CORONARY-ARTERY BYPASS-SURGERY AS TREATMENT FOR ISCHEMIC HEART-FAILURE - THE PREDICTIVE VALUE OF VIABILITY ASSESSMENT WITH QUANTITATIVE POSITRON-EMISSION-TOMOGRAPHY FOR SYMPTOMATIC AND FUNCTIONAL OUTCOME

Objectives: To determine the predictive value of quantitative evaluati on of myocardial viability on changes in left ventricular function, ex ercise capacity, and quality of life after coronary artery bypass graf ting in patients,vith ischemic heart failure (congestive heart failure , New York Heart Association class greater than or equal to III) with and without angina. Methods: Thirty-five patients, 14 with congestive heart failure and angina (CHF-angina) and 21 with congestive heart fai lure without angina (CHF-no angina) were studied at baseline and 6 mon ths after coronary bypass grafting, Left ventricular function was eval uated with transthoracic echocardiography and radionuclide ventriculog raphy, Myocardial viability was assessed with [F-18]-2-fluoro-2-deoxy- D-glucose using positron emission tomography, Peak aerobic capacity (p eak oxygen consumption) and anaerobic threshold were assessed with tre admill exercise test and quality of life with a questionnaire. Results : A total of 286 of 336 dysfunctional left ventricular segments were v iable. There were two perioperative deaths (5.7%) and three late death s. Left ventricular ejection fraction increased from 23% +/- 7% to 32% +/- 9% (p < 0.0001), and a linear correlation was found between the n umber of viable segments and the changes in ejection fraction (r = 0.6 5; p = 0.0001). Receiver operating characteristics curve identified ei ght viable segments as the best predictor for increase of ejection fra ction more than 5 percentage points. Peak oxygen consumption increased from 15 +/- 4 to 22 +/- 5 ml/kg per minute (g < 0.0001), Preoperative ly, anaerobic threshold was identified in one patient from the CHF-ang ina group and in all from the CHF-no angina group and increased from 1 3 +/- 4 to 19 +/- 4 ml/kg per minute (p < 0.0001), Quality of life sco res improved significantly in both groups. No correlation was found be tween the amount of viable dysfunctional myocardium and changes in exe rcise capacity or quality of life. Conclusions: In patients with posti schemic congestive heart failure the amount of viable myocardium dicta tes the degree of improvement in left ventricular function after revas cularization.