Heart failure & cardiomyopathies
Retained Metabolic Flexibility of the Failing Human Heart
Authors' conclusion
Our findings show that even in nonischemic heart failure with reduced ejection fraction with severely impaired systolic function, significant cardiac metabolic flexibility is retained, including the ability to alter substrate use to match both arterial supply and changes in workload. Increasing LCFA uptake and oxidation is associated with improved myocardial energetics and contractility.
Study context
- Population
- Patients with nonischemic HFrEF (LVEF 34.9±9.1)invasive sampling n=9
- Participants
- 20 patients
- Comparison
- Insulin+glucose infusion vs Intralipid infusion
- Outcome
- Cardiac substrate use, energetics and function
- Follow-up
- At rest
Methodological detailsseparate infusions (I+G and Intralipid) in each patient, CMR and phosphorus-31 MR spectroscopy, invasive arteriovenous sampling and pressure-volume loops (n=9)
- Separate infusions (I+G and Intralipid) in each patient
- CMR and phosphorus-31 MR spectroscopy
- Invasive arteriovenous sampling and pressure-volume loops (n=9)
Main finding
As reported in the abstract
| Group | LVEF | Glucose share of total energy substrate for ATP production | Long-chain fatty acid (LCFA) share of total substrate |
|---|---|---|---|
| Baseline | 34.9±9.1 | ||
| I+G | 33.7±8.2 | 70±14% | 19±26% |
| Intralipid | 39.9±9.3 | 17±16% | 73±17% |
LVEF
Baseline34.9±9.1
I+G33.7±8.2
Intralipid39.9±9.3
Glucose share of total energy substrate for ATP production
Baseline— not stated in the abstract
I+G70±14%
Intralipid17±16%
Long-chain fatty acid (LCFA) share of total substrate
Baseline— not stated in the abstract
I+G19±26%
Intralipid73±17%
- I+G vs Intralipid: P = 0.002 — glucose share of total energy substrate
- Intralipid vs I+G: P = 0.009 — LCFA share of total substrate
- Intralipid vs I+G: P < 0.001 — LVEF across baseline, I+G and Intralipid
- Myocardial energetics (PCr/ATP) better with Intralipid than with I+G
- 1.86±0.25 versus 2.01±0.33; P=0.02
Further findings
Substrate use and ischemic metabolism during increased cardiac workload · 65% maximal heart rate
- LCFA uptake and oxidation again increased during both infusions
- No evidence of systolic dysfunction or lactate efflux
Original publication
Retained Metabolic Flexibility of the Failing Human Heart. Circulation. Published 18 May 2023. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →