Incremental proximal methods for large scale convex optimization

Laboratory for Information and Decision Systems Report LIDS-P-2847We consider the minimization of a sum∑m [over]i=1 fi (x) consisting of a large number of convex component functions fi . For this problem, incremental methods consisting of gradient or subgradient iterations applied to single components have proved very effective. We propose new incremental methods, consisting of proximal iterations applied to single components, as well as combinations of gradient, subgradient, and proximal iterations. We provide a convergence and rate of convergence analysis of a variety of such methods, including some that involve randomization in the selection of components.We also discuss applications in a few contexts, including signal processing and inference/machine learning.United States. Air Force Office of Scientific Research (grant FA9550-10-1-0412

1-year impact on medical practice and clinical outcomes of FFRCT the ADVANCE registry

OBJECTIVES The 1-year data from the international ADVANCE (Assessing Diagnostic Value of Non-invasive FFRCT in Coronary Care) Registry of patients undergoing coronary computed tomography angiography (CTA) was used to evaluate the relationship of fractional flow reserve derived from coronary CTA (FFRCT) with downstream care and clinical outcomes.BACKGROUND Guidelines for management of chest pain using noninvasive imaging pathways are based on short- to intermediate-term outcomes.METHODS Patients (N = 5,083) evaluated for clinically suspected coronary artery disease and in whom atherosclerosis was identified by coronary CTA were prospectively enrolled at 38 international sites from July 15, 2015, to October 20, 2017. Demographics, symptom status, coronary CTA and FFRCT findings and resultant site-based treatment plans, and clinical outcomes through 1 year were recorded and adjudicated by a blinded core laboratory. Major adverse cardiac events (MACE), death, myocardial infarction (MI), and acute coronary syndrome leading to urgent revascularization were captured.RESULTS At 1 year, 449 patients did not have follow-up data. Revascularization occurred in 1,208 (38.40%) patients with an FFRCT 0.80 (relative risk [RR]: 6.87; 95% confidence interval [CI]: 5.59 to 8.45; p 0.80 (RR: 1.81; 95% CI: 0.96 to 3.43; p = 0.06). Time to first event (all-cause death or MI) occurred in 38 (1.20%) patients with an FFRCT 0.80 (RR: 1.92; 95% CI: 0.96 to 3.85; p = 0.06). Time to first event (cardiovascular death or MI) occurred cardiovascular death or MI occurred more in patients with an FFRCT 0.80 (25 [0.80%] vs. 3 [0.20%]; RR: 4.22; 95% CI: 1.28 to 13.95; p = 0.01).CONCLUSIONS The 1-year outcomes from the ADVANCE FFRCT Registry show low rates of events in all patients, with less revascularization and a trend toward lower MACE and significantly lower cardiovascular death or MI in patients with a negative FFRCT compared with patients with abnormal FFRCT values. (Assessing Diagnostic Value of Non-invasive FFRCT in Coronary Wave [ADVANCE]; NCT02499679) (C) 2020 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation.Cardiolog

Interactions Among Vitamin D, Atrial Fibrillation, and the Renin-Angiotensin-Aldosterone System

Cardiolog

Diagnostic performance of non-invasive imaging for stable coronary artery disease : ameta-analysis

Background: To determine diagnostic performance of non-invasive tests using invasive fractional flow reserve (FFR) as reference standard for coronary artery disease (CAD). Methods: Medline, Embase, and citations of articles, guidelines, and reviews for studies were used to compare non-invasive tests with invasive FFR for suspected CAD published through March 2017. Results: Seventy-seven studies met inclusion criteria. The diagnostic test with the highest sensitivity to detect a functionally significant coronary lesion was coronary computed tomography (CT) angiography [88%(85%\u201390%)], followed by FFR derived from coronary CT angiography (FFRCT) [85%(81%\u201388%)], positron emission tomography (PET) [85%(82%\u201388%)], stress cardiac magnetic resonance (stress CMR) [81%(79%\u201384%)], stress myocardial CT perfusion combined with coronary CT angiography [79%(74%\u201383%)], stress myocardial CT perfusion [77%(73%\u201380%)], stress echocardiography (Echo) [72%(64%\u201378%)] and stress single-photon emission computed tomography (SPECT) [64%(60%\u201368%)]. Specificity to rule out CAD was highest for stress myocardial CT perfusion added to coronary CT angiography [91%(88%\u201393%)], stress CMR [91%(90%\u201393%)], and PET [87%(86%\u201389%)]. Conclusion: A negative coronary CT angiography has a higher test performance than other index tests to exclude clinically-important CAD. A positive stress myocardial CT perfusion added to coronary CT angiography, stress cardiac MR, and PET have a higher test performance to identify patients requiring invasive coronary artery evaluation

The New Frontier of Cardiac Computed Tomography Angiography : Fractional Flow Reserve and Stress Myocardial Perfusion

