Authors
St. Jude Medical Inc.
Title
Cardiac Resynchronization Therapy - Pacemaker (CRTP) System. St. Jude Medical Frontier model 5508L and Frontier II model 5586 cardiac resynchronization therapy pacemakers (CRT-P) supported on the model 3510 programmer platforms with the model 3307, v4.8m programmer software.
References
US Food and Drug Administration. Premarket Approval Application Number: P030035/S3. Available at: accessdata.fda.gov
Background
None.
Purpose
To determine the safety and effectiveness of cardiac resynchronization pacing therapy using the Frontier Model 5508 pulse generator and the Aescula 1055K Left Heart Lead.
Design
Prospective, double-blind, randomized, controlled, multi-center trial 144 patients Symptomatic ischemic or non-ischemic dilated cardiomyopathy, not due to reversible causes LV end-diastolic diameter > 54 mm LVEF ≤ 35% QRS ≥ 140 ms Stable but advanced heart failure due to LV dysfunction (diagnosed for at least 6 months) despite stable conventional medical therapy
Exclusion Criteria
Can walk >450 meters during the 6-minute walk test Have standard bradycardia indications or likely to need pacing within the next 6 months NYHA I/II History of persistent or chronic atrial fibrillation or history of atrial fibrillation requiring intervention to revert to normal sinus rhythm Have an ICD or are being considered for an ICD Contraindications to an emergency thoracotomy Considered status 1 for cardiac transplantation and are likely to receive transplantation within 1 year Prosthetic valve replacement Severe musculoskeletal disorder Under 18 years of age Pregnant or planning pregnancy in next 6 months Currently participating or participating within past 30 days in any clinical investigation Life expectancy less than 6 months
Follow-Up
Average 19.9 ± 8.9 (range 0.8 - 35.4) months
Treatment Regimen
Implantation of CRT-P system Randomized in 2:1 fashion to CRT-ON or CRT-OFF Crossover allowed after 6-month follow-up
Results
Primary End Points: Freedom from system-related complications through 6 months: 90.7% (one-sided 95% lower confidence interval of 86.4%) Freedom from pulse generator-related complications through 6 months: 100% (one-sided 95% lower confidence interval of 97.1%) Freedom from Aescula lead-related complications through 6 months: 93.3% (one-sided 95% lower-confidence interval of 89.5%) Rate of successful implantation of Aescula lead: 84% (one-sided 95% lower confidence interval of 78%) Aescula lead pacing threshold at 6 months: 2.10 V (one-sided 95% upper confidence interval of 2.34 V)
Summary
CRT demonstrates an acceptable safety profile with regard to the pulse generator and lead.