Thromboembolism in peripartum cardiomyopathy: a systematic review

Background: Women with peripartum cardiomyopathy (PPCM) are at an increased risk of arterial and venous thromboembolic events. The review summarizes the evidence on the incidence of thromboembolic complications in women with PPCM, diagnostic approaches, related outcomes, and effects of therapies that have been used. Methods: English articles were retrieved from Web of Science and PubMed using search terms to capture studies related to PPCM (or postpartum cardiomyopathy) and all combinations of thrombosis- and embolism-related Keyword. A total of 347 articles from PubMed and 85 from Web of Science were obtained, and after removing duplicates, 327 articles were screened for original data and classified into four domains: epidemiology, risk factors, diagnosis, and therapy of thromboembolism in PPCM. Ultimately, 30 articles were included. Data were synthesized in summary tables for each domain. Results: Studies in the United States and Europe reported varying incidence for thromboembolism in PPCM, up to 14% in 6 months. Risk factors include elevated levels of coagulation factors, decreased protein C and S activity, decreased fibrinolysis, and a low left ventricular ejection fraction (LVEF). Cesarean delivery and post-operative status were correlated with a higher incidence of thromboembolic complications. Diagnosis relied mostly on ultrasonography and magnetic resonance and depended on the suspected location of thrombus. Anticoagulation has been used mostly for PPCM patients with a reduced LVEF, with the duration varying across guidelines and healthcare systems. Unfractionated heparin and low molecular weight heparin (LMWH) were considered safe choices during pregnancy, while warfarin and novel oral anticoagulants (NOACs) were used postpartum. The association of bromocriptine with risk of thromboembolic complications remains debated. Conclusions: There are important gaps in our understanding of the epidemiology, risk stratification, and optimal secondary prevention of thromboembolism in PPCM. Larger prospective studies with detailed phenotyping are required.