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Impact of system delay on infarct size, myocardial salvage index, and left ventricular function in patients with
Jacob Lønborg1, Mikkel Malby Schoos, Henning Kelbæk
1Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark. jacoblonborg@gmail.com
Insights
Minimizing system delay in ST-elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI) significantly reduces infarct size and improves left ventricular function. Shorter delays lead to better myocardial salvage index (MSI) and overall outcomes.
Area of Science:
- Cardiology
- Interventional Cardiology
- Cardiovascular Imaging
Background:
- Reperfusion delay in ST-elevation myocardial infarction (STEMI) is linked to myocardial damage, but previous studies on symptom onset to treatment duration yielded conflicting results.
- System delay, defined as the time from first medical contact to first balloon angioplasty, is less prone to bias and is a modifiable factor.
Purpose of the Study:
- To evaluate the impact of system delay on myocardial salvage index (MSI) and final infarct size in STEMI patients treated with primary percutaneous coronary intervention (PCI).
Main Methods:
- Cardiovascular magnetic resonance (CMR) was used to assess MSI and infarct size in STEMI patients.
- Myocardial area at risk was measured within 1–7 days, and final infarct size was measured at 90 ± 21 days post-intervention.
- Patients were categorized into three groups based on system delay: 0–120 minutes, 121–180 minutes, and >180 minutes.
Main Results:
- Shorter system delay correlated with smaller infarct size (8% vs. 10% vs. 13%) and larger MSI (0.77 vs. 0.72 vs. 0.68) across the delay groups (P < .001 and P = .005, respectively).
- System delay as a continuous variable independently predicted smaller infarct size (r = 0.30, P < .001) and larger MSI (r = -0.25, P < .001).
- A system delay of ≤120 minutes was associated with improved left ventricular function (P = .019) and volumes (P = .022).
Conclusions:
- Reduced system delay in primary PCI for STEMI patients leads to smaller infarct size, enhanced MSI, and improved left ventricular function.
- Minimizing system delay is critical to maximize the benefits of primary PCI in STEMI treatment.
Background:
The association between reperfusion delay and myocardial damage has previously been assessed by evaluation of the duration from symptom onset to invasive treatment, but results have been conflicting. System delay defined as the duration from first medical contact to first balloon dilatation is less prone to bias and is also modifiable. The purpose was to evaluate the impact of system delay on myocardial salvage index (MSI) and infarct size in patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention (PCI).
Methods:
In patients with ST-elevation myocardial infarction, MSI and final infarct size were assessed using cardiovascular magnetic resonance. Myocardial area at risk was measured within 1 to 7 days, and final infarct size was measured 90 ± 21 days after intervention. Patients were grouped according to system delay (0 to 120, 121 to 180, and >180 minutes).
Results:
In 219 patients, shorter system delay was associated with a smaller infarct size (8% [interquartile range 4-12%], 10% [6-16%], and 13% [8-17%]; P < .001) and larger MSI (0.77 [interquartile range 0.66-0.86], 0.72 [0.59-0.80], and 0.68 [0.64-0.72]; P = .005) for a system delay of up to 120, 121 to 180, and >180 minutes, respectively. A short system delay as a continuous variable independently predicted a smaller infarct size (r = 0.30, P < .001) and larger MSI (r = -0.25, P < .001) in multivariable linear regression analyses. Finally, shorter system delay (0-120 minutes) was associated with improved function (P = .019) and volumes of left ventricle (P = .022).
Conclusions:
A shorter system delay resulted in smaller infarct size, larger MSI, and improved LV function in patients treated with primary PCI. Thus, this study confirms that minimizing system delay is crucial for primary PCI-related benefits.
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