A registry analysis of patients undergoing aortic valve replacement in the United Kingdom found that two series of prosthetic aortic valves were associated with significantly increased hazards of death or reinterventions. The valves were the Sorin Mitroflow series and the Sorin Biological series.

Meanwhile, three series of prosthetic aortic valves were associated with significantly decreased hazards of death or reintervention. Those three valves were the Edwards Lifesciences Perimount series, the Edwards Lifesciences Perimount Magna series and the Medtronic Hancock series.

Lead researcher Graeme L. Hickey, PhD, of the University of Liverpool in the U.K., and colleagues published their results online Nov. 7 in JAMA Internal Medicine.

In this observational study, the researchers analyzed 54,866 patients who underwent first-time elective and urgent isolated aortic valve replacement procedures from 1998 to 2013. They obtained data from the National Adult Cardiac Surgery Audit, a registry that tracks adult cardiac surgery procedures performed in UK National Health Service hospitals, some private hospitals and some hospitals in Ireland. In all, 344 surgeons at 37 hospitals performed the operations.

During the study, the biological valve implantation rates increased from 59 percent in 1998 and 1999 to 86 percent in 2012 and 2013.

During a median follow-up period of 4.1 years, there were 13,104 deaths and 723 reinterventions.

The researchers noted that the 10-year overall freedom from reintervention or death rates for the Sorin Mitroflow series and Sorin Biological series valves were 33.8 percent and 41.4 percent, respectively, compared with 47.2 percent for the non-Sorin biological valves. Meanwhile, the Edwards Lifesciences Perimount series, the Edwards Lifesciences Perimount Magna series and the Medtronic Hancock series prosthetic valves had a significant reduction in hazard.

The researchers cited a few limitations of the study, including that the valve-specific data were not subject to the same quality management as the clinical variables data. They also mentioned that surgeons could have made coding errors. In addition, they noted that the study had a short follow-up period and did not track other clinical outcomes besides death or reinterventions.

“By analyzing 15 years of data on [aortic valve replacement] procedures in England and Wales, we identified 2 prosthetic valves that may warrant further scrutiny through additional studies,” the researchers wrote. “As Taylor noted about valve monitoring nearly three decades ago, ‘overreaction is as inappropriate as complacency.’ Given the limitations of the study, the signals shown here should only serve as hypothesis generating and not misinterpreted as causal effects.”