Which among the following is false regarding rheumatic hea disease?

Rheumatic fever is principally a disease of childhood, with a median age of 10 years. Acute rheumatic fever may develop varying degrees of pancarditis with associated valve insufficiency, hea failure, pericarditis, and even death. With chronic rheumatic hea disease, patients develop valve stenosis with varying degrees of regurgitation, atrial dilation, arrhythmias, and ventricular dysfunction. Chronic rheumatic hea disease remains the leading cause of mitral valve stenosis and valve replacement in adults. The mitral valve is most commonly and severely affected (65-70% of patients), and the aoic valve is second in frequency (25%). The tricuspid valve is deformed in only 10% of patients and is almost always associated with mitral and aoic lesions. The pulmonary valve is rarely affected.