Pulmonary vascular disease & thromboembolismCohort study
Agreement of thermodilution and direct Fick methods for cardiac output across varying haemodynamic conditions
- retrospective analysis
Authors' conclusion
Although TD shows a predictable bias across flow states, it remains a clinically reliable method for estimating elevated PVR. These findings support the clinical utility of TD in PH assessment, while emphasizing the need for direct Fick measurement in low-output states-particularly in patients evaluated for advanced therapies such as transplantation.
Study context
- Population
- Patients undergoing right heart catheterization with simultaneous QTD and QF measurements (2014–22)
- Participants
- 852 right heart catheterizations
- Exposure
- compare QTD with Fick-derived Q across haemodynamic states
Main finding
As reported in the abstract
heart failure
64%
pulmonary arterial hypertension
20%
Observational data: associations, not effects.
Further findings
Correlation of QTD with QF
- r
- 0.78
- P
- P < 0.001
Flow-dependent bias of QTD
L/min
- overestimating Q in low-flow states
- +0.1
- underestimating it in normal/high flow
- −0.48
PVRTD identification of elevated PVRF at 2 and 5 Wood unit thresholds
- area under the curve
- 0.97
- P
- P < 0.001
Agreement between QTD and QF by tricuspid regurgitation severity
- Agreement unaffected by tricuspid regurgitation severity
Original publication
Summarised from the published abstract; every number is checked against it