Discussion
obesity, VTE, RV (dys)function, heart failure, RV dysfunction
OBESITY, EVENTS, HEART FAILURE, RECURRENCE
The aim of the present analysis was to examine the temporal pattern of changes in RV function, i.e. complete or partial recovery versus persistence or deterioration of abnormal findings, in patients having suffered acute, intermediate-risk PE. We examined the patient population participating in a prospective multicentre multinational single-arm study. Our main results are the following: (i) RV dilatation was the most frequently (41%) reported abnormal echocardiographic finding at the time of the index PE; (ii) in almost two-thirds of the patients, RV function parameters as assessed by echocardiography had already recovered by day 6, and this improvement was maintained over the 6-month follow-up; however, almost one out of four patients had at least one abnormal echocardiographic finding at 6 months; and (iii) the median levels of NT-proBNP remained elevated in patients with at least one abnormal echocardiographic finding at 6 days but decreased and approached normal values at 6 months even among patients with persisting echocardiographic abnormalities.Our results extend those of previous reports on the temporal changes of RV dimensions and function after acute PE. They may help to improve the level of evidence regarding long-term outcomes since our patient population was included in a prospective management study with standardised initial and chronic (over 6 months) treatment of PE. In an early small observational study dating back to the vitamin K antagonist era, it was reported that RV function normalised in the vast majority of PE patients within the first 5–13 days following treatment initiation [The present study adds to our knowledge on the patients’ long-term course after acute intermediate-risk PE in view of contemporary treatment with a direct oral anticoagulant (in this case, a thrombin inhibitor) over the entire 6-month period, and it also proposes a standardised approach to categorising, analysing and reporting echocardiographic follow-up data. In this regard, it must be emphasised that our ‘algorithm’ was not developed as a new prognostic score in acute PE but rather as a guidance for following RV dysfunction with echocardiographic parameters used in everyday clinical practice. We believe that the parameter groups and the steps developed for our analysis may be useful for future studies with serial assessments of RV (dys)function, especially when multiple centres in different countries are involved. Since the assessment of RV function may be crucial for the resumption of daily activities during follow-up after acute PE [Although RV function is expected to recover early after acute PE in the majority of the patients, there are cases where RV recovers at a later stage or even fails to recover completely [The observation that obesity was an independent determinant of persistently compromised RV function in our study is of interest but not totally unexpected. Previous studies have reported that obesity negatively affects the cardiovascular system [Strengths of the present study include: (i) the participation of patients from 42 centres across 9 European countries, covering a broad spectrum of clinical settings in which the follow-up took place; (ii) the prospective follow-up of RV function at 6 days and 6 months after the diagnosis of acute PE; (iii) the prospective categorisation of echocardiographic parameters to permit standardised assessment of RV function and its changes over time, and (iv) the assessment of both echocardiographic and biochemical parameters for the evaluation of RV (dys)function and (presumably right) heart failure at baseline and during follow-up. However, our analysis also has some limitations. Firstly, not all parameters related to RV function were available for all patients at all visits. In addition, an association of the kinetics of echocardiographic RV parameters with the primary clinical endpoint of the study, recurrence of symptomatic or fatal VTE at 6 months, could not be established due to the small absolute number of recurrent events [In conclusion, our results indicate that in the majority of patients with acute intermediate-risk PE who were switched early (on the third day) to a direct oral anticoagulant, echocardiographic parameters reflecting RV function normalised within 6 days and remain normal throughout the first 6 months. The levels of NT-proBNP also improved during 6-month follow-up. Almost one in four patients, however, still had at least one abnormal echocardiographic finding suggesting some degree of persisting RV dysfunction and possibly the need for continued follow-up over the long term.