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Your search keyword '"Zaheer Yousef"' showing total 4 results
Start Over Author "Zaheer Yousef" Publisher elsevier
4 results on '"Zaheer Yousef"'

1. Phosphatidylthreonine is a procoagulant lipid detected in human blood and elevated in coronary artery disease

Author

Ali A. Hajeyah, Majd B. Protty, Divyani Paul, Daniela Costa, Nader Omidvar, Bethan Morgan, Yugo Iwasaki, Beth McGill, P. Vincent Jenkins, Zaheer Yousef, Keith Allen-Redpath, Shin Soyama, Anirban Choudhury, Rito Mitra, Parveen Yaqoob, James H. Morrissey, Peter W. Collins, and Valerie B. O'Donnell

Subjects
phospholipids, phospholipids/metabolism, phospholipids/biosynthesis, vascular biology, platelets, phosphatidylthreonine, Biochemistry, QD415-436
Abstract

Aminophospholipids (aPL) such as phosphatidylserine are essential for supporting the activity of coagulation factors, circulating platelets, and blood cells. Phosphatidylthreonine (PT) is an aminophospholipid previously reported in eukaryotic parasites and animal cell cultures, but not yet in human tissues. Here, we evaluated whether PT is present in blood cells and characterized its ability to support coagulation. Several PT molecular species were detected in human blood, washed platelets, extracellular vesicles, and isolated leukocytes from healthy volunteers using liquid chromatography–tandem mass spectrometry. The ability of PT to support coagulation was demonstrated in vitro using biochemical and biophysical assays. In liposomes, PT supported prothrombinase activity in the presence and absence of phosphatidylserine. PT nanodiscs strongly bound FVa and lactadherin (nM affinity) but poorly bound prothrombin and FX, suggesting that PT supports prothrombinase through recruitment of FVa. PT liposomes bearing tissue factor poorly generated thrombin in platelet poor plasma, indicating that PT poorly supports extrinsic tenase activity. On platelet activation, PT is externalized and partially metabolized. Last, PT was significantly higher in platelets and extracellular vesicle from patients with coronary artery disease than in healthy controls. In summary, PT is present in human blood, binds FVa and lactadherin, supports coagulation in vitro through FVa binding, and is elevated in atherosclerotic vascular disease. Our studies reveal a new phospholipid subclass, that contributes to the procoagulant membrane, and may support thrombosis in patients at elevated risk.

Published
2024
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2. Upgrading to cardiac resynchronisation therapy: Concordance of real-world experience with clinical guidelines

Author

Laura Tan, Sashiananthan Ganesananthan, Hani Huzaien, Hossam Elsayed, Nisar Shah, Parin Shah, and Zaheer Yousef

Subjects
Heart failure, HFrEF, Cardiac resynchronisation therapy, CRT upgrade, CRT revision, Diseases of the circulatory (Cardiovascular) system, RC666-701
Abstract

Objective: Revision to cardiac resynchronisation therapy (CRT) in patients with existing pacemakers with worsening heart failure (HF) can improve symptoms and cardiac function. We identify factors that predict improvement in left ventricular ejection fraction (LVEF) within a year of CRT revision. Methods: We performed a retrospective study of 146 consecutive patients (16% female, mean age 73 ± 11 years, mean LVEF 27 ± 8%) undergoing revision to CRT (January 2012 to May 2018) in a single tertiary centre. LVEF was measured pre-revision and 3, 6 and 12 months post-upgrade. Results: At 6 months, 68% of patients demonstrated improvement in LVEF (mean ΔLVEF + 6.7% ± 9.6). Compared to patients in atrial fibrillation (AF), patients with sinus rhythm had a greater improvement in LVEF at 6 months (sinus 8.4 ± 10.3% vs. AF 4.2 ± 8.0%, p = 0.02). Compared to ischaemic cardiomyopathy (ICM), patients with non-ischaemic cardiomyopathy (NICM) had a greater improvement in LVEF at 6 months (NICM 8.4 ± 9.8% vs ICM 4.8 ± 9.2%, p = 0.05). Patients with RV pacing ≥40% at baseline had a greater improvement in LVEF at 6 months (≥40% RV pacing 9.3 ± 10.2 vs.

