Physical Activity Volume, Intensity, and Mortality: Harmonized Meta-Analysis of Prospective Cohort Studies.

INTRODUCTION: It is unclear whether moderate-to-vigorous physical activity (MVPA) is associated with a lower mortality risk, over and above its contribution to total physical activity volume. METHODS: 46,682 adults (mean age: 64 years) were included in a meta-analysis of nine prospective cohort studies. Each cohort generated tertiles of accelerometry-measured physical activity volume and volume-adjusted MVPA. Hazard ratios (HR, with 95% confidence intervals) for mortality were estimated separately and in joint models combining volume and MVPA. Data was collected between 2001 and 2019 and analyzed in 2023. RESULTS: During a mean follow-up of 9 years, 4,666 deaths were recorded. Higher physical activity volume, and a greater contribution from volume-adjusted MVPA, were each associated with lower mortality hazard in multivariable-adjusted models. Compared to the least active tertile, higher physical activity volume was associated with a lower mortality (HRs: 0.62; 0.58, 0.67 and 0.50; 0.42, 0.60 for ascending tertiles). Similarly, a greater contribution from MVPA was associated with a lower mortality (HRs: 0.94; 0.85, 1.04 and 0.88; 0.79, 0.98). In joint analysis, a lower mortality from higher volume-adjusted MVPA was only observed for the middle tertile of physical activity volume. CONCLUSIONS: The total volume of physical activity was associated with a lower risk of mortality to a greater extent than the contribution of MVPA to physical activity volume. Integrating any intensity of physical activity into daily life may lower mortality risk in middle-aged and older adults, with a small added benefit if the same amount of activity is performed with a higher intensity.

Independent, Stratified, and Joint Associations of Sedentary Time and Physical Activity With Cardiovascular Disease: A Systematic Review.

BACKGROUND: Recent statistics highlight cardiovascular diseases (CVD) as a major global cause of death. This review examines the methodological approaches and the main results of independent, stratified, and joint association of sedentary time (ST) and physical activity (PA) on CVD outcomes. METHODS: We searched PubMed, Embase, Web of Science, and Scopus for prospective cohorts that examined the independent, stratified, or joint associations of ST and PA with CVD outcomes. Independent associations were defined as analyses mutually adjusted for PA and ST. Stratified associations were considered when there was a reference group in each stratum of PA or ST, and joint associations were defined by a single reference group for all other combined categories of ST and PA levels. RESULTS: Of 45 articles, 69% explored independent association of ST or PA on CVD outcomes, while 31% using a stratified/joint approach. Most studies used self-reports for ST and PA and focused on CVD mortality. Mutually adjusted analyses identified ST positively and PA inversely associated to CVD outcomes. Stratified studies showed higher ST's pronounced impact on CVD for lower PA levels. High PA mitigated but did not eliminate ST's negative impact. Joint analyses revealed highest CVD risk in those with both high ST and low PA, and elevated risk in various intermediate combinations. CONCLUSIONS: Employing independent, stratified, and joint association approaches can yield distinct and complementary public health messages aimed at promoting cardiovascular health. Recommendations should aim to not only to encourage boosting PA levels, but also, concurrently decrease ST.

Device-measured sedentary time and intensity-specific physical activity in relation to all-cause and cardiovascular disease mortality: the UK Biobank cohort study.

BACKGROUND AND AIMS: Understanding the amounts of intensity-specific movement needed to attenuate the association between sedentary time and mortality may help to inform personalized prescription and behavioral counselling. Herein, we examined the joint associations of sedentary time and intensity-specific physical activity with all-cause and cardiovascular disease (CVD) mortality. METHODS: Prospective cohort study including 73,729 adults from the UK Biobank who wore an Axivity AX3 accelerometer on their dominant wrist for at least 3 days, being one a weekend day, between June 2013 and December 2015. We considered the median tertile values of sedentary time and physical activity in each intensity band to determine the amount of physical activity needed to attenuate the association between sedentary time and mortality. RESULTS: During a median of 6.9 years of follow-up (628,807 person-years), we documented 1521 deaths, including 388 from CVD. Physical activity of any intensity attenuated the detrimental association of sedentary time with mortality. Overall, at least a median of 6 min/day of vigorous physical activity, 30 min/day of MVPA, 64 min/day of moderate physical activity, or 163 min/day of light physical activity (mutually-adjusted for other intensities) attenuated the association between sedentary time and mortality. High sedentary time was associated with higher risk of CVD mortality only among participants with low MVPA (HR 1.96; 95% CI 1.23 to 3.14). CONCLUSIONS: Different amounts of each physical activity intensity may attenuate the association between high sedentary time and mortality.

