RETRACTED: Right to left ventricular volume ratio: A novel marker of disease severity in chronic thromboembolic pulmonary hypertension

This article has been retracted: please see Elsevier Policy on Article Withdrawal ( http://www.elsevier.com/locate/withdrawalpolicy ). This article has been retracted after the journal was approached by its authors bringing important matters to our attention. It has been retracted for two reasons: 1. because the statement that “all authors had seen and approved the manuscript” proved to be incorrect; and 2. because of uncertainties over informed consent being adequately documented. We were notified that an error occurred because of a misunderstanding between authors at different locations, concerning the nature of the Ethics approval that had been obtained from these patients. This new substudy, a retrospective analysis of their MRI data before and after surgery, was not separately submitted to relevant Ethics Committee nor was informed consent for the MRI substudy obtained from the patients.