Background: Right ventricular-pulmonary artery coupling (RVPAC) is a
predictor of outcome in pulmonary hypertension. However, the role of
this parameter in dilated cardiomyopathy (DCM) remains to be
established. The aim of this study was to assess the contribution of
RVPAC to the occurrence of severe heart failure (HF) symptoms in
patients with DCM using three-dimensional (3D) echocardiography.
Methods: We prospectively screened 139 outpatients with DCM, 105 of whom
were enrolled and underwent 3D echocardiographic assessment. RVPAC was
estimated non-invasively as the 3D right ventricular stroke volume (SV)
to end-systolic volume (ESV) ratio. Severe HF symptoms were defined by
New York Heart Association (NYHA) class III or IV. We evaluated
differences in RVPAC across NYHA classes and the ability of RVPAC to
predict severe symptoms. Results: Mean left ventricular (LV) ejection
fraction was 28±7%. Mean RVPAC was 0.77±0.30 and it was significantly
more impaired with increasing symptom severity (p=0.001). RVPAC was the
only independent correlate of severe HF symptoms, after adjusting for
age, diuretic use, LV systolic function, LV diastolic function and
pulmonary artery systolic pressure (OR 0.035 [95% CI, 0.004 –
0.312], p=0.003). By receiver-operating characteristic analysis, the
RVPAC cut-off value for predicting severely symptomatic status was 0.54
(area under the curve=0.712, p<0.001). Conclusion: 3D
echocardiographic SV/ESV ratio is an independent correlate of severe HF
symptoms in patients with DCM. 3D RVPAC might prove to be a useful risk
stratification tool for these patients, should it be further validated
in larger studies.
Three-Dimensional Right Ventriculo-Arterial Coupling as an Independent Correlate of Severe Heart Failure Symptoms in Patients with Dilated Cardiomyopathy
