Quality of care in surgical/interventional vascular medicine: what can routinely collected data from the insurance companies achieve?

Short Term Outcomes and Treatment Intensity of Major Cardiovascular Emergencies During the COVID-19 Pandemic in Germany

OBJECTIVE

There has been a decline in hospital admission rates in many countries since the beginning of the COVID-19 pandemic. Patient selection differed from episodes before the pandemic. This study investigated changes in baseline characteristics as well as the short term mortality rate and probability of receiving an invasive procedure while considering sex disparities.

METHODS

Claims data provided by Germany's second largest insurance fund, BARMER, were used. Patients without COVID-19 who were treated for ST segment elevation myocardial infarction (STEMI), non-ST segment elevation myocardial infarction (NSTEMI), acute limb ischaemia (ALI), and stroke between 1 January 2018 and 31 December 2021 were included. Outcomes were compared separately for both sexes between the years before the pandemic (2018/2019) and during the pandemic (2020/2021). Propensity scores with exact matching were used to balance confounders including age, drug prescriptions in the previous year, federal state, month of admission, domiciliary care, and the Elixhauser comorbidities. Short term death and probability of invasive procedures were determined using cumulative incidence functions and Cox regressions.

RESULTS

The cohort consisted of 140 989 hospitalisations of 122 340 individual patients (48.3% female) with 102 960 matched cases. Baseline characteristics were similar between episodes in the unmatched cohort. Earlier discharge was observed for all strata except for males with ALI or STEMI, where the probability of early discharge was unchanged. The probability of receiving an invasive procedure was increased for both sexes with ALI, NSTEMI, and STEMI but not for stroke. The analyses suggested neither a statistically significant increase of the in hospital mortality rate nor the 30 day mortality rate after the pandemic started.

CONCLUSION

There was no evidence for a direct or indirect impact of the pandemic on major short term hospital outcomes. While the probability of receiving an invasive procedure increased for STEMI, NSTEMI, and ALI, the overall short term mortality rate was unaffected for both sexes.

Editor's Choice - Long Term Outcomes After Invasive Treatment of Carotid Artery Stenosis: a Longitudinal Study of German Health Insurance Claims

OBJECTIVE

There is a paucity of observational data including long term outcomes after invasive treatment for carotid artery stenosis.

METHODS

This retrospective study used nationwide insurance claims from the third largest provider in Germany, DAK-Gesundheit. Patients who underwent inpatient carotid endarterectomy (CEA) or carotid artery stenting (CAS) between 1 January 2008 and 31 May 2017 were included. The Elixhauser comorbidity scores from longitudinally linked hospital episodes were used. Kaplan-Meier analysis and the log rank test were used to determine long term stroke free survival. Multivariable regression models were developed to adjust for confounding.

RESULTS

A total of 22 637 individual patients (41.6% female, median age 72.5 years) were included, of whom 15 005 (66.3%) were asymptomatic and 17 955 (79.3%) underwent CEA. After a median of 48 months, 5 504 any stroke or death events were registered. The mortality rate varied between 0.4% (CEA for asymptomatic stenosis) and 2.1% (urgent CAS for acute stroke patients) at 30 days, and between 4.1% and 8.4% at one year, respectively. The rate for any stroke varied between 0.6% (CEA for asymptomatic stenosis) and 2.5% (CAS for symptomatic patients) at 30 days, and between 2.5% and 6.4% at one year, respectively. The combined rate for any stroke and mortality at one year was 6.3% (CEA for asymptomatic stenosis), 8.7% (CAS for asymptomatic stenosis), and 12.5% (urgent CAS for acute stroke patients). After five years, the overall stroke rate was 7.4% after CEA and 9.0% after CAS. In adjusted analyses, both older age and van Walraven comorbidity score were associated with events, while treatment of asymptomatic stenosis was associated with lower event rates.

CONCLUSION

The current study revealed striking differences between previous landmark trials and real world practice. It further suggested excess deaths among invasively treated asymptomatic patients.

