Introduction: Survival with good neurologic outcome following out-of-hospital cardiac arrest (OHCA) requires intensive post-ROSC care. In response to a recent decline in OHCA survival rates in Detroit, we conducted an analysis to identify factors contributing to this regression. Methods: CARES data from Detroit EMS transports were analyzed, including adult non-traumatic OHCA patients treated from 2014-2018 at four hospitals. Patient demographics, conditions of the arrest, and post-ROSC interventions including left heart catheterization, (LHC) and targeted temperature management, (TTM), were correlated to survival to hospital discharge and discharge with CPC 1 or 2. We calculated crude and adjusted survival rates across sites. Survival rates were adjusted for Utstein criteria using multilevel multi-variable regression analyses. Results: A total of 5,175 CARES patients were included. There was no difference in Utstein criteria between years, other than a small increase in the rate of witnessed arrest. We noted a steady decrease in LHC, and steady increase in TTM rate over the 5 years. There was a system-wide decrease in survival to hospital discharge during 2018, though the percentage of patients discharged with CPC 1 or 2 was similar. We found a strong, though insignificant, trend for LHC rate and survival: 0.72 (p = 0.1057), R 2 : 0.88, Adjusted R 2 : 0.76; and for survival with CPC 1 or 2: 0.59 (p = 0.5172), R 2 : 0.72, Adjusted R 2 : 0.44. In 2018, the rate of patients with LHC and good CPC nearly doubled. Conclusion: During the study period, we found a steady increase in TTM rate and concomitant decrease in LHC rate. The rate of LHC correlated best with survival to hospital discharge. In 2018, an increase in the proportion of patients with CPC 1 or 2 receiving LHC occurred, despite a decline in the overall rate of LHC.