Right ventricular stroke work index from echocardiography in patients with pulmonary arterial hypertension-the role in short-term follow-up assessment.

Abstract

Aims: Right ventricular (RV) failure causes high mortality in patients with pulmonary arterial hypertension (PAH). RV stroke work index (RVSWi) poses as a potential predictor of outcome. We evaluated how RVSWi by echocardiography (ECHO) or right heart catheterization (RHC) is altered following PAH treatment and if RVSWi is an indicator of outcome in PAH.

Methods and results: Fifty-four patients with PAH performed ECHO and RHC (median, 0 days between examinations) at baseline and treatment follow-up. RVSWi_RHC was computed as (mPAP-mRAP)×SVi_RHC, (mPAP, mean pulmonary arterial pressure; mRAP, mean right atrial pressure; SVi, stroke volume indexed to body surface area). ECHO-derived RVSWi was calculated as RVSWi_ECHO-Mean = TR_meanPG × SVi_ECHO and RVSWi_ECHO-Max = TR_maxPG × SVi_ECHO (TR_meanPG and TR_maxPG: tricuspid regurgitant mean and maximum pressure gradient). Invasive sPAP, mPAP, and pulmonary vascular resistance decreased and SVi increased from baseline to follow-up (P < 0.01 for all). RVSWi_RHC and RVSWi_ECHO (Mean and Max) did not differ from baseline to follow-up (P > 0.05). Forty patients died during 109 ± 24 months. In univariate Cox proportional hazard analysis, age > 65 years, 6-minute-walk test < 160 m, WHO class III-IV and indexed right atrial volume were associated with long-term mortality, but none of the RVSWi methods. In multivariate analysis with clinical parameters, both RVSWi_ECHO methods were independently associated with mortality.

Conclusion: The RVSWi methods did not differ from baseline to short-term follow-up and were not associated with long-term outcomes in univariate analysis. However, baseline RVSWi_ECHO was associated with mortality when adjusting for clinical parameters.