As compared with conventional anticoagulant therapy, combined antiplatelet therapy after the placement of coronary-artery stents reduces the incidence of both cardiac events and hemorrhagic and vascular complications.

Background-Multislice computed tomography angiography (CTA) is a promising technology for imaging patients with suspected coronary artery disease. Compared with 16-slice CTA, the improved spatial and temporal resolution of 64-slice CTA (0.6-versus 1.0-mm slice thickness and 330-versus 420-ms gantry rotation time) is associated with an increase in radiation dose. The objective of this retrospective investigation was to compare the estimated dose received during 16-and 64-slice CTA in daily practice and to investigate the impact of different scan protocols on dose and image quality. Methods and Results-Radiation dose was estimated for 1035 patients undergoing coronary CTA. Scanning algorithms with and without an ECG-dependent dose modulation and with a reduced tube voltage were investigated on dose estimates and image quality. In the entire patient cohort, radiation dose estimates were 6.4Ϯ1.9 and 11.0Ϯ4.1 mSv for 16-and 64-slice CTA, respectively (PϽ0.01). The reduction in radiation dose estimates ranged between 37% and 40% and between 53% and 64% with the use of ECG-dependent dose modulation and with the combined use of the dose modulation and a reduced tube voltage, respectively. The reduction in dose estimates was not associated with a reduction in diagnostic image quality as assessed by the signal-to-noise ratio and by the frequency of coronary segments with diagnostic image quality. Conclusions-The increase in spatial and temporal resolution with 64-slice CTA is associated with an increased radiation dose for coronary CTA. Dose-saving algorithms are very effective in reducing radiation exposure and should be used whenever possible.

SummaryBackground Current guidelines recommend potent platelet inhibition with prasugrel or ticagrelor for 12 months after an acute coronary syndrome managed with percutaneous coronary intervention (PCI). However, the greatest antiischaemic benefit of potent antiplatelet drugs over the less potent clopidogrel occurs early, while most excess bleeding events arise during chronic treatment. Hence, a stage-adapted treatment with potent platelet inhibition in the acute phase and de-escalation to clopidogrel in the maintenance phase could be an alternative approach. We aimed to investigate the safety and efficacy of early de-escalation of antiplatelet treatment from prasugrel to clopidogrel guided by platelet function testing (PFT).

Machine learning combining clinical and CCTA data was found to predict 5-year ACM significantly better than existing clinical or CCTA metrics alone.