Pretest Score for Predicting Microbubble Contrast Agent Use in Stress Echocardiography: A Method to Increase Efficiency in the Echo Laboratory

Background. In stress echocardiography, contrast agents are used selectively to improve endocardial border definition. Early identification of candidates may facilitate use of these agents in small and medium volume laboratories where resources are limited. Methods. We studied 15232 patients who underwent stress echocardiography. Contrast agent was used if 2 or more ventricular segments were not adequately visualized without contrast. Logistic regression models were used to evaluate the association between individual characteristics and contrast use. An 11-point score was derived from the significant characteristics. Results. Variables associated with microbubble use were age, sex, smoking, presence of multiple risk factors, bodymass index (BMI), referral for dobutamine stress echocardiography, history of coronary artery disease, and abnormal baseline electrocardiogram. All variables except BMI were given a score of 1 if present and 0 if absent; BMI was given a score of 0 to 4 according to its value. An increased score was directly proportional to increased likelihood of contrast use. The score cutoff value to optimize sensitivity and specificity was 5. Conclusions. A pretest score can be computed from information available before imaging. It may facilitate contrast agent use through early identification of patients who are likely to benefit from improved endocardial border definition

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Background. In stress echocardiography, contrast agents are used selectively to improve endocardial border definition. Early identification of candidates may facilitate use of these agents in small and medium volume laboratories where resources are limited. Methods. We studied 15232 patients who underwent stress echocardiography. Contrast agent was used if 2 or more ventricular segments were not adequately visualized without contrast. Logistic regression models were used to evaluate the association between individual characteristics and contrast use. An 11-point score was derived from the significant characteristics. Results. Variables associated with microbubble use were age, sex, smoking, presence of multiple risk factors, bodymass index (BMI), referral for dobutamine stress echocardiography, history of coronary artery disease, and abnormal baseline electrocardiogram. All variables except BMI were given a score of 1 if present and 0 if absent; BMI was given a score of 0 to 4 according to its value. An increased score was directly proportional to increased likelihood of contrast use. The score cutoff value to optimize sensitivity and specificity was 5. Conclusions. A pretest score can be computed from information available before imaging. It may facilitate contrast agent use through early identification of patients who are likely to benefit from improved endocardial border definition

Relationship between HgbA1c and Myocardial Blood Flow Reserve in Patients with Type 2 Diabetes Mellitus: Noninvasive Assessment Using Real-Time Myocardial Perfusion Echocardiography

To study the relationship between glycosylated hemoglobin (HgbA1c) and myocardial perfusion in type 2 diabetes mellitus (T2DM) patients, we prospectively enrolled 24 patients with known or suspected coronary artery disease (CAD) who underwent adenosine stress by real-time myocardial perfusion echocardiography (RTMPE). HgbA1c was measured at time of RTMPE. Microbubble velocity (β min−1), myocardial blood flow (MBF, mL/min/g), and myocardial blood flow reserve (MBFR) were quantified. Quantitative MCE analysis was feasible in all patients (272/384 segments, 71%). Those with HgbA1c > 7.1% had significantly lower βreserve and MBFR than those with HgbA1c ≤ 7.1% (P 2 as normal, HgbA1c > 7.1% significantly increased the risk for abnormal MBFR, (adjusted odds ratio: 1.92, 95% CI: 1.12–3.35, P=0.02). Optimal glycemic control is associated with preservation of MBFR as determined by RTMPE, in T2DM patients at risk for CAD

Prognostic value of a negative peak supine bicycle stress echocardiography with or without concomitant ischaemic stress electrocardiographic changes: a cohort study

Background: a negative peak supine bicycle exercise stress echocardiography (ESE) was shown to have a long-term favourable prognostic value. Data on the long-term prognosis of ischaemic electrocardiographic (ISECG) changes in the setting of a negative peak supine bicycle ESE are lacking. Design: we evaluated the prognostic value of negative peak supine bicycle ESE with or without concomitant ISECG changes in a referral population evaluated for chest pain after an inconclusive first-line work-up including clinical evaluation and exercise ECG stress. Methods: from 2003 to 2010, patients who underwent a peak supine bicycle ESE and were deemed to be negative were evaluated. Two groups based on concomitant stress ECG tracing were analysed-those with normal stress ECG and those with ISECG changes. The primary endpoint was cumulative incidence of cardiovascular death, hospitalizations for acute coronary syndrome and coronary revascularizations. Results: a total of 371 patients (mean age 59.1±12.1 years, 49.9% women) were studied. Of those, 141 (38.0%) had concomitant ISECG changes. Mean follow-up was 3.46±1.76 years. The primary endpoint occurred in 3.0% of patients, (2.2% in those with normal stress ECG, and in 4.3% with ISECG changes, p=0.251); with unadjusted hazard ratio for primary endpoint of 2.04 (95%CI 0.62-6.69, p=0.239) in patients with ISECG changes compared to those with normal stress ECG. Conclusions: in an outpatient population without known CAD evaluated for chest pain after inconclusive first-line work-up, a negative peak supine bicycle ESE confers an excellent prognosis regardless of the nature of concomitant stress ECG abnormalities

Exploring the Power and Promise of in Silico Clinical Trials with Application in COVID-19 Infection

Background: COVID-19 pandemic has dramatically engulfed the world causing catastrophic damage to human society. Several therapeutic and vaccines have been suggested for the disease in the past months, with over 150 clinical trials currently running or under process. Nevertheless, these trials are extremely expensive and require a long time, which presents the need for alternative cost-effective methods to tackle this urgent requirement for validated therapeutics and vaccines. Bearing this in mind, here we assess the use of in silico clinical trials as a significant development in the field of clinical research, which holds the possibility to reduce the time and cost needed for clinical trials on COVID-19 and other diseases. Methods: Using the PubMed database, we analyzed six relevant scientific articles regarding the possible application of in silico clinical trials in testing the therapeutic and investigational methods of managing different diseases. Results: Successful use of in silico trials was observed in many of the reviewed evidence. Conclusion: In silico clinical trials can be used in refining clinical trials for COVID-19 infection. Keywords: in silico, clinical trials, COVID-19, SARS-CoV-2, vaccine Ho