The increased number of patients with coronary artery disease (CAD) in developed countries is of great clinical relevance and involves a large burden of the healthcare system. The management of these patients is focused on relieving symptoms and improving clinical outcomes. Therefore the ideal test would provide the correct diagnosis and actionable information. To this aim, several non-invasive functional imaging modalities are usually used as gatekeeper to invasive coronary angiography (ICA), but their diagnostic yield remains low with limited accuracy when compared to obstructive CAD at the time of ICA or invasive fractional flow reserve (FFR). Invasive FFR is considered the gold standard for the evaluation of functionally relevant CAD. Therefore, an urgent need for non-invasive techniques that evaluate both the functional and morphological severity of CAD is growing. Coronary computed tomography angiography (CCTA) has emerged as a unique non-invasive technique providing coronary artery anatomic imaging. More recently, the evaluation of FFR with CCTA (FFRCT) has demonstrated high diagnostic performance compared to invasive FFR. Additionally, stress myocardial computed tomography perfusion (CTP) represents a novel tool for the diagnosis of ischemia with high diagnostic accuracy. Compared to nuclear imaging and cardiac magnetic resonance imaging, both FFRCT and stress-CTP, allow us to integrate the anatomical evaluation of coronary arteries with the functional relevance of coronary artery lesions having the potential to revolutionize the diagnostic paradigm of suspected CAD. FFRCT and stress-CTP could be assimilated in diagnostic pathways of patients with stable CAD and will likely result in a decrease of invasive diagnostic procedures and costs. The current review evaluates the technical aspects and clinical experience of FFRCT and stress-CTP in the evaluation of functionally relevant CAD discussing the strengths and weaknesses of each approach

Interpreting results of coronary computed tomography angiography-derived fractional flow reserve in clinical practice

Cardiolog

Diagnostic Accuracy of Single-shot 2-Dimensional Multisegment Late Gadolinium Enhancement in Ischemic and Nonischemic Cardiomyopathy

Purpose:The aim of this study was to assess the reliability of single-shot 2-dimensional multislice late gadolinium enhancement (2D-MSLGE) compared with gold standard single-slice 2D inversion recovery segmented gradient echo (2D-SSLGE).Materials and Methods:Sixty-seven patients prospectively underwent clinically indicated cardiac magnetic resonance (CMR) imaging and were enrolled. The image quality was assessed using a 4-point scale. Segments positive for LGE were classified as ischemic or nonischemic for 2D-MSLGE and 2D-SSLGE. Interobserver and intraobserver variability was assessed for both sequences by 2 readers. The endpoints were as follows: (a) detection of myocardial segments involved by LGE and (b) classification of LGE as ischemic and nonischemic pattern. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy value were calculated for the 2 endpoints.Results:2D-MSLGE and 2D-SSLGE were successfully performed in all patients with comparable image quality (1.56\ub10.59 vs. 1.54\ub10.58, P=0.84). For the overall population, 2D-MSLGE correctly identified 1093 of 1139 myocardial segments positive for LGE (96%; 95% confidence interval [CI]: 95%-97%), as compared with 2D-SSLGE. Similarly, 2D-MSLGE correctly identified 1128 of 1139 (99%; 95% CI: 98%-99%) and 1108 of 1139 (97%; 95% CI: 96%-98%) of nonischemic and ischemic LGE patterns.Interobserver and intraobserver variability for quantification of LGE using 2D-MSLGE was 0.98 and 0.99, respectively. The acquisition time was shorter for 2D-MSLGE as compared with 2D-SSLGE (2.0\ub10.5 vs. 6.0\ub12.0 min, P: 0.01).Conclusions:As compared with 2D-SSLGE, 2D-MSLGE is a reliable tool in both ischemic and nonischemic cardiac disease; it is associated with shorter scan times without the need for prolonged breath holding and may be beneficial for those with dysrhythmia

Reliability of single breath hold three-dimensional cine kat-ARC for the assessment of biventricular dimensions and function

Purpose: To assess the accuracy and reproducibility of 3D-cine k-adaptative-t-autocalibrating reconstruction for cartesian sampling (3D cine kat-ARC) for quantification of biventricular volumes, ejection fraction and LV mass in clinical practice. Method: 74 patients underwent cardiac magnetic resonance for clinical indications. In the whole population 3D cine kat-ARC and 2D cine bSSFP images were acquired on short axis view. Subsequently, the population was divided in three subgroups (dilated, hypetrophic, other phenotypes). Two experienced observers performed analysis of volumes, biventricular function and left ventricular mass in the overall population and subgroups using an off-line workstation. Statistical analysis was performed using Student's t-test, linear regression and Bland-Altman plot, correlation coefficient \u3b72 and the intraclass correlation coefficient (ICC). A cut-off value of p < 0.05 was considered statistically significant. Results: Biventricular volumes, function and left ventricular mass evaluated with 3D cine kat-ARC sequences did not show any significant difference compared to 2D bSSFP sequences in the overall population (p > 0.05). Bland-Altman analysis showed limited bias and narrow limits of the agreement for all measurements in overall population. Subgroup analysis showed a statistically significant difference (p = 0.04) for left ventricular ejection fraction (LVEF) in patients with a dilated phenotype; showing a minimum overestimation tendency for 3D cine kat ARC (2D cine bSSFP LVEF = 46.44 \ub1 15.83% vs 3D cine kat-ARC LVEF = 48.36 \ub1 16.50 %). Conclusions: 3D cine kat-ARC 3D sequences allow an accurate evaluation of biventricular volumes and function in a single breath hold

