Discussion:
LV clot is not an uncommon, but serious complication following myocardial infarction. Data from the pre-thrombolytic era reports an incidence as high as 60% in autopsy specimens. Early myocardial revascularization has greatly reduced the incidence of LV clot and their current incidence varies between 15 – 30% depending upon the time of evaluation after the myocardial infarction (MI).2 They occur most commonly after anterior and apical infarcts than others. We believe a hypo/akinetic apex forms a better nidus for blood to stagnate and clot than the inflow and outflow portions with constant streaming of blood. Though LV clot is commonly caused by MI, it is also caused by pathologies such as dilated cardiomyopathy, myocarditis, takotsubo cardiomyopathy, ventricular myxoma and hypercoagulable states such as protein S and C deficiency and anti-phospholipid antibody syndrome.3 LV clots are mainly of two types – mural or protruding. Mural clots are flat and parallel to the endocardial surface with broader base. Protruding clots are pedunculated and highly mobile with a small stalk attaching them to the LV apex and they have high propensity to embolize. Embolization is the dreaded complication of LV clots with an annual incidence of around 10% and carrying more than thrice the risk of mortality compared to similar patients without LV clots.4 The management of LV clot is still murky and there are no consensus guidelines yet. It is generally accepted that huge mobile clots warrant early removal and small sessile ones can be managed conservatively with anti-coagulation. Though small clots have been documented to resolve over time, huge and mobile clots carry significant embolic risks.5 Our patient had a massive clot occupying majority of the LV with a tail hitting the aortic valve and posing a serious risk for imminent second embolic event. His scenario was further complicated by acute multiple brain infarcts. Open heart operation in acute infarcts is another grey area within the cardiac surgical community and we don’t have a guideline-based management protocol till date. Pre-operative acute stroke is a known risk factor for cardiac surgery. But there are many published reports proving the safety of cardiac surgery in acute embolic infarcts.6 We believe that unless the patient is moribund or having a massive infarct, acute embolic stroke should not defer open heart surgery specifically in patients with heavy embolic load like ours. Surgical approach for LV thrombectomy is varied. Concomitant procedures such as mitral valve or LV aneurysm repair dictates the approach most of the times. Ventriculotomy is better avoided for isolated LV thrombectomy as an incision in the LV wall can promote arrhythmogenicity in an already dysfunctional heart and will make future ventricular assist device insertions difficult if required.7 Trans-mitral approach can be used when the clot is small and limited to the apex, but can prove difficult in massive clots protruding into the LVOT like ours.8Trans-aortic approach is very simple and effective for LV thrombectomy as the aortic valve and LVOT are anatomically in line with the apex and a dilated apex in majority of these patients enhances the visualization further. Organised clots can be approached by a combined trans-mitral and trans aortic route to ensure complete thrombus removal and a thorough wash of the LV cavity from both its inlet and the outlet to catch residues if any.