Normal age- and sex-based values of right ventricular free wall and four-chamber longitudinal strain by speckle-tracking echocardiography: from the Copenhagen City heart study.

AIM: To promote the implementation of right ventricular (RV) longitudinal strain in clinical practice, we sought to propose normal values for RV free wall (RVFWLS) and four-chamber longitudinal strain (RV4CLS) and investigate the association with clinical and echocardiographic parameters in participants from the general population. METHODS AND RESULTS: Participants from the 5th Copenhagen City Heart Study (2011-2015)-a prospective cohort study-with available RV longitudinal strain measurements were included. RVFWLS and RV4CLS were assessed using two-dimensional speckle-tracking echocardiography. In total, 2951 participants were included. Amongst 1297 participants without cardiovascular disease or risk factors (median age 44, 63% female), mean values of RVFWLS and RV4CLS were - 26.7% ± 5.2 (95% prediction interval (PI) - 36.9, - 16.5) and - 21.7% ± 3.4 (95%PI - 28.4, - 15.0), respectively. Women had significantly higher absolute values of RVFWLS and RV4CLS than men (mean - 27.5 ± 5.5 vs. - 25.4 ± 4.5, p < 0.001 and - 22.3 ± 3.5 vs. - 20.6 ± 3.0, p < 0.001, respectively). Absolute values of RVFWLS but not RV4CLS decreased significantly with increasing age in unadjusted linear regression. Tricuspid annular plane systolic excursion, RV s' and left ventricular global longitudinal strain were the most influential parameters associated with both RVFWLS and RV4CLS in multiple linear regression. Participants with cardiovascular disease (n = 1531) had a higher proportion of abnormal values of RVFWLS and RV4CLS compared to the healthy population (8% vs. 4%, p < 0.001 and 8% vs. 3%, p < 0.001, respectively). CONCLUSION: This study proposed normal age- and sex-based values of RVFWLS and RV4CLS in a healthy population sample and showed significant sex differences in both measurements across ages.

Right ventricular free wall and four-chamber longitudinal strain in relation to incident heart failure in the general population.

AIMS: Right ventricular free wall (RVFWLS) and four-chamber longitudinal strain (RV4CLS) are associated with adverse events in various patient populations including patients with heart failure (HF). We sought to investigate the prognostic value of RVFWLS and RV4CLS for the development of incident HF in participants from the general population. METHODS AND RESULTS: Participants from the 5th Copenhagen City Heart Study (2011-2015) without known chronic ischaemic heart disease or HF at baseline were included. RVFWLS and RV4CLS were obtained using two-dimensional speckle-tracking echocardiography from the right ventricular (RV)-focused apical four-chamber view. The primary endpoint was incident HF. Among 2740 participants (mean age 54 ± 17 years, 42% male), 43 (1.6%) developed HF during a median follow-up of 5.5 years (IQR 4.5-6.3). Both RVFWLS and RV4CLS were associated with an increased risk of incident HF during follow-up independent of age, sex, hypertension, diabetes, body mass index and tricuspid annular plane systolic excursion (TAPSE), (HR 1.06, 95%CI 1.00-1.11, P = 0.034, per 1% absolute decrease and HR 1.14, 95%CI 1.05-1.23, P = 0.001, per 1% absolute decrease, respectively). Left ventricular ejection fraction (LVEF) modified the association between RV4CLS and incident HF (P for interaction = 0.016) such that RV4CLS was only of prognostic importance among those with LVEF < 55% (HR 1.21, 95%CI 1.11-1.33, P < 0.001 vs. HR 0.94, 95%CI 0.80-1.10, P = 0.43 in patients with LVEF ≥ 55%). CONCLUSION: In participants from the general population, both RVFWLS and RV4CLS were associated with a greater risk of incident HF independent of important baseline characteristics and TAPSE, and LVEF modified the relationship between RV4CLS and incident HF.

Left atrial contractile strain predicts recurrence of atrial tachyarrhythmia after catheter ablation.

