Devil in Disguise

• Editorials
• ethnic groups
• heart failure
• incidence
• peripartum cardiomyopathy
• pregnancy

See Article by S. Lee et al

Pregnancy-associated heart diseases substantially contribute to maternal morbidity and mortality. Among these, peripartum cardiomyopathy (PPCM), an idiopathic cardiomyopathy that causes heart failure with reduced left ventricular ejection fraction, represents one of the major life-threatening diseases in previously healthy women. The clinical course ranges from milder forms with slightly depressed left ventricular ejection fraction to severe forms with cardiogenic shock.^1,2 Although greater awareness and understanding of PPCM have developed over recent years, major gaps remain about epidemiology, risk factors, pathophysiology, and targeted therapy. As such, the exact diagnosis of PPCM remains a fundamental challenge in both clinical practice and scientific analysis.

In this issue of Circulation: Heart Failure, Lee et al³ present important data on the incidence and risk factors of PPCM in South Korea. The authors retrospectively analyzed a nationwide database that covers a total of 97% of the Korean population, hence expanding the knowledge of PPCM in Asian countries. The estimated incidence of PPCM in South Korea is 1:1741 (795 cases in 1 384 449 pregnancies; Figure). This compares well to the incidences reported in the United States and Germany but is markedly higher than those previously described in an analysis from Japan.^4–6 The incidence of PPCM differs widely depending on the ethnic/racial and regional background of women. Interestingly, Africans and African Americans are at a higher risk for developing PPCM, with an estimated incidence of 1:100 in Nigeria and 1:299 in Haiti,^1,3,7–9 whereas incidences in Caucasian populations range from 1:1000 in Germany to 1:10149 in Denmark.^1,5,6,10 In a Japanese cohort, the incidence was as low as 1:20 000¹¹; however, these results should be interpreted with caution because of methodological aspects, and …