”8 The restriction of the time frame to last month of pregnancy or first 5 months postpartum for diagnosis has been challenged. In a study by Elkayam et al., almost 20% of the patients developed symptoms of heart failure and were diagnosed with PPCM earlier than the last gestational month.9 A comparison between patients with early presentation and those with traditional criteria of PPCM revealed no significant differences in age, ethnic background, obstetrical history, and rate of gestational hypertension. Furthermore, maternal outcome, LVEF at the time of diagnosis, and its recovery over time were strikingly similar between the
two groups.9 Hence, a slightly different definition was proposed in the position statement from the Heart Failure Inhibitors,research,lifescience,medical Inhibitors,research,lifescience,medical Association of the European Society of Cardiology Working Group on PPCM.2 The authors believed that the time frame and echocardiographic cut-offs were arbitrary and could lead to underdiagnosis of PPCM. They eliminated the strict time limit to the diagnosis and proposed the following definition: “Peripartum cardiomyopathy
is an idiopathic cardiomyopathy presenting with HF secondary to left ventricular Inhibitors,research,lifescience,medical (LV) systolic dysfunction towards the end of pregnancy or in the months following delivery, where no other cause of HF is found.” Again, it is a diagnosis of exclusion. The left ventricle may not be dilated but the ejection fraction (EF) is nearly always reduced below 45%. The CO1686 incidence varies geographically. Based on available literature, the incidence of PPCM appears to be 1 in 1,000 in South Africa and 1 in 300 in Haiti.2-4 Whereas, a detailed retrospective review of the National Hospital Discharge Survey database Inhibitors,research,lifescience,medical (1990–2002) reported an estimated lower incidence of 1 case per 3,189 live births in the United States.3 The study also reported that patients with PPCM were older (mean age 29.7 vs. 26.9 years), were more likely to be black
(32.2% vs. 15.7%), and had a higher incidence of pregnancy-associated hypertensive disorders (22.5% vs. 5.87%) compared with national data. A similar study examined ICD-9 codes within the database of the Kaiser Permanent health system Inhibitors,research,lifescience,medical in southern California from 1996–2005 and estimated a PPCM incidence of 1 case per 4,025 live births, again reporting the highest incidence in African-American women.4 This study, however, had a high percentage of Hispanic women, the ethnicity with the lowest incidence of PPCM. Risk Factors The strongest until risk factor for PPCM appears to be African-American ethnicity (OR 15.7; CI 3.5–70.6).5 Other reported risk factors include age, pregnancy-induced hypertension or preeclampsia,3 multiparity, multiple gestations, obesity, chronic hypertension, and the prolonged use of tocolytics (Table 1).10 Table 1 Risk factors for peripartum cardiomyopathy. Pathophysiology The cause of PPCM remains unclear, but several mechanisms have been proposed, which indicates a potentially multi-factorial etiology (Table 2).