Fellow - Cardiovascular disease Allegheny General Hospital Pittsburgh, Pennsylvania, United States
Background: Giant cell myocarditis (GCM) is a rare, rapidly progressive disease, often presenting with heart failure and refractory ventricular arrhythmias and typically affecting young to middle-aged individuals. Diagnosis is confirmed via endomyocardial biopsy and outcomes are generally poor, with high rates of heart transplantation or death.
Methods: A 70-year-old male with no significant medical history presented with one week of worsening anxiety and dyspnea. Initial EKG demonstrated ST-segment elevation in aVR and V1, along with diffuse ST depression. Troponin was elevated at 1669 ng/L. Coronary angiography revealed a hazy 90% stenosis in the RCA, treated with successful PCI. The patient was transferred to the CCU in stable condition. Echocardiogram demonstrated severe LV global hypokinesis, LVEF 30%, with preserved apical segments.
On day 3, he developed recurrent non-sustained VT, requiring initiation of amiodarone and lidocaine. Repeat coronary angiography was unremarkable, and cardiac MRI was ordered. The patient later suffered cardiac arrest with sustained VT despite anti-arrhythmic therapy and was intubated. His condition worsened with increasing vasopressor support, narrow pulse pressure, and elevated CVP; bedside echocardiogram showed severe biventricular failure. A multidisciplinary cardiogenic shock team decided to initiate VA-ECMO with Impella CP for venting. An endomyocardial biopsy was obtained during cannulation. He was initiated on high-dose steroids and biopsy returned as GCM. The patient was escalated to Impella 5.5 and underwent heart transplantation on day 12. He was successfully discharged to inpatient rehabilitation.
Outcome: GCM is a rare disease that is challenging to diagnose given its variable presentation, but it should be considered in patients with heart failure complicated by ventricular arrhythmias. Our patient’s initial presentation was suggestive of ACS with a hazy, severe RCA stenosis. After PCI, recurrent VT with an unrevealing repeat angiography and echocardiogram findings raised suspicion for an alternative diagnosis. Unfortunately, the patient decompensated prior to further evaluation with additional imaging. The abrupt deterioration with ventricular arrhythmias was suggestive of fulminant myocarditis, and given the severity of biventricular dysfunction, decision was made to proceed with VA-ECMO initiation. We chose to obtain an endomyocardial biopsy at the time of cannulation, even though we planned to initiate high-dose steroids after the procedure, to help guide medical therapy and prognosis. The biopsy results were consistent with GCM. Given the severity of our patient’s disease and high rate of mortality with GCM, he was listed as status 1 for transplant. Although his pre-transplant rejection risk was exceedingly low, he was placed on an aggressive immunosuppression regimen and monitoring schedule given the propensity of GCM to recur post-transplant.
Conclusion: This case underscores the importance of considering GCM in patients with heart failure and recurrent ventricular arrhythmias, even when the initial presentation is concerning ACS. Early recognition and intervention are critical, and obtaining an endomyocardial biopsy while placing patients on VA-ECMO allows for patient stabilization and a definitive diagnosis.
