In a large population of matched pharmacologic stress patients, myocardial perfusion PET was superior to SPECT in image quality, interpretive certainty, and diagnostic accuracy.

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Aims Positron emission tomography (PET) myocardial perfusion imaging (MPI) can non-invasively measure myocardial blood flow reserve (MBFR). We aimed to examine whether MBFR identifies patients with a survival benefit after revascularization, helping to guide post-test management. Methods and results We examined all-cause mortality in 12 594 consecutive patients undergoing Rb82 rest/stress PET MPI from January 2010 to December 2016, after excluding those with cardiomyopathy, prior coronary artery bypass surgery (CABG), and missing MBFR. Myocardial blood flow reserve was calculated as the ratio of stress to rest absolute myocardial blood flow. A Cox model adjusted for patient and test characteristics, early revascularization (percutaneous coronary intervention or CABG ≤90 days of MPI), and the interaction between MBFR and early revascularization was developed to identify predictors of all-cause mortality. After a median follow-up of 3.2 years, 897 patients (7.1%) underwent early revascularization and 1699 patients (13.5%) died. Ischaemia was present in 4051 (32.3%) patients, with 1413 (11.2%) having ≥10% ischaemia. Mean MBFR was 2.0 ± 1.3, with MBFR <1.8 in 4836 (38.5%). After multivariable adjustment, every 0.1 unit decrease in MBFR was associated with 9% greater hazard of all-cause death (hazard ratio 1.09, 95% confidence interval 1.08–1.10; P < 0.001). There was a significant interaction between MBFR and early revascularization (P < 0.001); such that patients with MBFR ≤1.8 had a survival benefit with early revascularization, regardless of type of revascularization or level of ischaemia. Conclusion Myocardial blood flow reserve on PET MPI is associated with all-cause mortality and can identify patients who receive a survival benefit with early revascularization compared to medical therapy. This may be used to guide revascularization, and prospective validation is needed.

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Stress-only imaging with HT-LSAC using the Astonish acquisition/processing method provides results equivalent to conventional rest/stress scanning. This new approach has the potential to significantly improve operational efficiency without sacrificing accuracy.

Astonish processing, which incorporates depth-dependent resolution recovery, improves image quality without sacrificing interpretative certainty or diagnostic accuracy. Application of simultaneously acquired attenuation correction, which includes scatter correction, to full-time and half-time images processed with this method, improves specificity and normalcy while maintaining high image quality.

Background Platelets play an important role in the pathophysiology of acute coronary syndromes. The interaction between the platelet glycoprotein lb receptor and von Willebrand factor is a critical event allowing platelet adhesion and aggregation and subsequent thrombus formation in vessels with high shear rates and damaged endothelium. Therefore, we tested the hypotheses that VCL, an antagonist of von Willebrand-glycoprotein lb binding domain, (1) attenuates/ abolishes cyclic flow variations in stenosed, endotheliuminjured coronary arteries in nonhuman primates and (2) reduces botrocetin-induced platelet aggregation in vitro after intravenous in vivo administration.Methods and Results Cyclic flow variations were established in anesthetized, open-chest baboons (n= 18). The baboons were divided into three groups. One group (n=8) received a bolus of VCL (4 mg/kg IV) followed by an infusion (6 mg * kg-1* h-') for 90 minutes (schedule A). Another group (n=6) received a 2-mg/kg bolus followed by an infusion of 3 mg* kg`1 h-1 for 90 minutes (schedule B). The third group received a placebo infusion of normal saline. Under dosing schedule A, cyclic flow variations were abolished in 7 of 8 baboons after 33 ± 18 minutes and markedly attenuated in 1. The frequency of cyclic flow variations fell from 18±9.4 per hour during the control period to 1±2.5 per hour after VCL infusion, P<.002. After cessation of infusion, cyclic flow variations remained abolished in 5 of 7