Left ventricular dilation and functional impairment assessed by gated SPECT are indicators of cardiac allograft vasculopathy in heart transplant recipients

Coronary angiography (CA) is the standard method for diagnosis of cardiac allograft vasculopathy (CAV). Little is known about the value of measuring left ventricular function over time, which can be derived from gated myocardial perfusion single-photon emission computed tomography (SPECT). We evaluated the potential of measuring myocardial perfusion and left ventricular function with gated SPECT, as compared with CA, to detect CAV in the follow-up of heart transplantation.One hundred sixty-one heart transplant recipients (137 men, 24 women, age 50.7 ± 12.2 years) were followed-up for 4.2 ± 2.0 years by annual routine gated perfusion SPECT and consecutive CA. Myocardial perfusion was quantified by summed stress, rest and difference scores (SSS, SRS and SDS, respectively). Left ventricular function (ESV, EDV and LVEF) was derived from gated SPECT. Both were compared with angiographically defined stages of CAV.ESV/EDV derived from gated SPECT increased from 61 ± 25 ml/169 ± 39 ml in patients with no CAV over 74 ± 38 ml/188 ± 55 ml in patients with moderate CAV to 153 ± 75 ml/278 ± 86 ml in patients with severe CAV (p0.01 and p0.001), whereas LVEF decreased from 64 ± 10% over 62 ± 11% to 47 ± 13% in patients with severe CAV (p0.001). Perfusion quantified by SRS and SSS increased from 1.2 ± 1.5/1.9 ± 2.3 over 1.9 ± 1.4/2.8 ± 2.0 to 6.5 ± 5.1/7.7 ± 5.8 in patients with severe CAV (p0.01). Overall, for the prediction of severe CAV, accuracy was found to be higher for gated SPECT functional analysis as compared with perfusion analysis.Impaired left ventricular function, as assessed by gated SPECT, correlated significantly with CAV. Thus, for this purpose, gated SPECT offers higher sensitivity than analysis of perfusion while having a comparable specificity.