Advanced chronic rheumatic heart disease associated with substantial myocardial and valvular fibrosis on cardiovascular magnetic resonance

Abstract

Introduction: Rheumatic heart disease (RHD) is a major public health concern, particularly in low- and middle-income countries. Cardiovascular magnetic resonance (CMR) is a reliable noninvasive technique that detects fibrosis and inflammation in cardiovascular diseases. The study aimed to investigate the association of advanced chronic RHD with myocardial and valvular fibrosis using multiparametric CMR.

Methods: We assessed myocardial tissue characteristics in chronic RHD using multiparametric CMR. Forty-seven patients with severe, advanced RHD booked for valve replacement surgery, diagnosed on echocardiography, and matched with 30 healthy controls were scanned using a 3T MRI Siemens Magnetom Skyra scanner (Siemens, Erlangen, Germany). Baseline demographic and clinical characteristics, CMR findings including late gadolinium enhancement (LGE), T1 mapping, and extracellular volume (ECV) measurements were reported.

Results: The mean age of patients was 42 ± 12.8 years; 29 (62%) were women (39 ± 12.1 years). LGE CMR detected focal myocardial fibrosis in 47 (100%) of RHD patients vs. 2 (7%) of controls (p < 0.001). In all RHD patients, LGE involving all segments was observed. Patterns of LGE were linear 12 (26%), patchy 17 (36%), and diffuse 18 (38%). The total mass of myocardial enhancement with LGE imaging was significantly different from control (26 ± 10.1 vs. 17 ± 9 g, p = 0.002), resulting in a total percentage of (26% ± 6% vs. 21% ± 6%, p = 0.01). We also report elevated mean native T1 (p < 0.001) and ECV (p < 0.001) in all RHD patients compared to controls, respectively. Myocardial fibrosis is abundant in patients with severe, chronic RHD.

Conclusion: We report a high fibrotic burden in patients with advanced chronic RHD. Our observations may provide an explanation for increased heart failure and mortality in RHD, as excess myocardial fibrosis has been strongly linked with mortality in other disease contexts.