Volume–outcome relationship in transcatheter aortic valve implantations in Germany 2008–2014: a secondary data analysis of electronic health records

Abstract

ObjectivesWe examine the volume–outcome relationship in isolated transcatheter aortic valve implantations (TAVI). Our interest was whether the volume–outcome relationship for TAVI exists on the centre level, whether it occurs equally for different outcomes and how it develops over time.DesignSecondary data analysis of electronic health records. The comprehensive German Federal Bureau of Statistics Diagnosis Related Groups database was queried for data on all isolated TAVI procedures performed in Germany between 2008 and 2014. Logistic and linear regression analyses were carried out. Risk adjustment was applied using a predefined set of patient characteristics to account for differences in the risk factor composition of the patient populations between centres and over time. Centres performing TAVI were stratified into groups performing <50, 50–99 and ≥100 procedures per year.SettingGermany 2008–2014.ParticipantsAll patients undergoing isolated TAVI in the observation period.InterventionsNone.Primary and secondary outcome measuresIn-hospital mortality, bleeding, stroke, probability of ventilation >48 hours, length of hospital stay and reimbursement.ResultsBetween 2008 and 2014, a total of 43 996 TAVI procedures were performed in 113 different centres in Germany with a total of 2532 cases of in-hospital mortality. Risk-adjusted in-hospital mortality decreases over the years and is lower the higher the annual procedure volume at the centre is. The magnitude of the latter effect declines over the observation period. Our results indicate a ceiling effect in the volume–outcome relationship: the volume–outcome relationship is eminent in circumstances of relatively unfavourable outcomes. Alongside improving outcomes, however, the volume–outcome relationship decreases. Also, a volume–outcome relationship seems to be absent in circumstances of constantly low event rates.ConclusionsThe hypothesised volume–outcome relationship for TAVI exists but diminishes and may disappear over time. This should be taken into account when considering mandatory minimum thresholds.

Bleeding Complications Drive In-Hospital Mortality of Patients with Atrial Fibrillation after Transcatheter Aortic Valve Replacement

“…As described previously, 1,16 we were able to use the Operationen-und Prozedurenschlüssel (OPS) codes to identify all TF-TAVR procedures performed (and reimbursed) in Germany between 2008 and 2016. Patients with a baseline diagnosis of pure aortic regurgitation and those with concomitant cardiac surgery or percutaneous coronary intervention were not included in this analysis.…”

Outcomes of transcatheter aortic valve implantations in high-volume or low-volume centres in Germany

“…The learning curve may be more pronounced in high-volume centres. Volume–outcome relationships have already been described in many different procedures,11–14 and have also been found in TAVI both in terms of hospitals and individual interventionalists 1 12 15–18. Annual minimum quantities may thus be useful to ensure optimal outcomes.…”

“…In Germany, transcatheter aortic valve implantation (TAVI) has been used for over 10 years to treat patients with severe aortic valve stenosis 1 2. Since even patients at low operative risk benefit especially from transfemoral (TF)-TAVI, the indication is increasingly being extended to patients at lower surgical risk 3–6.…”

The Relation between Volume and Outcome of Transcatheter and Surgical Aortic Valve Replacement: A Systematic Review and Meta-Analysis

“…Replacement. Six studies [6][7][8][9][10][11] comprising 115,596 patients were included and had a population period ranging from 2005 to 2016; three were from the U.S., two were from Germany, and the last one analyzed patients from South and North America and Europe. Two studies used clinical data; the rest used less evidenced administrative data.…”

“…So, did this situation happen to other meta-analysis studies about the volume-outcome relationship [29,30]? Second, if the volume-outcome relationship was investigated year by year, we may notice a magnitude attenuation in more recent years [9]. It can be explained by the plateau of the longitudinal learning curve [27].…”