Heart failure & cardiomyopathiesSecondary analysis
Association between functional Status and cardiac function in chronic heart failure: insights from the cardiac microcurrent (C-MIC) II Trial
- post hoc analysis of the randomized cardiac microcurrent (C-MIC) II trial
Authors' conclusion
In advanced HF, improvements in health status and submaximal functional capacity associate modestly with LVEF, while LVEF correlates more closely with peak VO2. Cardiac function, functional capacity, and health status represent related but distinct domains, supporting multidimensional assessment in HF trials.
Study context
- Population
- Ambulatory patients with chronic heart failure (HF) with reduced ejection fraction on optimal guideline-directed medical therapy, non-ischaemic dilated cardiomyopathy, New York Heart Association (NYHA) Class III–IV symptoms, and baseline left ventricular ejection fraction (LVEF) 25–35%
- Participants
- 65 ambulatory patients
- Comparison
- Correlations between changes in Kansas City Cardiomyopathy Questionnaire Overall Summary Score (KCCQ-OSS), 6MWD, core lab-assessed LVEF and site-assessed LVEF, and peak VO2
Primary result
As reported in the abstract
Pearson r (n = 63)
r = 0.39; 95% CI: 0.16-0.58; P = .0015
Further findings
Change in 6MWD vs change in core lab-assessed LVEF · baseline to 6 months
- Pearson r (n = 61)
- r = 0.39; 95% CI: 0.15-0.58; P = .0022
- modest correlation
Change in KCCQ-OSS vs change in 6MWD
- Pearson r (n = 62)
- r = 0.63; 95% CI: 0.46-0.76; P < .0001
- strong correlation
Changes in KCCQ-OSS and 6MWD vs change in peak VO2
- KCCQ-OSS vs peak VO2, not significant
- P = 0.06
- 6MWD vs peak VO2, not significant
- P = 0.30
Change in LVEF vs change in peak VO2
- Pearson r (n = 55)
- r = 0.41; 95% CI: 0.16-0.61; P = .002
- modest correlation
LVEF vs peak VO2 · 6 months
- Pearson r at 6 months (n = 59)
- r = 0.56; 95% CI: 0.35-0.71; P < .0001
- Baseline correlations with peak VO2 weak to modest
Baseline characteristics
- Mean age
- 60.0 ± 9.7 years
- Baseline LVEF
- 29.8 ± 3.3%
- Baseline 6MWD
- 291.4 ± 61.6 m
- KCCQ-OSS
- 42.6 ± 22.7
Original publication
Summarised from the published abstract; every number is checked against it