Transcatheter mitral valve replacement for degenerated mitral valve bioprostheses, failure of mitral valvuloplasty and native valve with severe mitral annulus calcification: a systematic review and meta-analysis

Background Although transcatheter technology has achieved some success in the field of mitral valves, the feasibility of applying it to patients with degenerated mitral valve bioprostheses (valve-in-valve, ViV), failure of mitral valvuloplasty (valve-in-ring, ViR) and serious mitral annulus calcification (vale-in-MAC, ViMAC) has not been effectively evaluated. Methods By searching published literature before December 5, 2020 in four databases, we found all the literature related to the evaluation of feasibility assessment of TMViV, TMViR and TMViMAC. Outcomes focused on all-cause mortality within 30 days, bleeding and LVOT obstruction. Results A total of six studies were included, and all of them were followed up for at least 30 days. After analysis of the ViV–ViR group, we obtained the following results: the all-cause mortality within 30 days of the ViV group was lower than that of the ViR group. Life-threatening or fatal bleeding was more likely to occur in the ViR group after surgery. At the same time, the ViR group was more prone to left ventricular outflow tract obstruction. However, in the ViMAC–ViR group, only the all-cause mortality within 30 days and stroke were statistically significant. In the indirect comparison, we found that TMViV had the best applicability, followed by TMViR. There were few TMViMAC available for analysis, and it requires further studies to improve the accuracy of the results. Conclusion TMViV and TMViR had good applicability and could benefit patients who underwent repeat valve surgery. The feasibility of TMViMAC needs to be further explored and improved.

Massive Myocardial Calcification—A Heart Of Stone!

A 71-year-old female was admitted in the emergency room after effort-related syncope. She had past medical history of obesity and hypertension treated with lercanidipine. No relevant family history. Physical examination revealed systolic murmur (grade 2/6). ECG showed sinus rhythm and left bundle brunch block (Supplementary figure). Lab results were unremarkable including troponin I. Transthoracic echocardiography (TTE) revealed moderate left ventricular (LV) hypertrophy [septal thickness 14 mm (normal: 6–9mm)], extensive mitral annulus calcification (MAC) with exuberant myocardial calcification at the level of posterior leaflet that invaded adjacent LV walls, systolic anterior motion of the anterior mitral leaflet causing LV outflow tract (LVOT) obstruction (maximum gradient 34 mmHg) and moderate mitral regurgitation (MR) (Panel A). Exercise echocardiogram provoked LVOT gradient >100mmHg and severe MR. Continuous ECG monitoring during 13 days demonstrated no arrhythmic events. Cardiac CT showed multiple calcifications extending from mitral annulus to LV anterior and lateral walls and cardiac MRI was compatible with caseous MAC (Panels B-F). Coronary angiography showed 50% stenosis of mid left anterior descending artery. Normal thoracic CT and ACE, and negative IGRA excluded sarcoidosis and tuberculosis. Comprehensive study, including calcium metabolism and autoantibodies, excluded metabolic and inflammatory aetiologies of myocardial calcification, which was assumed as dystrophic in the context of MAC. No syncope occurred after bisoprolol 2.5 mg, oral rehydration and discontinuation of lercanidipine. However, rest and exercise TTE failed to show improvement of LVOT gradient or MR and patient remained on NYHA class II-III, despite maximal tolerated dose of bisoprolol (5 mg), being therefore referred to cardiac surgery.