Clinical significance and management of right heart thrombi: more questions than answers.

Pulmonary embolism (PE) remains one of the leading causes of cardiovascular morbidity and mortality [1]. Acute PE has a spectrum of clinical syndromes and varying clinical outcomes [2, 3]. Estimation of patient prognosis helps to prioritise appropriate management strategies. Risk stratification of patients with PE may identify patients at high risk of early PE-related death who may benefit from escalated surveillance or therapy [4, 5]. Alternatively, clinicians may consider patients deemed at low risk for early complications (i.e. all-cause mortality, recurrent venous thromboembolism (VTE), and major bleeding) as candidates for partial or complete outpatient PE treatment [6]. According to the recent European Society of Cardiology (ESC) guidelines [7], risk assessment of patients diagnosed with PE should rely on the sequential application of a validated clinical score (i.e. pulmonary embolism severity index (PESI) or simplified PESI (sPESI)), imaging testing assessing right ventricle (RV) function (i.e. echocardiography or computed tomographic pulmonary angiography), and cardiac biomarkers (i.e. cardiac troponins). Though the guidelines state that patients who have acute PE associated with right heart thrombi (RHT) have a potentially life-threatening condition, the authors did not formally incorporate the presence or absence of RHT into their PE prognostication algorithm.