Prognostic value of Rb-82 positron emission tomography myocardial perfusion imaging in coronary artery bypass patients.
OBJECTIVE
We sought to determine the prognostic value of positron emission tomography (PET) myocardial perfusion imaging (MPI) in patients with prior coronary artery bypass graft (CABG) surgery. PET MPI has recently been shown to provide incremental risk stratification for patients with suspected coronary artery disease (CAD), but the prognostic utility of PET MPI in CABG patients has not been well studied.


RESULTS
A multi-centre PET registry of 7061 patients who underwent Rb-82 PET MPI from four participating centres was screened. Nine hundred and fifty-three CABG patients were identified and their images were analysed. Outcomes of all-cause mortality and cardiac death were collected. With a mean follow-up of 2.4 ± 1.4 years, 128 (13.4%) all-cause deaths and 44 (4.6%) cardiac deaths were observed. Multivariable analyses, adjusted for clinical variables, demonstrated that the summed stress score (SSS) was a significant independent predictor of both all-cause mortality [HR: 1.60 (per 1 category increase in SSS); 95% CI: 1.34-1.92; P < 0.001] and cardiac death (HR: 1.80; 95% CI: 1.33, 2.44; P < 0.001). The receiver-operator characteristic (ROC) curves showed that the addition of SSS increased the area under the curve (AUC) from 0.645 to 0.693 (P = 0.014) for all-cause mortality, and from 0.612 to 0.704 (P = 0.027) for cardiac death. SSS also improved the net reclassification improvement (NRI) for all-cause mortality (category-free NRI = 0.422; 95% CI: 0.240-0.603; P < 0.001) and cardiac death (category-free NRI = 0.552; 95% CI: 0.268-0.836; P < 0.001).


CONCLUSIONS
PET MPI provides independent and incremental prognostic value to clinical variables in predicting all-cause mortality and cardiac death in CABG patients.
Department of Medicine (Cardiology and Nuclear Medicine), The University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON, Canada K1Y 4W7.
Ally
A
Pen
Department of Medicine (Cardiology and Nuclear Medicine), The University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON, Canada K1Y 4W7.
Yeung
Y
Yam
Department of Medicine (Cardiology and Nuclear Medicine), The University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON, Canada K1Y 4W7.
Li
L
Chen
Brigham and Women's Hospital, Boston, MA, USA.
Sharmila
S
Dorbala
Brigham and Women's Hospital, Boston, MA, USA.
Marcelo F
MF
Di Carli
Niagara Falls Memorial Medical Center, Buffalo, NY, USA.
Michael E
ME
Merhige
Geisinger Medical Center, Danville, PA, USA.
Brent A
BA
Williams
Emory University School of Medicine, Atlanta, GA, USA.
Emir
E
Veladar
Cedars-Sinai Medical Center, Los Angeles, CA, USA.
James K
JK
Min
Boston University Biostatistics and Harvard Clinical Research Institute, Boston, MA, USA.
Michael J
MJ
Pencina
Cedars-Sinai Medical Center, Los Angeles, CA, USA.
Daniel S
DS
Berman
Department of Medicine (Cardiology and Nuclear Medicine), The University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON, Canada K1Y 4W7.
Rob S
RS
Beanlands
Emory University School of Medicine, Atlanta, GA, USA.
Leslee J
LJ
Shaw
Department of Medicine (Cardiology and Nuclear Medicine), The University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON, Canada K1Y 4W7 bchow@ottawaheart.ca.
Benjamin J W
BJ
Chow
D000368:Aged; D000704:Analysis of Variance; D019540:Area Under Curve; D002423:Cause of Death; D001026:Coronary Artery Bypass / Q000379:methods / Q000401:mortality*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000401:mortality / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D055414:Myocardial Perfusion Imaging / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods*; D011182:Postoperative Care / Q000379:methods; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012372:ROC Curve; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012414:Rubidium Radioisotopes; D015996:Survival Rate; D016896:Treatment Outcome
D012414:Rubidium Radioisotopes
All-cause mortality; Cardiac death; Coronary artery bypass graft; Myocardial perfusion imaging; Positron emission tomography; Prognosis; Rubidium-82