Is there a cure for mitral stenosis?

Not exactly. There are several treatment options but no medicine can open the valve. These treatments can reduce the blockage but the falve is still abnormal or replaced with an artificial valve. Sometime a ballon can be inserted thru the valve to stretch it open and improve flow. Rarely can the valve be repaired (unlike a leaking valve which is usually repaired). It can be replaced with an artificial valve.
Often. Diuretics, which increase urine formation, can reduce blood pressure in the lungs by reducing the volume of circulating blood. Beta-blockers, digoxin , and calcium channel blockers help control heart rhythms. Anticoagulants may be needed to prevent clot formation in people with atrial fibrillation. If drug therapy does not reduce the symptoms satisfactorily, the valve may be repaired or replace.