Heart Failure

Utility of Direct Fick Cardiac Output in Patients With LVADs

Journal of Cardiac Failure, 2026Single-center retrospective cohortSource: Abstract onlyDOI: 10.1016/j.cardfail.2026.03.033PMID 42162642

Authors: Single-center authors
Journal / date: Journal of Cardiac Failure, 2026
DOI / URL: 10.1016/j.cardfail.2026.03.033 | PMID 42162642
Source basis: Abstract only
Study type: Single-center retrospective cohort
Population: 140 LVAD patients, 151 RHCs with simultaneous measured VO₂ (3/2021-4/2025)
Methods: Compared direct Fick CI (measured VO₂) vs indirect Fick CI using Dehmer, LaFarge, Bergstra, BMI-adjusted Dehmer equations
Key findings:

Poor correlation between indirect and direct Fick CI (R = 0.25-0.42)
Differences >25% between methods were common
Only direct Fick CI predicted the composite of death / heart transplant / HF hospitalization (OR 0.44, p=0.022 for higher direct CI)

Estimated VO₂ formulas substantially mis-classify cardiac output in LVAD patients and are not prognostic in this population.
For LVAD outpatient and inpatient decision-making (titrating pump speed, evaluating RHF, planning transplant listing), direct Fick with measured VO₂ should be the standard at centers with the capability.
Thermodilution accuracy is also unreliable in LVAD patients (continuous flow), so this finding has practical workflow implications.

Caveats / limitations: Single center, retrospective, modest N. Indirect equations may perform differently in non-magnetically levitated devices.
Referenced trials pulled forward: None.