Prediction of Changes in Left Ventricular Ejection Fraction after Off-Pump Coronary Artery Bypass Grafting Surgery by Myocardial Perfusion Single-Photon Emission Computed Tomography

Document Type: Original Article

Authors

1 Resident of Community Medicine, Department of Community Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

2 Cardiac Surgeon, Department of Cardiac Surgery, Mashhad University of Medical Sciences, Mashhad, Iran

3 Nuclear Physician, The Persian Gulf Nuclear Medicine Research Center, Bushehr University of Medical Sciences, Bushehr, Iran

4 Nuclear Physician, Nuclear Medicine Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

Abstract

Introduction: Left ventricular ejection fraction (LVEF) is considered to be the single most important prognostic factor in patients with previous myocardial infarction. LVEF is not improved in all patients after coronary artery bypass grafting (CABG). This study aimed to assess the possibility of prediction of LVEF changes after CABG using myocardial perfusion gated signle photon emission computed tomography (GSPECT).
Materials and Methods: Overall, 48 patients with mean LVEF of 30.2% (±4.7) underwent Echocardiography and GSPECT after injection of Tc-99m-MIBI at rest. Myocardial uptake was evaluated in 17 myocardial segments and was compared with age and gender matched normal data pool. The risks and benefits of CABG were explained to the patients and 16 cases (15 male and 1 female) with the mean age of 61.1 years (±10.8) accepted to undergo off-pump CABG. All the patients were followed-up for at least six months and echocardiography and GSPECT were repeated at the end of follow up.
Results: The mean LVEF was increased from of 31.1% (±3.5) to 34.5% (±3.6) after surgery (P<0.001). Delta LVEF was defined as ΔLVEF=LVEF (before CABG) - LVEF (after CABG). ΔLVEF was within the range of 0-8% with the mean of 3.4% (±2.5). The number of non-viable myocardial segments was not significantly different between patients with ΔLVEF ≥ 5% and those with smaller changes. Myocardial perfusion was estimated for all segments, and the mean global uptake was defined by adding the mean uptake in all segments, divided by 17. The mean global uptake was 53.1% in our patients. Regression analysis revealed that ΔLVEF after CABG can be predicted reliably using the following formula: ΔLVEF= -33.8 + (0.77 × mean global uptake) (P<0.01).
Conclusion: Our study showed that change of LVEF after CABG can be predicted reliably using mean global uptake in preoperative myocardial perfusion SPECT at rest.

Keywords


  1.  Sciagrà R, Leoncini M. Gated single-photon emission computer tomography. Q J Nucl Med Mol Imaging. 2005; 49:19-29.
  2. Germano G, Kiat H, Kavanagh PB, Moriel M, Mazzanti M, Su HT, et al. Automatic quantification of ejection fraction from gated myocardial perfusion SPECT. J Nucl Med. 1995; 36:2138-47.
  3. Aghasadeghi K, Ahmadi A, Zibaeenezhad M, Heydari S, Abtahi F, Zamirian M, et al. Correlation between fasting blood sugar and resting blood pressure in Teachers residing in Shiraz, Iran 2009. Iran Cardiovasc Res J. 2011; 5:14-8.
  4. Einstein AJ, Moser KW, Thompson RC, Cerqueira MD, Henzlova MJ. Radiation dose to patients from cardiac diagnostic imaging. Circulation. 2007; 116:1290-305.
  5. Hlatky MA, Califf RM, Harrell FE, Lee KL, Mark DB, Pryor DB. Comparison of predictions based on observational data with the results of randomized controlled clinical trials of coronary artery bypass surgery. J Am Coll Cardiol. 1988; 11:237-45.
  6. Ekici B, Ercan EA, Cehreli S, Töre HF. The effect of emotional status and health-related quality of life on the severity of coronary artery disease. Kardiol Pol. 2014; 72:617-23.
  7. Ambrosio G, Betocchi S, Pace L, Losi MA, Perrone-Filardi P, Soricelli A, et al. Prolonged impairment of regional contractile function after resolution of exercise-induced angina. Evidence of myocardial stunning in patients with coronary artery disease. Circulation. 1996; 94:2455-64.
  8. Kloner RA, Allen J, Cox TA, Zheng Y, Ruiz CE. Stunned left ventricular myocardium after exercise treadmill testing in coronary artery disease. Am J Cardiol. 1991; 68:329-34.
  9. Cerqueira MD, Allman KC, Ficaro EP, Hansen CL, Nichols KJ, Thompson RC, et al. Recommendations for reducing radiation exposure in myocardial perfusion imaging. J Nucl Cardiol. 2010; 17:709-18.
  10.  Berman DS, Hachamovitch R, Kiat H, Cohen I, Cabico JA, Wang FP, et al. Incremental value of prognostic testing in patients with known or suspected ischemic heart disease: a basis for optimal utilization of exercise technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography. J Am Coll Cardiol. 1995; 26:639-47.
  11.  Ghesani M, DePuey EG, Rozanski A. Role of F‐18 FDG Positron Emission Tomography (PET) in the Assessment of Myocardial Viability. Echocardiography. 2005; 22:165-77.
  12.  Leoncini M, Marcucci G, Sciagrà R, Mondanelli D, Traini AM, Magni M, et al. Comparison of baseline and low-dose dobutamine technetium-99m sestamibi scintigraphy with low-dose dobutamine echocardiography for predicting functional recovery after revascularization. Am J Cardiol. 2000; 86:153-7.
  13.  Santiago JF, Heiba SI, Jana S, Mirzaitehrane M, Dede F, Abdel-Dayem HM. Transient ischemic stunning of the myocardium in stress thallium-201 gated SPET myocardial perfusion imaging: segmental analysis of myocardial perfusion, wall motion and wall thickening changes. Eur J Nucl Med Mol Imaging. 2002; 29:979-83.
  14.  Leoncini M, Sciagrà R, Maioli M, Bellandi F, Marcucci G, Sestini S, et al. Usefulness of dobutamine Tc-99m sestamibi-gated single-photon emission computed tomography for prediction of left ventricular ejection fraction outcome after coronary revascularization for ischemic cardiomyopathy. Am J Cardiol. 2002; 89:817-21.
  15.  Hachamovitch R, Berman DS, Shaw LJ, Kiat H, Cohen I, Cabico JA, et al. Incremental prognostic value of myocardial perfusion single photon emission computed tomography for the prediction of cardiac death: differential stratification for risk of cardiac death and myocardial infarction. Circulation. 1998; 97:535-43.
  16.  Hachamovitch R, Rozanski A, Shaw LJ, Stone GW, Thomson LE, Friedman JD, et al. Impact of ischaemia and scar on the therapeutic benefit derived from myocardial revascularization vs. medical therapy among patients undergoing stress-rest myocardial perfusion scintigraphy. Eur Heart J. 2011; 32:1012-24.
  17.  Ragosta M, Beller GA, Watson DD, Kaul S, Gimple LW. Quantitative planar rest-redistribution 201Tl imaging in detection of myocardial viability and prediction of improvement in left ventricular function after coronary bypass surgery in patients with severely depressed left ventricular function. Circulation. 1993; 87:1630-41.
  18.  Dakik HA, Howell JF, Lawrie GM, Espada R, Weilbaecher DG, He ZX, et al. Assessment of Myocardial Viability With 99mTc-Sestamibi Tomography Before Coronary Bypass Graft Surgery Correlation With Histopathology and Postoperative Improvement in Cardiac Function. Circulation. 1997; 96:2892-8.