Accuracy of noninvasive estimation of pulmonary wedge pressure by echocardiographic indices in heart transplant recipients.

BACKGROUND

Pulmonary capillary wedge pressure (PCWP) can be estimated from transmitral or color M-mode Doppler flow propagation velocities. However, it has been recommended to not use these indices in heart transplant recipients. Our aim was to compare the accuracy of color M-mode, Doppler, and Doppler tissue imaging (DTI)-derived indices to predict PCWP in heart transplant recipients.

METHODS

We studied 50 consecutive heart transplant recipients scheduled for routine right-sided heart catheterization and endomyocardial biopsy. Their mean age was 49 ± 17 years and the mean time after heart transplantation was 29 ± 41 months. An echocardiogram was performed immediately after the invasive procedure. We analysed PCWP, transmitral flow velocity variables (peak velocity during early filling (E) and deceleration time [DT]), color M-mode Doppler flow propagation velocity (Vp), and mitral annulus peak early diastolic velocity (E') from DTI. Doppler estimated-PCWP (ePCWP) was calculated as follows: (5.27 × E/Vp) + 4.6.

RESULTS

Mean ejection fraction was 66 ± 11%. The mean invasive measured PCWP was 11.14 ± 5.4 mm Hg and the mean noninvasive ePCWP was 11.13 ± 1.8 mm Hg (r = 0.66; P < .0001). A good correlation was present between invasive PCWP and mitral PW-Doppler and DTI parameters: peak E 91 ± 22 cm/s (r = 0.34; P = .02) and DT 143 ± 26 s (r = -0.436; P = .002), E/E' ratio medial mitral annulus 10 ± 4 cm/s (r = 0.353; P = .026) and E/E' ratio lateral mitral annulus 6 ± 2 cm/s (r = 0.462; P = .002). E/Vp was the most accurate index for predicting PCWP (r = 0.615; P < .0001).

CONCLUSIONS

Compared with other indirect Doppler indices, E/Vp showed the best correlation to predict PCWP in heart transplant recipients. Despite previous recommendations, PCWP can be accurately estimated from color M-mode indices, giving useful information and avoiding the risks of invasive measurements.