Quantifying mitral stenosis in MAC: are we doing it right?

Abstract Introduction and objectives Degenerative mitral valve disease due to mitral annular calcification (MAC) is a growing problem that represents a therapeutic challenge. Unlike regurgitation, quantification of mitral stenosis (MS) severity is not well established in this condition. To date, the usefulness of conventional echocardiographic parameters in this subgroup has not been demonstrated, as they were developed in the context of the rheumatic etiology. Quantifying their severity is essential for choosing different therapeutic approaches. We evaluated the usefulness of different echocardiographic methods for assessing MS severity in the context of MAC compared to the established gold standard. Furthermore, MS was correlated with the degree of MAC severity by CT. Methods We retrospectively evaluated patients with MAC who underwent 3D TEE and CT as part of their valvular disease evaluation between 2019 and 2022. MVA was determined by 3D transesophageal planimetry. Severe MS was considered an MVA 1.5 cm², and the degree was assessed according to the following parameters: mean mitral gradient (MMG), PHT, and PHT-derived area. MAC severity was assessed using the Guerrero score by CT. Results One hundred and sixteen patients with a mean age of 82 ± 6 years were included, 61% women. Thirteen percent had severe MS (Table 1). A cutoff for MMG of 7 mmHg yielded an S of 73% and an SE of 98% (AUC/ROC 0.875) for determining a severe MS. The PHT showed an AUC of 0.904 with an optimal cutoff point of 153 ms (S 60%, E 98%). The mean bias between the MVA by 3D TEE and the area by PHT was minimal (–0.047; 95% CI –0.217–0.122) with reasonable agreement (ICC 0.60, p 0.05). The severe MS group had a higher CT score (median 6), suggesting an association between MS severity and MAC. Conclusions Although 3D planimetry measurement remains the method of choice for quantifying MS, the use of THP and mean gradient has proven to be reliable and accurate tools for assessing MS severity in the context of MAC. Calculating the MVA by PHT shows good discriminatory ability for severe MS compared to the established gold standard. These methods not only complement the current standard but also offer great potential for improving diagnosis, monitoring, and planning more effective therapeutic interventions in the future.Table 1 Clinical & echo characteristics