Provocative testing of the pulmonary circulation: advances and unresolved issues

In this issue of the European Respiratory Journal , Oliveira et al. [1] from Harvard Medical School (Boston, MA, USA) report on rapid recovery of pulmonary vascular pressures after maximum incremental cycling exercise. The authors combined right heart catheterisation with concurrent cardiopulmonary exercise test in 95 patients referred for unexplained dyspnoea. 36 patients had precapillary pulmonary hypertension (PH) during exercise, defined by the authors as displaying a peak exercise mean pulmonary artery pressure (mPAP) ≥30 mmHg, a peak wedged pulmonary artery pressure (PAWP) <20 mmHg and a peak pulmonary vascular resistance (PVR) ≥1.5 Wood units (WU). 28 patients had postcapillary PH during exercise defined by a peak PAWP ≥20 mmHg. 31 matched controls with normal resting mPAP were selected based on a maximum oxygen uptake ≥80% predicted in the absence of exercise PH based on the aforementioned criteria. Workload and oxygen uptake at the ventilatory threshold and at peak exercise were lower in the exercise PH patients, which confirm the relevance of exercise pulmonary haemodynamic measurements in unexplained dyspnoea. However, most of the exercise-induced increase in PAWP and mPAP was reversed within 2 min of recovery. The important message is that pulmonary haemodynamics have to be measured during, but not after, an exercise stress test for the diagnosis of exercise PH. Expert consensus standardisation of provocative testing of the pulmonary circulation is needed <http://ow.ly/4nsNbU>