be influenced by prosthesis mass.

OBJECTIVES

To explore the effects of prosthesis mass on temporal and limb loading asymmetry in people with TTA following seven days of acclimation and community use.

METHODOLOGY

Eight individuals with transtibial amputation participated. A counterbalanced repeated measures study, involving three sessions (each one week apart) was conducted, during which three load conditions were examined: no load, light load and heavy load. The light load and heavy load conditions were achieved by adding 30% and 50% of the mass difference between legs, at a proximal location on the prosthesis. Kinematic and ground reaction force data was captured while walking one week after the added mass. Symmetry indices between the prosthetic and intact side were computed for temporal (Stance and Swing time) and limb loading measures (vertical ground reaction force Peak and Impulse).

FINDINGS

Following seven days of acclimation, no significant differences were observed between the three mass conditions (no load, light load and heavy load) for temporal (Stance time: p=0.61; Swing time: p=0.13) and limb loading asymmetry (vertical ground reaction force Peak: p=0.95; vertical ground reaction force Impulse: p=0.55).

CONCLUSIONS

Prosthesis mass increase at a proximal location did not increase temporal and limb loading asymmetry during walking in individuals with TTA. Hence, mass increase subsequent to replacing proximally located prosthesis components may not increase gait asymmetry, thereby allowing more flexibility to the clinician for component selection.

Trends and outcomes of non-primary PCI at sites without cardiac surgery on-site: The early Michigan experience

Introduction

Non-primary percutaneous coronary intervention (non-PPCI) recently received certificate of need approval in the state of Michigan at sites without cardiac surgery on-site (cSoS). This requires quality oversight through participation in the BMC2 registry. While previous studies have indicated the safety of this practice, real-world comprehensive outcomes, case volume changes, economic impacts, and readmission rates at diverse healthcare centers with and without cSoS remain poorly understood.

Methods

Consecutive patients undergoing non-PPCI at 47 hospitals (33 cSoS and 14 non-cSoS) in Michigan from April 2016 to March 2018 were included. Using propensity-matching, patients were analyzed to assess outcomes and trends in non-PPCI performance at sites with and without cSOS.

Results

Of 61,864 PCI’s performed, 50,817 were non-PPCI, with 46,096 (90.7%) performed at sites with cSoS and 4,721 (9.3%) at sites without cSoS. From this cohort, 4,643 propensity-matched patients were analyzed. Rates of major adverse cardiac events (2.6% vs. 2.8%; p = 0.443), in-hospital mortality (0.6% vs. 0.5%; p = 0.465), and several secondary clinical and quality outcomes showed no clinically significant differences. Among a small subset with available post-discharge data, there were no differences in 90-day readmission rates, standardized episode costs, or post-discharge mortality. Overall PCI volume remained stable, with a near three-fold rise in non-PPCI at sites without cSoS.

Conclusions

Non-PPCI at centers without cardiac SoS was associated with similar comprehensive outcomes, quality of care, 90-day episode costs, and post-discharge mortality compared with surgical sites. Mandatory quality oversight serves to maintain appropriate equivalent outcomes and may be considered for other programs, including the performance of non-PPCI at ambulatory surgical centers in the near future.

Association of Operator and Hospital Experience With Procedural Success Rates and Outcomes in Patients Undergoing Percutaneous Coronary Interventions for Chronic Total Occlusions

Background:

An inverse relationship has been described between procedural success and outcomes of all major cardiovascular procedures. However, this relationship has not been studied for percutaneous coronary intervention (PCI) of chronic total occlusion (CTO).

Methods:

We analyzed the data on patients enrolled in Blue Cross Blue Shield of Michigan Cardiovascular Consortium registry in Michigan (January 1, 2010 to March 31, 2018) to evaluate the association of operator and hospital experience with procedural success and outcomes of patients undergoing CTO-PCI. CTO-PCI was defined as intervention of a 100% occluded coronary artery presumed to be ≥3 months old.

Results:

Among 210 172 patients enrolled in the registry, 7389 (3.5%) CTO-PCIs were attempted with a success rate of 53%. CTO-PCI success increased with operator experience (45% and 65% in the lowest and highest experience tertiles) and was the highest for highly experienced operators at higher experience centers and the lowest for inexperienced operators at low experience hospitals. Multivariable logistic regression models (with spline transformed prior operator and institutional experience) demonstrated a positive relationship between prior operator and site experience and procedural success rates (likelihood ratio test=141.12, df=15, P <0.001) but no relationship between operator and site experience and major adverse cardiac event (likelihood ratio test=19.12, df=15, P =0.208).

Conclusions:

Operator and hospital CTO-PCI experiences were directly related to procedural success but were not related to major adverse cardiac event among patients undergoing CTO-PCIs. Inexperienced operators at high experience centers had significantly higher success but not major adverse cardiac event rates compared with inexperienced operators at low experience centers. These data suggested that CTO-PCI safety and success could potentially be improved by selective referral of these procedures to experienced operators working at highly experienced centers.

