Increased production of inflammatory cytokines in patients with silent myocardial ischemia

OBJECTIVES The aim of the study was to examine the inflammatory cytokines in patients with myocardial ischemia to evaluate whether silent ischemia patients exibit any particular cytokine pattern. BACKGROUND Silent myocardial ischemia is frequently observed in patients with coronary artery disease. Various endogenous mechanisms control a patient’s perceived intensity of pain. Among them, the inflammatory process and the related cytokine production are known to modulate the threshold for activating the primary afferent nociceptors. METHODS Seventy-eight patients with reproducible exercise-induced myocardial ischemia were studied: 34 symptomatic patients, with rest and/or stress angina; 44 asymptomatic patients, with no symptoms during daily life activities or during positive exercise stress test. Venous blood samples were taken from all patients to evaluate the expression of CD11b receptors both on neutrophils and monocytes. Frozen plasma samples (at −80°C) were used to quantify the anti-inflammatory (interleukin-4 and -10, transforming growth factor-β) and the proinflammatory cytokines (tumor necrosis factor-α, interferon-γ, interleukin-1β and -6). RESULTS In asymptomatic patients lower CD11b receptor expression and higher concentration of anti-inflammatory cytokines were observed. Proinflammatory cytokine production was similar in the two groups. CONCLUSIONS The data suggest that an “anti-inflammatory pattern” of cytokine production correlates with silent ischemia and that the immune and inflammatory system activation may be crucial for angina symptoms.