Association Between Early Q Waves and Reperfusion Success in Patients With ST-Segment-Elevation Myocardial Infarction Treated With Primary Percutaneous Coronary Intervention: A Cardiac Magnetic Resonance Imaging Study.

Abstract

BACKGROUND:

Pathological early Q waves (QW) are associated with adverse outcomes in patients with ST-segment-elevation myocardial infarction (STEMI). Primary percutaneous coronary intervention (PCI) may therefore be less beneficial in patients with QW than in patients without QW. Myocardial salvage index and microvascular obstruction (MVO) are markers for reperfusion success. Thus, to clarify the benefit from primary PCI in STEMI patients with QW, we examined the association between baseline QW and myocardial salvage index and MVO in STEMI patients treated with primary PCI.

METHODS AND RESULTS:

The ECG was assessed before primary PCI for the presence of QW (early) in 515 STEMI patients. The patients underwent a cardiac magnetic resonance imaging scan at day 1 (interquartile range [IQR], 1-1) and again at day 92 (IQR, 89-96). Early QW was observed in 108 (21%) patients and was related to smaller final myocardial salvage index (0.59 [IQR, 0.39-0.69] versus 0.65 [IQR, 0.46-0.84]; P<0.001) and larger MVO (1.4 [IQR, 0.0-5.4] versus 0.0 [IQR, 0.0-2.4]; P<0.001) compared with non-QW. QW remained associated with both final myocardial salvage index (β=-0.12; P=0.03) and MVO (β=0.18; P=0.001) after adjusting for potential confounders.

CONCLUSIONS:

Patients presenting with their first STEMI and early QW in the ECG had smaller myocardial salvage index and more extensive MVO than non-QW despite treatment within 12 hours after symptom onset. However, final myocardial salvage index in patients with QW was substantial, and patients with QW still benefit from primary PCI.

CLINICAL TRIAL REGISTRATION:

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01435408.

• Authors: Divan Gabriel Topal, Jacob Lønborg, Kiril Aleksov Ahtarovski, Lars Nepper-Christensen, Steffen Helqvist, Lene Holmvang, Frants Pedersen, Peter Clemmensen, Kari Saünamaki, Erik Jørgensen, Kasper Kyhl, Ali Ghotbi, Mikkel Malby Schoos, Christoffer Göransson, Litten Bertelsen, Dan Høfsten, Lars Køber, Henning Kelbæk, Niels Vejlstrup, Thomas Engstrøm
• Journal: Circulation. Cardiovascular interventions (Circ Cardiovasc Interv) Vol. 10 Issue 3 (Mar 2017) ISSN: 1941-7632 [Electronic] United States
• PMID: 28264870 (Publication Type: Journal Article, Randomized Controlled Trial)
• Copyright: © 2017 American Heart Association, Inc.

Topics

• Action Potentials
• Aged
• Electrocardiography
• Female
• Heart Conduction System (physiopathology)
• Heart Rate
• Humans
• Magnetic Resonance Imaging
• Male
• Middle Aged
• Patient Selection
• Percutaneous Coronary Intervention (adverse effects)
• Predictive Value of Tests
• Risk Factors
• ST Elevation Myocardial Infarction (diagnosis, physiopathology, therapy)
• Time Factors
• Treatment Outcome