Gallium-68 DOTATATE –Positron Emission Tomography/ Computed Tomography (PET/CT) imaging for the detection of the role of inflammation in the pathogenesis of restenosis in patients treated with Percutaneous Balloon Mitral Valvotomy

Abstract

Background: Mitral stenosis is a well-known long-term sequel to chronic rheumatic heart disease (RHD). Percutaneous mitral balloon valvotomy (PMBV) is a non-surgical technique for dilatation of the mitral valve. Restenosis post PMBV is a common problem. The mechanism through which this process occurs is still unclear. However, it has been suggested that restenosis following PBMV may have an inflammatory aetiology based on findings of elevated inflammatory markers in patients post PBMV. Aims and Objectives: This study aimed to evaluate the role of inflammation in mitral valve restenosis following PBMV. The study also sought to demonstrate the role of ongoing active rheumatic fever (based on serology) in patients post BMV with mitral restenosis. Methods: This was a single centre, descriptive cross-sectional study conducted at the Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) between 1 April 2016 and 30 June 2016. Patients previously subjected to PBMV with evidence of restenosis, as detected by echocardiography underwent Positron Emission Tomography/ Computed Tomography (PET/CT) scan using Gallium-68 (Ga-68) DOTATATE , were recruited into the study. Twenty patients were identified and contacted, but 6 were not entered into the study; informed consent was obtained for the remaining patients. Serological testing for rheumatic fever was additionally performed in an attempt to establish a link between recurrence of rheumatic activity and inflammatory activity in the mitral valve. Results: The study population comprised of 13 patients. Eight (61.5%) patients were females. The mean age was 46.2 ± 11.8 years. Amongst patients with confirmed restenosis in the mitral valve, 54% failed to demonstrate Ga-68 DOTATATE uptake, while only 5% of patients demonstrated serological evidence of active rheumatic fever. A negative correlation was noted between the erythrocyte sedimentation rate (ESR) and time from balloon mitral valvotomy (BMV) (r = -0.6954, p= 0.0083). This implies that as the time from BMV increases, the ESR reduces. Conclusion: The study did not demonstrate significant Ga-68 DOTATATE uptake in mitral valves with echocardiographic evidence of restenosis post PMBV. Furthermore, in the majority of participants, serology did not confirm the role of ongoing rheumatic activity as the cause of mitral restenosis