Drivers of Variation in 90-Day Episode Payments After Percutaneous Coronary Intervention

BACKGROUND

Percutaneous coronary intervention (PCI) is a common and expensive procedure that has become a target for bundled payment initiatives. We described the magnitude and determinants of variation in 90-day PCI episode payments across a diverse array of patients and hospitals.

METHODS AND RESULTS

We linked clinical registry data from PCIs performed at 33 Michigan hospitals to 90-day episodes of care constructed using Medicare fee-for-service and commercial insurance claims from January 2012 to October 2016. Payments were price standardized and risk adjusted using clinical and administrative variables in an observed-over-expected framework. Hospitals were stratified into quartiles based on average episode payments. Payment components between the highest and the lowest quartiles were compared with identified drivers of variation (ie, index hospitalization/procedure, readmissions, postacute care, and professional fees). Among 40 925 90-day PCI episodes, the average risk-adjusted 90-day episode payment by hospital ranged between $22 154 and $27 205 with a median of $24 696 (interquartile range, $24 190-$25 643). Hospitals in the lowest and the highest quartiles had average episode payments of $23 744 and $26 504, respectively (difference, $2760). Readmission payments were the primary driver of this variation (46.2%), followed by postacute care (22.6%). Readmissions remained the primary driver of variation in key subgroups, including inpatient and outpatient PCI, as well as PCI for acute myocardial infarction and nonacute myocardial infarction indications.

CONCLUSIONS

Substantial hospital-level variation exists in 90-day PCI episode payments. Over half the variation between high- and low-payment hospitals was related to care after the index procedure, primarily because of readmissions and postacute care. Hospitals and policymakers should consider targeting these components when developing initiatives to reduce PCI-related spending.

Occurrence, management and outcome of immune-complex glomerulonephritis in dogs with suspected glomerulopathy in the UK

OBJECTIVES

To determine the proportion of dogs diagnosed with immune-complex glomerulonephritis in a large cohort of UK dogs with clinical suspicion of glomerular disease in which renal histopathology, including routine light microscopy, transmission electron microscopy and immunofluorescence, had been performed. The second objective was to describe treatment and long-term clinical outcome of dogs diagnosed with immune-complex glomerulonephritis.

MATERIALS AND METHODS

Sixty-two UK dogs that underwent renal biopsies for investigation of suspected glomerulopathy (urine protein-to-creatinine ratio persistently >0.5) were included in this retrospective multicentre study. Signalment, clinico-pathological abnormalities, histopathological diagnosis, treatment following diagnosis and survival were recorded.

RESULTS

Seventeen (27%) of the dogs with suspected glomerular disease were diagnosed with immune-complex glomerulonephritis and nine (53%) of these were still alive at the study end point, with a median follow-up of 366 days (range 52 to 1299). Six dogs diagnosed with immune-complex glomerulonephritis were treated with mycophenolate. Four received mycophenolate alone for immunosuppression and two received mycophenolate and chlorambucil; all these six dogs were alive at data collection [median follow-up time 712.5 days (range 73 to 1299)]. Seven dogs diagnosed with immune-complex glomerulonephritis did not receive immunosuppressive treatment; only one of these dogs was alive at study end point [median survival time 302 days (range 52 to 723)].

CLINICAL SIGNIFICANCE

Immune-complex glomerulonephritis may be less common in the UK than previously reported in North America and mainland Europe, reducing the likelihood of treatment modification following renal biopsy. Mycophenolate was the most commonly used immunosuppressant for cases of immune-complex glomerulonephritis.

Exploring the Healthcare Value of Percutaneous Coronary Intervention: Appropriateness, Outcomes, and Costs in Michigan Hospitals

BACKGROUND

Assessments of healthcare value have largely focused on measuring outcomes of care at a given level of cost with less attention paid to appropriateness. However, understanding how appropriateness relates to outcomes and costs is essential to determining healthcare value.

METHODS AND RESULTS

In a retrospective cohort study design, administrative data from fee-for-service Medicare patients undergoing percutaneous coronary intervention (PCI) in Michigan hospitals between June 30, 2010, and December 31, 2014, were linked with clinical data from a statewide PCI registry to calculate hospital-level measures of (1) appropriate use criteria scores, (2) 90-day risk-standardized readmission and mortality rates, and (3) 90-day risk-standardized episode costs. We then used Spearman correlation coefficients to assess the relationship between these measures. A total of 29 839 PCIs were performed at 33 PCI hospitals during the study period. A total of 13.3% were for ST-segment-elevation myocardial infarction, 25.0% for non-ST-segment-elevation myocardial infarction, 47.1% for unstable angina, 9.8% for stable angina, and 4.7% for other. The overall hospital-level mean appropriate use criteria score was 8.4±0.2. Ninety-day risk-standardized readmission occurred in 23.7%±3.7% of cases, 90-day risk-standardized mortality in 4.3%±0.6%, and mean risk-standardized episode costs were $26 159±$1074. Hospital-level appropriate use criteria scores did not correlate with 90-day readmission, mortality, or episode costs.

