ObjectiveMaladaptive repair contributes towards the development of heart failure following myocardial infarction (MI). The αvβ3 integrin receptor is a key mediator and determinant of cardiac repair. We aimed to establish whether αvβ3 integrin expression determines myocardial recovery following MI.Methods18F-Fluciclatide (a novel αvβ3-selective radiotracer) positron emission tomography (PET) and CT imaging and gadolinium-enhanced MRI (CMR) were performed in 21 patients 2 weeks after ST-segment elevation MI (anterior, n=16; lateral, n=4; inferior, n=1). CMR was repeated 9 months after MI. 7 stable patients with chronic total occlusion (CTO) of a major coronary vessel and nine healthy volunteers underwent a single PET/CT and CMR.Results18F-Fluciclatide uptake was increased at sites of acute infarction compared with remote myocardium (tissue-to-background ratio (TBRmean) 1.34±0.22 vs 0.85±0.17; p<0.001) and myocardium of healthy volunteers (TBRmean 1.34±0.22 vs 0.70±0.03; p<0.001). There was no 18F-fluciclatide uptake at sites of established prior infarction in patients with CTO, with activity similar to the myocardium of healthy volunteers (TBRmean 0.71±0.06 vs 0.70±0.03, p=0.83). 18F-Fluciclatide uptake occurred at sites of regional wall hypokinesia (wall motion index≥1 vs 0; TBRmean 0.93±0.31 vs 0.80±0.26 respectively, p<0.001) and subendocardial infarction. Importantly, although there was no correlation with infarct size (r=0.03, p=0.90) or inflammation (C reactive protein, r=−0.20, p=0.38), 18F-fluciclatide uptake was increased in segments displaying functional recovery (TBRmean 0.95±0.33 vs 0.81±0.27, p=0.002) and associated with increase in probability of regional recovery.Conclusion18F-Fluciclatide uptake is increased at sites of recent MI acting as a biomarker of cardiac repair and predicting regions of recovery.Trial registration numberNCT01813045; Post-results.

To assess whether targeted cognitive freehand-assisted transperineal biopsies using a Precisionpoint TM device still require additional systematic biopsies to avoid missing clinically significant prostate cancer, and to investigate the benefit of a quadrant-only biopsy approach to analyse whether a quadrant or extended target of the quadrant containing the target only would have been equivalent to systematic biopsy. Patients and MethodsPatients underwent combined systematic mapping and targeted transperineal prostate biopsies at a single institution. Biopsies were performed using the Precisionpoint device (Perineologic, Cumberland, MD, USA) under either local anaesthetic (58%, 163/282), i.v. sedation (12%, 34/282) or general anaesthetic (30%, 85/282). A mean (range) of 24 (5-42) systematic and 4.2 (1-11) target cores were obtained. Magnetic resonance imaging (MRI) scans were reported using the Likert scale. Clinically significant cancer was defined as Gleason 7 or above. Histopathological results were correlated with the presence of an MRI abnormality within a spatial quadrant and the other adjoining or non-adjoining (opposite) quadrants. Histological concordance with radical prostatectomy specimens was analysed. ResultsA total of 282 patients were included in this study. Their mean (range) age was 66.8 (36-80) years, median (range) prostate-specific antigen level 7.4 (0.91-116) ng/mL and mean prostate volume 45.8 (13-150) mL. In this cohort, 82% of cases (230/282) were primary biopsies and 18% (52/282) were patients on surveillance. In all, 69% of biopsies (195/282) were identified to have clinically significant disease (Gleason ≥3 + 4). Any cancer (Gleason ≥3 + 3) was found in 84% (237/ 282) of patients. Of patients with clinically significant disease, the target biopsies alone picked up 88% (171/195), with systematic biopsy picking up the additional 12% (24/195) that the target biopsies missed. This altered with Likert score; 73% of Likert score 3 disease was detected by target biopsy, 92% of Likert score 4 and 100% of Likert score 5. Target biopsies with additional same-quadrant-only systematic cores picked up 75% (18/24) of significant cancer that was missed on target only, found in the same quadrant as the target. ConclusionSystematic biopsy is still an important tool when evaluating all patients referred for prostate biopsy, but the need is decreased with increasing suspicion on MRI. Patients with very high suspicion of prostate cancer (Likert score 5) may not require systematic cores, unless representative surrounding biopsies are required for other specific treatments (e.g. focal therapy, or operative planning). More prospective studies are needed to evaluate this in full.

ObjectivesIntraplaque angiogenesis and inflammation are key promoters of atherosclerosis and are mediated by the alpha-V beta-3 (αvβ3) integrin pathway. We investigated the applicability of the αvβ3-integrin receptor-selective positron emission tomography (PET) radiotracer 18F-fluciclatide in assessing human aortic atherosclerosis.MethodsVascular 18F-fluciclatide binding was evaluated using ex vivo analysis of carotid endarterectomy samples with autoradiography and immunohistochemistry, and in vivo kinetic modelling following radiotracer administration. Forty-six subjects with a spectrum of atherosclerotic disease categorised as stable (n=27) or unstable (n=19; recent myocardial infarction) underwent PET and CT imaging of the thorax after administration of 229 (IQR 217–237) MBq 18F-fluciclatide. Thoracic aortic 18F-fluciclatide uptake was quantified on fused PET-CT images and corrected for blood-pool activity using the maximum tissue-to-background ratio (TBRmax). Aortic atherosclerotic burden was quantified by CT wall thickness, plaque volume and calcium scoring.Results18F-Fluciclatide uptake co-localised with regions of increased αvβ3 integrin expression, and markers of inflammation and angiogenesis. 18F-Fluciclatide vascular uptake was confirmed in vivo using kinetic modelling, and on static imaging correlated with measures of aortic atherosclerotic burden: wall thickness (r=0.57, p=0.001), total plaque volume (r=0.56, p=0.001) and aortic CT calcium score (r=0.37, p=0.01). Patients with recent myocardial infarction had greater aortic 18F-fluciclatide uptake than those with stable disease (TBRmax 1.29 vs 1.21, p=0.02).ConclusionsIn vivo expression of αvβ3 integrin in human aortic atheroma is associated with plaque burden and is increased in patients with recent myocardial infarction. Quantification of αvβ3 integrin expression with 18F-fluciclatide PET has potential to assess plaque vulnerability and disease activity in atherosclerosis.