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.
In this study patients are enrolled 1-30 days after successful implantation of the Corox OTW
Steroid LV lead connected to a BIOTRONIK CRT-D device. Successful implantation is defined as when the pacing threshold of the Corox OTW Steroid LV lead is less than one-half of the maximum programmed output of the BIOTRONIK CRT-D at 0.5 ms without phrenic nerve stimulation.
Study Population Description
Study Population: Patients implanted with the Corox OTW Steriod LV lead.
250 subjects, at up to 100 sites
The evaluation of safety is based on the analysis of Corox over-the-wire Steroid lead related
adverse events that are classified into two types: observations and complications. Additionally, left ventricular lead pacing parameters (acute and chronic pacing thresholds and impedance values) will be evaluated. The study data will also be used to determine the ability of the Corox over-the-wire steroid lead to deliver chronic cardiac resynchronization pacing.
Followup Visits and Length of Followup
The patients will be followed for a period of three years. The specific visits that
are part of this registry are at enrollment, 3-months, 6-months, 1-year, and routine follow-ups (every subsequent 6 months). It is required that patients are seen at 3, 6, 12, 18, 24, 30, and 36 months post enrollment within ± 1-month at the first (3month) follow-up and at ± 45 days for all subsequent routine follow-ups thereafter.
Final Study Results
Actual Number of Patients Enrolled
Actual Number of Sites Enrolled
Patient Followup Rate
59% through three years
Final Safety Findings
Observations. A total of 23 (10.4%) of the enrolled patients have reported a Corox OTW
Steroid Unipolar lead related observation. The rate of Corox OTW Steroid Unipolar lead related observations per patient-year is 0.056. Ten observations were due to high LV lead threshold, 14 were from phrenic nerve stimulation, and one was from intermittent loss of capture.
Complications. A total of 9 (4.1%) of the enrolled patients experienced a Corox OTW Steroid Unipolar lead related complication. The rate of Corox OTW Steroid Unipolar lead related complications per patient-year is 0.019. The eight complications were: LV lead dislodgement (3), phrenic nerve stimulation (1), infection (2), high LV lead threshold (2), and lead integrity compromise (1).
Final Effectiveness Findings
At all scheduled follow-up intervals and interim visits, the CRT system provided appropriate biventricular pacing
with capture in 91.9% to 97.8% of subjects. The average overall LV lead impedance was 709 ± 176 ohms. When measured at 0.5 ms pulse width, the average LV lead threshold was 1.3 ± 0.9 ms at enrollment and for all follow-ups was 1.3 ± 1.1 V. In total 1200 subject visits had been reported in 221 subjects.
Study Strengths and Weaknesses
The study results they provide little long term follow-up of the lead. Overall the lead
appears to cause few complications although the data collection is weak and adverse events might have occurred but not been reported.
Recommendations for Labeling Changes
Updated to include the long-term post-approval study data and findings.