Cohort study of prediction of venous thromboembolism in emergency department patients with extremity symptoms.

Despite diagnostic algorithms, identification of venous thromboembolism (VTE) in emergency departments (ED) remains a challenge. We evaluated symptoms, background, and laboratory data in 27,647 ED patients presenting with pain, swelling, or other symptoms from the extremities, and identified predictors of VTE diagnosis within one year. Predictors of a clinical decision to perform phlebography, ultrasound, or computer tomography (CT) angiography of pelvic, lower, or upper extremity veins, CT of pulmonary arteries, or pulmonary scintigraphy at the ED or within 30 days, and the results of such investigations were also evaluated. A total of 3195 patients (11.6%) were diagnosed with VTE within one year. In adjusted analysis of patients in whom all laboratory data were available, a d-dimer value ≥ 0.5 mg/l (odds ratio [OR]: 2.602; 95% confidence interval [CI] 1.894-3.575; p < 0.001) at the ED and a previous diagnosis of VTE (OR: 6.037; CI 4.465-8.162; p < 0.001) independently predicted VTE within one year. Of diagnosed patients, 2355 (73.7%) had undergone imaging within 30 days after the ED visit and 1730 (54.1%) were diagnosed at this examination. Lower age (OR: 0.984; CI 0.972-0.997; p = 0.014), higher blood hemoglobin (OR: 1.023; CI 1.010-1.037; p < 0.001), C-reactive protein (OR: 2.229; CI 1.433-3.468; p < 0.001), d-dimer (OR: 8.729; CI 5.614-13.574; p < 0.001), and previous VTE (OR: 7.796; CI 5.193-11.705; p < 0.001) predicted VTE on imaging within 30 days, whereas female sex (OR 0.602 [95% CI 0.392-0.924]; p = 0.020) and a previous diagnosis of ischemic heart disease (OR 0.254 [95% CI 0.113-0.571]; p = 0.001) were negative predictors of VTE. In conclusion, analysis of 27,647 ED patients with extremity symptoms confirmed the importance of well-established risk factors for VTE. Many patients developing VTE within one year had initial negative imaging, highlighting the importance of continued symptom vigilance.

The prevalence of clinically relevant delayed intracranial hemorrhage in head trauma patients treated with oral anticoagulants is very low: a retrospective cohort register study.

BACKGROUND: Current guidelines from Scandinavian Neuro Committee mandate a 24-hour observation for head trauma patients on anticoagulants, even with normal initial head CT scans, as a means not to miss delayed intracranial hemorrhages. This study aimed to assess the prevalence, and time to diagnosis, of clinically relevant delayed intracranial hemorrhage in head trauma patients treated with oral anticoagulants. METHOD: Utilizing comprehensive two-year data from Region Skåne's emergency departments, which serve a population of 1.3 million inhabitants, this study focused on adult head trauma patients prescribed oral anticoagulants. We identified those with intracranial hemorrhage within 30 days, defining delayed intracranial hemorrhage as a bleeding not apparent on their initial CT head scan. These cases were further defined as clinically relevant if associated with mortality, any intensive care unit admission, or neurosurgery. RESULTS: Out of the included 2,362 head injury cases (median age 84, 56% on a direct acting oral anticoagulant), five developed delayed intracranial hemorrhages. None of these five cases underwent neurosurgery nor were admitted to an intensive care unit. Only two cases (0.08%, 95% confidence interval [0.01-0.3%]) were classified as clinically relevant, involving subdural hematomas in patients aged 82 and 87 years, who both subsequently died. The diagnosis of these delayed intracranial hemorrhages was made at 4 and 7 days following initial presentation to the emergency department. CONCLUSION: In patients with head trauma, on oral anticoagulation, the incidence of clinically relevant delayed intracranial hemorrhage was found to be less than one in a thousand, with detection occurring four days or later after initial presentation. This challenges the effectiveness of the 24-hour observation period recommended by the Scandinavian Neurotrauma Committee guidelines, suggesting a need to reassess these guidelines to optimise care and resource allocation. TRIAL REGISTRATION: This is a retrospective cohort study, does not include any intervention, and has therefore not been registered.

