Outcomes of mitral transcatheter edge-to-edge repair in patients with mitral annular calcification: A meta-analysis

Background: The impact of mitral annular calcification (MAC) on the clinical outcomes of patients undergoing mitral transcatheter edge-to-edge repair (MTEER) remains unclear. This meta-analysis aims to evaluate the clinical outcomes of MTEER among patients with moderate to severe MAC compared to those with mild or no MAC. Methods: We systematically searched PubMed, EMBASE, and Cochrane CENTRAL databases through March 31st, 2024, comparing clinical outcomes of MTEER among patients with moderate/severe (MAC+) versus no/mild MAC (MAC-). We assessed pooled estimates for procedural success, all-cause mortality, residual mitral regurgitation (MR) ≤ moderate, and New York Heart Association (NYHA) class III/IV status at one year. Results: Among five studies (2533 patients; mean age 76.4 ± 10.9 years, 39.8 % women), MAC+ patients were predominantly women (55.7 % vs 37.5 %, p < 0.001), older (87.9 ± 11.1 vs. 75.9 ± 9.1 years; mean difference (MD) = 3.99, p = 0.011) and had higher STS scores (7.7 ± 6.7 % vs. 4.9 ± 4.6 %; MD = 1.34, p < 0.001). MAC+ patients had comparable procedural success rates, residual MR < moderate, and NYHA III/IV at 1 year. However, all-cause mortality at 1 year was higher for MAC+ patients (Relative Risk = 1.56, 95 % CI = 1.06–2.29). Conclusions: MTEER is a safe and feasible option for carefully selected patients with MAC and significant MR, offering durable MR reduction and functional status improvement. Significantly higher one-year mortality associated with MAC despite significant MR reduction suggests an increased risk unrelated to valvular dysfunction and highlights the need for further investigation into identifying patients who benefit the most from MTEER.