Pulmonary vascular changes associated with isolated mitral stenosis in India

Area of Science:

• Cardiovascular Pathology
• Pulmonary Hypertension
• Rheumatic Heart Disease

Background:

• Isolated mitral stenosis frequently affects young individuals, with a notable predominance in males.
• Pulmonary vascular changes are a known complication of mitral stenosis.
• Severe pulmonary hypertension is often associated with rheumatic mitral stenosis in India.

Purpose of the Study:

• To investigate the spectrum of pulmonary vascular changes in isolated mitral stenosis.
• To correlate these vascular changes with hemodynamic data and patient demographics.
• To describe novel vascular lesions in mitral stenosis.

Main Methods:

• Analysis of lung biopsies from 90 patients undergoing valvotomy and necropsy findings from 10 patients.
• Measurement of medial thickness in pulmonary arteries.
• Correlation of vascular changes with hemodynamic data in 12 cases.

Main Results:

• All patients exhibited thickened pulmonary artery media, with moderate to considerable thickening in most.
• Intimal abnormalities, including edema, fibrosis, and muscularization, were common.
• Arterial and arteriolar occlusion by organized thrombi and intimal proliferation were observed, alongside lymphatic and bronchiolo-alveolar system changes.
• Dilation lesions (grade 4 hypertensive pulmonary vascular disease) were noted in 4 cases.
• More severe changes were prevalent in younger patients, indicating a link between juvenile rheumatic mitral stenosis and severe pulmonary hypertension.

Conclusions:

• Mitral stenosis induces significant and varied pulmonary vascular remodeling.
• The severity of medial hypertrophy correlates with pulmonary artery pressure.
• Juvenile rheumatic mitral stenosis in India is associated with severe pulmonary hypertension and distinct vascular pathology.