Cardiopulmonary outcomes of right heart dysfunction in the critically ill: a prospective observational trial

The exposure is any illness that leads to the development of right heart dysfunction in patients where the illness severity requires their admission to either an intensive care unit (ICU) or respiratory high dependency unit (HDU). The patients that have this exposure (condition) will be followed up for the duration of their hospital stay and then a further time point observation (where they will undergo further testing) at 3-6 months post hospital discharge. The in hospital component will be standard investigations and care as determined by the treating clinicians. Patients that have a clinically indicated transthoracic echocardiogram during their inpatient stay, and whose echocardiogram shows right heart dysfunction will be approached for participation. If they consent they will undergo a repeat echocardiogram approximately 72 hours after the first study to assess for persistence or resolution of the dysfunction. Other cares and investigations are as per the treating team. The follow-up process will involve a single outpatient clinic appointment at 3-6 months following hospital discharge. The duration of this appointment is expected to be 1-2 hours. It will involve taking a history and examining the participant, the participant completing 2 hard copy questionnaires (the Pulmonary Arterial Hypertension - Symptoms and Impact [PAH-SYMPACT] questionnaire and the Dyspnoea-12 questionnaire) and the participant undergoing a simultaneous cardiopulmonary exercise test and echocardiogram. This echocardiogram will be performed by the principal investigator. The cardiopulmonary exercise test will be a maximum effort, symptom limited exercise test performed on a stationary bike ergometer. This ergometer is a recumbent bike ergometer with the capacity to recline and tilt, allowing for more accurate and precise echocardiographic images to be taken. The echocardiographic component of participant follow-up will occur simultaneously with the cardiopulmonary exercise test, similar to convential exercise stress echocardiography. The active exercise component of this test is expected to last 8-12 minutes. All participants will undergo the same process/testing, however we will be performing a subgroup analysis comparing those whose right heart dysfunction had resolved on the repeat inpatient study with those right heart dysfunction was still present on the repeat inpatient study. 7 participants were recruited on the initial protocol, which included a standard cardiopulmonary exercise test and subsequent echocardiogram, rather than a combined (simultaneous) cardiopulmonary exercise test and echocardiogram. These participants have not yet had follow-up due to unexpected delays in equipment acquision. These participants, if consenting, will undergo the amended protocol however these patients will have their follow-up at approximately 6-12 months post hospital discharge, rather than 3-6 months post hospital discharge (which is the target time interval for the prospectively recruited patients).