- 作者：Mark R. Toshner ; Deepa Gopalan ; Jay Suntharalingam ; Carmen Treacy ; Elaine Soon ; Karen K. Sheares ; Nicholas W. Morrell ; Nicholas Screaton ; Joanna Pepke-Zaba
- 关键词：pulmonary hypertension ; chronic thromboembolic pulmonary hypertension
- 刊名：The Journal of Heart and Lung Transplantation
- 出版年：2010
- 出版时间：June 2010
- 年：2010
- 卷：29
- 期：6
- 页码：610-615
- 全文大小：505 K
Background
Relative area change (RAC) of the proximal pulmonary artery is a measurement of pulmonary artery distensibility and has been shown to correlate with vasoreactivity studies in patients with idiopathic pulmonary arterial hypertension. We have previously noted a relationship between invasive hemodynamic vasoreactivity testing and long-term response to sildenafil in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). We therefore set out to determine whether RAC can provide useful correlatory non-invasive data.Methods
Patients recruited to a randomized, controlled trial (RCT) of sildenafil at 40 mg 3 times daily underwent additional magnetic resonance imaging (MRI) at the baseline of the trial. Eighteen patients had an MRI that led to a diagnosis of inoperable distal CTEPH or significant residual CTEPH post-operatively. The primary end-point was improvement in 6-minute walk test (6MWT) with secondary end-points of right heart catheterization–based hemodynamics, N-terminal pro–brain natriuretic peptide (NT pro-BNP) and functional class. RAC assessed by MRI was correlated with trial end-points.
Results
Fourteen subjects with baseline MRI completed the protocol. RAC was the only baseline variable that correlated at 1 year to the primary end-point of improvement in 6MWT (r = 0.7, p = 0.006), and also to a change in NT pro-BNP (r = 0.59, p = 0.03). Using a cut-off of RAC over 20 % there was an 87.5 % sensitivity (95 % confidence interval [CI]: 45 % to 100 % ) and a 66.7 % specificity (95 % CI: 22 % to 96 % ) for an improvement in 6MWT of >40 meters.
Conclusions
RAC correlates with functional response to sildenafil, as measured by the 6MWT, and improved heart function, as measured by NT pro-BNP. RAC shows potential in understanding and possibly predicting treatment response.