The role of invasive cardiopulmonary exercise testing in patients with unexplained dyspnea: a systemic review

Background Dyspnoea is a common complaint that often remains unexplained with no diagnosis and poor management despite extensive, repetitive and costly testing. Invasive cardiopulmonary testing has been used in the evaluation of dyspnoea, however, its role is not yet well defined. We sought to perform a systematic review of the literature looking at the role of invasive cardiopulmonary testing in the evaluation of chronic dyspnoea and/or exercise intolerance. Methods and results We performed a literature review in accordance with PRISMA, analysing articles published in peer-reviewed journals between January 1st 1985 and January 31st 2020, available in 3 databases. The aim was to identify randomised and non-randomised clinical studies that focussed on the utility of invasive cardiopulmonary exercise test in the evaluation of dyspnoea. Emphasis was placed on studies that noted the use of exercise stress testing with the concomitant use of right heart catheterisation to evaluate hemodynamics as part of the work up for dyspnoea. We identified 6 retrospective studies that assessed the use of exercise hemodynamics to identify the aetiology of dyspnoea. Conclusion Invasive cardiopulmonary exercise test is a useful tool for identifying the cause of unexplained dyspnoea. It can be helpful in early recognition and prognostication of patients with heart failure with preserved ejection fraction and pulmonary hypertension. It has also shown to be beneficial for constructing a multidisciplinary approach to chronic dyspnoea.