Effect of technique on outcomes following bioresorbable vascular scaffold implantation: analysis from the ABSORB trials

BACKGROUND: Procedural technique may affect clinical outcomes after bioresorbable vascular scaffold (BVS) implantation. Prior studies suggesting such a relationship have not adjusted for baseline patient and lesion characteristics that may have influenced operator choice of technique and outcomes. OBJECTIVES: This study sought to determine whether target lesion failure (TLF) (cardiac death, target-vessel myocardial infarction, or ischemia-driven target lesion revascularization) and scaffold thrombosis (ScT) rates within 3 years of BVS implantation are affected by operator technique (vessel size selection and pre- and post-dilation parameters). METHODS: TLF and ScT rates were determined in 2,973 patients with 3,149 BVS-treated coronary artery lesions from 5 prospective studies (ABSORB II, ABSORB China, ABSORB Japan, ABSORB III, and ABSORB Extend). Outcomes through 3 years (and between 0 to 1 and 1 to 3 years) were assessed according to pre-specified definitions of optimal technique (pre-dilation, vessel sizing, and post-dilation). Multivariable analysis was used to adjust for differences in up to 18 patient and lesion characteristics...

Mesh-covered embolic protection stent implantation in ST-segment-elevation myocardial infarction: final 1-year clinical and angiographic results from the MGUARD for acute ST elevation reperfusion trial

The MGuard, a bare metal stent covered with a polymer mesh, was designed to reduce distal embolization during percutaneous coronary intervention in ST-segment-elevation myocardial infarction. In the MGUARD for Acute ST Elevation Reperfusion trial, the primary end point of complete ST-segment resolution was significantly improved with the MGuard compared with control. We evaluated 1-year clinical and angiographic results.METHODS AND RESULTS:Patients with ST-segment-elevation myocardial infarction ≤12 hours undergoing primary percutaneous coronary intervention of a single de novo native lesion were randomized to the MGuard versus any commercially available metallic stent (39.8% drug-eluting). Clinical follow-up was performed through 1 year, and angiography at 13 months was planned in 50 MGuard patients. There was no difference in major adverse cardiac events (1.8% versus 2.3%; P=0.75) at 30 days between the groups. Major adverse cardiac events at 1 year were higher with the MGuard, driven by greater ischemia-driven target lesion revascularization (8.6% versus 0.9%; P=0.0003). Conversely, mortality tended to be lower with the MGuard at 30 days (0% versus 1.9%; P=0.04) and at 1 year (1.0% versus 3.3%; P=0.09). Late lumen loss at 13 months in the MGuard was 0.99±0.80 mm, and binary restenosis was 31.6%.CONCLUSIONS:In patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention, a trend toward reduced 1-year mortality was present in patients treated with the MGuard stent. Target lesion revascularization and major adverse cardiac events rates during follow-up were higher in the MGuard group than in the control stent group, and angiographic late loss of the MGuard was consistent with that expected from bare metal stents.

Awareness and the EEG power spectrum: analysis of frequencies.

BACKGROUND: Power spectral analysis is a well-established method for the analysis of EEG signals. Spectral parameters can be used to quantify pharmacological effects of anaesthetics on the brain and the level of sedation. This method, in numerous variations, has been applied to depth of anaesthesia monitoring and has been incorporated into several commercially available EEG monitors. Because of the importance of EEG spectral analysis, we evaluated the performance of each frequency in the power spectrum regarding detection of awareness. METHODS: Ninety artefact-free EEG segments of length 8 s were obtained from a database that contains perioperatively recorded EEG data. For the present analysis, EEG data were selected from 39 patients with propofol-remifentanil or sevoflurane-remifentanil anaesthesia with a period of awareness. Half of the EEG segments were recorded during periods of awareness as defined by an adequate response to the command 'squeeze my hand'. The other half were from unresponsive patients. The power spectral density was calculated for each segment. The performance of each frequency bin of the power spectrum as a detector of awareness was assessed with a remapped prediction probability rPK, i.e. the prediction probability PK mapped to a range of 0.5-1. RESULTS: The remapped prediction probability was high (rPK>0.8) for low frequencies (<15 Hz) and for high frequencies (>26 Hz), with a minimum (rPK<0.55) at 21 Hz. Indentations in the 'performance spectrum' occur at the power-line frequency (50 Hz) and its harmonics and at 78 Hz, probably caused by the continuous impedance measurement of another device used in parallel. With the exception of the indentations, the remapped prediction probability of the high frequencies (>35 Hz) was >0.95. CONCLUSIONS: The best performance for the detection of awareness was achieved by EEG power spectral frequencies from >35 Hz up to 127 Hz. This frequency band may be dominated by muscle activity. The frequency band between 15 and 26 Hz may be of limited value, as reflected by lower rPK values.

[Approximate entropy of anesthesia EEG: compromise between calculation time and clinical validity]. / Approximate Entropy von Narkose-EEG: Kompromiss zwischen Rechenzeit und klinischer Aussagekraft.

Approximate entropy, a measure of regularity, can be used to analyze the electroencephalogram of patients in general anesthesia to discriminate between different states of consciousness. EEG burst suppression patterns reflect a state of deep anesthesia. Due to the instationary character of this EEG pattern approximate entropy values do not correctly classify the patient state. Possible solutions to this problem may be limited by the demand of computing power for entropy calculation and the reaction time following changes in patient state. Different approaches for an online monitoring application are examined.