BACKGROUND & AIMS: BACKGROUND:Transcatheter aortic valve implantation (TAVI) is safe and effective for patients with aortic stenosis (AS) who have a high operative risk. However, there is still debate on the effect of TAVI in AS patients with reduced left ventricular ejection fraction (REF). The objective of the review is to clarify the efficacy of TAVI and the impact of REF on the 30-day and midterm mortality in these patients. METHODS:Studies on TAVI were searched in PubMed, Embase, and the Cochrane Library databases and were included in this review following predefined criteria. Data were extracted and pooled risk ratios (RR) were synthesized to explore the relationship between REF and 30-day plus midterm mortality. RESULTS:Twenty-eight studies comprising 14,099 patients were included in the analysis of the association of REF with the prognosis of patients after TAVI. An average increase in left ventricular ejection fraction of 8-10 % was observed among these patients after TAVI. REF was not related to the 30-day mortality [RR = 1.90, 95 % confidence interval (CI) = 0.80-4.47]; however, it was related to the midterm mortality (RR = 1.49, 95 %CI = 1.14-1.93) of patients undergoing TAVI. Patients with low-flow and low-gradient AS had a higher 30-day mortality (RR = 1.54, 95 %CI = 1.11-2.13) and midterm mortality rate (RR = 1.69, 95 %CI = 1.33-2.14) compared with AS patients without these characteristics. The mortality of TAVI patients was significantly lower than that of those undergoing conservative therapy, and was similar to that of patients undergoing surgical aortic valve replacement. CONCLUSION:REF was not associated with 30-day mortality, but it was associated with the midterm mortality of TAVI patients. Patients with REF could benefit from TAVI compared with conservative therapy.

背景与目标：

BACKGROUND & AIMS: SOURCE CITATION:Armstrong PW, Pieske B, Anstrom KJ, et al. Vericiguat in patients with heart failure and reduced ejection fraction. N Engl J Med. 2020;382:1883-93. 32222134.

背景与目标： 来源引用: Armstrong PW，Pieske B，Anstrom KJ等。心力衰竭和射血分数降低患者的Vericiguat。N Engl J Med。2020;382:1883-93。32222134。

BACKGROUND & AIMS: BACKGROUND:The purpose of this study was to develop a multi-harmonic phase analysis method to measure diastolic dyssynchrony from conventional gated SPECT myocardial perfusion imaging (MPI) data and to compare it with systolic dyssynchrony in normal subjects and in patients with end-stage renal disease (ESRD) and normal left-ventricular ejection fraction (LVEF). METHODS:121 consecutive patients with ESRD and normal LVEF and 30 consecutive normal controls were enrolled. Diastolic dyssynchrony parameters were calculated using 3-harmonic phase analysis. Systolic dyssynchrony parameters were calculated using the established 1-harmonic phase analysis. RESULTS:The systolic and diastolic dyssynchrony parameters were correlated, but significantly different in both control and ESRD groups, indicating they were physiologically related but measured different LV mechanisms. The systolic and diastolic dyssynchrony parameters were each significantly different between the control and the ESRD groups. Significant systolic and diastolic dyssynchrony were found in 47% and 65% of the entire ESRD group. CONCLUSION:Multi-harmonic phase analysis has been developed to assess diastolic dyssynchrony, which measured a new LV mechanism of regional function from gated SPECT MPI and showed a significantly higher prevalence rate than systolic dyssynchrony in patients with ESRD and normal LVEF.

背景与目标：

BACKGROUND & AIMS: :In the couse of evolution, calcium has emerged as the most versatile intracellular messenger. Its concentration within cells is controlled by reversible binding to specific protein acting as sensors to decode its information. The decoding operation is based on specific conformational changes in these sensor proteins. Other proteins intrinsic to membranes (plasma membrane, endosarcoplasmic reticulum, mitochondria, nuclear envelope) simply control calcium concentration by transporting it across membrane boundaries. Calcium is an ambivalent signaling agent. It carries information to all processes important to cell life, including excitation-contraction coupling, secretion, gene transcription and enzyme activity through protein phosphorylation-dephosphorylation. However, it also transmits signals that promote programmed demise of cells and, when escaping control, it may also precipitate toxic cell death.

