# Delayed CPK peak after primary PCI in STEMI: marker of reperfusion quality and short-term outcomes

## TL;DR

Delayed CPK peak after heart attack treatment may indicate poor reperfusion and worse outcomes in STEMI patients.

## Contribution

The study shows that time to peak CPK is a marker of reperfusion quality and short-term outcomes in STEMI patients undergoing primary PCI.

## Key findings

- Patients with TIMI 3 flow had a significantly shorter time to peak CPK compared to those without.
- Delayed CPK peak was associated with higher 30-day adverse event rates.
- Optimal reperfusion correlates with faster enzymatic washout and better outcomes.

## Abstract

Time to peak creatine phosphokinase (CPK) has historically been used as a surrogate marker of reperfusion in ST-elevation myocardial infarction (STEMI), but its significance in the contemporary primary percutaneous coronary intervention (PCI) era remains uncertain. We retrospectively analyzed 239 consecutive STEMI patients who underwent primary PCI at Tsukazaki Hospital between January 2021 and December 2024. Patients were categorized according to final post-PCI TIMI flow: TIMI 3 (Group A, n=194) and non-TIMI 3 (Group B, n=45). The median time to peak CPK was significantly shorter in Group A compared with Group B (365.0 vs. 684.0 minutes, p<0.001), whereas peak CPK levels did not differ significantly between the groups. At 30 days, the incidence of major adverse cardiovascular events plus congestive heart failure was significantly lower in Group A than in Group B (4.1% vs. 13.3%, log-rank p=0.01). These findings suggest that optimal post-PCI TIMI 3 flow is associated with faster enzymatic washout and better short-term outcomes, and that time to peak CPK may provide complementary information regarding reperfusion quality in STEMI patients.