A system (1) and apparatus comprising a multisensor guidewire (100/200/300) for use in interventional cardiology, e.g., Transcatheter Valve Therapies (TVT), comprises a plurality of optical sensors (10/20) for direct measurement of cardiovascular parameters, e.g. transvalvular blood pressure gradients and flow. A conventional outer coil wire (35) contains a shaped core wire (31) having a cross-section defining a channel surface (132), e.g. grooves (32), extending along its length, to position optical fibers (11) and optical sensors (10/20) in a channel (33). Advantageously, the core wire has a diameter that provides sufficient stiffness to the guidewire for use as a support guidewire for TVT, e.g. Transcatheter Aortic Valve Implantation (TAVI), while accommodating multiple sensors and fibers within a guidewire of outside diameter ≦0.89 mm. An optical connector (112) couples the guidewire to a control system (150). Optionally, the guidewire includes a contact force sensor (60), a pre-formed tip (400-1/400-2) and a separable micro-connector (140).