Cardiac MRI for Detection of Unrecognized Myocardial Infarction in Patients With End-Stage Renal Disease: Comparison With ECG and Scintigraphy
June 26th, 2009 Posted by: admin
OBJECTIVE. The purposes of this study were to use the myocardial
delayed enhancement technique of cardiac MRI to investigate the frequency of
unrecognized myocardial infarction (MI) in patients with end-stage renal
disease, to compare the findings with those of ECG and SPECT, and to examine
factors that may influence the utility of these methods in the detection of
MI.
SUBJECTS AND METHODS. We prospectively performed cardiac MRI, ECG,
and SPECT to detect unrecognized MI in 72 patients with end-stage renal
disease at high risk of coronary artery disease but without a clinical history
of MI.
RESULTS. Fifty-six patients (78%) were men (mean age, 56.2 ±
9.4 years) and 16 (22%) were women (mean age, 55.8 ± 11.4). The mean
left ventricular mass index was 103.4 ± 27.3 g/m2, and the
mean ejection fraction was 60.6% ± 15.5%. Myocardial delayed
enhancement imaging depicted unrecognized MI in 18 patients (25%). ECG
findings were abnormal in five patients (7%), and SPECT findings were abnormal
in 19 patients (26%). ECG findings were false-negative in 14 cases and
false-positive in one case. The accuracy, sensitivity, and specificity of ECG
were 79.2%, 22.2%, and 98.1% (p = 0.002). SPECT findings were
false-negative in six cases and false-positive in seven cases. The accuracy,
sensitivity, and specificity of SPECT were 81.9%, 66.7%, and 87.0% (not
significant). During a period of 4.9-77.9 months, 19 cardiac deaths were
documented, but no statistical significance was found in survival
analysis.
CONCLUSION. Cardiac MRI with myocardial delayed enhancement can
depict unrecognized MI in patients with end-stage renal disease. ECG and SPECT
had low sensitivity in detection of MI. Infarct size and left ventricular mass
can influence the utility of these methods in the detection of MI.
