Use Instructions

55
Baseline Characteristics
Baseline characteristics of subjects in the FIX-HF-5C2 study are presented in Table
13 along with baseline characteristics of the FIX-HF-5C study groups. Of primary
note are the comparisons between the OPTIMIZER group in the FIX-HF-5C2 study
and the Control group from the FIX-HF-5C study, as these groups form the primary
comparison groups for the efficacy analyses. At a nominal 0.05 level of significance,
FIX-HF-5C2 subjects were older (66.3 ± 8.9 vs. 62.8 ± 11.4), had a lower prevalence
of diabetes (30% vs. 48.8%), and a lower LVEDD value (57.7 ± 6.8 vs. 60.2 ± 7.0)
than subjects in the FIX-HF-5C Control group. Although FIX-HF-5C2 subjects had a
smaller LVEDD, LVEF between the two groups (34.1 + 6.1 vs. 32.5 + 5.2%) was not
statistically significantly different. Peak VO2 on CPX testing at baseline was similar
between the two groups, but the FIX-HF-5C2 subjects exercised for a full minute
longer on average than the FIX-HF-5C control group subjects (11.6 + 2.9 vs. 10.6 +
3.1 minutes). This difference was statistically significant (p<0.04).
Consistent with the study purpose and design, significantly more subjects in the FIX-
HF-5C2 study had permanent atrial fibrillation at baseline as evidenced by the
presence of atrial fibrillation on the baseline ECG tracing. Although it did not reach
statistical significance, there was only 1 NYHA Class IV subject in FIX-HF-5C2 while
8 subjects were NYHA Class IV in FIX-HF-5C. This difference reflects clinical
practice. It is not a regulatory limitation as the protocol was established before the
Indications for Use were narrowed to NYHA III subjects and NYHA IV subjects were
allowed in the FIX-HF-5C2 study. The clear clinical practice selection of NYHA Class
III subjects in the FIX-HF-5C2 study confirms that the NYHA III functional class group
is the appropriate target for CCM therapy. All other characteristics were similar
between the two groups.
Baseline medication usage is presented in the Table 14.