BACKGROUND: Despite improvement in treatment strategies of atrial fibrillation (AF), a considerable number of patients still experience recurrence of atrial tachyarrhythmia (ATA) following catheter ablation (CA). This study aimed to investigate the prognostic value of left atrial (LA) deformation analysis in a large group of patients undergoing CA for AF. METHODS: This study included 678 patients with AF. Echocardiography including two-dimensional speckle tracking echocardiography (2DSTE) was performed in all patients prior to CA. Logistic regression analysis was used to assess the association between ATA recurrence and LA strain during reservoir phase (LASr), LA strain during contraction phase (LASct), and LA strain during conduit phase (LAScd). RESULTS: During one-year follow-up, 274 (40%) experienced ATA recurrence. Median age of the included study population was 63.2 years (IQR: 55.5, 69.5) and 485 (72%) were male. Patients with recurrence had lower LASr (22.6% vs. 25.1%, p = 0.001) and LASct (10.7% vs. 12.4%, p < 0.001). No difference in LAScd was observed. After adjusting for potential clinical and echocardiographic confounders LASr (OR = 1.04, CI95% [1.01; 1.07], p = 0.015, per 1% decrease) and LASct (OR = 1.06, CI95% [1.02; 1.11], p = 0.007, per 1% decrease) remained independent predictors of recurrence. However, in patients with a normal-sized LA (LA volume index<34 mL/m2), only LASct remained an independent predictor of recurrence (OR = 1.07, CI95% [1.01; 1.12], p = 0.012, per 1% decrease). CONCLUSION: In patients undergoing CA for AF, LA deformation analysis by 2DSTE could be of use in risk stratification in clinical practice regarding ATA recurrence, even in patients with a normal-sized LA.

Lung ultrasound findings in hospitalized COVID-19 patients in relation to venous thromboembolic events: the ECHOVID-19 study.

PURPOSE: Several studies have reported thromboembolic events to be common in severe COVID-19 cases. We sought to investigate the relationship between lung ultrasound (LUS) findings in hospitalized COVID-19 patients and the development of venous thromboembolic events (VTE). METHODS: A total of 203 adults were included from a COVID-19 ward in this prospective multi-center study (mean age 68.6 years, 56.7% men). All patients underwent 8-zone LUS, and all ultrasound images were analyzed off-line blinded. Several LUS findings were investigated (total number of B-lines, B-line score, and LUS-scores). RESULTS: Median time from admission to LUS examination was 4 days (IQR: 2, 8). The median number of B-lines was 12 (IQR: 8, 18), and 44 (21.7%) had a positive B-line score. During hospitalization, 17 patients developed VTE (4 deep-vein thrombosis, 15 pulmonary embolism), 12 following and 5 prior to LUS. In fully adjusted multivariable Cox models (excluding participants with VTE prior to LUS), all LUS parameters were significantly associated with VTE (total number of B-lines: HR = 1.14, 95% CI (1.03, 1.26) per 1 B-line increase), positive B-line score: HR = 9.79, 95% CI (1.87, 51.35), and LUS-score: HR = 1.51, 95% CI (1.10, 2.07), per 1-point increase). The B-line score and LUS-score remained significantly associated with VTE in sensitivity analyses. CONCLUSION: In hospitalized COVID-19 patients, pathological LUS findings were common, and the total number of B-lines, B-line score, and LUS-score were all associated with VTE. These findings indicate that the LUS examination may be useful in risk stratification and the clinical management of COVID-19. These findings should be considered hypothesis generating. GOV ID: NCT04377035.

Normal values and reference ranges for left atrial strain by speckle-tracking echocardiography: the Copenhagen City Heart Study.

AIMS: Left atrial (LA) function assessed by two-dimensional speckle-tracking echocardiography has shown increasing clinical and prognostic significance. We sought to establish age- and sex-based normative values of LA strain in the general population and to assess the prognostic yield of lower limits of normality of LA strain in relation to future atrial fibrillation (AF). METHODS AND RESULTS: We determined normative values of peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and LA strain during the conduit phase (LACS) in 1641 healthy participants included in the fifth Copenhagen City Heart Study. In a secondary analysis, a validation cohort of 2016 participants, regardless of health status, were included to assess the prognostic value of the established reference values. In the healthy cohort, median age was 46 years (interquartile range 32-57), 62% were female. Median PALS, PACS, and LACS and corresponding limits of normality in the healthy participants were 39.4% (23.0-67.6%), 15.5% (6.4-28.0%), and 23.7% (8.8-44.8%), respectively. There was a tendency of lower values of PALS and LACS in males and older participants, while PACS tended to increase with advancing age. The established lower limits of normality showed high specificity (range 93-94%) regarding future AF, implying a low risk of developing AF in participants with LA strain above the lower limits of normality in their respective sex and age group. CONCLUSION: We report normal values for LA strain stratified by sex and age. The lower limits of normality showed high specificity regarding future AF.

