Incremental Value of Deformation Imaging and Hemodynamics Following Heart Transplantation: Insights From Graft Function Profiling.

OBJECTIVES: This study investigated to define graft dysfunction and to determine its incremental association with long-term outcome after heart transplantation (HT). BACKGROUND: Although graft failure is an established cause of late mortality after HT, few studies have analyzed the prognostic value of graft dysfunction at 1- and 5-year follow-up of HT. METHODS: Patients who underwent HT and completed their first annual evaluation with right heart catheterization and echocardiography at Stanford University between January 1999 and December 2011 were included in the study. Hierarchical clustering was used to identify modules to capture independent features of graft dysfunction at 1 year. The primary endpoint for analysis consisted of the composite of cardiovascular mortality, re-transplantation, or heart failure hospitalization within 5 years of HT. The study further explored whether changes in graft dysfunction between 1 and 5 years were associated with 10-year all-cause mortality. RESULTS: A total of 215 HT recipients were included in the study. Using hierarchical clustering, 3 functional modules were identified; among them, left ventricular global longitudinal strain (LVGLS), stroke volume index, and right atrial pressure (RAP) or pulmonary capillary wedge pressure (PCWP) captured key features of graft function. Graft dysfunction based on pre defined LVGLS in absolute value <14%, stroke volume index <35 ml/m2, RAP >10 mm Hg, or PCWP >15 mm Hg were present in 41%, 36%, and 27%, respectively. The primary endpoint at 5 years occurred in 52 patients (24%), whereas 10-year all-cause mortality occurred in 30 (27%) of 110 patients alive at 5 years. On multivariate analysis, RAP (standardized hazard ratio: 1.63), LVGLS (standardized hazard ratio: 1.39), and a history of hemodynamically compromising rejection within 1 year (hazard ratio: 2.18) were independent predictors of 5-year outcome. RAP at 5 years, as well as change in RAP from 1 to 5 years, was predictive of 10-year all-cause mortality. CONCLUSIONS: RAP and LVGLS at the first annual evaluation provide complementary prognostic information in predicting 5-year outcome after HT.

Relationship between echocardiographic and magnetic resonance derived measures of right ventricular size and function in patients with pulmonary hypertension.

BACKGROUND: Transthoracic echocardiographic (TTE) imaging is the mainstay of clinical practice for evaluating right ventricular (RV) size and function, but its accuracy in patients with pulmonary hypertension has not been well validated. METHODS: Magnetic resonance imaging (MRI) and TTE images were retrospectively reviewed in 40 consecutive patients with pulmonary hypertension. RV and left ventricular volumes and ejection fractions were calculated using MRI. TTE areas and indices of RV ejection fraction (RVEF) were compared. RESULTS: The average age was 42 ± 12 years, with a majority of women (85%). There was a wide range of mean pulmonary arterial pressures (27-81 mm Hg) and RV end-diastolic volumes (111-576 mL), RVEFs (8%-67 %), and left ventricular ejection fractions (26%-72%) by MRI. There was a strong association between TTE and MRI-derived parameters: RV end-diastolic area (by TTE imaging) and RV end-diastolic volume (by MRI), R(2) = 0.78 (P < .001); RV fractional area change by TTE imaging and RVEF by MRI, R(2) = 0.76 (P < .001); and tricuspid annular plane systolic excursion by TTE imaging and RVEF by MRI, R(2) = 0.64 (P < .001). By receiver operating characteristic curve analysis, an RV fractional area change < 25% provided excellent discrimination of moderate systolic dysfunction (RVEF < 35%), with an area under the curve of 0.97 (P < .001). An RV end-diastolic area index of 18 cm(2)/m(2) provided excellent discrimination for moderate RV enlargement (area under the curve, 0.89; P < .001). CONCLUSIONS: Echocardiographic estimates of RV volume (by RV end-diastolic area) and function (by RV fractional area change and tricuspid annular plane systolic excursion) offer good approximations of RV size and function in patients with pulmonary hypertension and allow the accurate discrimination of normal from abnormal.