Left ventricular diastolic dysfunction attenuates outcomes in chronic pulmonary thromboembolism

BackgroundLeft ventricular diastolic dysfunction in chronic thromboembolic pulmonary hypertension is classically attributed to the negative effects of pulmonary hypertension on left ventricular filling. Recent evidence, however, suggests diastolic dysfunction may exist independent of pulmonary hypertension and moreover may be masked by an under-filled left ventricle. MethodsConsecutive patients undergoing pulmonary endarterectomy (2007 - 2018) were included (n=1266). Left ventricular diastolic dysfunction was assessed using pulmonary arterial wedge pressure and in nested cohorts utilising multi-modal cardiac imaging. Diagnostic baseline, outcome data, and long-term mortality outcomes were assessed. Results135 individuals had a wedge pressure >15mmHg following surgery, of whom 60% had a normal wedge pressure pre-operatively. No patients had a formal diagnosis of heart-failure preserved ejection fraction. Haemodynamic, functional and patient-related outcomes were all worse in this patient subgroup and associated with a higher requirement for peri-operative non-invasive ventilation and impaired long-term survival. Post-operative cardiac imaging confirmed evidence of left ventricular diastolic dysfunction in patients with an elevated wedge pressure. Pre-operative left atrial dilatation alone predicted post-operative wedge elevation with accuracy (sensitivity 67%, specificity 100%), and was superior to echocardiography. ConclusionsLeft ventricular diastolic dysfunction is strongly associated with all pulmonary endarterectomy outcome measures, however the majority of patients do not have an elevated wedge pressure pre-operatively and are not diagnosed with heart failure. Standard pre-operative work-up should include assessment for diastolic dysfunction to aid risk categorisation and guide therapy decisions.