85 research outputs found

    Effect of sacubitril/valsartan on recurrent events in the prospective comparison of ARNI with ACEI to determine impact on global mortality and morbidity in heart failure trial (PARADIGM-HF)

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    Aims: Recurrent hospitalizations are a major part of the disease burden in heart failure (HF), but conventional analyses consider only the first event. We compared the effect of sacubitril/valsartan vs. enalapril on recurrent events, incorporating all HF hospitalizations and cardiovascular (CV) deaths in PARADIGM-HF, using a variety of statistical approaches advocated for this type of analysis. Methods and results: In PARADIGM-HF, a total of 8399 patients were randomized and followed for a median of 27 months. We applied various recurrent event analyses, including a negative binomial model, the Wei, Lin and Weissfeld (WLW), and Lin, Wei, Ying and Yang (LWYY) methods, and a joint frailty model, all adjusted for treatment and region. Among a total of 3181 primary endpoint events (including 1251 CV deaths) during the trial, only 2031 (63.8%) were first events (836 CV deaths). Among a total of 1195 patients with at least one HF hospitalization, 410 (34%) had at least one further HF hospitalization. Sacubitril/valsartan compared with enalapril reduced the risk of recurrent HF hospitalization using the negative binomial model [rate ratio (RR) 0.77, 95% confidence interval (CI) 0.67–0.89], the WLW method [hazard ratio (HR) 0.79, 95% CI 0.71–0.89], the LWYY method (RR 0.78, 95% CI 0.68–0.90), and the joint frailty model (HR 0.75, 95% CI 0.66–0.86) (all P < 0.001). The effect of sacubitril/valsartan vs. enalapril on recurrent HF hospitalizations/CV death was similar. Conclusions: In PARADIGM-HF, approximately one third of patients with a primary endpoint (time-to-first) experienced a further event. Compared with enalapril, sacubitril/valsartan reduced both first and recurrent events. The treatment effect size was similar, regardless of the statistical approach applied

    An Assessment Of The Forces Acting Upon A Centrifugal Impeller Using Full Load, Full Pressure Hydrocarbon Testing.

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    LecturePg. 111-122Although turbocompressors have been designed, built, and used in increasingly stringent conditions for more than 80 years, the turbomachinery industry, like all comparable industries, can only design and manufacture its products within the realm of existing knowledge and foreseeable operating, engineering, and scientific parameters. As end users of turbocompressors continue to implement ever more complex and demanding assortments of processes and process variables into their operations (i.e., equipment efficiencies, higher pressures, and the like), previously unseen combinations of factors can create new and unpredictable forces and effects on equipment. These unpredictable forces may, at different times, cause destructive results in the end user's facility, such as in piping, valves, gauges, tanks, etc. It is possible for these forces, which may only exist under the unique circumstances present at the end user's site, occasionally to manifest themselves in the centrifugal compressor rotor. When this occurs, the rotors may exhibit such phenomena as rotordynamic excitation, less than anticipated aerothermal performance, or even a physical failure of a rotor or other component. When this unfortunate circumstance occurs, turbocompressor OEMs dedicated to both customer satisfaction and continued expansion of knowledge and technical responsiveness, will investigate (typically in cooperation with the end user) to determine, if possible, the full range of dynamics that may be occurring during process operation at the end user's site, so that the turbomachines can, if possible, be made to withstand the unforeseen forces. These efforts typically involve some combination of analytical studies and research testing; analytical work to provide a sound computational model, and testing to provide the data necessary to calibrate or bound the models. The test program and results described herein represent an OEMs and end user's efforts to identify the cause of repeated impeller failures in an offshore gas reinjection compressor. A machine identical to the field units was fully instrumented with aerodynamic and mechanical instrumentation (including radial and axial vibration probes, dynamic and static straingauges, dynamic pressure transducers, and other interstage pressure and temperature instrumentation). The compressor was then tested at full load and full pressure on hydrocarbon gas at the OEMs facility. Descriptions of the instrumentation and test procedure are provided. Concurrently, analytical efforts were undertaken to help understand the aerodynamic forces that may be contributing to the failures. Results from both the testing and the computational studies are presented along with the conclusions derived from both efforts

