Gender differences in the evaluation of coronary artery disease with a cadmium-zinc telluride camera

Coronary artery disease remains one of the most significant causes of morbidity and mortality among women. The published literature shows the importance of standard single photon emission computed tomography in the evaluation of women with known or suspected ischaemic heart disease, in terms of target intervention and clinical treatment. The purpose of the present study was to ascertain the diagnostic accuracy of cadmium-zinc-telluride (CZT) myocardial perfusion imaging according to gender, within a prospective database of patients with known or suspected coronary artery disease, using coronary angiography as the reference standard.

Included in the study were 309 consecutive patients, of whom 248 were men (80 %), with known or suspected coronary artery disease and who had been referred to our laboratory for stress–rest myocardial perfusion imaging. All patients underwent coronary angiography within 30 days. All patients underwent a single-day stress–rest low-dose ultrafast protocol. Fifteen minutes after the end of the stress (dose range 185 to 222 MBq of ^99mTc-tetrofosmin), all patients underwent the first scan with an acquisition time of 7 min. The rest scan (dose range 370 to 444 MBq of ^99mTc-tetrofosmin) was acquired from 30 min to 45 min after injection, with an acquisition time of 6 min. Images were visually inspected, and summed stress scores (SSS) and summed rest scores (SRS) were obtained.

Image quality was graded “good” or better in more than 90 % of patients. On coronary angiography, left main trunk stenosis, left anterior descending artery stenosis, left circumflex artery stenosis and right coronary artery stenosis were seen in 3, 155 , 142 and 131 patients, respectively. In women, the mean SSS and SRS were 8 ± 5 and 3 ± 1, respectively. Semiquantitative regional and global SSS were good discriminants of coronary artery disease, and the overall area under the receiver operator characteristic (ROC) curve was 0.822 (95 % CI 0.685 – 0.959). The value was comparable to that obtained in men (overall ROC area 0.884, 95 % CI 0.836 – 0.933).

A low-dose protocol with a CZT camera can be routinely used in women with known or suspected coronary artery disease without loss of accuracy and with lower radiation exposure of the patients.