Contributor: Elise Vo
Decoupling of diastolic pulmonary artery pressure and PCWP (greater than 5 mmHg difference) during ramp testing in continuous flow LVAD patients is a significant predictor for HF hospitalization and all-cause mortality. This decoupling is also represented as the diastolic pressure gradient (dPAP-PCWP). dPAP and PCWP decoupling (increased DPG) may indicate intrinsic pulmonary vascular pathology and associated right ventricular strain.
Sixty three CF-LVAD patients (mean age 60+/-12, 40% female, 52% ICM) undergoing right heart catheterization with hemodynamic ramp testing were evaluated. Twenty seven patients (42%) had decoupling at baseline speed. After CF-LVAD revolution per minute speed was increased, 30 patients (48%) had de-novo decoupling. Imamura et al. found that decoupling was the only significant predictor for mortality and HF readmission in multivariate analysis (HR 1.09, 95% confidence interval 1.04-1.24, p<0.05).
No study is perfect. This is a small, single center analysis. There was wide variation in time from LVAD implantation to ramp study, and ramp testing was used to optimize CVP and PCWP, but not decoupling. The population having ramp studies is highly selected.
In a heartbeat… Decoupling between the dPAP and PCWP among CF-LVAD patients undergoing ramp study predicts all-cause mortality and HF hospitalization.