Association between arterial health and cognition in adolescents: The PANIC study.

We investigated the associations of the measures of arterial health with cognition in adolescents and whether physical activity (PA) or sedentary time (ST) confounds these associations. One hundred sixteen adolescents (71 boys) aged 15.9 ± 0.4 participated in the study. PA and ST were assessed using a combined accelerometer/heart rate monitor. Overall cognition was computed from the results of psychomotor function, attention, working memory, and paired-associate learning tests. Pulse wave velocity was measured by impedance cardiography, carotid intima-media thickness, and carotid artery distensibility by carotid ultrasonography. Systolic and diastolic blood pressure (SBP and DBP) were measured using an aneroid sphygmomanometer. SBP was inversely associated with overall cognition (standardized regression coefficient [ß] = -0.216, 95% confidence interval (CI) -0.406 to -0.027, p = 0.025). Pulse wave velocity (ß = -0.199, 95% CI -0.382 to -0.017, p = 0.033) was inversely associated with working memory task accuracy. SBP was directly associated with reaction time in the attention (ß = 0.256, 95% CI 0.069 to 0.443, p = 0.008) and errors in the paired-associate learning tasks (ß = 0.308, 95% CI 0.126 to 0.489, p = 0.001). Blood pressure was inversely associated with overall cognition. PA or ST did not confound the associations. Results suggest that preventing high blood pressure is important for promoting cognition in adolescents.

Direct Comparison of the European Society of Cardiology 0/1-Hour Vs. 0/2-Hour Algorithms in Patients with Acute Chest Pain.

BACKGROUND: The recent guidelines from the European Society of Cardiology recommends using high-sensitivity cardiac troponin (hs-cTn) in either 0/1-h or 0/2-h algorithms to identify or rule out acute myocardial infarction (AMI). Several studies have reported good diagnostic accuracy with both algorithms, but few have compared the algorithms directly. OBJECTIVE: We aimed to compare the diagnostic accuracy of the algorithms head-to-head, in the same patients. METHODS: This was a secondary analysis of data from a prospective observational study; 1167 consecutive patients presenting with chest pain to the emergency department at Skåne University Hospital (Lund, Sweden) were enrolled. Only patients with a hs-cTnT sample at presentation AND after 1 AND 2 h were included in the analysis. We compared sensitivity, specificity, and negative (NPV) and positive predictive value (PPV). The primary outcome was index visit AMI. RESULTS: A total of 710 patients were included, of whom 56 (7.9%) had AMI. Both algorithms had a sensitivity of 98.2% and an NPV of 99.8% for ruling out AMI, but the 0/2-h algorithm ruled out significantly more patients (69.3% vs. 66.2%, p < 0.001). For rule-in, the 0/2-h algorithm had higher PPV (73.4% vs. 65.2%) and slightly better specificity (97.4% vs. 96.3%, p = 0.016) than the 0/1-h algorithm. CONCLUSION: Both algorithms had good diagnostic accuracy, with a slight advantage for the 0/2-h algorithm. Which algorithm to implement may thus depend on practical issues such as the ability to exploit the theoretical time saved with the 0/1-h algorithm. Further studies comparing the algorithms in combination with electrocardiography, history, or risk scores are needed.

A Single High-Sensitivity Cardiac Troponin T Strategy for Ruling Out Myocardial Infarction.

Background: Ruling out acute myocardial infarction (AMI) in the emergency department (ED) is challenging. Studies have shown that a high-sensitivity cardiac troponin T (hs-cTnT) <5 ng/L or <6 ng/L at presentation (0 h) can be used to rule out AMI. The objective of this study was to identify whether an even higher hs-cTnT threshold can be used for a safe rule out of AMI in the ED. Methods: The derivation cohort consisted of 24,973 ED patients with a primary complaint of chest pain. In this cohort, we identified the highest concentration of 0 h hs-cTnT that corresponded to a negative predictive value (NPV) of ≥99.5% for the primary endpoint of AMI/all-cause death within 30 days and the secondary endpoint of all-cause death within one year. The results were validated in two cohorts consisting of 132,021 and 1167 ED chest pain patients. Results: The 0 h hs-cTnT threshold corresponding to a NPV of ≥99.5% for the primary endpoint was <9 ng/L (NPV: 99.6% and 95% CI: 99.5-99.7). This cutoff provided a sensitivity of 96.2% (95% CI: 95.2-97.1) and identified 59.7% of the patients as low risk compared to 35.8% and 43.9% with a 0 h hs-cTnT <5 ng/L and <6 ng/L, respectively. The results were similar in the validation cohorts and seemed to perform even better in patients where the 0 h hs-cTnT was measured >3 h after symptom onset and in those with a nonischemic ECG and nonhigh risk history. Conclusions: A 0 h hs-cTnT cutoff of <9 ng/L safely rules out AMI/death within 30 days in a majority of chest pain patients and is a more effective strategy than the currently recommended <5 ng/L and <6 ng/L cutoffs. This trial is registered with NCT03421873.