Association Between Haptoglobin Phenotype and Microvascular Obstruction in Patients With ST-Segment Elevation Myocardial Infarction : A Cardiac Magnetic Resonance Study

Objectives: This study aimed to evaluate the correlation between different haptoglobin (Hp) phenotypes and myocardial infarction characteristics as detected by cardiac magnetic resonance (CMR) in consecutive patients after ST-segment elevation myocardial infarction (STEMI). Background: Hp is a plasma protein that prevents iron-mediated oxidative tissue damage. CMR has emerged as the gold standard technique to detect left ventricular ejection fraction (LVEF), extent of scar with late gadolinium enhancement (LGE) technique, microvascular obstruction (MVO), and myocardial hemorrhage (MH) in patients with STEMI treated by primary percutaneous coronary intervention (pPCI). Methods: One hundred forty-five consecutive STEMI patients (mean age 62.2 \ub1 10.3 years; 78% men) were prospectively enrolled and underwent Hp phenotyping and CMR assessment within 1 week after STEMI. Results: CMR showed an area at risk (AAR) involving 26.6 \ub1 19.1% of left ventricular (LV) mass with a late LGE extent of 15.2 \ub1 13.1% of LV mass. MVO and MH occurred in 38 (26%) and 12 (8%) patients, respectively. Hp phenotypes 1-1, 2-1, 2-2 were observed in 15 (10%), 62 (43%), and 68 (47%), respectively. Multivariable analysis demonstrated that body mass index, Hp2-2, diabetes, and peak troponin I were independent predictors of MVO with Hp2-2 associated with the highest odds ratio (OR) (OR: 5.5 [95% confidence interval [CI]: 2.1 to 14.3; p < 0.001]). Hp2-2 significantly predicted both the presence (area under the curve [AUC]: 0.63 [95% CI: 0.53 to 0.72; p = 0.008]) and extent of MVO (AUC: 0.63 [95% CI: 0.54 to 0.72; p = 0.007]). Conclusions: Hp phenotype is an independent predictor of MVO. Therefore, Hp phenotyping could be used for risk stratification and may be useful in assessing new therapies to reduce myocardial reperfusion injury in patients with STEMI

Incremental Diagnostic Value of Stress Computed Tomography Myocardial Perfusion With Whole-Heart Coverage CT Scanner in Intermediate- to High-Risk Symptomatic Patients Suspected of Coronary Artery Disease

Objectives: The goal of this study was to evaluate the diagnostic accuracy of stress computed tomography myocardial perfusion (CTP) for the detection of functionally significant coronary artery disease (CAD) by using invasive coronary angiography (ICA) plus invasive fractional flow reserve (FFR) as the reference standard in consecutive intermediate- to high-risk symptomatic patients. Background: Stress CTP recently emerged as a potential strategy to combine the anatomic and functional evaluation of CAD in a single scan. Methods: A total of 100 consecutive symptomatic patients scheduled for ICA were prospectively enrolled. All patients underwent rest coronary computed tomography angiography (CTA) followed by stress static CTP with a whole-heart coverage CT scanner (Revolution CT, GE Healthcare, Milwaukee, Wisconsin). Diagnostic accuracy and overall effective dose were assessed and compared versus those of ICA and invasive FFR. Results: The prevalence of obstructive CAD and functionally significant CAD were 69% and 44%, respectively. Coronary CTA alone demonstrated a per-vessel and per-patient sensitivity, specificity, negative predictive value, positive predictive value, and accuracy of 98%, 76%, 99%, 63%, and 83% and of 98%, 54%, 96%, 68%, and 76%, respectively. Combining coronary CTA with stress CTP, per-vessel and per-patient sensitivity, specificity, negative predictive value, positive predictive value, and accuracy were 91%, 94%, 96%, 86%, and 93% and 98%, 83%, 98%, 86%, and 91%, with a significant improvement in specificity, positive predictive value, and accuracy in both models. The mean effective dose for coronary CTA and stress CTP were 2.8 \ub1 1.4 mSv and 2.5 \ub1 1.1 mSv. Conclusions: The inclusion of stress CTP for the evaluation of patients with an intermediate to high risk for CAD is feasible and improved the diagnostic performance of coronary CTA for detecting functionally significant CAD