Mitral Annular Calcification-Related Valvular Disease: A Challenging Entity

Mitral valve annular calcification-related valvular disease is increasingly common due to the rising prevalence of age-related mitral annular calcifications. Mitral annular calcification alters the structure and function of the mitral valve annulus, which in turn causes mitral valve regurgitation, stenosis, or both. As it frequently coexists with comorbid conditions and overlapping symptoms, mitral annular calcification-related valvular disease poses significant diagnostic and therapeutic challenges. For instance, left ventricular diastolic dysfunction hinders the assessment of mitral valvular disease. Detection of mitral annular calcifications and assessment of related mitral valve disease hinge on two-dimensional echocardiography. Comprehensive assessment of mitral annular calcifications and related mitral valve disease may require multidetector computed tomography and three-dimensional echocardiography. Invasive hemodynamic testing with exercise helps identify the cause of symptoms in patients with comorbid conditions, and transcatheter interventions have emerged as a viable therapeutic option for older patients. After an outline of the normal mitral annulus, we examine how mitral annular calcifications lead to mitral valve disease and how to accurately assess mitral regurgitation and stenosis. Lastly, we review surgical and transcatheter approaches to the management of mitral annular calcification-related mitral valve regurgitation, stenosis, or both.

Impact of Mitral Annular Calcium and Mitral Stenosis on Outcomes After Transcatheter Aortic Valve Implantation

Mitral annular calcium (MAC) is a common finding in patients undergoing transcatheter aortic valve implantation (TAVI) and may be associated with mitral stenosis (MAC-MS). Their impact on post-TAVI outcomes remains controversial. We sought to assess the impact of MAC and MAC-MS on clinical outcomes following TAVI. We included 1,177 patients who consecutively underwent TAVI in our institution between January 2008 and May 2018. MAC diagnosis reposed on echocardiogram and computed tomography. The combination of MAC and a mean transmitral gradient ≥ 5 mmHg defined MAC-MS. The study included 1,177 patients, of whom 504 (42.8%) had MAC and 85 (7.2%) had MAC-MS. Patients with and without MAC had similar outcomes except for a higher rate of pacemaker implantation in MAC patients (adjusted HR: 1.32, 95% CI: 1.03-1.69, p = 0.03). The subgroup of patients with severe MAC had similar outcomes. However, MAC-MS was an independent predictor of all-cause mortality at 30 days (adjusted HR: 2.30, 95% CI: 1.08-4.86, p = 0.03) and 1 year (adjusted HR: 1.73, 95% CI: 1.04-2.89, p = 0.04). In conclusion, MAC is present in nearly half of the patients treated with TAVI but MAC-MS is far less frequent. In itself, even severe, MAC does not influence outcomes while MAC-MS is an independent predictor of all-cause 1-year mortality. Measurement of mean transmitral gradient identifies patients with MAC at high risk after TAVI.

A meta-analysis of impact of mitral stenosis on outcomes after transcatheter aortic valve implantation

OBJECTIVES

To determine whether concomitant mitral stenosis (MS) impairs outcomes after transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis (AS), we performed a meta-analysis of currently available evidence.

METHODS

To identify all observational comparative studies of outcomes after TAVI for AS in patients with MS vs patients with no-MS, we searched databases (MEDLINE and EMBASE) using web-based search engines (PubMed and OVID). Studies meeting the following criteria were included; the design was an observational study; the study population was patients undergoing TAVI for AS; outcomes in patients with MS were compared with those in patients with no-MS. Study-specific estimates were then pooled using inverse variance-weighted averages of logarithmic odds and hazard ratios in the random-effects model.

RESULTS

We identified six eligible studies including 111 621 patients undergoing TAVI. In pooled analyses, postprocedural incidence of ≥ moderate paravalvular aortic regurgitation (PAR) (P = .02), early all-cause mortality (P = .008), early incidence of myocardial infarction (MI) (P = .01), and midterm all-cause mortality (P = .03) after TAVI were significantly higher in patients with MS than in patients with no-MS. There were no significant differences in early incidence of stroke, major bleeding, acute kidney injury, and new permanent pacemaker implantation after TAVI between patients with MS and patients with no-MS. When the study for mitral annular calcification was excluded in the pooled analyses, no results except for MI were substantially altered but the significance for early incidence of MI disappeared (P = .10).

CONCLUSION

Postprocedural incidence of ≥ moderate PAR, early all-cause mortality, early incidence of MI, and midterm all-cause mortality after TAVI are higher in patients with MS than in patients with no-MS.