Elsevier

JACC: Cardiovascular Imaging

Volume 2, Issue 9, September 2009, Pages 1060-1068
JACC: Cardiovascular Imaging

Original Research
Increasing Benefit From Revascularization Is Associated With Increasing Amounts of Myocardial Hibernation: A Substudy of the PARR-2 Trial

https://doi.org/10.1016/j.jcmg.2009.02.017Get rights and content
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Objectives

We sought to determine: 1) whether F-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) parameters identify high-risk patients who gain benefit from revascularization; 2) whether there is a cut point for such benefit; and 3) predictors of outcome in patients with severe left ventricular (LV) dysfunction due to coronary artery disease.

Background

Patients with ischemic LV dysfunction might benefit from revascularization but not without risk. The FDG PET imaging can detect viable myocardium that recovers after revascularization. In the PARR-2 (PET and Recovery Following Revascularization-2) trial, FDG PET imaging showed a nonsignificant trend for improved outcome compared with standard care. Understanding the predictors of outcome from this prospective trial should help better identify patients at risk and which patients most benefit from revascularization.

Methods

This post hoc analysis included 182 patients with left ventricular ejection fraction (LVEF) <35% and coronary artery disease, being considered for revascularization work-up, and randomized to the PET arm of PARR-2. The primary outcome was a composite of cardiac death, myocardial infarction, or cardiac repeat hospital stay at 1 year.

Results

There is an interaction between PET mismatch and protocol revascularization such that higher mismatch, when combined with revascularization, yields fewer primary outcome events (p = 0.02). On the basis of adjusted Cox modeling, with reduced mismatch (<7%), the risk is not significantly different with or without revascularization. As mismatch increases above this mark, risk is reduced with revascularization. Increasing creatinine (for a 10-μmol/l increase: hazard ratio: 1.03, 95% confidence interval: 1.01 to 1.06, p = 0.010) is also associated with increased risk, whereas decreasing LVEF (for a 2% decrease: hazard ratio: 1.08, 95% confidence interval: 0.99 to 1.18, p = 0.087) trends toward an association with increased risk.

Conclusions

In this post hoc analysis, patients with ischemic cardiomyopathy with larger amounts of mismatch have improved outcome with revascularization. Renal function was also an independent predictor of outcome. The FDG PET seems to define high-risk patients that gain benefit from revascularization. (PET and Recovery Following Revascularization [PARR 2]; NCT00385242)

Key Words

fluorodeoxyglucose
heart failure
ischemic heart disease
viability

Abbreviations and Acronyms

CKD
chronic kidney disease
FDG
F-18-fluorodeoxyglucose
ICD
implantable cardioverter-defibrillator
LV
left ventricle/ventricular
EF
ejection fraction
MI
myocardial infarction
PET
positron emission tomography
RNA
radionuclide angiogram

Cited by (0)

The study was supported by grants from the Canadian Institute for Health Research (grant # MCT 37412), the Heart and Stroke Foundation of Ontario Grant-in-Aid (HSFO Grant #s NA4316 and T5222), and HFSO Program Grant on Molecular Function and Imaging (grant #PRG6242). The funding was supplemented by a University/Government/Industry Program: the Ontario Research and Development Challenge Fund with MDS Nordion (ORDCF-00-May-0710), to provide part-time coordinator salary support. Dr. Beanlands is a Career Investigator supported by the HSFO. None of the authors have any holdings that would present a conflict of interest to the publication of these data.