Time course of functional recovery after coronary artery bypass grafting surgery according to the preoperative reversibility of perfusion impairment on myocardial SPECT

Abstract

Ischaemic dysfunctional myocardium with reversible perfusion impairment tends to recover function earlier after revascularisation surgery than myocardium with a persistent decrease in perfusion.

Comparison of Contrast-Enhanced MRI with 18F-FDG PET/201Tl SPECT in Dysfunctional Myocardium: Relation to Early Functional Outcome After Surgical Revascularization in Chronic Ischemic Heart Disease

“…The early functional recovery could be associated with improved hospital outcome and comparable long-term results. The early functional outcome could be considered as a surrogate prognostic marker, although an improvement could still happen late, especially in more severely injured myocardium (11)(12)(13)36). Our data suggested that a multimodality diagnostic strategy for viability detection might provide complementary information for decision making in certain cases that are most likely to benefit from surgical revascularization.…”

“…However, not all patients with ischemic cardiomyopathy recover in function after successful revascularization, despite the presence of viable myocardium identified using various noninvasive imaging techniques (4)(5)(6)(7)(8)(9)(10). The functional outcome and temporal variations could reflect the pathophysiologic mechanism of the dysfunction (11,12). Patients with early functional recovery could have a shorter hospital stay, a lower early postoperative morbidity and mortality, and, possibly, a better longterm functional outcome.…”

Prediction of long-term reverse left ventricular remodeling after revascularization or medical treatment in patients with ischemic cardiomyopathy: a comparative study between SPECT and MRI

“…Firstly, some segments may require a much longer time to functionally recover. It was shown that most of the hibernating segments improved their function 14 months after surgical revascularization [7], and other evidence shows that a significant proportion of segments require 16-24 months after CABG to reach functional recovery [13,22]. In our patients, the largest improvement of LVEF was observed at 12 months after CABG within the responder group; the LVEF improved from 33.8% at baseline to 44.3% at 12 months, with a subsequent slight decline to 41.2% at 24 months.…”

“…Trials using MRI published to date have mostly evaluated the short-term left ventricular segmental functional improvement, within a few months of CABG (typically up to 6 months) [8][9][10][11][12][16][17][18][19][20][21]. However, it is known that the majority of hibernating segments may show functional recovery with a much longer delay of up to 14-24 months [7,13,22], so the previous trials may have missed these improvements. Furthermore, most of these trials focused on improvement of segmental function, and no distinct parameter was found to quantify the extent of viable myocardium necessary for significant LV reverse remodeling and ejection fraction improvement.…”

“…In recent years, both single-photon-emission computed tomography (SPECT) and magnetic resonance imaging (MRI) have been shown to be powerful predictors of myocardial viability after surgery [8][9][10][11][12][13][14]. The underlying mechanism of reversible LV dysfunction in viable myocardium can be either myocardial stunning (contractile dysfunction after an ischemic insult despite adequate perfusion) or hibernation (contractile dysfunction and decreased myocardial metabolism as a result of prolonged reduction of perfusion) [15].…”