28 Stratos LV/LV-T Technical Manual

The study was designed to enroll 265 patients. However, the study was terminated early due to slow patient enrollment. There were no safety issues involved in the termination decision. Due to the lack of patient data, the AVAIL CLS/CRT study alone was insufficient to support CRT pacing effectiveness or an ablate and pace indication.

The cumulative enrollment duration was 416.7 months with a mean duration of 9.7 months for Group 1, 522.4 months with a mean duration of 10.4 months for Group 2, and 261.1 months with a mean duration of 10.4 months for Group 3. 73 (61.9%) of the study patients had enrollment durations greater than 6 months.

There were 158 adverse events (115 observations in 68 patients and 43 complications in 34 patients). There were no unanticipated adverse device effects reported.

The overall protocol violation non-compliance rate is 0.4% in Group 1, 0.5% in Group 2, and 0.4% in Group 3. The overall follow-up compliance rate is 99.8% in all groups.

There were 3 patient deaths reported, two in Group 2 and one in Group 3. The clinical investigators and clinical events committee determined that none of these deaths were related to the study devices.

Both the CRT pacing and the RV pacing only groups showed improvements in the primary composite endpoint of quality of life and six-minute walk distance between the baseline evaluation and the six-month follow-up. In addition, there was a trend towards improvement between the combined CRT pacing groups compared to the RV pacing only group at six months.