Left atrial strain predicts incident atrial fibrillation in the general population: the Copenhagen City Heart Study.

BACKGROUND: Left atrial (LA) strain parameters have been demonstrated to be valuable predictors of atrial fibrillation (AF) in several patient cohorts. The purpose of this study was to investigate whether LA strain, assessed by two-dimensional speckle-tracking echocardiography, can be used to predict the development of AF in the general population. METHODS AND RESULTS: This prospective longitudinal study included 4466 participants from the fifth Copenhagen City Heart Study. All participants underwent a health examination, including echocardiographic measurements of LA strain. Participants with prevalent AF at baseline were excluded. The primary endpoint was incident AF. During a median follow-up period of 5.3 years, 154 (4.3%) participants developed AF. In univariable analysis, peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and LA strain during the conduit phase were significantly associated with the development of AF. PALS [hazard ratio (HR) 1.05, 95% confidence interval (CI) (1.03-1.07), P < 0.001, per 1% decrease] and PACS (HR 1.08, 95% CI (1.05-1.12), P < 0.001, per 1% decrease] remained independent predictors of AF in multivariable analysis. In addition, PALS and PACS remained significantly associated with AF development even in participants with normal-sized atria and normal left ventricular (LV) systolic function. CONCLUSION: In the general population, PALS and PACS independently predict incident AF. These findings remained consistent even in participants with normal-sized LA and normal LV systolic function.

Echocardiographic abnormalities and predictors of mortality in hospitalized COVID-19 patients: the ECHOVID-19 study.

AIMS: The present study had two aims: (i) compare echocardiographic parameters in COVID-19 patients with matched controls and (2) assess the prognostic value of measures of left (LV) and right ventricular (RV) function in relation to COVID-19 related death. METHODS AND RESULTS: In this prospective multicentre cohort study, 214 consecutive hospitalized COVID-19 patients underwent an echocardiographic examination (by pre-determined research protocol). All participants were successfully matched 1:1 with controls from the general population on age, sex, and hypertension. Mean age of the study sample was 69 years, and 55% were male participants. LV and RV systolic function was significantly reduced in COVID-19 cases as assessed by global longitudinal strain (GLS) (16.4% ± 4.3 vs. 18.5% ± 3.0, P < 0.001), tricuspid annular plane systolic excursion (TAPSE) (2.0 ± 0.4 vs. 2.6 ± 0.5, P < 0.001), and RV strain (19.8 ± 5.9 vs. 24.2 ± 6.5, P = 0.004). All parameters remained significantly reduced after adjusting for important cardiac risk factors. During follow-up (median: 40 days), 25 COVID-19 cases died. In multivariable Cox regression reduced TAPSE [hazard ratio (HR) = 1.18, 95% confidence interval (CI) [1.07-1.31], P = 0.002, per 1 mm decrease], RV strain (HR = 1.64, 95%CI[1.02;2.66], P = 0.043, per 1% decrease) and GLS (HR = 1.20, 95%CI[1.07-1.35], P = 0.002, per 1% decrease) were significantly associated with COVID-19-related death. TAPSE and GLS remained significantly associated with the outcome after restricting the analysis to patients without prevalent heart disease. CONCLUSIONS: RV and LV function are significantly impaired in hospitalized COVID-19 patients compared with matched controls. Furthermore, reduced TAPSE and GLS are independently associated with COVID-19-related death.

MOSES: A Streaming Algorithm for Linear Dimensionality Reduction.

This paper introduces Memory-limited Online Subspace Estimation Scheme (MOSES) for both estimating the principal components of streaming data and reducing its dimension. More specifically, in various applications such as sensor networks, the data vectors are presented sequentially to a user who has limited storage and processing time available. Applied to such problems, MOSES can provide a running estimate of leading principal components of the data that has arrived so far and also reduce its dimension. MOSES generalises the popular incremental Singular Vale Decomposition (iSVD) to handle thin blocks of data, rather than just vectors. This minor generalisation in part allows us to complement MOSES with a comprehensive statistical analysis, thus providing the first theoretically-sound variant of iSVD, which has been lacking despite the empirical success of this method. This generalisation also enables us to concretely interpret MOSES as an approximate solver for the underlying non-convex optimisation program. We find that MOSES consistently surpasses the state of the art in our numerical experiments with both synthetic and real-world datasets, while being computationally inexpensive.