Is There Still a Chance for Direct Surgical Valve–in–mac? A Single–center Experience

Background A clear standard for the treatment of mitral annular calcification (MAC) has yet to be established. Conventional surgical strategies continue to be associated with high mortality rates, whereas percutaneous Valve–in–MAC (ViM) procedures have shown promising results (Figure 1), although still limited by the risks of LVOT obstruction, embolization, and apical perforation. In recent years, several reports have described hybrid surgical “off–label” implantation of an aortic transcatheter heart valve (THV), proposed ad a way to mitigate these risks through more controlled device deployment. Here, we present our single–center experience of transatrial direct surgical Valve–in–MAC (TADS–ViM). Methods Between July 2022 and October 2024, n=16 patients affected by severe mitral valve steno–regurgitation underwent TADS–ViM. A mini–thoractotomy access was performed in one subject. On CPB, the anterior leaflet was removed and single– or bi–commissural sutures were applied in all cases to reduce valve area and circularize the annulus. After pre–dilatation, a SAPIEN 3 Ultra THV was inflated ∼30/70% atrio–ventricular, commissurally aligned. Four–to–nine single atrial U–stitches were placed to avoid embolization. An eventual post–dilatation was performed to improve stent frame expansion after knot tying. Results Procedural success rate was 100%. CT–scan analyses confirmed severe MAC (Figure 2, score: 8.5 [7,9]; area: 607±97 mm2, predicted neo–LVOT: 205 [165, 283] mm2, n=2 complete obstruction). Median clamp time was 89 [68, 125] min. A 26 and 29 mm devices were implanted in n=5 and n=11 patients, respectively. 50% of the patients underwent concomitant procedures (n=6 AVR; n=4 CABG; n=2 aortic surgery). No cases of LVOT obstruction were reported, but one patient required revision for major bleeding due to apex lesion during balloon inflation. 30–day mortality rate was 18.8% (n=3), mainly due to sepsis. At a median follow–up of 1 year, survival rate was 75% (n=12). One patient required percutaneous closure of bi–commissural leaks at 2.5 years. Conclusions TADS–ViM may represent a valid alternative to complex surgical decalcification strategies or challenging ViMAC procedures. Concomitant targets may also be surgically addressed and small anatomies –not amenable of percutaneous approach– treated as well. However, mortality rate of these fragile and comorbid patients remains high. The implementation of less invasive and durable solutions to treat MAC is mandatory.