In January 2005, the oversight responsibility of the Post-Approval Studies Program was transferred to the Division of Epidemiology (DEPI) of the Office of Surveillance and Biometrics (OSB)/Center for Devices and Radiological Health (CDRH).
The CDRH Post-Approval Studies Program encompasses design, tracking, oversight, and review responsibilities for studies mandated as a condition of approval of a premarket approval (PMA) application, protocol development product (PDP) application, or humanitarian device exemption (HDE) application. The program helps ensure that well-designed post-approval studies (PAS) are conducted effectively and efficiently and in the least burdensome manner.
CDRH has established an automated, internal tracking system that efficiently identifies the reporting status of active PAS studies ordered since January 1, 2005 based on study timelines incorporated in study protocols and agreed upon by the CDRH and applicants. This system represents CDRH's effort to ensure that all PAS commitments are fulfilled in a timely manner.
In addition, CDRH launched this publicly available webpage to keep all stakeholders informed of the progress of each PAS. The webpage displays general information regarding each PAS, as well as the overall study status (based on protocol-driven timelines and the adequacy of the data) and the applicant's reporting status for each submission due.
The rate of device system related adverse events (number of Events/100 Device Months) is slightly
higher in the CRT-D compared to ICD (0.54 in CRT-D vs. 0.36 in ICD) in this PAS Registry that is expected and consistent to the findings in the IDE study. The Registry showed a higher rate of early ERI (elective replacement indicator) in CRT-D group (4.1%) compared to ICD only group (2.7%) with longer follow-up indicating rapid battery depletion secondary to increased amount of pacing needed over time for cardiac resynchronization. The incidence of device-related adverse events for CRT-D in the Registry is in the acceptable range.
Final Effectiveness Findings
The cohort of combined IDE and Registry for followed out through 5 years showed CRT-D
reduced a 32% relative risk of all-cause mortality in LBBB subpopulation as compared to ICD (p=0.028). CRT-D was also associated with significant reduction in the risk of a first heart failure event and recurrent heart failure events in both the LBBB subsets and all subjects in combined IDE and Registry.
Study Strengths and Weaknesses
Strength: long-term follow-up (5 years) Weakness: small sample size (394 patients) insufficient to test statistical significance