The Association between Hypertensive Disorders of Pregnancy and Peripartum Cardiomyopathy

Peripartum cardiomyopathy (PPCM) is a diagnosis of exclusion and a heterogeneous disorder that presents during the last month of pregnancy or the first five months postpartum. It is a rare but potentially life-threatening illness. A lot of work has been done trying to discover the causes of this condition, and several risk factors have been identified, including hypertension during pregnancy (HDP), ethnicity, advanced age, and multiple gestations. HDP affects 40% of cases of PPCM, and the strength of the association increases with increasing severity of hypertension. Among PPCM patients, there is a 1.5 times higher prevalence of HDP and a four-fold higher prevalence of preeclampsia (PE). Besides, the risk of PPCM markedly increases among women with HDP (5-21 times) compared with normotensive women. The experimental work done in animal models has provided support for the angiogenic-imbalance theory proposed regarding the association between these two conditions. The presence of the same risk factors also supports the prevalence of the coexistence of PE and PPCM. During the last part of gestation, the placenta secretes more anti-angiogenic factors, which leads to the development of both PE and PPCM. However, not all patients with HDP develop PPCM. In fact, most PPCM patients do not show any signs of HDP. Further work in these patients elucidated that there is an underlying susceptibility in some women that predisposes them to develop this condition and results in a worse prognosis as compared with those PPCM patients who have HDP. Better provision of care, genetic variations, and association with HDP have been cited as some of the factors affecting prognosis. HDP has also been found to increase the risk of other forms of cardiomyopathies in the future. A lot of work still needs to be done to uncover all the pathologic mechanisms and genetic variations involved in this disorder. More intensive and focussed research may help in developing new therapies to better manage this condition and address all of its complications.