Mitral Annular Calcification Treatment & Management

Updated: Mar 06, 2017
  • Author: Saurabh Sharma, MD, FACC, FACP; Chief Editor: David J Maron, MD, FACC, FAHA  more...
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Approach Considerations

The presence of asymptomatic mitral annular calcification (MAC) does not require specific medical therapy. Because of the association between MAC and atherosclerosis, valvular disease, stroke, and other vascular diseases, appropriate medical management of concomitant cardiovascular risk factors is recommended. [90]

Interestingly, a study from the Multi-Ethnic Study of Atherosclerosis (MESA) cohort determined that while several cardiovascular risk factors predicted incident MAC, the severity of MAC at the time of first detection was the primary predictor of MAC progression. [91] This would suggest that while atherosclerotic processes may initiate MAC, they are only modestly associated with its progression. [91] Indeed, the potential regression of MAC with medical therapy has not been examined, but studies done with aortic valve calcification have shown no regression despite treatment with angiotensin-converting enzyme (ACE) inhibitors and statins. [92, 93]

MAC has also been associated with chronic kidney disease (CKD), and its presence on echocardiography should alert the physician to the possible presence of decreased renal function. [54, 55]

No endocarditis prophylaxis is indicated in patients with isolated MAC. [90]

According to the 2008 American College of Chest Physicians guidelines for valvular and structural heart disease, antithrombotic therapy with aspirin is recommended in patients with MAC but without atrial fibrillation who have experienced systemic embolism, ischemic stroke, or transient ischemic attack. [93] For recurrent events despite aspirin therapy, anticoagulation with a vitamin K antagonist is suggested (target international normalized ratio, 2.5; range, 2-3). In patients with MAC who have a single embolus documented to be calcific, data are not sufficient to recommend either for or against antithrombotic therapy.

Patients with isolated MAC do not require hospitalization. However, these patients are at increased risk for major cardiovascular events (eg, stroke, myocardial infarction). Given the strong association with atherosclerosis, cardiovascular risk factor modification (eg, hypertension, hyperlipidemia) and appropriate follow-up is important.


Surgical Care for MAC

No surgical treatment is indicated for mitral annular calcification (MAC), unless correction of concomitant mitral regurgitation or mitral stenosis is needed. In fact, severe MAC makes valve surgery more difficult. Risks and benefits of surgery must be carefully assessed in patients with significant MAC, as increased surgical mortality has been observed in these patients. For those patients with documented calcific emboli or repeated thromboembolism despite anticoagulation, valve replacement may be considered.

Mitral valve replacement in the setting of severe MAC can cause complications such as left ventricular rupture. MacVaugh et al reported unusual complications during mitral valve replacement in the presence of calcification of the annulus in 1971. [94] In the perioperative period, patients developed acute posterior myocardial infarction, ventricular aneurysm, or hemorrhage from the left ventricle. Spencer et al reported that debridement of the calcified mitral annulus at the time of valve replacement led to left ventricular rupture in 3 cases. [95]


Impact of MAC in Transcatheter Aortic Valve Replacement

A 2016 report showed that mitral annular calcificaiton (MAC) has prognostic implications in Transcatheter Aortic Valve Replacement (TAVR). [96] Of 761 patients studied, 49.3% had MAC. Severe MAC was found to be an independent strong predictor of overall mortality following TAVR and cardiovascular mortality, as well as an independent strong predictor of new permanent pacemaker implantation after TAVR.


Impact of MAC in Transcatheter Mitral Valve Replacement

Severe mitral annular calcification (MAC) has been considered a contraindication for percutaneous mitral valve repair. Manipulation of wires and large balloons during transcatheter mitral valve replacement (TMVR) or repair may cause an increased risk of stroke or myocardial infarction due to a release of calcific debris, resulting in cerebral or coronary emboli. However, this procedure has been used as a less invasive alternative for patients who are deemed to be either very high risk or unsuitable for conventional mitral valve surgery owing to multiple comorbidities, including old age and left ventricular dysfunction.

Case reports have described various approaches to TMVR, such as a transapical approach, [97]  a transseptal approach combined with transapical externalization of the wire, [98]  an open left atrial approach, and an isolated transvenous-transseptal approach. [99] In most of these case reports, patients had circumferential MAC that may have provided adequate anchorage for the prosthesis. Moderate circumferential MAC allows stable anchoring of the prosthesis. In contrast, if the MAC is severe, it poses a risk of annular rupture during valve deployment. If MAC is noncircumferential, it may not provide enough anchorage for the prosthesis, thereby potentially causing a periprosthetic leak or dislodgement due to exposure to high systolic pressure.