The skåne emergency medicine (SEM) cohort.

BACKGROUND: In the European Union alone, more than 100 million people present to the emergency department (ED) each year, and this has increased steadily year-on-year by 2-3%. Better patient management decisions have the potential to reduce ED crowding, the number of diagnostic tests, the use of inpatient beds, and healthcare costs. METHODS: We have established the Skåne Emergency Medicine (SEM) cohort for developing clinical decision support systems (CDSS) based on artificial intelligence or machine learning as well as traditional statistical methods. The SEM cohort consists of 325 539 unselected unique patients with 630 275 visits from January 1st, 2017 to December 31st, 2018 at eight EDs in the region Skåne in southern Sweden. Data on sociodemographics, previous diseases and current medication are available for each ED patient visit, as well as their chief complaint, test results, disposition and the outcome in the form of subsequent diagnoses, treatments, healthcare costs and mortality within a follow-up period of at least 30 days, and up to 3 years. DISCUSSION: The SEM cohort provides a platform for CDSS research, and we welcome collaboration. In addition, SEM's large amount of real-world patient data with almost complete short-term follow-up will allow research in epidemiology, patient management, diagnostics, prognostics, ED crowding, resource allocation, and social medicine.

Complications in Emergency Department Patients with Acute Coronary Syndrome with Contemporary Care.

INTRODUCTION: With the implementation of early reperfusion therapy, the number of complications in patients with acute coronary syndrome (ACS) has diminished significantly. However, ACS patients are still routinely admitted to units with high-level monitoring such as the coronary or intensive care unit (CCU/ICU). The cost of these admissions is high and there is often a shortage of beds. The aim of this study was to analyze the complications in contemporary emergency department (ED) patients with ACS and to map patient management. METHODS: This observational study was a secondary analysis of data collected in the ESC-TROP trial (NCT03421873) that included 26,545 consecutive chest pain patients ≥18 years at five Swedish EDs. Complications were defined as the following within 30 days: death, cardiac arrest, cardiogenic shock, pulmonary edema, severe ventricular arrhythmia, high-degree atrioventricular (AV) block that required a pacemaker, and mechanical complications such as papillary muscle rupture, cardiac tamponade, or ventricular septum defects (VSDs). Complications were identified via diagnosis and/or intervention codes in the database, and manual chart review was performed in cases with complications. RESULTS: Of all 26,545 patients, 2,463 (9.3%) were diagnosed with ACS, and 151 of these (6.1%) suffered any complication within 30 days. Mean age was higher in patients with (79.2 years) than without (69.4 years) complications, and more were female (39.7% vs. 33.0%). Eighty-four (3.4% of all ACS patients) patients died, 33 (1.3%) had cardiac arrest, 22 (0.9%) respiratory failure, 13 (0.5%) high-degree AV block, 10 (0.4%) cardiogenic shock, 12 (0.5%) severe ventricular arrhythmia, and 2 each (<0.1%) had VSD or cardiac tamponade. Almost 30% of the complications were present already at the ED, and 40% of patients with complications were not admitted to the CCU/ICU. Only 80 (53%) of the patients with complications underwent coronary angiography and 62 (41%) were revascularized with percutaneous coronary intervention or coronary artery bypass grafting. CONCLUSION: With current care, serious complications occurred in only 6 out of 100 ACS patients, and 2 of these complications were present already at the ED. Four out of 10 ACS patients with complications were not admitted to the CCU/ICU and about half did not undergo coronary angiography. Further research is needed to improve risk assessment in ED ACS patients, which may allow more effective use of cardiac monitoring and hospital resources.

Sedentary behavior and lifespan brain health.

