Balloon catheters and stent delivery systems including bifurcated stent delivery systems are disclosed. An example bifurcated stent delivery system may include an elongate shaft including a proximal section, a midshaft section, and a distal section. The proximal section may include a tubular member having a plurality of slots formed therein. The slots may be arranged in one or more sections having differing slot densities. The midshaft section may include a guidewire port in fluid communication with a guidewire lumen formed in the shaft. A main branch balloon may be coupled to the shaft. A side branch balloon may be disposed adjacent to the main branch balloon. A stent may be disposed on the main branch balloon and on the side branch balloon.