It is necessary to use side clamps to construct proximal anastomoses in off-pump coronary artery bypass, and this can be related to neurologic complications. Recently a new device, the HEARTSTRING device, was developed. We present a 78-year-old man who underwent emergent bypass surgery using the HEARTSTRING device to avoid a side clamp. We found atherosclerotic debris from the punched hole and, unfortunately, a postoperative neurological complication resulted. We strongly suggest that it is most important that potential candidates for the HEARTSTRING device be carefully selected to reduce possible neurologic complications. We report that while this new device is useful, there is a potential pitfall in using it; that it is a possible source of atheroembolism.