Meta-Analysis of Hospital-Volume Relationship in Transcatheter Aortic Valve Implantation

Impact of Surgeon Experience and Centre Volume on Outcome After Off-Pump Coronary Artery Bypass Surgery: Results From the European Multicenter Study on Coronary Artery Bypass Grafting (E-CABG) Registry

AIM

The aim of this study was to assess the impact of surgeon experience and centre volume on early operative outcomes in patients undergoing off-pump coronary artery bypass (OPCAB) surgery.

METHOD

Of 7,352 patients in the European Multicenter Study on Coronary Artery Bypass Grafting (E-CABG) registry, 1,549 underwent OPCAB and were included in the present analysis. Using adjusted regression analysis, we compared major early adverse events after procedures performed by experienced OPCAB surgeons (i.e., ≥20 cases per year; n=1,201) to those performed by non-OPCAB surgeons (n=348). Furthermore, the same end points were compared between procedures performed by OPCAB surgeons in high OPCAB volume centres (off-pump technique used in >50% of cases; n=894) and low OPCAB volume centres (n=307).

RESULTS

In the experienced OPCAB surgeon group, we observed shorter procedure times (β -43.858, 95% confidence interval [CI] -53.322 to -34.393; p<0.001), a lower rate of conversion to cardiopulmonary bypass (odds ratio [OR] 0.284, 95% CI 0.147-0.551; p<0.001), a lower rate of prolonged inotrope or vasoconstrictor use (OR 0.492, 95% CI 0.371-0.653; p<0.001), a lower rate of early postprocedural percutaneous coronary interventions (OR 0.335, 95% CI 0.169-0.663; p=0.002), and lower 30-day mortality (OR 0.423, 95% CI 0.194-0.924; p=0.031). In high OPCAB volume centres, we found a lower rate of prolonged inotrope use (OR 0.584, 95% CI 0.419-0.814; p=0.002), a lower rate of postprocedural acute kidney injury (OR 0.382, 95% CI 0.198-0.738; p=0.004), shorter duration of intensive care unit (β -1.752, 95% CI -2.240 to -1.264; p<0.001) and hospital (β -1.967; 95% CI -2.717 to -1.216; p<0.001) stays, and lower 30-day mortality (OR 0.316, 95% CI 0.114-0.881; p=0.028).

CONCLUSIONS

Surgeon experience and centre volume may play an important role on the early outcomes after OPCAB surgery.

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.

Hospital variation of 30-day readmission rate following transcatheter aortic valve implantation

OBJECTIVES

Thirty-day readmission rate is one of the hospital quality metrics. Outcomes of transcatheter aortic valve implantation (TAVI) have improved significantly, but it remains unclear whether hospital-level variance in 30-day readmission rate exists in the contemporary TAVI era.

METHODS

From the 2017 US Nationwide Readmission Database, endovascular TAVI were identified. The unadjusted 30-day readmission rate and 30-day risk-standardised readmission rate (RSRR) were calculated and we then conducted model testing to determine the relative contribution of hospital characteristics, patient-level covariates and economic status to the variation in readmission rates observed between the hospitals.

RESULTS

A total of 44 899 TAVI from 338 hospitals were identified. The range of unadjusted 30-day readmission rate and 30-day RSRR was 2.0%-33.3% and 9.4%-15.3%, respectively. Median 30-day RSRR was 11.8% and there was a significant hospital-level variation (median OR 1.22, 95% CI 1.16 to 1.32, p<0.01) and this was similar in both readmissions caused due to major cardiac and non-cardiac conditions. Patient, hospital and economic factors accounted for 9.6%, 1.9% and 3.8% of the variability in hospital readmission rate, respectively.

CONCLUSIONS

There was significant hospital-level variation in 30-day RSRR following TAVI. Further measures are required to mitigate this variance in the readmission rate.

Effect of institutional transcatheter aortic valve replacement volume on mortality: A systematic review and meta-analysis

OBJECTIVE

We sought to conduct a systematic review and network meta-analysis to examine the association between institutional transcatheter aortic valve replacement (TAVR) volume and all-cause mortality.

BACKGROUND

Since inception in 2011, there has been an exponential increase in the number of TAVR centers across the world. Multiple studies have questioned if a relationship exists between institutional TAVR volume and patient outcomes.

METHODS

We performed a systematic literature search for relevant articles using a combination of free text terms in the title/abstract related to volume, TAVR, and patient outcomes. Two reviewers independently screened all titles/abstracts for eligibility based on pre-specified criteria. All-cause mortality data was pooled from eligible studies and centers were categorized as low-(30-50 cases), intermediate-, or high-volume (75-130 cases) based on their annual TAVR volumes.

RESULTS

Our search yielded an initial list of 11,153 citations, 120 full text studies were reviewed and 7 studies met all inclusion and exclusion criteria, yielding a total of 1,93,498 TAVRs. Categorized according to center's annual volume; 25,062 TAVRs were performed in low-, 77,093 in intermediate- and 91,343 in high-volume centers. Network meta-analysis showed a relative reduction in mortality rates of 37%, 23% and 19%, for high volume versus low volume centers, high volume versus intermediate volume centers and intermediate versus low volume centers, respectively.

CONCLUSIONS

Existing research clearly shows an inverse relationship between annual TAVR procedural volume and all-cause mortality. We need to focus on development of strong referral networks and consolidation rather than expansion of existing TAVR centers to improve patient outcomes, while ensuring adequate access-to-care.