One of the greatest challenges of observational research is discerning the "effect" of the exposure of interest from underlying secular (or other) trends. So in a sense, this analysis is best used in descriptive terms, rather than as an attempt to ascribe causation to any one of the multiple moving parts (e.g., the evolution of the outbreak itself, the change in reperfusion protocol, or the regional differences in patterns of disease and care). In the pre-outbreak and outbreak periods in both Hubei and non-Hubei provinces, the proportion of cases with S-FMC #12 h was similar. However, the majority (w55%) of patients presenting with STEMI were categorized as "walk-in" patients and another w30% were "transfers." Even in the defined pre-outbreak period, PPCI was not offered to w20% of patients presenting with STEMI. While at first blush 20% of STEMI patients not receiving PPCI seems high, in comparison to prior studies from China, this represents substantial improvement over time (7) . Perhaps the overriding lesson from this analysis is the importance of reperfusion therapies for STEMI as a whole, with modifications based upon the specific care patterns within regional networks and systems, and individualized to the patient. 