背景与目标： : 在进化过程中，钙已成为最通用的细胞内信使。其在细胞内的浓度通过与作为传感器解码其信息的特定蛋白质的可逆结合来控制。解码操作基于这些传感器蛋白的特定构象变化。膜固有的其他蛋白质 (质膜，内质网，线粒体，核膜) 通过跨膜边界运输钙来控制钙浓度。钙是一种矛盾的信号传导剂。它为所有对细胞生命重要的过程提供信息，包括通过蛋白质磷酸化-去磷酸化的激发-收缩偶联，分泌，基因转录和酶活性。但是，它还传输促进细胞程序性死亡的信号，并且在逃避控制时，它还可能沉淀有毒细胞死亡。

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BACKGROUND & AIMS: BACKGROUND:Non-traditional EKG parameters such as QRS pattern and QRS duration (QRSd) are being investigated in acute coronary syndrome as prognostic markers. Following an infarction, the heart attempts to compensate for myocardial loss through remodeling which eventually lowers the ejection fraction (LVEF). Our objective is to evaluate the relationship between the QRSd at the time of NSTEMI and extent of coronary artery disease (CAD) and changes in LVEF. METHODS AND RESULTS:Patients admitted with NSTEMI between 08/01/2006 and 9/30/2012 were included. Patients were classified into high or low QRSd at cutoff value of 90ms noted on initial EKG after excluding bundle-branch block. A total of 536 patients with mean age of 66±14years were included. 49% were male and majority were African American (73%). Patients within the higher QRSd group had a lower LVEF at the time of the NSTEMI compared to those with QRSd <90ms (47±15% vs. 50±13%; p<0.038). The LVEF remained lower in the high QRS group on follow up to 12months (47±15% vs. 52±11%; p<0.001). The high QRSd group had a higher incidence of severe LV dysfunction at baseline (27% vs. 18%; p<0.045). Logistic regression analysis revealed that a QRSd ≥90ms was also independently associated with a severely reduced LVEF on follow-up (OR=2.7; CI 1.55-4.69; p<0.001). CONCLUSION:QRSd ≥90ms at the time of NSTEMI is predictive of three-vessel/left main coronary artery involvement and a lower LVEF. This depression in LVEF is maintained for up to 12months. Thus, the QRSd at time of NSTEMI has additional prognostic significance.

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BACKGROUND & AIMS: UNLABELLED:This study investigates the feasibility of routine clinical 201Tl gated perfusion SPECT (gated Tl), and compares quantitative left ventricular ejection fraction (LVEF) and visually-assessed regional wall motion and thickening to analogous values obtained from 99mTc-sestamibi gated perfusion SPECT (gated MIBI). METHODS:We studied 121 patients with a rest gated Tl (3-3.5 mCi, 35 sec/ projection/poststress gated MIBI (25-30 mCi, 25 sec/projection) separate dual-isotope protocol on a 90 degrees dual-detector camera. Automatic quantitation of LVEFs was accomplished using previously developed and validated software, while visual scoring of motion and thickening was performed using four-point scales. RESULTS:Average myocardial counts were lower in gated Tl images (306 +/- 81 counts/pixel) compared to gated MIBI images (789 +/- 237 counts/pixel). The quality of gated Tl images was ranked as excellent, good, fair and poor in 24.0%, 42.1%, 24.8% and 9.1%, respectively, of the patients, compared to 43.0%, 43.8%, 9.1% and 4.1%, respectively, for gated MIBI images. Quantitative-gated Tl and gated MIBI LVEFs correlated well (y = 0.11 + 1.05x, r = 0.918, SEE = 6.35). Possible poststress myocardial stunning may have caused gated Tl LVEFs to overestimate gated MIBI LVEFs by a larger (p = 0.03) amount in ischemic patients (n = 47, y = -0.69 + 1.09x, r = 0.914, s.e.e. = 6.44) compared to nonischemic patients (n = 64, y = -1.58 + 1.05x, r = 0.919, s.e.e. = 5.93), the residual difference in LVEFs for this latter group being likely due to different isotope resolution in conjunction with small left ventricles. Exact agreement between gated Tl and gated MIBI segmental myocardial function in 41 nonischemic patients was 92.2% (kappa = 0.619) and 95.4% (kappa = 0.586) for motion and thickening scores, respectively. CONCLUSION:Thallium-201 gated SPECT imaging can be effectively performed on the majority of patients in our clinical environment and offers the opportunity to assess both myocardial perfusion and function using one injection and one imaging sequence, similarly to what is done with 99mTc-based agents.

