Computer-automated monitoring systems can help detect medical devices with potential safety risks

A computerized, automated safety monitoring system for cardiovascular device clinical outcomes registry implemented in Massachusetts led to the discovery of a drug-eluting stent with a significantly higher rate of serious adverse cardiac events than other similar stents, according to a study in the November 10 issue of JAMA. The findings suggest that such systems appear feasible and useful in identifying new cardiovascular devices with a lower frequency of premature safety concerns that were not observed in premarket approval studies.

"Ensuring the safety of medical devices is a challenge for current monitoring methods, which rely heavily on voluntary reporting of adverse events. Automated monitoring of clinical records may provide early warning for post-market safety assessments of medical devices."

Frederic S. Resnic, MD, M.Sc., of Brigham and Women's Hospital and Harvard Medical School in Boston, and colleagues examined the feasibility of using an automated safety monitoring system to assess safety signals for recently introduced cardiovascular devices in hospitals (i.e., to provide early warning of the safety of these devices). The study included an analysis of seven recently introduced cardiovascular devices using clinical data from CathPCI records, a national cardiovascular database performed in Massachusetts, of all adult patients who underwent percutaneous coronary intervention (PCI), which involves balloon angioplasty or stent placement to open narrowed coronary arteries, in Massachusetts between April 2003 and September 2007. Patient, physician, and hospital data on 74,427 PCI procedures performed during the study period were evaluated.

Of the 21 safety analyses performed, 3 generated a recurrent or persistent safety signal involving 2 implanted devices, prompting the need for detailed sensitivity analyses according to the study protocol. These safety alerts included an increased risk of postprocedural myocardial infarction and an increased risk of major adverse cardiac events (MACE) after Taxus Express2 DES implantation. At the end of the study period, the incidence of postprocedural myocardial infarction was 27.6% higher in patients who received the Taxus Express2 DES than in those who received the other DESs (2.87% vs. 2.25%; absolute risk increase, 0.62%). The 21.1% increase in the MACE rate was driven by an increased difference in the postprocedural MACE rate in the Taxus Express2 DES-treated group compared with the control group (4.24% vs. 3.50%; absolute increase, 0.74%); a persistent safety alert for MACE was triggered in July 2007. No increased risk of death was observed in the exposed groups.

The researchers observed an increased rate of major vascular complications after implantation of the Angio-Seal STS vascular closure device. At the end of the observation period, the matched Angio-Seal STS patient group had a 51.3% increased risk of major vascular complications compared with the control group (1.09% vs. 0.72%; absolute risk increase, 0.37%).

Sensitivity analyses confirmed the increased risk after use of the Taxus Express2 stent but not after use of the Angio-Seal STS device.

"In conclusion, automated safety monitoring of medical devices using automated monitoring tools on detailed clinical records is feasible and can effectively help identify emerging potential safety risks of devices after they are marketed," the authors write. "Automated surveillance of medical products can complement existing public health strategies by providing an additional mechanism to assess the relative safety of approved medical products and improve the quality of care."