Myocardial microstructure assessed by T1 mapping after on-pump and off-pump coronary artery bypass grafting.

Background: The correlation between the release of cardiac biomarkers after revascularization, in the absence of late gadolinium enhancement (LGE) or myocardial edema, and the development of myocardial tissue damage remains unclear. This study sought to identify whether the release of biomarkers is associated with cardiac damage by assessing myocardial microstructure on T1 mapping after on-pump (ONCAB) and off-pump coronary artery bypass grafting (OPCAB). Methods: Seventy-six patients with stable multivessel coronary artery disease (CAD) and preserved systolic ventricular function were included. T1 mapping, high-sensitive cardiac troponin I (cTnI), creatine kinase myocardial band (CK-MB) mass, and ventricular dimensions and function were measured before and after procedures. Results: Of the 76 patients, 44 underwent OPCAB, and 32 ONCAB; 52 were men (68.4%), and the mean age was 63±8.5 years. In both OPCAB and ONCAB the native T1 values were similar before and after surgeries. An increase in extracellular volume (ECV) values after the procedures was observed, due to the decrease in hematocrit levels during the second cardiac resonance. However, the lambda partition coefficient showed no significant difference after the surgeries. The median peak release of cTnI and CK-MB were higher after ONCAB than after OPCAB [3.55 (2.12-4.9) vs. 2.19 (0.69-3.4) ng/mL, P=0.009 and 28.7 (18.2-55.4) vs. 14.3 (9.3-29.2) ng/mL, P=0.009, respectively]. Left ventricular ejection fraction (LVEF) was similar in both groups before and after surgery. Conclusions: In the absence of documented myocardial infarction, T1 mapping did not identify structural tissue damage after surgical revascularization with or without cardiopulmonary bypass (CPB), despite the excessive release of cardiac biomarkers.

Abnormal release of cardiac biomarkers in the presence of myocardial oedema evaluated by cardiac magnetic resonance after uncomplicated revascularization procedures.

AIMS: To analyse the association of myocardial oedema (ME), observed as high T2 signal intensity (HT2) in cardiac magnetic resonance imaging, with the release of cardiac biomarkers, ventricular ejection, and clinical outcomes after revascularization. METHODS AND RESULTS: Patients with stable coronary artery disease with the indication for revascularization were included. Biomarker levels [troponin I (cTnI) and creatine kinase MB (CK-MB)] and T2-weighted and late gadolinium enhancement (LGE) images were obtained before and after the percutaneous or surgical revascularization procedures. The association of HT2 with the levels of biomarkers, with and without LGE, evolution of left ventricular ejection fraction (LVEF), and 5-year clinical outcomes were assessed. A total of 196 patients were divided into 2 groups: Group 1 (HT2, 40) and Group 2 (no HT2, 156). Both peak cTnI (8.9 and 1.6 ng/mL) and peak CK-MB values (44.7 and 12.1 ng/mL) were significantly higher in Group 1. Based on the presence of new LGE, patients were stratified into Groups A (no HT2/LGE, 149), B (HT2, 9), C (LGE, 7), and D (both HT2/LGE, 31). The peak cTnI and CK-MB values were 1.5 and 12.0, 5.4 and 44.7, 5.0 and 18.3, and 9.8 and 42.8 ng/mL in Groups A, B, C, and D, respectively, and were significantly different. The average LVEF decreased by 4.4% in Group 1 and increased by 2.2% in Group 2 (P = 0.057). CONCLUSION: ME after revascularization procedures was associated with increased release of cardiac necrosis biomarkers, and a trend towards a difference in LVEF, indicating a role of ME in cardiac injury after interventions.

Serotonergic control of ingestive and post-ingestive behaviors in pigeons (Columba livia): the role of 5-HT1A receptor-mediated central mechanisms.

Central injections of serotonin (5-HT) produce hyperdipsic and hypnogenic behavioral effects that are correlated to decreased Fos-immunorreactivity of 5-HT neurons in free-feeding pigeons. We herein (1) probed the role of 5-HT(1A) receptors on the 5-HT- or 8-OH-DPAT-evoked postprandial behaviors and (2) described the sleep-waking states (waking, W; drowsiness, D; slow-wave sleep, SWS; rapid-eye movement sleep, REMS) and sleep architecture of free-feeding pigeons after these treatments. Latency, frequency and duration of feeding, drinking, preening, exploratory and sleep-like behaviors (SLB) were examined after intracerebroventricular (ICV) injections of 5-HT (0, 50 or 150 nmol) or 8-OH-DPAT (DPAT, 0 or 30 nmol) in pigeons pretreated with the 5-HT(1A) antagonist WAY100635 (WAY, 0, 0.1, 0.3 or 1 nmol). Additionally, the acute (1h) waking-sleep-related electrographic activity in the hippocampus (HP) was examined after ICV injections of 5-HT (150 or 300 nmol) or DPAT (30 or 60 nmol) in pigeons pretreated with WAY (0 or 1 nmol). 5-HT and DPAT acutely increased drinking and then sleep: all doses of WAY attenuated the 5-HT (50 nmol) -induced dipsogenic effect, but left unchanged the effects of the 150 nmol 5-HT dose. The WAY 0.1 nmol dose blocked the SLB induced by the 5-HT 50 nmol dose. Given before the vehicle (VEH) injections, WAY does not affect water or food intake, but increased the SLB duration at all doses. DPAT injections increased feeding, drinking and SLB. All the WAY doses attenuated the DPAT-induced drinking and feeding responses, and the WAY 0.1 and 0.3 nmol doses reduced DPAT-induced SLB. DPAT or 5-HT injections decreased the duration of electrographically-determined waking, increased the durations of D and induced the emergence of SWS and REMS states indistinguishable from the hippocampal EEG associated with spontaneous sleep, as judged from visual and spectral analysis. WAY (1 nmol) increased SWS and D, and potentiated the 5-HT- and DPAT-induced SWS. These data suggest that 5-HT-induced drinking depends on the activation of presynaptic 5-HT(1A) receptors, while 5-HT(1A) autoreceptor activation contributes to the 5-HT-induced sleep. 5-HT-induced drinking and sleep behaviors may thus be provoked by a 5-HT(1A)-evoked, rebound-like reduction in central 5-HTergic activity. These data also indicate that an ongoing, tonic and inhibitory influence of central 5-HT circuits may participate in the control of feeding, drinking and rest behaviors in pigeons during the wake, nibbling diurnal state. These mechanisms appear to be comparable to those found in mammals, suggesting that they may represent a conserved, plesiomorphic functional trait of the amniotes brain.