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BACKGROUND & AIMS: OBJECTIVES:This study aimed to assess the incremental prognostic value of global circumferential strain (GCS), as measured using cardiac magnetic resonance (CMR) tagging, in addition to baseline clinical characteristics, left ventricular ejection fraction (LVEF), and late gadolinium enhancement (LGE), in the prediction of major adverse cardiovascular events (MACE) in an unselected cohort of patients. BACKGROUND:LVEF is a powerful predictor of mortality and is used for guiding treatment decisions. It is, however, subject to limitations. The value of GCS measured by CMR tagging in patients with suspected cardiac disease has not been fully explored despite its being considered as the gold standard noninvasive method of assessment of LV deformation. METHODS:We prospectively evaluated data from 539 consecutive patients referred for CMR who underwent a CMR protocol that included cine imaging, tagging, and LGE. The primary endpoint was the prevalence of MACE, defined as a composite of all-cause mortality, heart failure-related hospitalization, and aborted sudden cardiac death. RESULTS:MACE occurred in 62 of 539 patients (11.5%) over a mean follow-up period of 2.2 years. History of ischemic heart disease (IHD) and beta-blocker use were both significant clinical predictors of adverse outcomes. All 3 CMR parameters were significant multivariate predictors of the primary outcome when added to significant clinical predictors (LVEF, hazard ratio [HR]: 0.96 [95% confidence interval [CI]: 0.94 to 0.99; p = 0.005]; presence of LGE, HR: 2.07 [95% CI: 1.03 to 4.14; p = 0.04]; GCS, HR: 1.11 [95% CI: 1.02 to 1.21; p = 0.041]). Global chi-square increased significantly with the addition of both LGE and GCS. Both the presence of LGE and reduced GCS had independent prognostic value in the overall cohort. Patients with LVEF ≥35% but LGE present and reduced GCS had a poor outcome similar to that in those with LVEF <35%. CONCLUSIONS:We found, in a large-scale cohort of patients, that GCS, in addition to clinical variables, LVEF, and LGE, had incremental independent prognostic value. This measure could provide further risk stratification, especially in patients with mild LV impairment.

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BACKGROUND & AIMS: :Heart failure with preserved ejection fraction (HFpEF) is a complex clinical entity that is poorly understood yet present in up to 5.5% of the general population. Proven therapies for this disorder are lacking, even though it has a similar prognosis to that of heart failure with reduced ejection fraction (HFrEF). Innovative imaging techniques have provided in-depth understanding of the unique pattern of left ventricular mechanics in patients with HFpEF who progress through preclinical (Stages A to B) and clinical (Stages C to D) American College of Cardiology/American Heart Association heart failure stages. This review highlights the mechanical basis of this disorder from the cellular and myofiber level to chamber dysfunction. As each chamber of the heart is examined, specific biomarkers and echocardiographic parameters with diagnostic and prognostic values are discussed. Finally, novel phenotyping methods including machine learning are reviewed that integrate these mechanics into clinical groups to advise and treat patients.

背景与目标： : 射血分数保留的心力衰竭 (HFpEF) 是一种复杂的临床实体，目前尚不清楚，但存在于多达5.5% 的普通人群中。尽管这种疾病的预后与射血分数降低的心力衰竭 (HFrEF) 相似，但缺乏针对这种疾病的可靠疗法。创新的成像技术为通过临床前 (A至B阶段) 和临床 (C至D阶段) 进展的HFpEF患者提供了对左心室力学独特模式的深入了解美国心脏病学会/美国心脏协会心力衰竭阶段。这篇评论强调了从细胞和肌纤维水平到腔室功能障碍的这种疾病的机械基础。在检查心脏的每个腔室时，将讨论具有诊断和预后价值的特定生物标志物和超声心动图参数。最后，回顾了包括机器学习在内的新型表型方法，这些方法将这些机制整合到临床组中，以建议和治疗患者。

