Minimally Invasive Direct Coronary Arterial Bypass (MIDCAB) for Unprotected Left Main Coronary Stenosis

Introduction: Single-vessel disease of the left anterior descending (LAD) coronary artery may be surgically revascularized by left internal mammary artery (LIMA) grafting either through a sternotomy or a non-sternotomy approach (MIDCAB). Left main coronary artery disease is usually managed by coronary artery bypass grafting (CABG) with cardiopulmonary bypass for circulatory support. We present a case of minimally invasive direct coronary artery bypass for the management of a high-risk patient with non-ST-elevation myocardial infarction (NSTEMI) and new heart failure with reduced ejection fraction (HFrEF).

Case Presentation: A very active and high-functioning 96-year-old male with extensive peripheral vascular disease (PAD), as well as known coronary artery disease, presented with NSTEMI. The patient was subsequently found to have new HFrEF (Left Ventricular Ejection Fraction = 20%). Due to a newly reduced ejection fraction and recurrent chest pain despite maximal medical management, cardiac catheterization was performed and revealed a 95% occlusion of the left main coronary artery (LMCA) at the ostium (Fig 1) as well as 50% occlusion of the left circumflex artery in a left dominant system. Surgical consultation for conventional CABG was obtained, however given the patient’s prohibitive surgical risk – STS (short-term-risk) risk of mortality score of 19.8% – as well as the advantageous ostial anatomy of the lesion, it was decided to perform Impella-assisted percutaneous coronary intervention (PCI) of the LMCA. For vascular access planning in the context of the patient’s known PAD, a CT angiogram of the abdomen and pelvis was obtained, yielding evidence of extensive bilateral femoral PAD and therein precluding the use of an Impella device for hemodynamic support. Given the paucity of data supporting medical management of LMCA disease, as well as the extensive area of at-risk myocardium in the setting of the patient’s left-dominant circulation, medical management was not considered a viable solution for achieving the patient’s goals of enhanced survival. Upon further discussion with heart team, the decision was made to pursue surgical revascularization with a MIDCAB procedure. The patient was successfully managed with this approach, in which a left internal mammary artery was anastomosed to the left anterior descending coronary artery without immediate complications.

Right coronary artery

Left Main Coronary Artery           

Conclusion: We believe the MIDCAB may serve as a useful management strategy in isolated patients who bear either 1) unacceptably high surgical risk, or 2) prohibitive comorbidities for either CABG with sternotomy or high-risk PCI with Impella support. Furthermore, this case highlights the utility of multidisciplinary heart teams in the management of complex high-risk coronary artery stenosis.

Garly St Croix MD

Michel Ibrahim MD

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