Contemporary Results of Operations for Mitral Regurgitation Caused by Posterior Mitral Valve Prolapse: The AATS Adult Quality Gateway.

OBJECTIVE

In patients undergoing surgical repair of posterior mitral valve prolapse, we compared outcomes in high- and low-volume mitral surgery hospitals to those predicted by the AATS Adult Quality Gateway (AQG) and the Society of Thoracic Surgeons Adult Cardiac Surgery Database (STS-ACSD).

METHODS

Five hospitals performed 1,517 mitral valve operations, 1,471 repairs (97%) and 46 replacements (3.0%), in the AQG training set of 55,246 adult patients. Mitral repair techniques included leaflet resection (80%), creating artificial chordae (20%), and anuloplasty (99%); surgical approach was sternotomy or partial sternotomy in 945 (64%) and anterior thoracotomy or robotic in 525 (36%). The remaining 14 hospitals performed 159 mitral valve operations, 145 repairs (91%) and 14 (8.8%) replacements.

RESULTS

In high-volume hospitals, predicted mortality by AQG was 0.87% and by STS-ACSD 0.77%; however, observed mortality was 1 patient (0.070%). For major morbidity and mortality, AQG predicted 8.1% and STS-ACSD 6.5%, but observed was 4.0%. Patients undergoing valve replacement were more likely to be older and more symptomatic and had more tricuspid regurgitation and mitral anular calcification. All repair outcomes were worse (e.g., operative mortality was 3/145 [2.1%]) in low-volume hospitals.

CONCLUSIONS

Requiring limited data entry and employing novel statistical methodology (e.g. virtual twins), AQG provided predictions similar to those of STS-ACSD, both confirming and augmenting understanding of the volume-outcome relationship in surgical management of posterior mitral valve prolapse.