Limb Related Outcomes of Endovascular vs. Open Surgical Revascularisation in Patients with Peripheral Arterial Occlusive Disease: A Report from the Prospective GermanVasc Cohort Study

OBJECTIVE

The goal of this study was to compare clinical outcomes in patients with peripheral arterial occlusive disease undergoing revascularisation by peripheral endovascular intervention (EVI), bypass surgery, endarterectomy (EA), and hybrid surgery in an unselected real world setting.

METHODS

This was a German, prospective, multicentre, comparative cohort study, enrolling patients at hospital admission for revascularisation at 35 vascular centres with 12 months of follow up. Primary composite endpoints were major amputation or death, major adverse limb events, and any minor or major amputation. Twelve month incidences and hazard ratios (HRs) for the four subgroups and 95% confidence intervals (CIs) were estimated using Kaplan-Meier functions and Cox proportional hazard models. Sociodemographic and clinical characteristics, pharmacological treatment, and comorbidities were used to adjust for patient differentials (unique identifier ClinicalTrials.gov: NCT03098290).

RESULTS

In total, 4 475 patients were analysed (mean age 69 years, 69.4% males, and 31.5% suffering from chronic limb threatening ischaemia). After 12 months of follow up, 5.3% (95% CI 3.6 - 6.9%) of the patients experienced either death or major amputation, 7.2% (95% CI 4.8 - 9.6%) major adverse limb event, and 6.6% (95% CI 5.0 - 8.2%) any minor or major amputation. Compared with EVI, bypass surgery was associated with an increased risk of amputation or death (HR 2.59, 95% CI 1.75 - 3.85), major adverse limb event (HR 1.93, 95% CI 1.11 - 3.36), and any minor or major amputation (HR 2.12, 95% CI 1.42 - 3.16), and hybrid surgery with an increased risk of amputation or death (HR 2.29, 95% CI 1.27 - 4.13) and major adverse limb event (HR 1.62, 95% CI 1.03 - 2.54). After adjusting for patient differentials, no significant differences among study groups remained.

CONCLUSION

More favourable outcomes after EVI were completely attributed to differentials in patient characteristics and not procedure type. The current study emphasised that all competing approaches performed similarly in a real world setting.

The Relationship Between Hospital Procedure Volume and Outcomes After Endovascular or Open Surgical Revascularisation for Peripheral Arterial Disease: An Analysis of Health Insurance Claims Data

OBJECTIVE

There is a paucity of data on the relationship between hospital procedure volume and outcomes after inpatient treatment of symptomatic peripheral arterial disease (PAD). This study aimed to generate meaningful hypotheses to support the ongoing discussion.

METHODS

Data derived from BARMER, Germany's second largest insurance provider, were linked with nationwide hospital procedure volumes from mandatory hospital quality reports. All endovascular (EVR) and open surgical revascularisations (OSR) provided to patients (≥ 40 years) with symptomatic PAD between 1 January 2013 and 31 December 2018 were included. Hospital volume was defined as the number of procedures performed by a hospital in the previous calendar year (in quartiles). Freedom from re-intervention, amputation, and overall mortality rate within 12 months after discharge were analysed using multivariable Cox proportional hazards models. In hospital mortality was determined by generalised estimating equations logistic regression models.

RESULTS

There were 88 187 revascularisations (72.4% EVR; EVR: 72.7 years and 45.2% females; OSR: 71.9 years and 41.9% females) registered by 668 hospitals. No statistically significant association was found between 12 month freedom from re-intervention and hospital volume (EVR: 4; quartile HR 1.05; 95% CI 0.94 - 1.16. OSR: 4; quartile HR 1.05; 95% CI 0.92 - 1.21). Patients with OSR had a decreased hazard of 12 month mortality in a high volume hospital compared with a low volume hospital (HR 0.85; 95% CI 0.73 - 0.98), but not with EVR (HR 1.03; 95% CI 0.91 - 1.16). Patients who were treated in hospitals with highest volumes showed decreased hazards of 12 month freedom from amputation when compared with low volume hospitals (EVR: HR 0.72; 95% CI 0.52 - 0.99. OSR: HR 0.61; 95% CI 0.44 - 0.85).

