Simultaneous Multi-slice (SMS) imaging has great potential for high acceleration rates with minimal loss in SNR. However, due to the unfavorable coil geometry only moderate acceleration rates have been achieved in cardiac applications. Outer volume suppression (OVS) has been proposed to overcome this limitation by suppressing unwanted signal from extra-cardiac tissues such as chest and back. Despite OVS, existing reconstruction techniques may suffer from residual leakage artifacts or noise amplification. In this work, we sought to extend SPIRiT to a readout-concatenated space to improve image quality in highly accelerated perfusion and cine imaging while mitigating leakage and noise amplification.