Abstract 4135893: The Importance of Genetic Testing in Diagnosis and Management of Peripartum Cardiomyopathy: A Case Study

Introduction: At least 15% of women diagnosed with peripartum cardiomyopathy (PPCM) are found to have a pathogenic genetic variant associated with dilated cardiomyopathy. We present a patient with PPCM who required orthotopic heart transplantation (OHT) for cardiogenic shock. Her explant pathology and genetic testing played a critical role in identifying the etiology of her cardiomyopathy. Case Description: A 22-year-old primigravid woman with a history of asthma presented in labor and underwent a Cesarean delivery for non-reassuring fetal heart tones. She had noted exertional dyspnea, a dry cough, and orthopnea in her final weeks of pregnancy but had an otherwise uncomplicated pregnancy. Immediately following delivery, she suffered a cardiac arrest with pulseless electrical activity and developed cardiogenic shock. She was found to have severe biventricular systolic dysfunction with a left ventricular (LV) ejection fraction of 10%. She was cannulated on veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and transferred to our center. She was transitioned from VA-ECMO to an axillary Impella 5.5 device but continued to require inotropic support without evidence of LV recovery. Therefore, she was listed for and successfully underwent OHT. Explant pathology (Figure 1) revealed arrhythmogenic cardiomyopathy (ACM). Her family history was significant for a maternal grandfather who died of an unspecified arrhythmia at age 57. Genetic testing via a commercial arrhythmia and cardiomyopathy panel revealed a pathogenic desmoplakin ( DSP) truncating variant ( DSP tv) p.Ser1894Leufs*34 in the N-terminal constitutive NMD-competent region, confirming the diagnosis of ACM. The patient had minor cutaneous findings, including curly hair, consistent with the clinical presentation of DSP -mediated ACM. Discussion: This case highlights the importance of genetic testing in all patients with PPCM, as well as attention to the explant pathology in those who undergo OHT. These practices can elucidate the mechanism of cardiomyopathy, inform the risks of disease progression and of relapse with subsequent pregnancy, and allow for cascade testing of family members.