CONCLUSIONS

Among Medicare patients undergoing PCI in Michigan, we found hospital-level appropriate use criteria scores did not correlate with 90-day readmission, mortality, or episode costs. This finding suggests that a comprehensive understanding of healthcare value requires multidimensional consideration of appropriateness, outcomes, and costs.

Outcomes After Percutaneous Coronary Intervention in Patients With a History of Cerebrovascular Disease: Insights From the Blue Cross Blue Shield of Michigan Cardiovascular Consortium

BACKGROUND

Because of shared risk factors between coronary artery disease and cerebrovascular disease, patients with a history of transient ischemic attack (TIA) or stroke are at greater risk of developing coronary artery disease, which may require percutaneous coronary intervention (PCI). However, there remains a paucity of research examining outcomes after PCI in these patients.

METHODS AND RESULTS

We analyzed consecutive patients who underwent PCI between January 1, 2013, and March 31, 2016, at 47 Michigan hospitals and identified those with a history of TIA/stroke. We used propensity score matching to adjust for differences in baseline characteristics and compared in-hospital outcomes between patients with and without a history of TIA/stroke. We compared rates of 90-day readmission and long-term mortality in a subset of patients. Among 98 730 patients who underwent PCI, 10 915 had a history of TIA/stroke. After matching (n=10 618 per group), a history of TIA/stroke was associated with an increased risk of in-hospital stroke (adjusted odds ratio, 2.04; 95% confidence interval, 1.41-2.96; P<0.001). There were no differences in the risks of other in-hospital outcomes. In a subset of patients with postdischarge data, a history of TIA/stroke was associated with increased risks of 90-day readmission (adjusted odds ratio, 1.22; 95% confidence interval, 1.09-1.38; P<0.001) and long-term mortality (hazard ratio, 1.23; 95% confidence interval, 1.07-1.43; P=0.005).

CONCLUSIONS

A history of TIA/stroke was common in patients who underwent PCI and was associated with increased risks of in-hospital stroke, 90-day readmission, and long-term mortality. Given the devastating consequences of post-PCI stroke, patients with a history of TIA/stroke should be counseled on this increased risk before undergoing PCI.

Association between ultrasonographic appearance of urine and urinalysis in dogs and cats

OBJECTIVE

To evaluate association between ultrasonographic urine echogenicity and sediment examination in dogs and cats.

MATERIALS AND METHODS

Dogs and cats undergoing ultrasound-guided cystocentesis at a multidisciplinary referral hospital. Ultrasonographic images were stored and reviewed by a single, blinded, board-certified radiologist. Urine appearance was described as "echoic" or "anechoic". Urine sediment was examined for bacteriuria, pyuria, haematuria, crystalluria and urine-specific gravity and then classified as "active" or "inactive."

RESULTS

Of the 194 cases included in this study, urine was echoic in 52 and anechoic in 142. Sediment was active in 52 and inactive in 142 samples. Sensitivity and specificity of echoic urine for active sediment were 40% (95% CI: 27 to 55%) and 78% (95% CI: 70 to 85%), respectively. Positive predictive value and negative predictive value of echoic urine for active sediment were 40% (CI 30 to 52%) and 78% (CI 74 to 82%), respectively. If urine-specific gravity was <1.015 urine was always described ultrasonographically as anechoic.

CLINICAL SIGNIFICANCE

Association between sediment analysis and ultrasonographic appearance of urine is poor. Echoic urine had low positive predictive value for active sediment in this study, suggesting that echoic urine alone should not prompt urinary investigations in the absence of other clinical suspicion. Despite a negative predictive value of 78%, urinalysis is still indicated for anechoic urine, especially if urine specific gravity is low.

Primary percutaneous coronary intervention at centers with and without on-site surgical support: Insights from the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2)

BACKGROUND

Primary percutaneous coronary intervention (PPCI) is being increasingly performed nationally at sites without on-site cardiac surgery; however, recent guidelines only provide a Class IIa recommendation for this practice. The state of Michigan has permitted PPCI without on-site surgery under a closely monitored system that mandates auditing of all procedures and quarterly feedback on quality and outcomes. This study sought to compare outcomes of patients undergoing PPCI at centers with and without on-site surgery in the state of Michigan.

METHODS

Consecutive patients who underwent PPCI at 47 hospitals in Michigan from January 2010 to December 2015 were included. From this cohort, 4,091 patients from sites with and without on-site cardiac surgery were propensity matched in a 1:1 fashion to compare baseline characteristics, procedural details, and in-hospital outcomes.