    Prognostic implications of left ventricular global longitudinal strain in heart failure patients with narrow QRS complex treated with cardiac resynchronization therapy: a subanalysis of the randomized EchoCRT trial

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    Aim: Left ventricular (LV) global longitudinal strain (GLS) reflects LV systolic function and correlates inversely with the extent of LV myocardial scar and fibrosis. The present subanalysis of the Echocardiography Guided CRT trial investigated the prognostic value of LV GLS in patients with narrow QRS complex. Methods and results: Left ventricular (LV) global longitudinal strain (GLS) was measured on the apical 2-, 4- and 3-chamber views using speckle tracking analysis. Measurement of baseline LV GLS was feasible in 755 patients (374 with cardiac resynchronization therapy (CRT)-ON and 381 with CRT-OFF). The median value of LV GLS in the overall population was 7.9%, interquartile range 6.2–10.1%. After a mean follow-up period of 19.4 months, 95 patients in the CRT-OFF group and 111 in the CRT-ON group reached the combined primary endpoint of all-cause mortality and heart failure hospitalization. Each 1% absolute unit decrease in LV GLS was independently associated with 11% increase in the risk to reach the primary endpoint (Hazard ratio 1.11; 95% confidence interval 95% 1.04–1.17, P < 0.001), after adjusting for ischaemic cardiomyopathy and randomization treatment among other clinically relevant variables. When categorizing patients according to quartiles of LV GLS, the primary endpoint occurred more frequently in patients in the lowest quartile (<6.2%) treated with CRT-ON vs. CRT-OFF (45.6% vs. 28.7%, P = 0.009) whereas, no differences were observed in patients with LV GLS ≥6.2% treated with CRT-OFF vs. CRT-ON (23.7% vs. 24.5%, respectively; P  = 0.62). Conclusion: Low LV GLS is associated with poor outcome in heart failure patients with QRS width <130 ms, independent of randomization to CRT or not. Importantly, in the group of patients with the lowest LV GLS quartile, CRT may have a detrimental effect on clinical outcomes

    Community-Acquired Methicillin-Resistant Staphylococcus aureus in Institutionalized Adults with Developmental Disabilities1

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    Methicillin-resistant Staphylococcus aureus (MRSA) has recently been reported to emerge in the community setting. We describe the investigation and control of a community-acquired outbreak of MRSA skin infections in a closed community of institutionalized adults with developmental disabilities. In a 9-month period in 1997, 20 (71%) of 28 residents had 73 infectious episodes. Of the cultures, 60% and 32% obtained from residents and personnel, respectively, grew S. aureus; 96% and 27% were MRSA. All isolates were genetically related by pulsed-field gel electrophoresis and belonged to a phage type not previously described in the region. No known risk factors for MRSA acquisition were found. However, 58 antibiotic courses had been administered to 16 residents during the preceding 9 months. Infection control measures, antibiotic restriction, and appropriate therapy resulted in successful termination of this outbreak. Selective antibiotic pressure may result in the emergence, persistence, and dissemination of MRSA strains, causing prolonged disease

    The effect of QRS duration on cardiac resynchronization therapy in patients with a narrow QRS complex: a subgroup analysis of the EchoCRT trial

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    Aims In EchoCRT, a randomized trial evaluating the effect of cardiac resynchronization therapy (CRT) in patients with a QRS duration of <130 ms and echocardiographic evidence of left ventricular dyssynchrony, the primary outcome occurred more frequently in the CRT when compared with the control group. According to current heart failure guidelines, CRT is recommended in patients with a QRS duration of ≥120 ms. However, there is some ambiguity from clinical trial data regarding the benefit of patients with a QRS duration of 120-130 ms. Methods and results The main EchoCRT trial was prematurely terminated due to futility. For the current subgroup analysis we compared data for CRT-ON vs. -OFF in patients with QRS < 120 (n = 661) and QRS 120-130 ms (n = 139). On uni- and multivariable analyses, no significant interaction was observed between the two groups and randomized treatment for the primary or any of the secondary endpoints. On multivariable analysis, a higher risk for the primary endpoint was observed in patients with a QRS duration of 120-130 ms randomized to CRT-ON vs. CRT-OFF (hazard ratio 2.18, 95% CI 1.02-4.65; P = 0.044). However, no statistically significant interaction, compared with patients with QRS < 120 ms randomized to CRT-ON vs. CRT-OFF, was noted (P-interaction = 0.160). Conclusions In this pre-specified subgroup analysis of EchoCRT, no benefit of CRT was evident in patients with a QRS duration of 120-130 ms. These data further question the usefulness of CRT in this patient populatio

