36 Stratos LV/LV-T Technical Manual

Primary Endpoint: Six Minute Walk Test & QOL (Effectiveness)

The purpose of Primary Endpoint 1 was to evaluate the effectiveness of the CRT (Groups 1 and 2) compared to RV only (Group 3) pacing as measured by the average composite rate of improvement in six minute walk test and QOL.

•Stratos LV Effectiveness (Group 2 compared to Group 3): The average composite rate for Group 2 (N=30) was 48.1% with a standard error of 12.3%. The average composite rate for Group 3 (N=15) was 33.0% with a standard error of 12.3%. The difference in the mean composite rate between Group 2 and Group 3 is 15.1%. The p value for superiority is 0.442.

•Protos DR/CLS Effectiveness (Group 1 compared to Group 3): The average composite rate for the Group 1 (N=23) is 36.8% with a standard error of 7.9%. The average composite rate for Group 3 (N=15) is 33.0% with a standard error of 12.3%. The difference in the mean composite rate between Group 1 and Group 3 is 3.8%. The p value for superiority is 0.788.

Table 8 presents the average composite rate of improvement in six minute walk test distance and QOL score, the average 6- minute walk test distance and the average QOL score at Baseline and at the Six-Month follow-up, as well as the average difference in 6-minute walk test distance and QOL score between Baseline and the Six-Month follow-up for the CRT (Groups 1 and 2) and RV only (Group 3) for those patients with six minute walk test data and complete QOL data at both Baseline and the Six-Month follow-up.