Bayer's best-selling blood-thinning drug Xarelto has also proved effective in preventing heart attacks and strokes in patients suffering from certain types of artery disease, the company said on Wednesday. The drug is approved to prevent strokes in patients with irregular heart beats and clots, among other uses, but to widen its use Bayer has been testing Xarelto on patients with coronary artery disease (CAD) or peripheral artery disease (PAD).