Discussion
Contradictory evidence exists in comparison of complications and all-cause mortality in trials involving off-pump CABG and conventional on-pump CABG. Meta-analysis performed have shown an increase in all-cause long-term mortality in patients with off-pump CABG compared to the traditional modality [11]. A 2014 meta-analysis of more than 20 studies found statistically significant 7% increase in long-term all-cause mortality with off-pump relative to on-pump CABG [11]. While in 2016, meta-analysis of 100 studies found no difference between the two techniques when comparing myocardial infarctions and all cause mortality [15]. A 2018 meta-analysis composed of more than 8000 patients reported higher mortality in OPCABG compared to on-pump CABG after 4 years or longer post procedure [16]. The population based evidence aside, each patient’s clinical circumstances warrant a personalized approach.
There exist alternative strategies to improve outcomes and reduce peri-operative complications in off-pump coronary artery bypass grafting. Minimally invasive strategies employed during off-pump CABG, like minimally invasive direct CABG, have benefits that include faster recovery and improved results [12]. Percutaneous mechanical circulatory devices used during off-pump CABG may provide the additional circulatory support necessary during the necessary intra-operative cardiac manipulations and anesthesia that decrease cardiac output. Use of Impella devices have been previously described [13, 14]. Multiple cases have showed the utilization of Impella 5.0 device during off-pump- CABG [13, 14]. The Impella 5.0 device utilizes a 21 French pump motor with peak flow up to 5.0L/min.
The device used on our patient provides up to 3.5L/min of circulatory support. More important the Impella CP requires only only the insertion of additional peripheral vascular access via transfemoral approach with a lower profile system (Impella CP sheath outer diameter 17F, ~4.7 mm) when compared to the larger profile and more invasive Impella Recover LP 5.0 system.
Novel use of Impella CP with a peak flow rate of 3.5L/min in our case provided appropriate circulatory support for optimal recovery. Using the smaller motor size (catheter max outer diameter 14F) along with decreased power requirement may lead to decreased complications resulting from the use of Impella devices. Utility of smaller sized pump may have decreased the incidence of valve dysfunction, thromboembolic complications thrombosis, ventricular perforation, bleeding and vascular complications [8]. As this was an off-label use of the Impella device, caution should be advised prior to repeating our approach and further research is necessary to advance this burgeoning multi-disciplinary field.