BACKGROUND: Activated mast cells (MC) present in the myocardium of patients with cardiomyopathy may contribute to left ventricular dilatation and systolic dysfunction. We sought to determine whether peripheral levels of tryptase, an MC-specific protease, are related to indices of left ventricular size and function, as well as congestive heart failure (CHF) or coronary artery disease (CAD). METHODS AND RESULTS: Serum tryptase was measured in 85 patients undergoing cardiac catheterization with left ventriculography and coronary angiography and examined in relation to left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), congestive heart failure (CHF), and angiographically evident CAD. Systemic tryptase levels were lower in patients with increased (>90 mL) LVEDV (6.2 [5.3-8.0] mcg/L versus 8.3 [6.6-10.3] mcg/L, P=.01) and in patients with CHF (6.2 [3.6-7.3] mcg/L versus 8 [6.2-10] mcg/L, P=.02) and tended to be lower in patients with depressed (<55%) LVEF (6.8 [5.2-9] mcg/L versus 8 [6.3-9.9] mcg/L, P=NS). Linear regression did not show a significant relationship between tryptase levels with either LVEF or LVEDV. Finally, tryptase levels were consistently elevated in relation to the presence of CAD. CONCLUSION: Despite increased numbers of MC in the myocardium of patients with cardiomyopathy, systemic levels of MC tryptase appear to be lower in relation to LV systolic dysfunction, LV dilatation, or clinical CHF. In contrast, the presence of angiographically significant CAD is associated with elevated systemic tryptase levels.
BACKGROUND: Activated mast cells (MC) present in the myocardium of patients with cardiomyopathy may contribute to left ventricular dilatation and systolic dysfunction. We sought to determine whether peripheral levels of tryptase, an MC-specific protease, are related to indices of left ventricular size and function, as well as congestive heart failure (CHF) or coronary artery disease (CAD). METHODS AND RESULTS: Serum tryptase was measured in 85 patients undergoing cardiac catheterization with left ventriculography and coronary angiography and examined in relation to left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), congestive heart failure (CHF), and angiographically evident CAD. Systemic tryptase levels were lower in patients with increased (>90 mL) LVEDV (6.2 [5.3-8.0] mcg/L versus 8.3 [6.6-10.3] mcg/L, P=.01) and in patients with CHF (6.2 [3.6-7.3] mcg/L versus 8 [6.2-10] mcg/L, P=.02) and tended to be lower in patients with depressed (<55%) LVEF (6.8 [5.2-9] mcg/L versus 8 [6.3-9.9] mcg/L, P=NS). Linear regression did not show a significant relationship between tryptase levels with either LVEF or LVEDV. Finally, tryptase levels were consistently elevated in relation to the presence of CAD. CONCLUSION: Despite increased numbers of MC in the myocardium of patients with cardiomyopathy, systemic levels of MC tryptase appear to be lower in relation to LV systolic dysfunction, LV dilatation, or clinical CHF. In contrast, the presence of angiographically significant CAD is associated with elevated systemic tryptase levels.