Procedural volume and outcomes for transcatheter aortic-valve replacement

Selected in The New England Journal of Medicine by L. Biasco

The aim of the study was to evaluate the relationship between volume of TAVR procedures and 30-day outcomes, to determine the persistence of a volume–outcome association...

References

Authors

Vemulapalli S, Carroll JD, Mack MJ, Li Z, Dai D, Kosinski AS, Kumbhani DJ, Ruiz CE, Thourani VH, Hanzel G, Gleason TG, Herrmann HC, Brindis RG, Bavaria JE

Reference

N Engl J Med. 2019 Jun 27;380(26):2541-2550

Published

June 2019

Link

Read the abstract

Reviewer

Luigi Biasco

@BiascoDr

Interventional cardiologist / Cardiologist

Ciriè, Italy

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My Comment

Why this study – the rationale/objective?

The aim of the study by Vemulapalli et al was to evaluate the relationship between volume of TAVR procedures and 30-day outcomes, to determine the persistence of a volume-outcome association even after the initial period after implementation of a percutaneous aortic valve programme and to assess whether patient and hospital characteristics differ according to procedural volume.

How was it executed – the methodology?

Population: retrospective analysis of 96,256 TAVR patients enrolled in the US Transcatheter Valve Therapy (TVT) Registry treated between 2015 and 2017 in 554 centres by 2,935 operators.
Primary outcome: risk-adjusted mortality at 30 days.

What is the main result?

The median annual TAVR volume per hospital was 54 procedures, while annual procedural volume per operator was 27 procedures.
A nonlinear association between mortality and annualized hospital volume of transfemoral TAVR procedures, with a plateau reached after about 40 procedures-year/operator and 100 procedures-year/hospital.
Adjusted 30-day mortality was 3.54% (95% CI, 2.59 to 4.84) in the lowest-volume quartile and 2.84% (95% CI, 2.68 to 3.01) in the highest-volume quartile (odds ratio, 1.26; 95% CI, 0.91 to 1.75).
After exclusion of the first 6 or 12 months after the implementation of a TAVR programme in each centre, adjusted 30-day mortality remained higher (3,10% vs 2.34% at 12 months, OR 1.19, 95% CI 1.01-1.40) in low-volume as compared to high-volume centres.
Only 200 operators performed at least 75 cases per year.
Hospitals with lower procedural volumes had greater variability in outcomes than those with higher volumes. Moreover, hospitals with lower procedural volumes are more likely to be rural, and they perform TAVR on a higher percentage of racial and ethnic minorities.

Critical reading and relevance for clinical practice

This paper emphasizes the relationship between procedural volumes and outcomes in TAVR. As an original perspective, both operator and hospital volumes are taken into account, highlighting the fact that in TAVR, as in modern interventional cardiology, multiple skills and team working are needed to achieve optimal results.

As a positive aspect, operator’s volumes to reach the plateau of 30 days mortality is as low as 40/procedure years, a number that might be relatively easy to reach whether network referrals are available. On the other hand, this paper stresses on the evidence that a volume–mortality association persists in TAVR, even after the initial period after TAVR implementation and despite improved patient selection, techniques and reduction of the patient’s associated risk.