Added prognostic value of ischaemic threshold in radionuclide myocardial perfusion imaging: a common-sense integration of exercise tolerance and ischaemia severity

PURPOSE: Reversible ischaemia at radionuclide myocardial perfusion imaging (MPI) accurately predicts risk of cardiac death and nonfatal myocardial infarction (major adverse cardiac events, MACE). This prognostic penetrance might be empowered by accounting for exercise tolerance as an indirect index of ischaemia severity. The present study aimed to verify this hypothesis integrating imaging assessment of ischaemia severity with exercise maximal rate pressure product (RPP) in a large cohort of patients with suspected or known coronary artery disease (CAD). METHODS AND RESULTS: We analysed 1,502 consecutive patients (1,014 men aged 59 ± 10 years) submitted to exercise stress/rest MPI. To account for exercise tolerance, the summed difference score (SDS) was divided by RPP at tracer injection providing a clinical prognostic index (CPI). Reversible ischaemia was documented in 357 patients (24 %) and was classified by SDS as mild (SDS 2-4) in 180, moderate (SDS 5-7) in 118 and severe (SDS >7) in 59. CPI values of ischaemic patients were clustered into tertiles with lowest and highest values indicating low and high risk, respectively. CPI modified SDS risk prediction in 119/357 (33 %) patients. During a 60-month follow-up, MACE occurred in 68 patients. Kaplan-Meier analysis revealed that CPI significantly improved predictive power for MACE incidence with respect to SDS alone. Multivariate Cox analysis confirmed the additive independent value of CPI-derived information. CONCLUSION: Integration of ischaemic threshold and ischaemia extension and severity can improve accuracy of exercise MPI in predicting long-term outcome in a large cohort of patients with suspected or known CAD

New Trends in Image Analysis and Processing

Workshops on: Assistive Computer Vision and Robotics Emerging Aspects on Handwritten Signature Processing Multimedia for Cultural Heritage Pattern Recognition in Proteomics, Structural Biology and Bioinformatics Social Behaviour Analysi

ITA-JPN Broadband VLBI Experiment for Optical Clock Comparison

NICT has developed a broadband VLBI (very-long-baseline interferometry) system for intercontinental frequency transfer. After domestic tests in Japan, a 2.4 m diameter VLBI station was exported and installed at Medicina astronomy observatory of INAF in Italy in 2018. We have started VLBI experiments for optical clock comparison on an Italy-Japan intercontinental baseline. Reference signals generated by an ytterbium (Yb) optical lattice clock at INRiM in Torino and by a strontium (Sr) lattice clock at NICT headquarters in Koganei are compared by a series of links, which include a coherent optical fiber link between INRiM and Medicina and intercontinental VLBI observation between Medicina and Koganei. A series of VLBI experiments was performed from Oct. 2018 to Feb. 2019. Yb and Sr lattice clocks were repeatedly operated throughout the same period for frequency comparison