Challenges of a Big MAC
A 75-year-old female patient with history of hypertension and diabetes presented 3 years previously with worsening fatigue and exercise intolerance. Evaluation at that time revealed the presence of severe aortic stenosis, severe mitral annular calcification (MAC), and three-vessel coronary artery disease. She subsequently underwent an aortic valve replacement and multivessel coronary artery bypass grafting. Intraoperatively, inspection of the mitral valve showed an extensive circumferential calcification of the valve that was densely embedded across the mitral annulus. Because decalcification maneuvers would be very challenging technically and associated with increased risk of atrioventricular groove disruption, no intervention was performed on the mitral valve. The patient did well following the operation but re-presented 3.5 years later with recurrent progressive fatigue and exertional dyspnea. She can walk for only 1 block before having to stop due to dyspnea. She reported 10 kg of weight gain in the preceding year from inactivity. Repeat evaluation showed the presence of a normally functioning aortic prosthesis, preserved biventricular systolic function, and patent coronary grafts. Severe MAC was again noted (Figure 1). Averaged mean mitral diastolic gradient was 9 mmHg at rest (heart rate was 60 BPM); this is associated with mild mitral regurgitation (MR). As part of her evaluation, a supine bike stress echocardiogram was performed; the results are summarized in Figure 2.
In this patient with severe MAC, which of the following statements is correct?