Insights into malignant mitral valve degenerative diseasefrom a sudden cardiac death cohort highlighting significantmeasurement differences from normal

Joseph Westaby,Luciana Bicalho, Emelia Zullo & Mary N Sheppard

Aims: Mitral valve prolapse (MVP) is an acceptedcause of sudden cardiac death (SCD) in most autopsyseries. Diagnosis at autopsy relies upon subjectiveassessment with no established objective pathologicalcriteria. This study set out to establish objective mea-surements to help pathologists dealing with SCD.Methods: We diagnosed 120 (1.5%) cases of MVP in8108 cases of SCD. We measured the mitral annulus,anterior and posterior leaflets, rough zone and mitralannular disjunction (MAD) in 27 MVP cases andcompared them to 54 age- and sex-matched normalmitral valves.Results: Age of death was 3916 years, with 59females and 61 males. History of mild MV diseasewas present in 19 (16%). Eleven (9%) died associatedwith exertion. Left ventricular hypertrophy was pre-sent in nine (15%) females and 10 (16%) males. BothMV leaflets showed thickening and ballooning in allindividuals. MVP showed highly significantlyincreased annular circumference, elongation andthickening of both leaflets as well as increased MAD(allP<0.001). Left ventricular fibrosis was presentin 108 (90%), with interstitial fibrosis in the postero-lateral wall and papillary muscle in 88 (81%) andcoexisting replacement fibrosis in 40 (37%).Conclusion: This is the largest MVP associated withSCD series highlighting a young cohort with equalrepresentation of males and females. There is involve-ment of both leaflets with significant annular dilata-tion, elongation and thickening of both leaflets withMAD. Left ventricular fibrosis explains arrhythmia.Our quantitative measurements should serve as a ref-erence for pathologists assessing post-mortem heartsfor MVP.