Anatomic classification of mitral annular calcification for surgical and transcatheter mitral valve replacement

Abstract

Background and Aim of the Study: A systematic approach to quantify mitral annular calcification (MAC) in all-comers by multidetector computed tomography (MDCT) is essential to guide treatment, but lacking.Methods: From September 2015 to July 2019, 82 patients with MAC underwent MDCT at two institutions to evaluate for surgical mitral valve replacement (SMVR), transcatheter mitral valve replacement (TMVR), or medical management. Type 1 MAC was defined as <270°annular calcium and Type 2 as ≥270°. Absence/presence of predicted left ventricular outflow tract (LVOT) obstruction with virtual valve placement was used to further define Type 2 MAC into 2A/B for our treatment algorithm.Results: Type 1 MAC was present in 51.2%, Type 2A in 18.3%, and Type 2B in 30.5%. Operable Type 1 patients (50.0%) underwent hybrid transatrial TMVR or SMVR. Type 2A underwent a variety of treatments, and Type 2B surgical candidates (40.0%) underwent hybrid transatrial TMVR secondary to difficult suture anchoring with significant MAC and predicted LVOT obstruction. At a follow-up of 29.6 ± 12.0 months, mortality was 42.7% with 46.3% in the intervention group and 39.0% in the medical group (p = 0.47). All percutaneous TMVR patients expired. This translated to a disproportionate number of Type 2A deaths (80.0% with intervention), but all were high/extreme surgical risk. The hybrid TMVR group consisted of 95.0% Type 1/2B patients and had a lower Society of Thoracic Surgeons predicted risk of operative mortality (7.4% vs. 9.2%, p = 0.43)/mortality. Conclusions:The highest mortality was seen in percutaneous TMVR Type 2A MAC patients, but they were at the greatest risk. Here we provide an objective MAC treatment algorithm for all-comers based on operability/anatomy.

Systematic approach of mitral valve interventions in the setting of mitral annular calcification: A step forward in improving outcomes

“…Heart team‐based algorithmic approaches to determine the management of mitral valve dysfunction in the setting of MAC are greatly needed. Following that line, the study by Alexis et al 12 is an important addition to the MAC literature. A key point from this paper is that developing a MAC treatment algorithm is challenging but achievable.…”

“…In this issue of Journal of Cardiac Surgery , Alexis et al 12 proposed a MAC algorithm that attempts to shed more light on the systematic approach to determine the anatomic feasibility of patients with MAC requiring SMVR, TMVR, or a hybrid procedure. All patients underwent MDCT imaging to obtain standard anatomic measurements and MAC analysis.…”

Commentary: From bailout to standardized approach in mitral annulus calcification: It's a short step

“…The use of multidetector computed tomography in addition to the analysis of the cardiac images using commercially available software, allowing one to simulate the valve position, have provided essential details during the preoperative planning. Using multidetector computed tomography analysis, Alexis and colleagues 3 recently reported an interesting MAC classification according to the extension of annular calcification and furthermore observed that a simulated reduction of neo-LVOT area ≤170 mm 2 , thickness of left ventricular septal, the aortomitral angle measurement, and the annular eccentricity with a cut-off ≥30%, may strongly predict early surgical failure.…”

Mitral annular calcification: Bad versus worse

“…We congratulate Alexis et al 1 and the structural heart teams from Mount Sinai and Columbia for this series of high‐risk patients with mitral annular calcification (MAC) undergoing mitral intervention and for their novel classification of MAC based on treatment algorithm. Surgically, the presence of MAC is associated with risk of valve replacement over repair 2 and risk of ventricular rupture, myocardial infarction, and atrioventricular dissociation 3 .…”

“…Alexis et al 1 propose a simple and potentially powerful conceptual model of mitral intervention based on MAC and risk of LVOTO. As the growth of transcatheter mitral interventions continues particularly for elderly patients, we are appreciating the growing importance of MAC both for technical success but also as a harbinger for poor overall prognosis.…”