The diagnostic accuracy and outcomes after coronary computed tomography angiography vs. conventional functional testing in patients with stable angina pectoris: a systematic review and meta-analysis

Aims: To systematically review and perform a meta-analysis of the diagnostic accuracy and post-test outcomes of conventional exercise electrocardiography (XECG) and single-photon emission computed tomography (SPECT) compared with coronary computed tomography angiography (coronary CTA) in patients suspected of stable coronary artery disease (CAD). Methods and results: We systematically searched for studies published from January 2002 to February 2013 examining the diagnostic accuracy (defined as at least ≥50% luminal obstruction on invasive coronary angiography) and outcomes of coronary CTA (≥16 slice) in comparison with XECG and SPECT. The search revealed 11 eligible studies (N = 1575) comparing the diagnostic accuracy and 7 studies (N = 216.603) the outcomes of coronary CTA vs. XECG or/and SPECT. The per-patient sensitivity [95% confidence interval (95% CI)] to identify significant CAD was 98% (93–99%) for coronary CTA vs. 67% (54–78%) (P < 0.001) for XECG and 99% (96–100%) vs. 73% (59–83%) (P = 0.001) for SPECT. The specificity (95% CI) of coronary CTA was 82% (63–93%) vs. 46% (30–64%) (P < 0.001) for XECG and 71% (60–80%) vs. 48% (31–64%) (P = 0.14) for SPECT. The odds ratio (OR) of downstream test utilization (DTU) for coronary CTA vs. XECG/SPECT was 1.38 (1.33–1.43, P < 0.001), for revascularization 2.63 (2.50–2.77, P < 0.001), for non-fatal myocardial infarction 0.53 (0.39–0.72, P < 0.001), and for all-cause mortality 1.01 (0.87–1.18, P = 0.87). Conclusion: The up-front diagnostic performance of coronary CTA is higher than of XECG and SPECT. When compared with XECG/SPECT testing, coronary CTA testing is associated with increased DTU and coronary revascularization

Artifact Correction of Light Induced Detuning in QCM‑D Experiments

The quartz crystal microbalance with dissipation (QCM-D) has become an efficient and versatile measurement technique for investigating in situ the external stimuli responsiveness such as pH, temperature, or chemical gradients of surface-active substances at solid–liquid interfaces. However, light responsive adsorption investigation is more challenging presumably since the quartz crystal itself reacts to optical stimulation, showing frequency and dissipation shifts known as light induced detuning (LID). This yields an effective measurement artifact and makes data interpretation with respect to dynamic interactions of light responsive materials rather challenging. Here we introduce a simple guideline for correcting the artifacts of the QCM sensor response on irradiation to ensure quantitative analysis for light responsive materials via OCM-D. We also show that the LID depends on the adsorption properties of the sensor and the solvent properties (ionic concentration or viscosity), providing a guideline to minimize impact of the LID