Aim: The aim of this study was to evaluate the possible impact of stress-induced left ventricular (LV) diastolic dysfunction at cadmium-zinc-telluride (CZT) imaging, on the detection of significant coronary artery disease (CAD).
Methods and results: Four hundred and twenty-five consecutive patients underwent myocardial perfusion imaging at rest and after stress with a low-dose CZT protocol and the evaluation of coronary anatomy by invasive or computed coronary angiography. The summed difference score (SDS) was calculated in every patient. Left ventricular ejection fraction and peak filling rate (PFR) at baseline and after stress were derived from gated CZT images and the '% stress-to-rest' PFR difference, as an indicator of stress-induced diastolic dysfunction, determined. In the study population, the mean SDS was 5 ± 4, while mean stress PFR and rest PFR were 2.5 ± 0.8 end-diastolic volumes (EDV)/s and 2.5 ± 0.7 EDV/s, respectively. There was a strict correlation between the presence and extent of CAD and both myocardial SDS and '% stress-to-rest' PFR (P < 0.001 for both). Interestingly, while myocardial SDS and '% stress-to-rest' PFR were significantly correlated (P < 0.001), they resulted independent predictors of the presence of significant CAD (P < 0.001 and P < 0.032, respectively). Of note, at receiving operating characteristic analysis, a '% stress-to-rest' PFR ≤3 showed 71% sensitivity in unmasking the presence of significant coronary luminal narrowings.
Conclusion: The present study shows that the assessment of stress-induced diastolic dysfunction with an ultrafast scintigraphic protocol can improve the accuracy in detection of significant ischaemic heart disease.
Keywords: CZT; Coronary artery disease; Diastolic function; Peak filling rate.
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