Published
2021
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3. Upgrading to cardiac resynchronisation therapy: Concordance of real-world experience with clinical guidelines

Author

Nisar Shah, Zaheer Yousef, Laura Tan, Hani Huzaien, Hossam Elsayed, Sashiananthan Ganesananthan, and Parin Shah

Subjects
Cardiac function curve, medicine.medical_specialty, Concordance, Cardiomyopathy, Heart failure, 030204 cardiovascular system & hematology, 03 medical and health sciences, 0302 clinical medicine, Internal medicine, medicine, Diseases of the circulatory (Cardiovascular) system, Sinus rhythm, 030212 general & internal medicine, cardiovascular diseases, Original Paper, Ejection fraction, business.industry, Retrospective cohort study, Atrial fibrillation, HFrEF, medicine.disease, CRT upgrade, CRT revision, RC666-701, Cardiology, cardiovascular system, Cardiac resynchronisation therapy, Cardiology and Cardiovascular Medicine, business, circulatory and respiratory physiology
Abstract

Objective: Revision to cardiac resynchronisation therapy (CRT) in patients with existing pacemakers with worsening heart failure (HF) can improve symptoms and cardiac function. We identify factors that predict improvement in left ventricular ejection fraction (LVEF) within a year of CRT revision. Methods: We performed a retrospective study of 146 consecutive patients (16% female, mean age 73 ± 11 years, mean LVEF 27 ± 8%) undergoing revision to CRT (January 2012 to May 2018) in a single tertiary centre. LVEF was measured pre-revision and 3, 6 and 12 months post-upgrade. Results: At 6 months, 68% of patients demonstrated improvement in LVEF (mean ΔLVEF + 6.7% ± 9.6). Compared to patients in atrial fibrillation (AF), patients with sinus rhythm had a greater improvement in LVEF at 6 months (sinus 8.4 ± 10.3% vs. AF 4.2 ± 8.0%, p = 0.02). Compared to ischaemic cardiomyopathy (ICM), patients with non-ischaemic cardiomyopathy (NICM) had a greater improvement in LVEF at 6 months (NICM 8.4 ± 9.8% vs ICM 4.8 ± 9.2%, p = 0.05). Patients with RV pacing ≥40% at baseline had a greater improvement in LVEF at 6 months (≥40% RV pacing 9.3 ± 10.2 vs.

Published
2021

4. Improvement in cardiac energetics by perhexiline in heart failure due to dilated cardiomyopathy

Author

Michael Kuehl, Frank Thies, Francisco Leyva, Lynne Williams, Khalid Abozguia, Michael P. Frenneaux, Zaheer Yousef, Sarah Bowater, Anton J. M. Wagenmakers, Roger Beadle, and John D. Horowitz

Subjects
medicine.medical_specialty, Ejection fraction, business.industry, Dilated cardiomyopathy, medicine.disease, Placebo, R1, Phosphocreatine, chemistry.chemical_compound, chemistry, Heart failure, Internal medicine, Perhexiline, medicine, Cardiology, Cardiology and Cardiovascular Medicine, business, Respiratory exchange ratio, Blood sampling, medicine.drug
Abstract

Objectives: The aim of this study was to determine whether short-term treatment with perhexiline improves cardiac energetics, left ventricular function, and symptoms of heart failure by altering cardiac substrate utilization. Background: Perhexiline improves exercise capacity and left ventricular ejection fraction (LVEF) in patients with heart failure (HF). P cardiac magnetic resonance spectroscopy can be used to quantify the myocardial phosphocreatine/adenosine triphosphate ratio. Because improvement of HF syndrome can improve cardiac energetics secondarily, we investigated the effects of short-term perhexiline therapy. Methods: Patients with systolic HF of nonischemic etiology (n= 50, 62 ± 1.8 years of age, New York Heart Association functional class II to IV, LVEF: 27.0 ± 1.44%) were randomized to receive perhexiline 200 mg or placebo for 1 month in a double-blind fashion. Clinical assessment, echocardiography, and P cardiac magnetic resonance spectroscopy were performed at baseline and after 1 month. A substudy of 22 patients also underwent cross-heart blood sampling at completion of the study to quantify metabolite utilization. Results: Perhexiline therapy was associated with a 30% increase in the phosphocreatine/adenosine triphosphate ratio (from 1.16 ± 0.39 to 1.51 ± 0.51; p< 0.001) versus a 3% decrease with placebo (from 1.36 ± 0.31 to 1.34 ± 0.31; p=0.37). Perhexiline therapy also led to an improvement in New York Heart Association functional class compared with placebo (p= 0.036). Short-term perhexiline therapy did not change LVEF. Cross-heart measures of cardiac substrate uptake and respiratory exchange ratio (which reflects the ratio of substrates used) did not differ between patients who received perhexiline versus placebo. Conclusions: Perhexiline improves cardiac energetics and symptom status with no evidence of altered cardiac substrate utilization. No change in LVEF is seen at this early stage. (Metabolic Manipulation in Chronic Heart Failure; NCT00841139).

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