A 50-year-old female presents with a history of idiopathic dilated cardiomyopathy. Over the past 6 months, she has become increasingly short of breath and has been requiring higher doses of diuretics. An echocardiogram reveals an ejection fraction of 20%, which is unchanged; however, severe central mitral regurgitation is present. She is optimized on ACE inhibitors, beta-blockers, spironolactone and digoxin. An ECG shows a left bundle branch block and sinus rhythm. Which of the following is the next appropriate course of action?
A. Mitral valve repair or replacement
B. Biventricular pacing
C. Add nifedipine for further afterload reduction
D. The Alfieri stitch