Can one die from mitral stenosis?

Yes: Absolutely, although this is rare in the United States. Causes of death would include stroke (secondary to associated atrial fibrillation) or end-stage congestive heart failure.

Yes if untreated: Mitral stenosis is tightness in the mitral valve which makes filling of the main pumping chamber difficult. Typically it is a slowly progressing problem often a result of rheumatic fever many years earlier. The treatment is medical management until it progresses to a particular state at which point the valve is often replaced, but it can be repaired at times.