RESULTS

Of the 25,886 PPCIs performed at 47 hospitals in Michigan from 2010 to 2015, 21,610 (83.5%) were performed at sites with on-site surgery and 4,276 (16.5%) at sites without on-site surgery. Using propensity score matched cohorts (4,091 patients for each site type), we found no significant differences in baseline characteristics. Overall mortality (5.4% vs 5.8%; P=.442); composite outcome of in-hospital mortality, contrast-induced nephropathy, bleeding, and stroke (13.8% vs 12.8%; P=.152); and individual outcomes within the composite group showed no significant differences. Additionally, there were no clinically meaningful differences in rates of urgent/emergent coronary artery bypass graft or length of stay. Significant differences, however, were found in procedural access site, antiplatelet therapy, contrast volume, and anticoagulant strategy.

CONCLUSIONS

Primary PCI performed at centers with and without cardiac surgery have comparable outcomes and complication rates when performed with close monitoring of quality and outcomes.

Ninety-Day Readmission and Long-Term Mortality in Medicare Patients (≥65 Years) Treated With Ticagrelor Versus Prasugrel After Percutaneous Coronary Intervention (from the Blue Cross Blue Shield of Michigan Cardiovascular Consortium)

Ticagrelor and prasugrel were found to be superior to clopidogrel for the treatment of acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI); however, the comparative effectiveness of these 2 drugs remains unknown. We compared postdischarge outcomes among older patients treated with ticagrelor versus prasugrel after PCI for ACS. We linked clinical data from PCIs performed in older patients (age ≥65) for ACS at 47 Michigan hospitals to Medicare fee-for-service claims from January 1, 2013, to December 31, 2014, to ascertain rates of 90-day readmission and long-term mortality. We used propensity score matching to adjust for the nonrandom use of ticagrelor and prasugrel at discharge. Logistic regression and Cox proportional hazards models were used to compare rates of 90-day readmission and long-term mortality, respectively. Patients discharged on ticagrelor (n = 1,243) were more frequently older, female, had a history of cerebrovascular disease, and presented with ST- or non-ST-elevation myocardial infarction compared with prasugrel (n = 1,014). After matching (n = 756 per group), there were no significant differences in the rates of 90-day readmission (16.7% ticagrelor vs 14.6% prasugrel; adjusted odds ratio 1.15, 95% confidence interval 0.86 to 1.55, p = 0.35) or 1-year mortality (5.4% ticagrelor vs 3.7% prasugrel; hazard ratio 1.3, 95% confidence interval 0.8 to 2.2, p = 0.31). In conclusion, we found no significant differences in the rates of 90-day readmission or long-term mortality between older patients treated with ticagrelor and patients treated with prasugrel after PCI for ACS. In the absence of randomized data to the contrary, these 2 treatments appear similarly effective.

Appropriateness and Outcomes of Percutaneous Coronary Intervention at Top-Ranked and Nonranked Hospitals in the United States

OBJECTIVES

This study sought to compare the appropriate use and outcomes of percutaneous coronary intervention (PCI) between top-ranked and nonranked hospitals.

BACKGROUND

The U.S. News & World Report "Best Hospitals" rankings are an influential consumer-directed publication of hospital quality, and are commonly used in promotional campaigns by hospital systems.

METHODS

Hospitals in the National Cardiovascular Data Registry CathPCI registry between July 1, 2014, and June 30, 2015, were classified as top-ranked if they were included in the 2015 U.S. News & World Report 50 best "Cardiology and Heart Surgery" hospitals. The remaining were classified as nonranked. We compared in-hospital mortality, post-procedural bleeding, post-procedural acute kidney injury, and the proportion of appropriate PCI procedures between top-ranked and nonranked hospitals.

RESULTS

A total of 509,153 PCIs at 654 hospitals were included, of which 55,550 (10.9%) were performed at 44 top-ranked hospitals. After adjusting for patient case mix, PCIs performed at top-ranked hospitals had similar odds of in-hospital mortality (adjusted odds ratio [aOR]: 0.96; 95% confidence interval [CI]: 0.83 to 1.12; p = 0.64), acute kidney injury (aOR: 1.10; 95% CI: 0.98 to 1.22; p = 0.099), and bleeding (aOR: 1.15; 95% CI: 0.99 to 1.31; p = 0.052). Top-ranked hospitals had a slightly lower proportion of appropriate PCI compared with nonranked hospitals (89.2% vs. 92.8%; OR: 0.56; 95% CI: 0.45 to 0.69; p < 0.001).

CONCLUSIONS

PCI performed at top-ranked hospitals was not associated with superior outcomes compared with PCI at nonranked hospitals. The inclusion of metrics based on clinical data may be important for hospital quality rankings.