The authors of a systematic review and meta-analysis, looking at the effect of institutional transcatheter aortic valve implantation (TAVI) volume on mortality, have concluded that more focus is needed on “strong referral networks and consolidation” rather than expansion of existing TAVI centres. The review suggested that existing research points to an “inverse” relationship between annual TAVI centre procedure volume and all-cause mortality among patients.
Conducted by Devika Kir (University of Miami/Jackson Memorial Hospital, Miami, USA, previously Yale School of Medicine, New Haven, USA), Nihar Desai (Yale School of Medicine, New Haven, USA) and colleagues, the analysis sought to examine the association between institutional TAVI volume and all-cause mortality. Findings were published online in Catheterization and Cardiovascular Interventions.
The study team wrote that since its inception in 2011, there has been an “exponential” increase in the number of centres performing TAVI across the world. They add that multiple studies have questioned if a relationship exists between institutional TAVI volume and patient outcomes. Kir and colleagues sought to establish whether this link could be drawn.
A systematic literature search for relevant articles using a combination of free text terms in the title or abstract related to volume, TAVR [TAVI], and patient outcomes was performed, with all titles and abstracts then screened for eligibility based upon pre-specified criteria.
All-cause mortality data were pooled from eligible studies and centres were categorised as low (30–50 cases), intermediate, or high-volume (75–130 cases) based upon their TAVI volumes.
The search yielded a list of 11,153 citations. In total, 120 full-text studies were reviewed, and seven met all inclusion and exclusion criteria, yielding a total of 193,498 TAVI procedures among them. Categorising these into their centre’s annual volume, this meant that around 25,062 of the procedures were performed at low-volume centres, 77,093 at intermediate-volume centres and 91,343 in high volume centres. The analysis showed a relative reduction in mortality rates of 37%, 23% and 19% for high volume versus low volume centres, high volume versus intermediate volume centres, and intermediate versus low volume centres, respectively.
In conclusion, Kir and colleagues write that the existing research “clearly shows an inverse relationship between annual TAVI procedural volume and all-cause mortality”. This, they state, suggests a “need to focus on development of strong referral networks and consolidation rather than expansion of existing TAVI centres to improve patient outcomes, while ensuring adequate access-to-care”.
Commenting on the findings to Cardiovascular News, Kir said: “This volume-outcome relationship has persisted despite evolution of the techniques and operator experience, and hence, we need to focus on development of strong referral networks and consolidation rather than expansion of existing TAVI centres. With the expansion of TAVI to low-surgical risk patients, we need to focus on optimisation of patient outcomes, while ensuring adequate access.”