An improved guide wire for use with cardiovascular catheters, particularly angioplasty or balloon dilatation catheters. The guide wire has a solid core wire which makes up the proximal end of the guide wire. The core wire is tapered toward the distal end to increase flexibility. The tapered distal end of the core wire is surrounded by a coil spring, which may be made completely or partially from a highly radiopaque material. A tapered transition device is attached to the coil spring at a selected distance from the distal end of the guide wire. The transition device is roughly bullet-shaped with a tapered distal edge which provides a smooth transition to aid the dilatation catheter in crossing a stenosis. The tapered transition device also serves to predilate very tight stenoses, making it easier to cross the lesion with an angioplasty balloon or other therapeutic device. The transition device can be made of metal or plastic with a radiopaque filler for easier visualization by x-ray or fluoroscopy. A removably attachable handle for maneuvering the guide wire and a method of use for the improved guide wire are also disclosed. An angioplasty catheter with a reinforced proximal shaft, which allows easier one-handed operation of the catheter and guide wire system, is also presented.