The objective of this study was to test the hypothesis that the extent and severity of left ventricular myocardial hypoperfusion at rest, in addition to signs of left ventricular myocardial scar, are related to adverse long-term outcome in patients with non–ST-segment elevation myocardial infarction (NSTEMI).
Background
Multidetector computed tomography (MDCT) is a noninvasive test with a spatial resolution that allows for the assessment of transmural myocardial perfusion. In patients with suspected NSTEMI, the assessment of myocardial hypoperfusion could be clinically useful.
Methods
MDCT was performed at rest before invasive treatment in 396 patients with NSTEMI. The transmural involvement of left ventricular hypoperfusion, the presence of intramyocardial fat or calcification, a summed defect score adding the extent of left ventricular myocardial hypoperfusion (0 to 64 point scale), and the transmural attenuation ratio between the subendocardial and the subepicardial myocardium were assessed. The study endpoint was a combination of death and hospitalization due to heart failure.
Results
The median follow-up time of the study was 50 months, and the study endpoint was reached in 56 (15%) of the patients. In a Cox proportional hazards survival model with adjustments for known risk factors, both the summed defect score and transmural attenuation ratio were independently associated with adverse outcome (hazard ratio [HR]: 1.07; 95% confidence interval [CI]: 1.02 to 1.11; p = 0.004 and HR: 0.61; 95% CI: 0.44 to 0.85; p = 0.003, respectively). The presence of intramyocardial fat or calcification was also associated with adverse outcome (HR: 3.5; 95% CI: 1.2 to 10.7; p = 0.03) when compared with patients without any perfusion defect.
Conclusions
The extent and severity of left ventricular myocardial hypoperfusion at rest and signs of left ventricular myocardial scar assessed with MDCT before invasive treatment is strongly linked to adverse long-term outcome in patients with NSTEMI.
Key Words
computed tomography
myocardial infarction
perfusion
prognosis
Abbreviations and Acronyms
CTA
computed tomography angiography
LVEF
left ventricular ejection fraction
MDCT
multidetector computed tomography
NSTEMI
non–ST-segment myocardial infarction
SDS
summed defect score
TAR
transmural attenuation ratio
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This research was supported by the Danish Agency for Science, Technology and Innovation, The Danish Council for Strategic Research (Eastern Denmark Initiative To imprOve Revascularization Strategies, grant 09-066994), The Research Fund of Rigshospitalet, and the A.P. Møller and Chastine McKinney Møller Foundation, Copenhagen, Denmark. Drs. Linde and Kofoed have received lecturing fees from Toshiba Medical Systems. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
