Outcomes of right heart dysfunction in the acutely and severely unwell: protocol for a prospective, longitudinal observational study using multimodal assessment.

Introduction: The relationship of acute right heart dysfunction (RHD) with long-term cardiopulmonary dysfunction and its' associated morbidity has not been clearly elucidated. We propose a prospective, observational study to assess the natural history of acute RHD using a combination of imaging, functional and qualitative assessment methods, including the recently described combination of simultaneous maximal effort cardiopulmonary exercise testing and stress echocardiography.

Methods And Analysis: We propose a single-centre study of patients ≥18 years admitted to either the intensive care or respiratory close observation units with RHD on transthoracic echocardiography (TTE). Participants will undergo a repeat TTE ~72 hours after the initial study, with a final TTE performed prior to discharge in patients who have a prolonged (>1 week) stay. Inpatient clinical, biochemical and therapeutic indices will be collected contemporaneously. At ~6 months postdischarge, participants will undergo evaluation with validated symptom assessment tools (Dyspnoea-12 and PAH-SYMPACT Questionnaires) and a combined maximal effort cardiopulmonary exercise test and stress echocardiogram. This study is an observational, hypothesis-generating study with a recruitment target of 100 patients established based on typical admission rates of the relevant hospital departments. Measures of central tendency and dispersion will be used to describe the cohort. Inferential statistics will be used to compare the two a priori defined groups of those whose RHD had resolved prior to hospital discharge and those whose dysfunction persisted at time of discharge.

Ethics And Dissemination: This study has received ethics approval from the local ethics committee (Nepean and Blue Mountains Local Health District approval, project 2021/ETH12111). Written informed consent will be sought from all patients prior to recruitment. The results will be submitted for publication in a relevant peer-reviewed journal and presented at an appropriate national/international conference.

Study Registration: Australian New Zealand Clinical Trials Registry, ANZCTR12623000309684.