Abstract
Introduction: Pulmonary arterial hypertension (PAH) is a severe, low survival and rapidly progressive disease, characterised by an increase in the distal vascular resistance and decrease in the compliance. Right heart catheterisation (RHC) is the standard procedure for the PAH diagnosis and regular response to therapy assessment. Although the severe RHC associated risks are reduced, minimising the number of the interventions is highly desirable for improving patients' life quality.
Aim: The aim of the current study is to evaluate whether non-invasive measures of pulmonary vascular resistance and compliance can be used to assess the response to treatment in PAH patients.
Methods: 93 patients diagnosed with PAH at RHC, underwent magnetic resonance imaging (MRI) of the main pulmonary artery at baseline and one year follow-up. At baseline, 56 patients were treatment naive and 37 on PAH therapy. A 3-element Windkessel model, using as input MRI flow and area waveforms, was implemented to compute the pulmonary resistance, RWk and compliance, CWk (Lungu et al., J Biomech 2014; 47:2941-7). RWk and CWk were compared at baseline with invasive pulmonary resistance, PVR, and vascular compliance, CSV computed as stroke volume to pulse pressure ratio.
Results: At baseline, RWk correlated with PVR (p<0.05, r=0.35), and CWk correlated with CSV (p<0.01, r=0.49). At follow-up, statistically significant increase of CWk (p<0.05), and decrease of RWk (p<0.01) was found for the treatment naive patients, whereas no significant changes were found in stable patients on therapy.
Conclusion: The non-invasive proposed metrics have the potential to assess the response to PAH therapy, reducing the RHC interventions at follow-up.
- Copyright ©the authors 2016