Letters to the Editor
Earlier Diagnosis of Peripartum Cardiomyopathy (PPCM)
2020 Volume 84 Issue 9 Pages 1672-
Details
2020 Volume 84 Issue 9 Pages 1672-
To the Editor:
I appreciate the efforts of the authors of the article, “Imbalanced Angiogenesis in Peripartum Cardiomyopathy: Diagnostic value of Placenta Growth Factor”.1 They appropriately identified “one important limitation” in their article: namely, the timing of the blood draws in both groups. It is very important to identify the biomarkers of PPCM that will permit an earlier diagnosis, and in that process the timing of doing the analysis of biomarkers is critical.
Blood analysis of soluble FLT1 (sFLT1) and placenta growth factor (PlGF) for the reported 83 PPCM subjects and 30 normal pregnant subjects for determination of the ratio of sFLT1 to PlGF was done at markedly different times in relation to delivery. As a consequence of this time variation, results led to an incorrect conclusion that requires further research and analysis.
The report by Mebazaa et al indicated that blood draw for the women with normal pregnancy occurred at the time of delivery, whereas the blood draw for the PPCM subjects was at a median time of 4 weeks postpartum with an interquartile range of 3.4–4.6 weeks.1 It is well known that the angiogenic factors associated with pregnancy rapidly decline following delivery, being substantially derived from the placenta. It is not at all surprising that the sFLT1 to PlGF ratio was 9 (normal range) in the normal pregnancy group compared with 0.8 in the PPCM group, who had a late postpartum blood draw with sFLT1 levels reverting to non-pregnant levels.2
In the same issue of the Journal, the editorial by Sakuma and Anzai indicated that these findings would not be applicable to other countries because all subjects with any form of hypertension had been excluded from the South African study.3 Most series reports of PPCM identify gestational hypertension or preeclampsia and/or eclampsia to be common risk factors for developing pregnancy-associated cardiomyopathy and heart failure.
This report should encourage us to standardize the time of blood draws for analysis of the anti-angiogenic protein, sFLT1, and the pro-angiogenic protein, PlGF. Early but incomplete studies indicate that blood levels of these proteins in PPCM subjects, when measured before, at, or immediately after delivery, show elevated sFLT1 levels,4–6 and higher sFLT1 to PlGF ratio.7
The Mebazaa report indicated that no diagnosis of PPCM occurred in the prenatal time period and all postpartum diagnoses of PPCM were made relatively late postpartum.1 However, it is becoming apparent that there is potential to make a diagnosis of PPCM prenatally.7 It is important to pursue the best diagnostic markers, which at this time are blood sFLT1, PlGF and B-type natriuretic peptide (BNP), which with stress on the left ventricle often rises before any fall in left ventricular ejection fraction.
Increasingly, it is becoming apparent that earlier diagnosis results in better outcomes. With increasing awareness of PPCM, this earlier diagnosis should be our goal – a goal that can save/improve the lives of new mothers and their progeny.
