Most Read Articles
01 Dec 2020
Tetanus toxoid 5 Lf, diphtheria toxoid 2 Lf, pertussis toxoid 2.5 mcg, filamentous haemagglutinin 5 mcg, fimbriae types 2 and 3 5 mcg, pertactin 3 mcg
Dr. Hsu Li Yang, Dr. Tan Thuan Tong, Dr. Andrea Kwa, 08 Jan 2021
Antimicrobial resistance has become increasingly dire as the rapid emergence of drug resistance, especially gram-negative pathogens, has outpaced the development of new antibiotics. At a recent virtual symposium, Dr Hsu Li Yang, Vice Dean (Global Health) and Programme Leader (Infectious Diseases), NUS Saw Swee Hock School of Public Health, presented epidemiological data on multidrug-resistant (MDR) gram-negative bacteria (GNB) in Asia, while Dr Tan Thuan Tong, Head and Senior Consultant, Department of Infectious Diseases, Singapore General Hospital (SGH), focused on the role of ceftazidime-avibactam in MDR GNB infections. Dr Andrea Kwa, Assistant Director of Research, Department of Pharmacy, SGH, joined the panel in an interactive fireside chat, to discuss challenges, practical considerations, and solutions in MDR gram-negative infections. This Pfizer-sponsored symposium was chaired by Dr Ng Shin Yi, Head and Senior Consultant of Surgical Intensive Care, SGH.
Jairia Dela Cruz, 3 days ago
Spending too much time sitting cannot be good for the body, and rising to one's feet breaks up such a behaviour and yields small, but meaningful, reductions in certain cardiovascular disease (CVD) risk factors, according to the results of a meta-analysis.
3 days ago
Use of thyroid hormone therapy does not seem to protect older adults with subclinical hypothyroidism against mortality, but it appears to confer survival benefits to those aged <65 years, results of a study have shown.

Adding endothelial shear stress to stenosis severity may improve prediction of abnormal PET result

Stephen Padilla
04 Sep 2020

A low-to-moderate positive association exists between lesion plaque burden (PB) and indices of endothelial shear stress (ESS), a recent study has shown. ESS, like PB, increases with stenosis severity and is higher in lesions paired with abnormal positron emission tomography (PET) results.

“ESS is a moderate predictor of impaired vasodilating capability, performing equally with PB and stenosis severity,” the researchers said. “The addition of ESS to stenosis severity can improve prediction of an abnormal PET result.”

C. Anagnostopoulos from the Academy of Athens Biomedical Research Foundation in Greece led the team of researchers which investigated the association of local ESS with PB and with stenosis severity, as well as their comparative performance in predicting impaired coronary vasodilating capability assessed by PET myocardial perfusion imaging (MPI). Results of the study were presented at the ESC Congress 2020: The Digital Experience (ESC 2020).

Forty-nine patients (mean age, 65.3±6.3 years; 29 males) who underwent PET-MPI with 15O-water or 13N-ammonia and computed tomography coronary angiography (CTCA) participated in the study. Abnormal PET was defined as >1 contiguous segment showing both stress Myocardial Blood Flow ≤2.3 mL/g/min and Myocardial Flow Reserve ≤2.5 for 15O-water or <1.79 mL/g/min and ≤2.0 for 13N-ammonia, respectively.

Stenosis severity on CTCA was classified as follows: <30 percent, 31–50 percent, 51–70 percent, and 71–90 percent. The researchers then applied computational fluid dynamics to every vessel, assuming a mean pressure of 100 mm Hg as the inlet boundary condition and a coronary velocity profile of 1 ml/sec as the outlet. They also calculated ESS for the full length of a stenosis (total) and in the proximal (prox), minimum lumen area (MLA), and distal (dist) stenotic segments. Atherosclerotic PB was defined as lesion plaque volume/lesion vessel volume x100.

Evaluation of 85 coronary vessels showed a positive correlation between ESS and PB (r[total]=0.544; r[prox]=0.528; r[MLA]=0.529; r[dist]=0.474; pall<0.001). Stenosis severity resulted in a progressive increase in all ESS indices and PB as compared to segments with a <30-percent stenosis (p≤0.004 for all comparisons). PB and ESS indices were also higher in lesions with impaired vasodilating capacity as compared to those without (p≤0.02 for all comparisons). [Anagnostopoulos C, et al, ESC Congress 2020]

Moreover, all ESS indices demonstrated equal performance with PB and stenosis >50 percent in predicting an abnormal PET-MPI (area under the curve [AUC], from 0.682 to 0.780; p-diff>0.05 for all comparisons.

The predictive ability of the model was increased with the pairwise combination of stenosis >50 percent with the ESS segments (except the distal one) over stenosis alone (AUC [stenosis >50 percent+ESS(total)]=0.80; AUC [stenosis >50 percent+ESS(prox)]=0.797; AUC [stenosis >50 percent+ESS(MLA)]=0.822; p-diff ≤0.01 for all comparisons; AUC [stenosis >50 percent+ESS(dist)]=0.768; p-diff=0.07).

“Advances in CTCA imaging enable assessment of coronary plaque burden, a predictor of myocardial perfusion abnormalities and more recently, with the use of CFD of ESS, an established contributor to atherosclerotic plaque development and progression,” the researchers noted.

Digital Edition
Asia's trusted medical magazine for healthcare professionals. Get your MIMS Doctor - Malaysia digital copy today!
Sign In To Download
Editor's Recommendations
Most Read Articles
01 Dec 2020
Tetanus toxoid 5 Lf, diphtheria toxoid 2 Lf, pertussis toxoid 2.5 mcg, filamentous haemagglutinin 5 mcg, fimbriae types 2 and 3 5 mcg, pertactin 3 mcg
Dr. Hsu Li Yang, Dr. Tan Thuan Tong, Dr. Andrea Kwa, 08 Jan 2021
Antimicrobial resistance has become increasingly dire as the rapid emergence of drug resistance, especially gram-negative pathogens, has outpaced the development of new antibiotics. At a recent virtual symposium, Dr Hsu Li Yang, Vice Dean (Global Health) and Programme Leader (Infectious Diseases), NUS Saw Swee Hock School of Public Health, presented epidemiological data on multidrug-resistant (MDR) gram-negative bacteria (GNB) in Asia, while Dr Tan Thuan Tong, Head and Senior Consultant, Department of Infectious Diseases, Singapore General Hospital (SGH), focused on the role of ceftazidime-avibactam in MDR GNB infections. Dr Andrea Kwa, Assistant Director of Research, Department of Pharmacy, SGH, joined the panel in an interactive fireside chat, to discuss challenges, practical considerations, and solutions in MDR gram-negative infections. This Pfizer-sponsored symposium was chaired by Dr Ng Shin Yi, Head and Senior Consultant of Surgical Intensive Care, SGH.
Jairia Dela Cruz, 3 days ago
Spending too much time sitting cannot be good for the body, and rising to one's feet breaks up such a behaviour and yields small, but meaningful, reductions in certain cardiovascular disease (CVD) risk factors, according to the results of a meta-analysis.
3 days ago
Use of thyroid hormone therapy does not seem to protect older adults with subclinical hypothyroidism against mortality, but it appears to confer survival benefits to those aged <65 years, results of a study have shown.