A retrospective review of more than 24,000 patients who underwent an electrocardiogram (ECG) has found that nearly one-quarter had mitral annulus calcification. Researchers from Mayo Clinic (Rochester, USA), who carried out the study, reported that mitral valve dysfunction was more than twice as prevalent for those patients, who also were at higher risk of all-cause mortality.
The research suggests that mitral annulus calcification is a predictor of mortality, as well as a marker of valvular and cardiovascular disease. The findings are outlined in an article, “Prevalence and natural history of mitral annulus calcification and related valve dysfunction,” published in Mayo Clinic Proceedings.
Among the key findings from the study, researchers found that a moderate or greater degrees of mitral valve dysfunction was more than twice as common in patients with mitral annulus calcification than without.
Furthermore, they report that, after adjustment for comorbidities, mitral annulus calcification was associated with higher mortality, as well as noting that mortality was highest in patients with mitral annulus calcification and mitral valve dysfunction.
“The association between mitral annulus calcification and mitral valve dysfunction is important to understand because it affects treatment considerations for valve dysfunction,” says Patricia Pellikka the study’s corresponding author. “Mitral valve surgery is associated with high risk for patients with mitral annulus calcification, in part because advanced age can be a factor. Severe calcification makes mitral valve procedures more challenging to perform. Our study aimed to assess the characteristics and risk factors of mitral annulus calcification, and the prognostic impact of associations with mitral valve dysfunction.”
Of 24,414 patients evaluated with an ECG, 5,502, or 23%, had mitral annulus calcification, according to the study. Mitral valve disease was observed in 16% of those patients. Among patients with mitral annulus calcification, 54% of those with mitral valve dysfunction were female, and frailty was common.
The presence of mitral annulus calcification was associated with higher mortality, after statistical adjustment. Mitral valve dysfunction increased mortality, regardless of the presence of mitral annulus calcification. But patients with both conditions had the highest mortality, the study finds.
“Mitral annulus calcification has been known to be associated with cardiovascular disease and mortality, but we did not previously appreciate the strength of this relationship even after adjustment for multiple clinical and echocardiographic variables,” says Pellikka. “Patients with calcification more commonly had not only mitral valve dysfunction, but also aortic valve disease. For clinicians, suspicion for valve diseases should be increased and evaluations carefully performed for patients with mitral annulus calcification.”
The highest risk group of patients with mitral annulus calcification are women and patients who have aortic valve disease, left ventricular outflow tract obstruction and renal dysfunction. Patients with any valve dysfunction in the setting of mitral annulus calcification should have regular follow-up visits with their physician. Periodic follow-up imaging also is appropriate, and echocardiography works well for this purpose, Pellikka adds.
The study was supported by a grant from Abbott Structural Heart.