Clinical Research
Interventional Cardiology
Impact of Primary Coronary Angioplasty Delay on Myocardial Salvage, Infarct Size, and Microvascular Damage in Patients With ST-Segment Elevation Myocardial Infarction: Insight From Cardiovascular Magnetic Resonance

https://doi.org/10.1016/j.jacc.2009.08.024Get rights and content
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Objectives

We investigated the extent and nature of myocardial damage by using cardiovascular magnetic resonance (CMR) in relation to different time-to-reperfusion intervals.

Background

Previous studies evaluating the influence of time to reperfusion on infarct size (IS) and myocardial salvage in patients with ST-segment elevation myocardial infarction (STEMI) have yielded conflicting results.

Methods

Seventy patients with STEMI successfully treated with primary percutaneous coronary intervention within 12 h from symptom onset underwent CMR 3 ± 2 days after hospital admission. Patients were subcategorized into 4 time-to-reperfusion (symptom onset to balloon) quartiles: ≤90 min (group I, n = 19), >90 to 150 min (group II, n = 17), >150 to 360 min (group III, n = 17), and >360 min (group IV, n = 17). T2-weighted short tau inversion recovery and late gadolinium enhancement CMR were used to characterize reversible and irreversible myocardial injury (area at risk and IS, respectively); salvaged myocardium was defined as the normalized difference between extent of T2-weighted short tau inversion recovery and late gadolinium enhancement.

Results

Shorter time-to-reperfusion (group I) was associated with smaller IS and microvascular obstruction and larger salvaged myocardium. Mean IS progressively increased overtime: 8% (group I), 11.7% (group II), 12.7% (group III), and 17.9% (group IV), p = 0.017; similarly, MVO was larger in patients reperfused later (0.5%, 1.5%, 3.7%, and 6.6%, respectively, p = 0.047). Accordingly, salvaged myocardium markedly decreased when reperfusion occurred >90 min of coronary occlusion (8.5%, 3.2%, 2.4%, and 2.1%, respectively, p = 0.004).

Conclusions

In patients with STEMI treated with primary percutaneous coronary intervention, time to reperfusion determines the extent of reversible and irreversible myocardial injury assessed by CMR. In particular, salvaged myocardium is markedly reduced when reperfusion occurs >90 min of coronary occlusion.

Key Words

myocardial salvage
myocardial infarction
microvascular injury
cardiovascular magnetic resonance
time to reperfusion

Abbreviations and Acronyms

CMR
cardiovascular magnetic resonance
IRA
infarct-related artery
IS
infarct size
LAD
left anterior descending artery
LGE
late gadolinium enhancement
LV
left ventricle/ventricular
LVEDV
left ventricular end-diastolic volume
LVEF
left ventricular ejection fraction
LVESV
left ventricular end-systolic volume
MVO
microvascular obstruction
PCI
percutaneous coronary intervention
PPCI
primary percutaneous coronary intervention
SSFP
steady-state free precession
STEMI
ST-segment elevation myocardial infarction
T2w-STIR
T2-weighted short tau inversion recovery
TE
echo time
TR
repetition time

Cited by (0)

Drs. Francone and Bucciarelli-Ducci contributed equally to this work.