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BACKGROUND & AIMS: :Poor left-ventricular function, hypertension, and left-ventricular hypertrophy in patients with coronary artery disease (CAD) undergoing coronary artery bypass grafting (CABG) are associated with increased operative risks. Between June 1994 and March 1996, 33 patients undergoing CABG, were randomized into 2 groups. One group (IABP group, n = 19) received IABP treatment on average for 2 hours prior to CPB, the other group (control group, n = 14) had no preoperative IABP, Cardiac performance was measured pre- and postoperatively by Swan-Ganz catheter. Mean age was 65 years and 90% were men. All patients had a preoperative LVEF < or = 40% (mean 32.6 +/- 11.1%), 3-vessel disease, established hypertension (WHO criteria), and LV hypertrophy (ventricular mass > or = 136 g/m2 [men] or > or = 110 g/m2 [women]). Ischemia time was similar in both groups while CPB-time was shorter in the IABP group, p < 0.05. There were no hospital deaths in the IABP group, but 3 in the control group suffered postoperative low cardiac output. Nine patients (64%) in the control group required IABP support postoperatively, but only 20% of the patients in the IABP group had a shorter ICU stay, 2.4 +/- 0.9 vs. 3.4 +/- 1.1 days, p < 0.01. Cardiac index increased significantly in the IABP group prior to CPB and was higher compared to control, p < 0.001. Five min after CBP cardiac index was higher in the IABP group than in the control group, p = 0.013, and continued to increase thereafter, while no further improvement was observed in controls. Preoperative IABP treatment in hypertensive patients with CAD, low LVEF and LV hypertrophy who are undergoing CABG is beneficial. An improved cardiac performance pre- and postoperatively was associated with a lower rate of hospital mortality and less postoperative morbidity, as well as shorter ICU stay. The treatment is cost-beneficial.

背景与目标： : 接受冠状动脉旁路移植术 (CABG) 的冠状动脉疾病 (CAD) 患者的左心室功能差，高血压和左心室肥厚与手术风险增加有关。在1994年6月和1996年3月之间，33例接受CABG的患者被随机分为两组。一组 (IABP组，n = 19) 在CPB前平均接受IABP治疗2小时，另一组 (对照组，n = 14) 术前无IABP，术前和术后用Swan-Ganz导管测量心脏性能。平均年龄65岁，90% 是男性。所有患者术前LVEF <或 = 40% (平均32.6 +/- 11.1%)，三支血管病变，既定的高血压 (WHO标准) 和左室肥大 (心室质量> 或 = 136g/m2 [男性] 或> 或 = 110g/m2 [女性])。两组的缺血时间相似，而IABP组的CPB时间较短，p <0.05。IABP组没有住院死亡，但对照组有3例术后低心输出量。对照组中有9例患者 (64%) 术后需要IABP支持，但IABP组中只有20% 患者的ICU住院时间较短，2.4 +/- 0.9 vs. 3.4 +/- 1.1天，p <0.01。在CPB之前，IABP组的心脏指数显着增加，并且与对照组相比更高，p <0.001。IABP组CBP心脏指数高于对照组后5分钟，p = 0.013，此后继续增加，而对照组未观察到进一步改善。术前IABP治疗对正在接受CABG的CAD，低LVEF和LV肥大的高血压患者有益。术前和术后心脏性能的改善与较低的医院死亡率和较低的术后发病率以及较短的ICU住院时间相关。这种治疗是有成本效益的。

BACKGROUND & AIMS: UNLABELLED:Electrocardiographic gating is increasingly used for (82)Rb cardiac PET/CT, but reference ranges for global functional parameters are not well defined. We sought to establish reference values for left ventricular ejection fraction (LVEF), end systolic volume (ESV), and end diastolic volume (EDV) using 4 different commercial software packages. Additionally, we compared 2 different approaches for the definition of a healthy individual. METHODS:Sixty-two subjects (mean age +/- SD, 49 +/- 9 y; 85% women; mean body mass index +/- SD, 34 +/- 10 kg/m(2)) who underwent (82)Rb-gated myocardial perfusion PET/CT were evaluated. All subjects had normal myocardial perfusion and no history of coronary artery disease (CAD) or cardiomyopathy. Subgroup 1 consisted of 34 individuals with low pretest probability of CAD (<10%), and subgroup 2 comprised 28 subjects who had no atherosclerosis on a coronary CT angiogram obtained concurrently during the PET/CT session. LVEF, ESV, and EDV were calculated at rest and during dipyridamole-induced stress, using CardIQ Physio (a dedicated PET software) and the 3 major SPECT software packages (Emory Cardiac Toolbox, Quantitative Gated SPECT, and 4DM-SPECT). RESULTS:Mean LVEF was significantly different among all 4 software packages. LVEF was most comparable between CardIQ Physio (62% +/- 6% and 54% +/- 7% at stress and rest, respectively) and 4DM-SPECT (64% +/- 7% and 56% +/- 8%, respectively), whereas Emory Cardiac Toolbox yielded higher values (71% +/- 6% and 65% +/- 6%, respectively, P < 0.001) and Quantitated Gated SPECT lower values (56% +/- 8% and 50% +/- 8%, respectively, P < 0.001). Subgroup 1 (low likelihood) demonstrated higher LVEF values than did subgroup 2 (normal CT angiography findings), using all software packages (P < 0.05). However, mean ESV and EDV at stress and rest were comparable between both subgroups (p = NS). Intra- and interobserver agreement were excellent for all methods. CONCLUSION:The reference range of LVEF and LV volumes from gated (82)Rb PET/CT varies significantly among available software programs and therefore cannot be used interchangeably. LVEF results were higher when healthy subjects were defined by a low pretest probability of CAD than by normal CT angiography results.

