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Objective: Protein kinase C (PKC) influences myocardial contractility and susceptibility to long-term cardiac dysfunction after ischemia–reperfusion injury. In diabetes, PKC inhibition has a protective effect in terms of microvascular dysfunction. SK-channel dysfunction also influences endothelial dysfunction in cardioplegic hypoxia–reoxygenation (CP-H/R). Here, we examine whether acute inhibition of PKC beta protects against CP-H/R–induced coronary endothelial and SK channel dysfunction. Methods: Isolated mouse coronary arterioles, half pretreated with selective PKC inhibitor ruboxistaurin (RBX), were subjected to hyperkalemic, cardioplegic hypoxia (1 hour), and reoxygenation (1 hour) with Krebs buffer. Sham control vessels were continuously perfused with oxygenated Krebs buffer without CP-H/R. After 1 hour of reoxygenation, responses to the endothelium-dependent vasodilator adenosine-diphosphate (ADP) and the SK-channel activator NS309 were examined. Endothelial SK-specific potassium currents from mouse heart endothelial cells were examined using whole-cell path clamp configurations in response to NS309 and SK channel blockers apamin and TRAM34. Results: CP-H/R significantly decreased coronary relaxation responses to ADP (P = .006) and NS309 (P = .0001) compared with the sham control group. Treatment with selective PKC beta inhibitor RBX significantly increased recovery of coronary relaxation responses to ADP (P = .031) and NS309 (P = .004) after CP-H/R. Treatment with RBX significantly increased NS309-mediated potassium currents following CP-H/R (P = .0415). Apamin and TRAM34 sensitive currents were significantly greater in CP-H/R + RBX versus CP-H/R mouse heart endothelial cells (P = .0027). Conclusions: Acute inhibition of PKC beta significantly protected mouse coronary endothelial function after CP-H/R injury. This suggests that acute PKC beta inhibition may be a novel approach for preventing microvascular dysfunction during CP-H/R.

Objective: To examine the effect of aging on postoperative neurocognitive decline (NCD) in cardiac surgery patients. Methods: Patients undergoing coronary artery bypass graft or open aortic valve replacement were administered the Repeatable Battery for the Assessment of Neuropsychological Status at preoperative, postoperative day (POD) 4, and 1 month. Blood samples were collected at preoperative, 6 hours postoperative, and POD 4. Plasma interleukin (IL)-6, tumor necrosis factor-α, and C-reactive protein (CRP) levels were quantified. Quality of life was measured with the 12-Item Short Form Health Survey. Data were analyzed using paired ratio and unpaired t tests with Welch's correction, and linear regression for cytokine levels. Results: NCD occurred in 15 patients (N = 33, 45.5%). Dichotomized at age extremes (