Determination of Fundamental Supersymmetry Parameters from Chargino Production at Lepii

If accessible at LEP II, chargino production is likely to be one of the few available supersymmetric signals for many years. We consider the prospects for the determination of fundamental supersymmetry parameters in such a scenario. The study is complicated by the dependence of observables on a large number of these parameters. We propose a straightforward procedure for disentangling these dependences and demonstrate its effectiveness by presenting a number of case studies at representative points in parameter space. Working in the context of the minimal supersymmetric standard model, we find that chargino production by itself is a fairly sensitive probe of the supersymmetry-breaking sector. For significant regions of parameter space, it is possible to test the gaugino mass unification hypothesis and to measure the gaugino contents of the charginos and neutralinos, thereby testing the predictions of grand unification and the viability of the lightest supersymmetric particle as a dark matter candidate. For much of the parameter space, it is also possible to set limits on the mass of the electron sneutrino, which provide a valuable guide for future particle searches.Comment: 52pp, Revtex, 30 figures available upon request, SLAC-PUB-6497, RU-94-67 (text and figures available in ps form by anonymous ftp from preprint.slac.stanford.edu, directory pub/preprints/hep-ph/9408

CT-derived fractional flow reserve (FFRct) for functional coronary artery evaluation in the follow-up of patients after heart transplantation

Objectives Invasively measured fractional fow reserve (FFR) is associated with outcome in heart transplant (HTx) patients. Coronary computed tomography angiography (CCTA)–derived FFR (FFRct) provides additional functional information from anatomical CT images. We describe the frst use of FFRct in HTx patients. Methods HTx patients underwent CCTA with FFRct to screen for cardiac allograft vasculopathy. FFRct was measured distal to each coronary stenosis>30% and FFRct≤0.8 indicated hemodynamically signifcant stenosis. FFRct was also measured at the most distal location of each vessel. Overall distal FFRct was calculated as the mean of the distal values in the left, right, and circumfex coronary artery in each patient. Results Seventy-three patients (age 56 (42–65) years, 63% males) at 11 (8–16) years after HTx were included. Eighteen (25%) patients had a focal hemodynamically signifcant stenosis (stenosis>30% with FFRct≤0.8). In the 55 patients without a hemodynamically signifcant focal FFRct stenosis (FFRct>0.80), the distal left anterior descending artery FFRct was<0.90 in 74% of the patients and 10 (18%) patients had≥1 coronary artery with a distal FFRct≤0.8, including 1 with a distal FFRct≤0.8 in all coronaries. Overall distal FFRct in patients without focal stenosis was 0.88 (0.86–0.91), 0.87 (0.86–0.90), and 0.88 (0.86–0.91) (median with 25th–75th percentile) at 5–9, 10–14, or≥15 years post-transplantation, respectively (p=0.93). Conclusions FFRct performed on CCTA scans of HTx patients demonstrated that 25% of patients had a focal coronary stenosis with FFRct≤0.8. Even without a focal stenosis, FFRct values are often abnormal in HTx patients. Key Points • This is the frst report describing the use of FFRct in in heart transplant patients. • FFRct identifes patients after heart transplantation with hemodynamically signifcant coronary stenosis. • Even without a focal stenosis, FFRct values are often abnormal in heart transplant patients

Use of Cardiac CT in the Routine Assessment of Cardiac Allograft Vasculopathy in Heart Transplant Patients: Results from the First 100 Consecutive Patients

PURPOSE: Cardiac allograft vasculopathy (CAV) is an accelerated form of coronary artery disease that affects heart transplant patients (HTx). Routine screening for CAV is warranted. We evaluated the feasibility and utility of cardiac CT to screen for CAV in 100 consecutive HTx patients at our center. METHODS: From Feb 2018 to Jan 2019 all consecutive HTxs who were more than five-years post-transplant were converted from using stress myocardial perfusion imaging to cardiac CT for the annual assessment of CAV. CAV was scored (0 (absent), 1 (mild), 2 (moderate), 3 (severe)) based on coronary CT angiography (CCTA) findings and compared with the most recently known CAV score before CCTA. RESULTS: CCTA was performed in 99 out of 100 patients who were planned for cardiac CT (56 (42-63) years, 65% men, and 11 (8-16) years post-transplant), 1 patient underwent only a calcium scan due to IV access problems. The median Agatston calcium score was 6 (0-85), and 38 patients had no detectable calcium. CCTA showed new obstructive coronary disease (>50% stenosis) in 20 patients. The CAV score was reclassified based on CCTA findings in 37 patients (p<0.001) (Figure 1). There were 53 CAV0, 22 CAV1, 11 CAV2 and 14 CAV3 patients. Mean heart rate during scanning was 75±11 beats per minute and beta-blockers were required in 63 patients. Median radiation dose was 2.5 (1.9-3.5) mSv. Two cases are presented in Figure 2. CONCLUSION: Cardiac CT can be successfully performed in HTxs with a low radiation dose. CCTA detects patients with significant coronary disease which leads to substantial reclassification of CAV grades