Co-Author(s):
Saligrama Ramegowda Kalpana, MD
Deepak Padmanabhan, MD, DM
Manish K Rai, MD, DM
Ankit Singh, MD, DM
Bharatraj Banavalikar, MD, DM
Darshan Krishnappa, MD, DM
SRI JAYADEVA INSTITUTE OF CARDIOVASCULAR SCIENCES & RESEARCH
SRI JAYADEVA INSTTUTE OF CARDIOVASCULAR SCIENCES & RESEARCH BANNERGHATTA MAIN ROAD, PHASE 3 9TH BLOCK, JAYANAGAR, BENGALURU- 560069
Introduction | Objectives: Atrial fibrillation and left atrial thrombus are less common in isolated mitral regurgitation than mitral stenosis or mixed mitral valve disease of rheumatic etiology. The histopathologic changes in patients with and without atrial fibrillation in patients with isolated rheumatic mitral regurgitation are unknown. We aimed to discern the differences in histological findings in patients with severe rheumatic mitral regurgitation with and without atrial fibrillation.
Methods: Patients with severe isolated rheumatic mitral regurgitation undergoing valve replacement surgery underwent endocardial biopsy from right atrial appendage (RAA), left atrial appendage (LAA), right atrial free wall (RAFW), left atrial free wall (LAFW), left posterior wall (LPW) and mitral valve. Group I consisted of patients in sinus rhythm and Group II included patients with atrial fibrillation. We analyzed and compared these samples between the two groups for myocyte hypertrophy, interstitial and endocardial fibrosis, inflammatory cells, Aschoff bodies, interstial adipose tissue, cellular vacuolation, and iron/amyloid deposition.
Results: Of the 25 patients , 12 were in Group I and 13 in group II. Myocyte hypertrophy was the most common histological finding and was more prevalent in Group I (100% vs 92.3%, p=0.33). More severe myocyte hypertrophy was seen in Group I (60% vs 18% showing severe hypertrophy, p=0.04) and in right atrium (22.7% vs 11.4%, p=0.059). Interstitial fibrosis was another common finding with near even distribution at all sites and without significant difference between the two groups. Prevalence and severity of vacuolar degeneration was higher in Group II (91% vs 60% showing severe changes, p=0.09). Interstitial adipose tissue deposition was more common in Group I (30% vs 25%, p=0.06).
Conclusions: Patients with severe rheumatic mitral regurgitation and atrial fibrillation have more vacuolar degeneration whereas myocyte hypertrophy and interstitial adipose tissue deposition are more common in sinus rhythm.