P189 Evaluation of the role of cardio-pulmonary exercise testing in the diagnosis of unexplained breathlessness

Introduction and Objectives Cardio-Pulmonary Exercise Testing (CPET) provides a non-invasive measurement of cardiac and pulmonary function. CPET offers a unique assessment tool for the investigation of patients with unexplained dyspnoea (UD). These individuals often undergo exhaustive, expensive and invasive assessment without definitive diagnosis. CPET can provide valuable diagnostic information and helps to focus further assessment of the dyspnoeic patient. The aim of this retrospective cohort study was to evaluate the outcome of CPET in patients with UD and to determine how clinically useful the test is at influencing further management. Methods CPET data were collected between February 2008 and February 2011 for patients with UD and analysed retrospectively. Data included demographics, pre-CPET investigation results, the CPET report and post-CPET clinic letters. This information was accessed via hospital reporting systems as well as a local CPET database and patient notes. Results Patient demographics and pre-CPET investigation data are shown in Abstract P189 table 1. Patients were assigned diagnoses based on test reports. A total of 96 (64%) patient letters were obtained to determine whether the test had affected the diagnostic outcome directly, indirectly or not at all. 78 (81%) of the tests resulted in direct outcomes, 12 (13%) resulted in indirect outcomes and 6 (6%) had no impact on further investigation or diagnosis. A significant proportion (27%) of patients undergoing CPET for UD responded normally to exercise and were discharged with reassurance. 15% were diagnosed with dysfunctional breathing and referred to a specialist physiotherapist for breathing retraining. 57 (38%) patients were diagnosed as having an exclusively normal or dysfunctional breathing response to exercise. Of these, many had undergone investigation prior to CPET including 19 ECG, 14 V/Q scans, nine CT scans, six coronary angiograms, four cardiac treadmill tests, two nuclear medicine stress tests and one cardiac MRI. Conclusions By introducing CPET at an earlier stage in the diagnostic algorithm for UD, many invasive and expensive investigations could have been avoided. CPET resulted in direct outcomes for 81% of the patients, highlighting the diagnostic importance of CPET in the investigation of UD.