Myocardial Expression of PPAR[gamma] and Exercise Capacity in Patients after Coronary Artery Bypass Surgery

Activation of PPARs may be involved in the development of heart failure (HF). We evaluated the relationship between expression of PPAR[gamma] in the myocardium during coronary artery bypass grafting (CABG) and exercise tolerance initially and during follow-up. 6-minute walking test was performed before CABG, after 1, 12, 24 months. Patients were divided into two groups (HF and non-HF) based on left ventricular ejection fraction and plasma proBNP level. After CABG, 67% of patients developed HF. The mean distance 1 month after CABG in HF was 397 [+ or -] 85 m versus 420 [+ or -] 93 min non-HF. PPAR[gamma] mRNA expression was similar in both HF and non-HF groups. 6MWT distance 1 month after CABG was inversely correlated with PPAR[gamma] level only in HF group. Higher PPAR[gamma] expression was related to smaller LVEF change between 1 month and 1 year (R = 0.18, p < 0.05), especially in patients with HF. Higher initial levels of IL-6 in HF patients were correlated with longer distance in 6MWT one month after surgery and lower PPAR[gamma] expression. PPAR[gamma] expression is not related to LVEF before CABG and higher PPAR[gamma] expression in the myocardium of patients who are developing HF following CABG may have some protecting effect.