Identification of Therapeutic Benefit from Revascularization in Patients With Left Ventricular Systolic Dysfunction: Inducible Ischemia Versus Hibernating Myocardium

OBJECTIVES: Although the recent surgical treatment of ischemic heart failure substudy reported that revascularization of viable myocardium did not improve survival, these results were limited by the viability imaging technique used and the lack of inducible ischemia information. We examined the relative impact of stress-rest rubidium-82/F-18 fluorodeoxyglucose positron emission tomography identified ischemia, scar, and hibernating myocardium on the survival benefit associated with revascularization in patients with systolic dysfunction.

METHODS: The extent of perfusion defects and metabolism-perfusion mismatch was measured with an automated quantitative method in 648 consecutive patients (age, 65±12 years; 23% women; mean left ventricular ejection fraction, 31±12%) undergoing positron emission tomography. Follow-up time began at 92 days (to avoid waiting-time bias); deaths before 92 days were excluded from the analysis.

RESULTS: During a mean follow-up of 2.8±1.2 years, 165 deaths (27.5%) occurred. Cox proportional hazards modeling was used to adjust for potential confounders, including a propensity score to adjust for nonrandomized treatment allocation. Early revascularization was performed within 92 days of positron emission tomography in 199 patients (33%). Hibernating myocardium, ischemic myocardium, and scarred myocardium were associated with all-cause death (P=0.0015, 0.0038, and 0.0010, respectively). An interaction between treatment and hibernating myocardium was present such that early revascularization in the setting of significant hibernating myocardium was associated with improved survival compared with medical therapy, especially when the extent of viability exceeded 10% of the myocardium.

CONCLUSIONS: Among patients with ischemic cardiomyopathy, hibernating, but not ischemic, myocardium identifies which patients may accrue a survival benefit with revascularization versus medical therapy. Connor McGovern Authentic Jersey

PMID: 23595888

Posted in Nuclear Imaging and tagged , , , , , .

2 Comments

  1. A very important paper!

    Many general cardiologist assume that the data supporting viability imaging is extensive, but as we know there is actually very little. STICH viability, PPAR-2, and HEART all suggested that when studied prospectively viability imaging doesn’t seem to be all that helpful. All the positive data on viability imaging (eg. Allman JACC 2002) is retrospective. This study is also retrospective but at least it is a very large cohort and demonstrates a dose-response relationship. I do wonder what other co-morbidities a patient in this study might have who has viable myocardium and doesn’t undergo revascularisation. That bias would be very hard to eliminate and would lead to such patients having a very high mortality.

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