Myocardial infarction complicated by ventricular septal defect with cardiogenic shock initially managed by percutaneous mechanical circulatory support as bridge to final surgical repair

Background:
Ventricular septal defect (VSD) is a rare but severe complication that can occur after myocardial infarction and is associated with high mortality rates. In the treatment of postinfarct ventricular septal rupture the need for immediate closure to avoid acute hemodynamic compromise must be weighed against the need for delayed repair to enable the acutely necrotic myocardium to organize and to develop fibrotic tissue. The hemodynamic support provided by mechanical circulatory support allows time for left ventricular recovery prior to operative management of ventricular septal rupture.

Case Description:
A 43-year-old male presented with anterior wall ST-segment-elevation acute coronary syndrome (STE-ACS) at our institution. The patient underwent emergency cardiac catheterization revealing single vessel disease. The subtotal occluded left coronary artery was percutaneously recanalized. Postinterventional transthoracic echocardiography showed a VSD in apical septal wall with a diameter of 15 mm. The left ventricular ejection fraction was initially mildly impaired and right ventricular function was reduced (TAPSE 14 mm). Over time, the patient developed a cardiogenic shock with pulmonary oedema requiring vasopressors and inotropes despite revascularization. Due to the clinical situation and progressing hemodynamic deterioration we discussed in consultation with the heart team for an urgent surgical repair vs. delayed repair and finally implanted the coaxial micropump ImpellaCP® as a bridge to final surgery. After 6 days ,there was a technical problem with Impella and the purge function of the device failed. After further discussion with the Heart Team, the Impella CP system was exchanged without any problems under fluoroscopic and echocardiographic control. After 19 days of mechanical circulatory support without any device-related complications, the patient underwent pericardial patch repair of the VSD and mitral valve replacement by mechanical prosthesis. Initially, there was no hemodynamically relevant mitral valve insufficiency. However, after reperfusion, a severe mitral valve insufficiency was detected intraoperatively. During the intraoperative inspection, a rupture of the tendon thread at the anterior mitral leaflet was detected. It can be assumed that a tear could have occurred during the Impella removal. The patient was discharged to the rehabilitation clinic after 3 weeks in good general condition. After one month, the systolic LVEF was still moderately impaired, but the right ventricular function had recovered completely. No residual shunt and mitral regurgitation were detected.

Conclusion:
VSD after myocardial infarction remains a challenging situation in daily clinical practice. Standard therapy is VSD-closure and if necessary myocardial revascularization. Valuable time can be gained in infarction-related VSD with mechanical circulatory support device as bridge to surgical treatment. With this report, we show that valuable time can be gained in infarction-related VSD with support of the ImpellaCP® device to surgical treatment (bridge to surgery). However, the benefit risk as well as potential iatrogenic complications, such as those that occurred in our case during Impella removal with mitral tendon rupture, should be weighed up.