CONCLUSION

This large retrospective analysis of insurance claims suggests that higher procedure volume is associated with lower major amputation rates, although there is a need for standardisation of the definition of volume stratification. Future studies should address the impact of subsequent outpatient care and surveillance to further examine the complex interaction between treatment and outcomes.

Initiation of SGLT2 Inhibitors and the Risk of Lower Extremity Minor and Major Amputation in Patients with Type 2 Diabetes and Peripheral Arterial Disease: A Health Claims Data Analysis

OBJECTIVE

To assess the association between long term risk of hospitalisation for heart failure (HHF) and lower extremity minor and major amputation (LEA) in patients initiating sodium glucose cotransporter 2 inhibitors (SGLT2i) suffering from type 2 diabetes and peripheral arterial disease (PAD). Outcomes were compared with patients without PAD and evaluated separately for the time periods before and after the official warning of the European Medicines Agency (EMA) in early 2017.

METHODS

This study used BARMER German health claims data including all patients suffering from type 2 diabetes initiating SGLT2i therapy between 1 January 2013 and 31 December 2019 with follow up until the end of 2020. New users of glucagon like peptide 1 receptor agonists (GLP1-RAs) were used as active comparators. Inverse probability weighting with truncated stabilised weights was used to adjust for confounding, and five year risks of HHF and LEA were estimated using Cox regression. Periods before and after the EMA warning were analysed separately and stratified by presence of concomitant PAD.

RESULTS

In total, 44 284 (13.6% PAD) and 56 878 (16.3% PAD) patients initiated SGLT2i or GLP1-RA, respectively. Before the EMA warning, initiation of SGLT2i was associated with a lower risk of HHF in patients with PAD (hazard ratio, HR, 0.85, 95% confidence interval, CI, 0.73 - 0.99) and a higher risk of LEA in patients without PAD (HR 1.79, 95% CI 1.04 - 2.92). After the EMA warning, the efficacy and safety endpoints were no longer statistically different between groups.

CONCLUSION

The results from this large nationwide real world study highlight that PAD patients exhibit generally high amputation risks. This study refutes the idea that the presence of PAD explains the excess LEA risk associated with initiation of SGLT2i. The fact that differentials among study groups diminished after the EMA warning in early 2017 emphasises that regulatory surveillance measures worked in everyday clinical practice.

Sex Disparities in Long-Term Mortality after Paclitaxel Exposure in Patients with Peripheral Artery Disease: A Nationwide Claims-Based Cohort Study

BACKGROUND

Randomized controlled trials have reported excess mortality in patients treated with paclitaxel-coated devices versus uncoated devices, while observational studies have reported the opposite. This study aims to determine the underlying factors and cohort differences that may explain these opposite results, with specific focus on sex differences in treatment and outcomes.

METHODS

Multicenter health insurance claims data from a large insurance fund, BARMER, were studied. A homogeneous sample of patients with an index of endovascular revascularization for symptomatic peripheral arterial occlusive disease between 2013 and 2017 was included. Adjusted logistic regression and Cox regression models were used to determine the factors predicting allocation to paclitaxel-coated devices and sex-specific 5-year all-cause mortality, respectively.

RESULTS

In total, 13,204 patients (54% females, mean age 74 ± 11 years) were followed for a median of 3.5 years. Females were older (77 vs. 71 years), and had less frequent coronary artery disease (23% vs. 33%), dyslipidemia (44% vs. 50%), and diabetes (29% vs. 41%), as well as being less likely to have a history of smoking (10% vs. 15%) compared with males. Mortality differences were mostly attributable to the female subgroup who were revascularized above the knee (hazard ratio, HR 0.78, 95% CI: 0.64-0.95), while no statistically significant differences were observed in males.

CONCLUSIONS

This study found that females treated above the knee benefited from paclitaxel-coated devices, while no differences were found in males. Ongoing and future registries and trials should take sex disparities into account.

