Background: Coronary artery bypass grafting (CABG) is the ideal revascularisation strategy for patients with complex coronary artery disease. While beneficial in patients with severe left ventricular dysfunction (LVD; ejection fraction [EF] <35%), this patient group presents a disproportionately high risk for postoperative mortality.
Hypothesis: Perioperative mechanical circulatory support (MCS) instituted for patients with severe LVD undergoing CABG will mitigate the occurrence of a low output state (LOS) and improve postoperative outcomes.
Methods: Seven patients with ischaemic cardiomyopathy and severe LVD presented with various stages of heart failure. Each underwent uncomplicated CABG with a preoperative microaxial (n=4) or durable (n=3) LVAD. Four patients met Medicare criteria for durable LVAD; three received a device during CABG. The remaining patients received a microaxial device prior to or at the time of CABG. An historical cohort of 61 patients who underwent conventional CABG was used for comparison.
Results: All microaxial patients survived to device explant. One died on day 12 postoperation due to aspiration. All durable LVAD patients were alive at latest follow-up, with one patient undergoing successful device explant after 302 days, with a recovered EF of 50%. Both microaxial (3.12 l/min, p=0.02) and durable LVAD (3.20 l/min, p=0.02) recipients demonstrated a significantly higher cardiac index 24 hours post-CABG compared to control patients (2.58 l/min).
Microaxial patients demonstrated equivalent time to vasopressor independence (1,877 versus 2,942 minutes, p=0.63), lactate normalisation (5 versus 373 minutes, p=0.30) and 24-hour vasoactive-inotropic score (VIS; 6.1 versus 3.9, p=0.52) compared to control patients. Durable LVAD, patients required vasopressors longer (7,336 versus 2,942 minutes, p<0.001), but had comparable lactate normalisation time and VIS. Length of stay was significantly longer for both microaxial and durable LVAD groups compared to controls. Primary device-related complications were gastrointestinal bleeding and reoperation for bleeding.
Conclusion: Perioperative MCS allows for improved haemodynamic support and mitigates the occurrence of LOS in patients with severe LVD undergoing CABG.