Non-invasive assessment of right ventricular function and pulmonary pressures in cardiogenic shock remains challenging: don't pack away the PAC just yet

Abstract

Abstract Background Cardiogenic shock (CS) is associated with high levels of morbidity and mortality despite advances in treatment. Patients with right ventricle (RV) dysfunction have been shown to have poorer outcomes. It is suggested that invasive monitoring through pulmonary artery catheter (PAC) placement can assist in guiding management to improve survival, though they are associated with adverse events. Purpose This study assessed the utility of non-invasive, echocardiographic assessment of RV performance and pulmonary artery pressures (PAP) in patients with CS. Methods Consecutive patients admitted to a North American quaternary cardiac intensive care unit who had PAC placement were recruited into this study. Invasive haemodynamic assessment was followed by transthoracic echocardiography (TTE) performed by a critical care cardiologist, blinded to the invasive measurements. TTE images were later reported by a second cardiologist, blinded to the invasive measurements and the patient. Correlations between RV and pulmonary invasive and non-invasive parameters were evaluated using Pearson's correlation. Results Overall, 96 assessments of 60 patients were compared. Patients were predominantly male (73%), aged 58±14 years and SCAI stage C (55%) and D (22%) at the time of assessment. Invasive measurements of right heart and pulmonary function was possible in all patients. Mean RAP was 8.5±4.7 mmHg, systolic PAP 37.5±9.9 mmHg, diastolic PAP 18.1±6.5 mmHg, mean PAP 25.1±7.2 mmHg, pulmonary capillary wedge pressure (PCWP) 16.0±16.4 mmHg, pulmonary vascular resistance (PVR) 157±99dyn s cm–5, RV stroke work index (RVSWI) 7.0±3.9 g min/m2 and PAP index (PAPi) 2.9±4.2. When compared to non-invasive echocardiographic parameters, there was little correlation with invasive values (Table). RVSWI moderately correlated with peak tricuspid regurgitation (TR) velocity, tricuspid annular plane systolic excursion (TAPSE) and estimated systolic PAP; while peak TR velocity was mild-moderately correlated with PAP and PCWP. No single non-invasive parameter demonstrated strong prediction of invasive values. Conclusion Non-invasive assessment of right heart and pulmonary haemodynamic parameters is of limited validity when compared with invasive monitoring through PAC in patients with CS. PAC remains the most reliable method of assessing the RV haemodynamic profile in CS. Future studies should evaluate the clinical benefit of invasive haemodynamic monitoring in this population. Funding Acknowledgement Type of funding sources: None.