The introduction of transcatheter aortic valve replacement (TAVR) into clinical practice in the United States has been a tightly controlled process aimed at optimizing patient outcomes and minimizing the learning curve. Many strategies have been used to reach a rational dispersion for this new technology, including choosing sites with enough volume, and adequate operator training funded by device manufacturing companies.

The existence of this learning curve, which is valid for any of the procedures interventional cardiologists perform daily, is impossible to deny. However, the degree to which experience is associated with outcomes as regards TAVR, specifically, was somewhat unclear.

Authors evaluated 42,988 procedures conducted at 395 hospitals submitted to the Transcatheter Valve Therapy (TVT) Registry between 2011 and 2015.

Also read: “Incidence, Characteristics, and Treatment of Valve Thrombosis After TAVR.”

Increasing volume was associated with lower in-hospital risk-adjusted outcomes, including mortality (p < 0.02), vascular complications (p < 0.003), and bleeding (p < 0.001), but it was not associated with stroke (p = 0.14).

From the 1st to the 400th case, risk-adjusted adverse outcomes declined, including mortality (3.57% to 2.15%), bleeding (9.5% to 5%), vascular complications (6.1% to 4.2%), and stroke (very subtly: 2% to 1.6%). Vascular and bleeding volume-outcome associations were nonlinear and presented a higher risk of adverse outcomes in the first 100 cases.

Conclusion

The adoption of TAVR into clinical practice showed that increasing experience is associated with better outcomes. This association, which could result from a prolonged learning curve, suggests that experience should be concentrated in higher volume heart valve centers.

Editorial

The effect mentioned in this work is much more marked in the first 100 cases (indicating the impact of a learning curve). After the first 100 cases, events continue to decrease much more gradually until they reach a plateau (something particularly true as regards stroke and vascular complications).

Results from this study, showing association between volume and clinical outcomes for TAVR, are quite different from what has been published for other procedures in our daily practice, such as coronary angioplasty (with the clear exception of chronic total occlusion rechanneling).

Original title: Procedural Experience for Transcatheter Aortic Valve Replacement and Relation to Outcomes. The STS/ACC TVT Registry.

Reference: John D. Carroll et al. J Am Coll Cardiol 2017;70:29-41.

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