Abstract
BackgroundAccurate determination of left ventricular filling pressure is essential for differentiation of pre-capillary pulmonary hypertension (PH) from pulmonary venous hypertension (PVH). Previous data suggest only a poor correlation between left ventricular end-diastolic pressure (LVEDP) and its commonly used surrogate, the pulmonary capillary wedge pressure (PCWP). However, no data exist on the diagnostic accuracy of PCWP in veterans. Furthermore, the effects of age and comorbidities on the PCWP-LVEDP relationship remain unknown.MethodsWe investigated the PCWP-LVEDP relationship in 101 patients undergoing simultaneous right and left heart catherization at a large VA hospital. PCWP performance was evaluated using correlation and Bland-Altman analyses. Area under Receiver Operating Characteristics curves (AUROC) for PCWP were determined.ResultsPCWP-LVEDP correlation was moderate (r = 0.57). PCWP-LVEDP calibration was poor (Bland-Altman limits of agreement −17.2 to 11.4 mmHg; mean bias −2.87 mmHg). 59 patients (58.4%) had pulmonary hypertension; 15 (25.4%) of those met pre-capillary PH criteria based on PCWP. However, if LVEDP was used instead of PCWP, 7/15 patients (46.6%) met criteria for PVH rather than pre-capillary PH. When restricting analysis to patients with a mean pulmonary artery pressure of ≥25 mmHg and pulmonary vascular resistance of >3 Wood units (n = 22), 10 patients (45.4%) were classified as pre-capillary PH based on PCWP ≤15 mmHg. However, if LVEDP was used, 4/10 patients (40%) were reclassified as PVH. Among patients with any type of pulmonary hypertension, PCWP discriminated moderately between high and normal LVEDP (AUROC, 0.81; 95%CI 0.69–0.94). PCWP-LVEDP correlation was particularly poor in patients with COPD or obesity.ConclusionReliance on PCWP rather than LVEDP results in misclassification of veterans as having pre-capillary PH rather than PVH in almost 50% of cases. This is clinically relevant, as misclassification may lead to inappropriate therapies and adverse events.
Highlights
Pulmonary hypertension (PH) is present when the mean PA pressure is $25 mmHg [1,2]
Hemodynamic and echocardiographic parameters are shown in table 2 and table 3. 95% of catheterizations were performed by one of two cardiologists
Mean bias was 22.87 mmHg (95%CI 2 4.316 to 21.42) with 95% limits of agreement ranging from 2 17.21 to 11.47 mmHg (Fig. 3). This indicates that pulmonary capillary wedge pressure (PCWP) underestimates left ventricular end-diastolic pressure (LVEDP) on average by 2.87 mmHg, and that even after exclusion of the 5% of patients with the highest differences between PCWP and LVEDP, PCWP underestimated LVEDP by as much as 17.21 mmHg and overestimated it by as much as 11.47 mmHg
Summary
Pulmonary hypertension (PH) is present when the mean PA pressure (mPAP) is $25 mmHg [1,2]. Right heart catheterization (RHC) with accurate assessment of LV filling pressures is of utmost importance in making a correct diagnosis of PAH, in selecting appropriate therapies, and in differentiating PVH from pre-capillary PH. LV filling pressures can be measured directly via left heart catherization (LHC) and assessment of LV end-diastolic pressure (LVEDP), or indirectly by measuring pulmonary capillary wedge pressure (PCWP) during RHC. A recent study suggested that when relying on measurement of PCWP alone, patients get misclassified (assigned to the wrong WHO PH group) in 50% of cases [8] This is due to poor correlation and poor agreement between PCWP and the more accurate (but less frequently measured) LVEDP. Previous data suggest only a poor correlation between left ventricular end-diastolic pressure (LVEDP) and its commonly used surrogate, the pulmonary capillary wedge pressure (PCWP). The effects of age and comorbidities on the PCWP-LVEDP relationship remain unknown
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
