Myocardial SPET in hypertrophic cardiomyopathy

Introduction and objectives. The aim of this study was to evaluate the diag nostic accuracy of myocardial SPET in patients with hypertrophyc cardiomyop athy (HC). Patients and methods. One hundred and six consecutive patients (aged 53 +/- 12 years, 50 women, 66 with dynamic obstruction) with an echocardiographic diagnosis of HC were studied with exercise-rest myocardial SPET with Tc-99 m-tetrofosmin. Forty-six (43%) of these patients had chest pain and in 31 ( 29%) a coronary angiography was performed. Fifty-six per cent of the patien ts were treated with beta-blockers and 23% with verapamil. Results. Angina during the exercise test was observed in only 8% of the pat ients. Perfusion defects were observed in 35% of the patients. Only 8 (26%) out of the 31 patients with angiography had coronary artery disease (steno sis > 50%). When fixed and reversible defects were considered as positive, the sensitivity was 50%, the specificity was 65%, the positive predictive v alue was 33% and the negative predictive value was 79%. Conclusions. Myocardial perfusion defects can be observed in more than one third of medically treated patients with HC. Only a quarter of catheterized patients, even with chest pain, have associated coronary artery disease. T he accuracy of SPET for the diagnosis of coronary artery disease in hypertr ophic cardiomyopathy is low. Thus, the value of this technique is limited i n these patients.