Higher levels of physical activity are known to benefit aspects of brain health across the lifespan. However, the role of sedentary behavior (SB) is less well understood. In this review we summarize and discuss evidence on the role of SB on brain health (including cognitive performance, structural or functional brain measures, and dementia risk) for different age groups, critically compare assessment approaches to capture SB, and offer insights into emerging opportunities to assess SB via digital technologies. Across the lifespan, specific characteristics of SB (particularly whether they are cognitively active or cognitively passive) potentially act as moderators influencing the associations between SB and specific brain health outcomes. We outline challenges and opportunities for future research aiming to provide more robust empirical evidence on these observations.

Relationship of device measured physical activity type and posture with cardiometabolic health markers: pooled dose-response associations from the Prospective Physical Activity, Sitting and Sleep Consortium.

AIMS/HYPOTHESIS: The aim of this study was to examine the dose-response associations of device-measured physical activity types and postures (sitting and standing time) with cardiometabolic health. METHODS: We conducted an individual participant harmonised meta-analysis of 12,095 adults (mean ± SD age 54.5±9.6 years; female participants 54.8%) from six cohorts with thigh-worn accelerometry data from the Prospective Physical Activity, Sitting and Sleep (ProPASS) Consortium. Associations of daily walking, stair climbing, running, standing and sitting time with a composite cardiometabolic health score (based on standardised z scores) and individual cardiometabolic markers (BMI, waist circumference, triglycerides, HDL-cholesterol, HbA1c and total cholesterol) were examined cross-sectionally using generalised linear modelling and cubic splines. RESULTS: We observed more favourable composite cardiometabolic health (i.e. z score <0) with approximately 64 min/day walking (z score [95% CI] -0.14 [-0.25, -0.02]) and 5 min/day stair climbing (-0.14 [-0.24, -0.03]). We observed an equivalent magnitude of association at 2.6 h/day standing. Any amount of running was associated with better composite cardiometabolic health. We did not observe an upper limit to the magnitude of the dose-response associations for any activity type or standing. There was an inverse dose-response association between sitting time and composite cardiometabolic health that became markedly less favourable when daily durations exceeded 12.1 h/day. Associations for sitting time were no longer significant after excluding participants with prevalent CVD or medication use. The dose-response pattern was generally consistent between activity and posture types and individual cardiometabolic health markers. CONCLUSIONS/INTERPRETATION: In this first activity type-specific analysis of device-based physical activity, ~64 min/day of walking and ~5.0 min/day of stair climbing were associated with a favourable cardiometabolic risk profile. The deleterious associations of sitting time were fully attenuated after exclusion of participants with prevalent CVD and medication use. Our findings on cardiometabolic health and durations of different activities of daily living and posture may guide future interventions involving lifestyle modification.

Trends in the association between meeting the physical activity guidelines and risk of mortality in US adults.

OBJECTIVE: To examine the trends in the association between meeting the physical activity (PA) guidelines and mortality in adults. METHODS: We included seventeen annual representative samples of US adults 1998-2014 (n = 482,756) and all-cause and cause-specific mortality ascertained through December 2019. Participants were grouped according to PA Guidelines: 150 or more min/week in aerobic PA and muscle-strengthening activities 2 or more times/week. To provide further context, we also examined the trends in mortality risk associated with other modifiable health factors. RESULTS: Meeting the PA guidelines was associated with lower 5-year mortality risk (HR = 0.59, 95%CI, 0.55, 0.63) based on the pooled analyses. We consistently observed an inverse association in all years, but there was a nonsignificant trend association (P for trend = 0.305) between meeting PA guidelines and 5-year mortality across the seventeen annual surveys. Meeting aerobic (HR = 0.58, 95%CI, 0.56, 0.61) and muscle-strengthening (HR = 0.86, 95%CI, 0.81, 0.90) guidelines were independently associated with 5-year mortality risk in pooled analyses, without any evidence for trends in the associations. Similar results were found with cause-specific mortality and 10-year mortality risk. In pooled analyses, attaining a high educational level, body mass index <30 kg/m2, being noncurrent smoker, nonheavy drinker, and living without history of hypertension and diabetes with 5-year mortality were 0.70 (95%CI, 0.67, 0.73), 1.19 (95%CI, 1.15, 1.23), 0.56 (95%CI, 0.54, 0.59), 0.85 (95%CI,0.79, 0.92), 0.91 (95%CI, 0.88-0.94) and 0.65 (95%CI, 0.88, 0.94), respectively. Only no history of diabetes showed a significant trend analysis (B = 0.77, 95%CI, 0.46, 0.91, P for trend <0.001). CONCLUSION: Meeting PA guidelines lower mortality risk and this association does not seem to have varied over time. Encouraging adults to meet the PA guidelines may provide substantial health benefits, despite social, demographic and lifestyle changes, as well as the advances in medical technology and pharmacological treatments.

