Background Several excellent screening methods for pulmonary hypertension (PH) or pulmonary arterial hypertension (PAH) in connective tissue diseases (CTD) such as systemic sclerosis (SSc) have been proposed (1)(2). We previously introduced a formula for estimating mean pulmonary arterial pressure (mPAP) using simple exercise Doppler echocardiography for CTD patients (3)(4).
Objectives To validate the applicable formula for selecting CTD patients who need RHC based on the results of their exercise Doppler echocardiography. We also investigated whether exercise Doppler echocardiography contributed to the more accurate detection of the patients who need RHC.
Methods A total of 231 CTD patients having either dyspnea or lower carbon monoxide diffusing capacity (DLCO) were performed Doppler echocardiography before and after exercise with the Master's double two-step test. Of 231 patients, 31 underwent RHC. Using the data from the 31, we derived a formula using tricuspid regurgitation pressure gradient at 3 minutes after exercise Doppler echocardiography for estimating mPAP (=0.270+0.387 x TRPG at 3 min. after exercise)(r2 =0.5367, P<0.0001), which was previously described (3). Validation with the additional 25 patients was performed. We compared its diagnostic value with Schreiber's formula (1) and DETECT algorithm (2).
Results Applying the formula to the validation cohort of 25 patients, which included 7 patients with borderline mPAP and 3 with manifest PH, gave a good correlation between the estimated and actual mPAP by RHC (Spearman r =0.7516, p<0.0001). In receiver operating characteristic, the area under the curve was 0.952. Using an estimated threshold of 17.5 mmHg for diagnosis of PH, the sensitivity and specificity were 100% and 79%, respectively. Among our 31 SSc patients, the sensitivity and specificity of Schreiber's formula for diagnosing PH were 86% and 31%, respectively. Applying DETECT algorithm to our 23 SSc patients with DLCO <60%, the sensitivity and specificity for diagnosing PAH were 83% and 41%, respectively.
Conclusions The provided formula for estimating mPAP gave a good correlation with actual mPAP by RHC. By adding this method as a part of screening for PH, selection of CTD patients potentially having PH would be more efficient.
Schreiber B et al. Improving the detection of pulmonary hypertension in systemic sclerosis using pulmonary function tests. Arthritis Rheum, 2011; 63: 3531.
Coghlan JG et al. Evidence-based detection of pulmonary arterial hypertension in systemic sclerosis: the DETECT study. Ann Rheum Dis, 2014; 73: 1340.
Yamasaki Y et al. Good detection of early pulmonary hypertension using exercise Doppler echocardiography in patients with connective tissue diseases and its comparison with other screening tool. EULAR 2014.
Suzuki K et al. Simple exercise echocardiography using a Master's two-step test for early detection of pulmonary hypertension. J Cardiol, 2013; 62: 176.
Disclosure of Interest None declared