Magnetic resonance vs technetium-99m pyrophosphate scintigraphy in the detection of perioperative myocardial necrosis.
BACKGROUND
Perioperative myocardial infarction (POMI) is a complication of coronary artery bypass grafting (CABG) with a potential prognostic impact. Technetium-99m pyrophosphate myocardial scintigraphy (MS) is used in the diagnosis of POMI; however it shows a limited sensitivity for subendocardial lesions. Cardiovascular magnetic resonance imaging (CMRI), in turn, has a high accuracy in the detection of myocardial necrosis.


OBJECTIVE
To compare CMRI and MS for the detection of POMI after CABG.


METHODS
A total of 24 patients with chronic coronary artery disease were studied using the delayed contrast enhanced CMRI and MS before and after CABG by analyzing the development of areas of perioperative myocardial necrosis (POMI). Biochemical markers of myocardial injury (CKMB and troponin I) were also determined before and after surgery.


RESULTS
Nineteen patients completed the study. Of these, 6 (32%) presented POMI on CMRI and 4 (21%) on MS (p = NS). Of the 323 left ventricular segments assessed, 17 (5.3%) showed perioperative necrosis on CMRI and 7 (2.2%) on MS (p = 0.013). Moderate agreement was observed between the methods (kappa = 0.46). There was disagreement regarding the diagnosis of POMI in 4 (21%) cases, most of them with small areas of perioperative necrosis on CMRI which were not visualized on MS. In all cases with POMI on CMRI, significant CKMB and troponin I elevations were observed.


CONCLUSIONS
Moderate diagnostic agreement was observed between the methods for the detection of POMI, but CMRI enabled visualization of small areas of perioperative myocardial necrosis which were not identified on MS and were associated with elevation of biochemical markers of myocardial injury.
Monte
Guilherme Urpia
GU
Instituto do Coração - Hospital das Clínicas da Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP - Brasil. gumonte@cardiol.br
Drager
Luciano Ferreira
LF
Souza
Fábio Solano de Freitas
FS
Avila
Luiz Francisco Rodrigues de
LF
Parga Filho
José Rodrigues
JR
César
Luiz Antônio Machado
LA
Izaki
Marisa
M
Meneghetti
José Cláudio
JC
Rochitte
Carlos Eduardo
CE
Kalil Filho
Roberto
R
D015415:Biomarkers / Q000097:blood; D002908:Chronic Disease; D003327:Coronary Disease / Q000097:blood / Q000601:surgery*; D052279:Creatine Kinase, MB Form / Q000097:blood; D005260:Female; D006801:Humans; D007431:Intraoperative Complications; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000473:pathology*; D009204:Myocardial Revascularization; D009336:Necrosis; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D016698:Technetium Tc 99m Pyrophosphate; D019210:Troponin I / Q000097:blood
D015415:Biomarkers; D019275:Radiopharmaceuticals; D019210:Troponin I; D016698:Technetium Tc 99m Pyrophosphate; D052279:Creatine Kinase, MB Form