Clinical significance of dynamic pulmonary vascular resistance in two populations at risk of pulmonary arterial hypertension

Abstract

AimsPatients at risk of pulmonary arterial hypertension (PAH) may present with abnormal dynamic pulmonary vascular resistance (PVR) during exercise. However, its clinical significance remains unclear. The present study aimed at analysing the meaning of dynamic PVR in two populations at risk of PAH: secundum atrial septal defect (ASD) and systemic sclerosis (SSc). Methods and resultsAdult patients with corrected ASD were consecutively selected from the database of Pediatric and Congenital Heart Disease of the University Hospitals Leuven. Patients with SSc were consecutively selected from the rheumatology database of the University Hospital Liège. At inclusion, all underwent a rest and bicycle stress echocardiography to obtain baseline right heart characteristics and dynamic PVR. Routine follow-up echocardiography was performed. Twentyeight patients with corrected ASD (mean age 41 + 17 years, 79% female) were followed for a median time of 3.7 [inter-quartile range (IQR) 2.9 -4.1] years. No patient developed PAH. Dynamic PVR was significantly associated with right atrial dilatation at latest follow-up (Spearman's r 0.51, P ¼ 0.013). Forty-five SSc patients (mean age 54 + 13 years, 76% female) were followed for a median time of 2.4 (IQR 0.8 -2.9) years. Thirteen patients (30%) developed PAH. Dynamic PVR was the only independent predictor of PAH (hazards ratio 1.22, 95% confidence interval 1.01-1.47). No significant right heart morphometric changes occurred. ConclusionDynamic PVR predicted PAH development in patients with SSc, whereas dynamic PVR was associated with right heart morphometric changes after ASD closure. The predictive role of dynamic PVR might depend on the underlying disease type. Larger studies are needed to confirm this hypothesis.--

An official European Respiratory Society statement: pulmonary haemodynamics during exercise

“…Patients at risk of PAH or pulmonary hypertension Certain conditions are associated with a significantly increased risk of PAH, in particular SSc, which is often used as a model to investigate the development of PAH and recognise early markers of PAH development [38,39]. Based on recent studies, exercise pulmonary hypertension may represent early pulmonary vascular involvement in SSc and may be predictive for development of PAH [129,[131][132][133][134][135]. In SSc, an abnormal PAP increase during exercise may result from pulmonary vasculopathy [37,41,43], but also from parenchymal lung disease and left heart disease [43,130,133,134,[136][137][138].…”

“…In addition, abnormal haemodynamic responses, measured either by exercise Doppler echocardiography or by RHC during exercise have been reported in family members of idiopathic or heritable PAH patients [29,121,139,140], in patients susceptible to high-altitude pulmonary oedema [28], in chronic thromboembolic disease [53,89,141], post-repair congenital heart disease (closed atrial septal defect) [134], lung disease [93,142,143], chronic heart failure [78] and valvular heart disease patients [144,145]. It is not clear whether any of these conditions is associated with PAH.…”

“…Exercise pulmonary hypertension is a clinically relevant entity [91,126,127,[131][132][133][134] and in certain conditions (e.g. SSc [131] and COPD [174]) may be predictive for the development of pulmonary hypertension.…”

Imaging the right heart pulmonary circulation unit: Insights from advanced ultrasound techniques

“…These authors observed that the slope of change in the relationship between PASP and cardiac index (CI) was significantly greater than in controls. In this regard, echo assessment of increased pulmonary vascular resistance and left ventricular filling pressure during exercise could represent a more specific diagnostic (precapillary vs postcapillary PH) and prognostic marker of patients with overt PH and/or at higher risk of PH …”

“…These authors observed that the slope of change in the relationship between PASP and cardiac index (CI) was significantly greater than in controls. In this regard, echo assessment of increased pulmonary vascular resistance and left ventricular filling pressure during exercise could represent a more specific diagnostic (precapillary vs postcapillary PH) and prognostic marker of patients with overt PH and/or at higher risk of PH 50,51. Interestingly, in a series of 124 patients with PAH or inoperable chronic thromboembolic PH and impaired RV pump function, Grünig et al52 showed that patients with low RV contractile reserve who were not able to increase sPAP during exercise had a significantly worse prognosis and needed intensified treatment.…”