ROLE OF "ISCHEMIA MODIFIED ALBUMIN" IN DETECTING MYOCARDIAL ISCHEMIA IN HYPERTROPHIC CARDIOMYOPATHY

Purpose: Myocardial ischemic events are well known to occur in patients with Hypertrophic Cardiomyopathy (HCM) as a consequence of small vessel disease and mismatch between left ventricular hypertrophy and coronary flow. Myocardial ischemia plays a major role in the course of the disease leading to progressive left ventricular fibrosis which represents the electrophysiological substrate of life-threatening arrhythmias. Ischemia modified albumin (IMA) has been recently suggested as an early marker of reversible myocardial ischemia in acute coronary syndromes. Aim of this study is to evaluate the role of IMA in detecting myocardial ischemia in HCM patients. Methods: IMA testing was performed in 51 consecutive HCM patients, 17 female (33%) and 34 male (67%), aged from 15 to 76 years (mean age 44 ±16.1), after 30 minutes supine position. IMA concentration was measured by the Albumin Cobalt Binding test (Ischemia Technologies, USA). Clinical data, 12-lead electrocardiogram and echocardiogram (2D, M-mode, CW and PW Doppler) were collected in all patients. Cardiac Magnetic Resonance (CMR) acquiring cine images, T2-weighted sequences for edema and late-enhancement (LE) sequences was performed in 22 patients. Results: Mean IMA levels were higher in patients with maximal left ventricular wall thickness (MLVWT) ≥ 25 mm compared with those with MLVWT < 25mm (102.6±8.23 KU/L vs 98.3±8.23 KU/L; p = 0.03). Patients with left atrial diameter (LAD) ≥ 50 mm had a mean IMA value higher than patients with LAD < 50 mm (104.2±6.99 KU/L vs 99± 8.54 KU/L; p = 0.03). Patients with Doppler E/A >1 had a mean IMA value lower than patients with Doppler E/A <1 or DT <150 ms (97.3±8.44 KU/L vs 101.7±8.31 KU/L; p = 0,04); A significant difference in IMA means was observed between patients with normal ejection fraction (FE > 50%) (101.28±8.32 KU/L) and those with FE ≤ 50% (94.7± 7.13 KU/L; p = 0.02). The presence of Q waves at the 12-lead electrocardiogram was associated with higher mean IMA levels if compared with the absence of Q waves (104.2±7.04 KU/L vs 99.3±8,39 KU/L; p = 0.03). Finally therapy with Verapamil was associated with mean IMA values lower than β-blockers therapy (96.8±4,20 KU/L vs 103.3±7.90 KU/L; p = 0.03). Conclusions: Higher levels of IMA were observed in HCM patients withsevere or massive myocardial hypertrophy as well as in patients with diastolic dysfunction. Therapy with Verapamil seems to be protective for ischemic events, nevertheless further studies are necessary to assess the usefulness of this marker in clinical practice. Pubblicato in Eur Heart J. 2007;28 Abstract Suppl: 471