Is rest-activity rhythm prospectively associated with all-cause mortality in older people regardless of sleep and physical activity level? The 'Como Vai?' Cohort study.

OBJECTIVE: This study aims to test the association of rest-activity rhythm (intradaily variability and interdaily stability) with all-cause mortality in an older adult cohort in Brazil. It also assesses whether the amount of time spent at each intensity level (i.e., physical activity and nocturnal sleep) interferes with this association. METHODS: This cohort study started in 2014 with older adults (≥60 years). We investigated deaths from all causes that occurred until April 2017. Rest-activity rhythm variables were obtained using accelerometry at baseline. Intradaily variability indicates higher rhythm fragmentation, while interdaily stability indicates higher rhythm stability. Cox proportional-hazard models were used to test the associations controlling for confounders. RESULTS: Among the 1451 older adults interviewed in 2014, 965 presented valid accelerometry data. During the follow-up period, 80 individuals died. After adjusting the analysis for sociodemographic, smoking, morbidity score, and number of medicines, an increase of one standard deviation in interdaily stability decreased 26% the risk of death. The adjustment for total sleep time and inactivity did not change this association. On the other hand, the association was no longer significant after adjusting for overall physical activity and moderate to vigorous physical activity. CONCLUSION: Rest-activity rhythm pattern was not associated with mortality when physical activity was considered, possibly because this pattern could be driven by regular exercise. Promoting physical activity remains a relevant strategy to improve population health.

Contractility, ventriculoarterial coupling, and stroke work after acute myocardial infarction using CMR-derived pressure-volume loop data.

BACKGROUND: Noninvasive left ventricular (LV) pressure-volume (PV) loops derived by cardiac magnetic resonance (CMR) have recently been shown to enable characterization of cardiac hemodynamics. Thus, such PV loops could potentially provide additional diagnostic information such as contractility, arterial elastance (Ea ) and stroke work (SW) currently not available in clinical routine. This study sought to investigate to what extent PV-loop variables derived with a novel noninvasive method can provide incremental physiological information over cardiac dimensions and blood pressure in patients with acute myocardial infarction (MI). METHODS: A total of 100 patients with acute MI and 75 controls were included in the study. All patients underwent CMR 2-6 days after MI including assessment of myocardium at risk (MaR) and infarct size (IS). Noninvasive PV loops were generated from CMR derived LV volumes and brachial blood pressure measurements. The following variables were quantified: Maximal elastance (Emax ) reflecting contractility, Ea , ventriculoarterial coupling (Ea /Emax ), SW, potential energy, external power, energy per ejected volume, and efficiency. RESULTS: All PV-loop variables were significantly different in MI patients compared to healthy volunteers, including contractility (Emax : 1.34 ± 0.48 versus 1.50 ± 0.41 mmHg/mL, p = .024), ventriculoarterial coupling (Ea /Emax : 1.27 ± 0.61 versus 0.73 ± 0.17, p < .001) and SW (0.96 ± 0.32 versus 1.38 ± 0.32 J, p < .001). These variables correlated to both MaR and IS (Emax : r2 = 0.25 and r2 = 0.29; Ea /Emax : r2 = 0.36 and r2 = 0.41; SW: r2 = 0.21 and r2 = 0.25). CONCLUSIONS: Noninvasive PV-loops provide physiological information beyond conventional diagnostic variables, such as ejection fraction, early after MI, including measures of contractility, ventriculoarterial coupling, and SW.

Prevalence and prognostic value of electrocardiographic abnormalities in hypokalemia: A multicenter cohort study.