How Does SARS-CoV-2 Infection Affect Survival of Emergency Cardiovascular Patients? A Cohort Study From a German Insurance Claims Database

Objective

A previous study revealed a preliminary trend towards higher in hospital mortality in patients admitted as an emergency with acute stroke during the COVID-19 pandemic in Germany. The current study aimed to further examine the possible impact of a confirmed SARS-CoV-2 infection on in hospital mortality.

Methods

This was a retrospective analysis of health insurance claims data from the second largest insurance fund in Germany, BARMER. Patients hospitalised for ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction, acute limb ischaemia (ALI), aortic rupture, acute stroke, or transient ischaemic attack (TIA) between 1 January 2017, and 31 October 2020, were included. Admission rates per 10 000 insured and mortality were compared between March − June 2017 – 2019 (pre-COVID) and March − June 2020 (COVID). Mortality rates were determined by the occurrence of a confirmed SARS-CoV-2 infection.

Results

A total of 316 718 hospitalisations were included (48.7% female, mean 72.5 years), and 21 191 (6.7%, 95% CI 6.6% – 6.8%) deaths occurred. In hospital mortality increased during the COVID-19 pandemic when compared with the three previous years for patients with acute stroke from 8.3% (95% CI 8.0 – 8.5) to 9.6% (95% CI 9.1 – 10.2), while no statistically significant changes were observed for STEMI, NSTEMI, ALI, aortic rupture, and TIA. When comparing patients with confirmed SARS-CoV-2 infection (2.4%, 95% CI 2.3 – 2.5) vs. non-infected patients, a higher in hospital mortality was observed for acute stroke (12.4% vs. 9.0%), ALI (14.3% vs. 5.0%), and TIA (2.7% vs. 0.3%), while no statistically significant differences were observed for STEMI, NSTEMI, and aortic rupture.

Conclusion

This retrospective analysis of claims data has provided hints of an association between the COVID-19 pandemic and increased in hospital mortality in patients with acute stroke. Furthermore, confirmed SARS-CoV-2 infection was associated with increased mortality in patients with stroke, TIA, and ALI. Future studies are urgently needed to better understand the underlying mechanism and relationship between the new coronavirus and acute stroke.

Sex Disparities in Long Term Outcomes After Open Surgery for Chronic Limb Threatening Ischaemia: A Propensity Score Matched Analysis of Health Insurance Claims

OBJECTIVE

Several studies suggest a disadvantage for women in peri-operative morbidity and mortality after open surgery in peripheral arterial occlusive disease. In addition to their heterogeneity regarding design and analysed cohorts, long term data are mostly missing. This study aimed to determine sex disparities in outcomes after open revascularisation in chronic limb threatening ischaemia (CLTI).

METHODS

Using health insurance claims data of the second largest insurance fund in Germany, BARMER, a large cohort of patients was sampled consecutively for analysis including index open surgical revascularisations of CLTI performed between 1 January 2010, and 31 December 2018. Propensity score matching was used to adjust for confounding. Sex related differences regarding overall survival, amputation free survival (AFS), and cardiovascular event free survival (CVEFS) during the five years after surgery were determined using Kaplan-Meier time to event curves, log rank test, logistic, and Cox regression.

RESULTS

Among 9 526 patients (49.5% women) in the entire cohort, 6 502 patients were matched. Before matching, women were older at presentation (78.0 vs. 71.8 years, p < .001) and suffered more often from multiple comorbidities (van Walraven score > 9, 55.5% vs. 50.6%, p < .001). During the hospital stay, there were 692 (7.3%) deaths, while 4 631 deaths (48.6%) occurred during the follow up. In the matched cohort, the median follow up was 746 days for women and 871 days for men. In the matched analyses, female sex was significantly associated with better overall survival (hazard ratio, HR, 0.80, log rank p < .001), AFS (HR 0.81, log rank p < .0001), and CVEFS (HR 0.84, log rank p < .001) five years after the index treatment.

CONCLUSION

In this largest propensity score matched analysis of health insurance claims to date from Germany, evidence was found for better long term outcomes in women after open surgical revascularisations for chronic limb threatening ischaemia. Future guidelines and studies should address the impact of sex on patient selection practice and outcomes to determine the underlying reasons for existing disparities.