The Natural History of Severe Calcific Mitral Stenosis

Background: Prevalence of calcific mitral stenosis (MS) increases with age; however, its natural history and relation to cardiac symptoms or comorbidities are not well defined. Objectives: This study assessed the prevalence of symptoms, comorbidities, and determinants of all-cause mortality in patients with severe calcific MS. Methods: The authors retrospectively investigated adults with isolated severe calcific MS and mitral valve area ≤1.5 cm² from July 2003 to December 2017. Inactivity was defined as requirement for assistance with activities of daily living. Results: Of 491 patients with isolated severe MS, calcific MS was present in 200 (41%; age 78 ± 11 years, 18% men, 32% with atrial fibrillation). Charlson Comorbidity Index was 5.1 ± 1.7 and 14 (7%) were inactive. Mitral valve area and transmitral gradient (TMG) were 1.26 ± 0.19 cm² and 8.1 ± 3.8 mm Hg, respectively. Symptoms were present at baseline in 120 (60%); 20 (10%) developed symptoms during follow-up of 2.8 ± 3.0 years. Kaplan-Meier survival at 1 year was 72% without intervention. Inactivity (hazard ratio [HR]: 6.59; 95% confidence interval [CI]: 3.54 to 12.3; p < 0.01), Charlson Comorbidity Index >5 (HR: 1.53; 95% CI: 1.04 to 2.26; p < 0.01), TMG ≥8 mm Hg (HR: 1.68; 95% CI: 1.12 to 2.51; p = 0.012), and right ventricular systolic pressure ≥50 mm Hg (HR: 2.27; 95% CI: 1.50 to 3.43; p < 0.01) were independently associated with mortality. Symptoms were not associated with mortality. Conclusion: Patients with isolated severe calcific MS had a high burden of comorbidities, resulting in high mortality without intervention. Symptoms were reported in 60%, but not associated with mortality. TMG ≥8 mm Hg and right ventricular systolic pressure ≥50 mm Hg were independently associated with mortality.