BACKGROUND: Hypokalemia is common in hospitalized patients and associated with ECG abnormalities. The prevalence and prognostic value of ECG abnormalities in hypokalemic patients are, however, not well established. METHODS: The study was a multicentered cohort study, including all ault patients with an ECG and potassium level <4.4 mmol/L recorded at arrival to four emergency departments in Denmark and Sweden. Using computerized measurements from ECGs, we investigated the relationship between potassium levels and heart rate, QRS duration, corrected QT (QTc) interval, ST-segment depressions, T-wave flattening, and T-wave inversion using cubic splines. Within strata of potassium levels, we further estimated the hazard ratio (HR) for 7-day mortality, admission to the intensive care unit (ICU), and diagnosis of ventricular arrhythmia or cardiac arrest, comparing patients with and without specific ECG abnormalities matched 1:2 on propensity scores. RESULTS: Among 79,599 included patients, decreasing potassium levels were associated with a concentration-dependent increase in all investigated ECG variables. ECG abnormalities were present in 40% of hypokalemic patients ([K+ ] <3.5 mmol/L), with T-wave flattening, ST-segment depression, and QTc prolongation occurring in 27%, 16%, and 14%. In patients with mild hypokalemia ([K+ ] 3.0-3.4 mmol/L), a heart rate >100 bpm, ST-depressions, and T-wave inversion were associated with increased HRs for 7-day mortality and ICU admission, whereas only a heart rate >100 bpm predicted both mortality and ICU admission among patients with [K+ ] <3.0 mmol/L. HR estimates were, however, similar to those in eukalemic patients. The low number of events with ventricular arrhythmia limited evaluation for this outcome. CONCLUSIONS: ECG abnormalities were common in hypokalemic patients, but they are poor prognostic markers for short-term adverse events under the current standard of care.

Comparison of diagnostic accuracy of current left bundle branch block and ventricular pacing ECG criteria for detection of occlusion myocardial infarction.

BACKGROUND: Electrocardiographic detection of patients with occlusion myocardial infarction (OMI) can be difficult in patients with left bundle branch block (LBBB) or ventricular paced rhythm (VPR) and several ECG criteria for the detection of OMI in LBBB/VPR exist. Most recently, the Barcelona criteria, which includes concordant ST deviation and discordant ST deviation in leads with low R/S amplitudes, showed superior diagnostic accuracy but has not been validated externally. We aimed to describe the diagnostic accuracy of four available ECG criteria for OMI detection in patients with LBBB/VPR at the emergency department. METHODS: The unweighted Sgarbossa criteria, the modified Sgarbossa criteria (MSC), the Barcelona criteria and the Selvester criteria were applied to chest pain patients with LBBB or VPR in a prospectively acquired database from five emergency departments. RESULTS: In total, 623 patients were included, among which 441 (71%) had LBBB and 182 (29%) had VPR. Among these, 82 (13%) patients were diagnosed with AMI, and an OMI was identified in 15 (2.4%) cases. Sensitivity/specificity of the original unweighted Sgarbossa criteria were 26.7/86.2%, for MSC 60.0/86.0%, for Barcelona criteria 53.3/82.2%, and for Selvester criteria 46.7/88.3%. In this setting with low prevalence of OMI, positive predictive values were low (Sgarbossa: 4.6%; MSC: 9.4%; Barcelona criteria: 6.9%; Selvester criteria: 9.0%) and negative predictive values were high (all >98.0%). CONCLUSIONS: Our results suggests that ECG criteria alone are insufficient in predicting presence of OMI in an ED setting with low prevalence of OMI, and the search for better rapid diagnostic instruments in this setting should continue.

Prognostic utility and characterization of left ventricular hypertrophy using global thickness.

Cardiovascular magnetic resonance (CMR) can accurately measure left ventricular (LV) mass, and several measures related to LV wall thickness exist. We hypothesized that prognosis can be used to select an optimal measure of wall thickness for characterizing LV hypertrophy. Subjects having undergone CMR were studied (cardiac patients, n = 2543; healthy volunteers, n = 100). A new measure, global wall thickness (GT, GTI if indexed to body surface area) was accurately calculated from LV mass and end-diastolic volume. Among patients with follow-up (n = 1575, median follow-up 5.4 years), the most predictive measure of death or hospitalization for heart failure was LV mass index (LVMI) (hazard ratio (HR)[95% confidence interval] 1.16[1.12-1.20], p < 0.001), followed by GTI (HR 1.14[1.09-1.19], p < 0.001). Among patients with normal findings (n = 326, median follow-up 5.8 years), the most predictive measure was GT (HR 1.62[1.35-1.94], p < 0.001). GT and LVMI could characterize patients as having a normal LV mass and wall thickness, concentric remodeling, concentric hypertrophy, or eccentric hypertrophy, and the three abnormal groups had worse prognosis than the normal group (p < 0.05 for all). LV mass is highly prognostic when mass is elevated, but GT is easily and accurately calculated, and adds value and discrimination amongst those with normal LV mass (early disease).