Change in incidence of patients with peripartum cardiomyopathy.

Hypertensive disorders of pregnancy (HDP) are associated with some patients with peripartum cardiomyopathy (PPCM). However, no studies have reported changes in the incidence of PPCM before and after the introduction of calcium channel blockers (CCBs) for HDP treatment in Japan. Thirteen patients (aged 25-43 years; mean age, 33 years) with PPCM from two hospitals in Nagasaki Prefecture were included. PPCM was defined as idiopathic cardiomyopathy that occurs in late pregnancy or the months following delivery, without other causes of heart failure and with a left ventricular ejection fraction <45%. We compared the incidence of PPCM between the nine years from January 2003 to December 2011 (prior to CCB initiation) and the nine years from January 2012 to December 2020 (after CCB initiation). The incidence of PPCM has decreased after CCB initiation compared to prior to CCB initiation (0.36/year, 1/1520 births vs. 1 patient/year, 1/610 births). Treatment with HDP, including CCB, may prevent the development of PPCM in Japan.