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BACKGROUND & AIMS: OBJECTIVES:This study sought to assess the time course of presumptive tachycardia-induced cardiomyopathy and the predictors of left ventricular (LV) functional recovery in such patients. BACKGROUND:Tachycardia-induced cardiomyopathy is a potentially reversible cardiomyopathy with effective treatment of the tachyarrhythmia. However, cases without improvement of LV systolic function were found occasionally. The diagnosis of tachycardia-induced cardiomyopathy can be challenging, and the role of echocardiographic imaging in the prediction of LV functional recovery is limited. METHODS:LV segmental longitudinal strains (LS) were evaluated by 2-dimensional speckle tracking in 71 consecutive patients (65 ± 16 years; 61% men) with tachyarrhythmia and reduced left ventricular ejection fraction (LVEF) without any other known cardiovascular disease, and 30 age and sex-matched control subjects. Relative apical LS ratio (RALSR) was defined using the equation: average apical LS / (average basal LS + average mid LS) as a marker of strain distribution. RESULTS:Compared with control subjects, patients with tachyarrhythmia had significantly lower global LS. Improvement in LVEF within 6 months after treatment of index arrhythmia was observed in 41 patients, and LVEF did not improve in 30 patients. In univariate analysis, lower LVEF at baseline (hazard ratio: 0.59 per 1 SD; p = 0.04) and higher RALSR (hazard ratio: 11.2 per 1 SD; p < 0.001) were associated with no recovery in LVEF during follow-up. In a multivariate logistic regression model, the significant predictor of LV systolic functional recovery was RALSR (hazard ratio: 22.9 per 1 SD; p = 0.001). A RALSR of 0.61 was sensitive (71%) and specific (90%) in differentiating LV systolic functional recovery (area under the curve: 0.88). CONCLUSIONS:The RALSR was associated with LV systolic functional recovery. This information might be useful for clinical evaluation and follow-up in patients with reduced LVEF.

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BACKGROUND & AIMS: OBJECTIVES:This study was designed to evaluate the evidence base for the 2014 American Heart Association/American College of Cardiology (AHA/ACC) guidelines for severe aortic stenosis (SAS) and preserved left ventricular ejection fraction by comparing the natural history of the disease in subgroups of low-gradient (LG) aortic stenosis patients with high-gradient (HG) patients. BACKGROUND:The 2014 AHA/ACC valvular disease guidelines recommend estimation of stroke volume index by echocardiography in patients with suspected LG SAS and preserved left ventricular ejection fraction. METHODS:PubMed, Embase, and Scopus databases were searched for all studies that have compared the natural history of SAS with preserved ejection fraction in flow-gradient patterns. We studied the following 3 subgroups: HG, low-flow low-gradient (LFLG), and normal-flow low-gradient (NFLG). The random effects model was used to pool individual study results. The end-point was long-term all-cause mortality. RESULTS:A total of 9 studies with 3,065 patients fulfilled the criteria. Compared to HG SAS, both LFLG and NFLG patients had a higher burden of comorbidities such as coronary artery disease and hypertension. Atrial fibrillation was more prevalent in LFLG patients. Moreover, end-diastolic volume index was smaller for LFLG patients and indexed aortic valve area was larger for NFLG patients. All-cause mortality was similar between HG and LFLG subgroups (relative risk: 1.07; 95% confidence interval: 0.83 to 1.38; p = 0.60), whereas patients with NFLG had a significantly lower all-cause mortality compared to the HG subgroup (relative risk: 0.64; 95% confidence interval: 0.47 to 0.86; p = 0.004). CONCLUSIONS:Patients with LFLG SAS have similar outcomes compared to HG SAS but worse compared to NFLG SAS. These findings support estimating stroke volume index in patients with suspected LG SAS. All analyses revealed high heterogeneity and further high-quality studies are necessary.

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