    Cardiac resynchronization therapy in patients with heart failure and narrow QRS complexes

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    Background: Cross correlation analysis (CCA) using tissue Doppler imaging has been shown to be associated with outcome after cardiac resynchronization therapy (CRT) in patients with heart failure (HF) with wide QRS. However, its significance in patients with narrow QRS treated with CRT is unknown. Objectives: The aim of the current study was to investigate the association of mechanical activation delay by CCA with study outcome in patients with HF enrolled in the EchoCRT trial. Methods: Baseline CCA could be performed from tissue Doppler imaging in the apical views in 807 of 809 (99.7%) enrolled patients, and 6-month follow-up could be performed in 610 of 635 (96%) patients with available echocardiograms. Patients with a pre-specified maximal activation delay ≥35 ms were considered to have significant delay. The study outcome was HF hospitalization or death. Results: Of 807 patients, 375 (46%) did not have delayed mechanical activation at baseline by CCA. Patients without delayed mechanical activation who were randomized to CRT-On compared with CRT-Off had an increased risk of poor outcome (hazard ratio: 1.70; 95% confidence interval: 1.13 to 2.55; p = 0.01) with a significant interaction term (p = 0.04) between delayed mechanical activation and device randomization for the endpoint. Among patients with paired baseline and follow-up data with no events before 6-month follow-up (n = 541), new-onset delayed mechanical activation in the CRT-On group showed a significant increase in unfavorable events (hazard ratio: 3.73; 95% confidence interval: 1.15 to 12.14; p = 0.03). Conclusions: In the EchoCRT population, absence of delayed mechanical activation by CCA was significantly associated with poor outcomes, possibly due to the onset of new delayed mechanical activation with CRT pacing. (Echocardiography Guided Cardiac Resynchronization Therapy [EchoCRT] Trial; NCT00683696)

    Cardiac-resynchronization therapy in heart failure with a narrow QRS complex.

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    BACKGROUND: Cardiac-resynchronization therapy (CRT) reduces morbidity and mortality in chronic systolic heart failure with a wide QRS complex. Mechanical dyssynchrony also occurs in patients with a narrow QRS complex, which suggests the potential usefulness of CRT in such patients. METHODS: We conducted a randomized trial involving 115 centers to evaluate the effect of CRT in patients with New York Heart Association class III or IV heart failure, a left ventricular ejection fraction of 35% or less, a QRS duration of less than 130 msec, and echocardiographic evidence of left ventricular dyssynchrony. All patients underwent device implantation and were randomly assigned to have CRT capability turned on or off. The primary efficacy outcome was the composite of death from any cause or first hospitalization for worsening heart failure. RESULTS: On March 13, 2013, the study was stopped for futility on the recommendation of the data and safety monitoring board. At study closure, the 809 patients who had undergone randomization had been followed for a mean of 19.4 months. The primary outcome occurred in 116 of 404 patients in the CRT group, as compared with 102 of 405 in the control group (28.7% vs. 25.2%; hazard ratio, 1.20; 95% confidence interval [CI], 0.92 to 1.57; P=0.15). There were 45 deaths in the CRT group and 26 in the control group (11.1% vs. 6.4%; hazard ratio, 1.81; 95% CI, 1.11 to 2.93; P=0.02). CONCLUSIONS: In patients with systolic heart failure and a QRS duration of less than 130 msec, CRT does not reduce the rate of death or hospitalization for heart failure and may increase mortality. (Funded by Biotronik and GE Healthcare; EchoCRT ClinicalTrials.gov number, NCT00683696.)
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