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result(s) for
"Kahan, Thomas"
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Blood pressure in atrial fibrillation and in sinus rhythm during ambulatory blood pressure monitoring: data from the TEMPLAR project
2024
The coexistence of hypertension and atrial fibrillation (AF) is common and accounts for a worse prognosis. Uncertainties exist regarding blood pressure (BP) measurements in AF patients by automated oscillometric devices. The Microlife WatchBP 03 AFIB ambulatory BP monitoring (ABPM) device including an AF algorithm with each measurement was used in 430 subjects aged >65 years referred for ABPM and with assumed paroxysmal AF to perform intra-individual comparisons of BP during both AF-indicated and sinus rhythm. Only subjects with >30% of measurements indicating AF and episodes >30 min for assumed AF and for sinus rhythm were included. Mean age was 78 ± 7 years, 43% were male, 77% hypertensive, and 72% were treated. Compared to sinus rhythm, 24-h mean arterial pressure was similar (87.2 ± 9.5 vs 87.5 ± 10.6 mm Hg,
p
= 0.47), whereas 24-h systolic BP tended to be lower (123.6 ± 13.9 vs 124.7 ± 16.1 mm Hg,
p
= 0.05) and night-time diastolic BP higher (64.6 ± 10.9 vs 63.3 ± 10.4 mm Hg,
p
= 0.01) in assumed AF. Diastolic (not systolic) BP variability was higher in AF (
p
< 0.001). Results were similar with heart rates <90 and ≥90 bpm. In conclusion, this is the first study to use intra-individual comparisons of averaged BP during an ABPM in assumed paroxysmal AF and sinus rhythm. Our results imply that ABPM is feasible and informative also in patients with AF. We also suggest that an AF detection algorithm offers a new approach to evaluate the reliability of averaged BP values in AF compared to SR during an ABPM.
Journal Article
Circulating vascular biomarkers in relation to physiological indices of aortic stiffness and endothelial function in hypertension
2025
Studies investigating the relation between circulating vascular biomarkers reflecting endothelial dysfunction and physiological methods to evaluate vascular function remain limited. We simultaneously evaluated the relation between circulating endothelial biomarkers with physiological non-invasive vascular methods in 107 hypertensive patients with a wide range of mean estimated glomerular filtration rate (eGFR). Endothelial glycocalyx hyaluronan (HA) and syndecan-1 (SDC-1), and cellular adhesion molecules (ICAM-1, VCAM-1, and E-selectin) were measured by enzyme-linked immunosorbent assays. Aortic stiffness (cfPWV) was assessed by pulse wave analysis. Endothelial function in different vascular beds was evaluated physiological by methods: flow mediated vasodilation (large arteries), pulse wave analysis and the reflection index change, using beta 2-adrenoceptor agonist stimulation (smaller resistance arteries), and laser Doppler fluxmetry and iontophoresis (skin microvascular function). Diastolic function and left atrial size were assessed by echocardiography. Mean blood pressure (BP) was 149 ± 17/87 ± 10 mm Hg, mean eGFR 74 (21–130) ml/min x 1.73 m
2
. HA was independently related to cfPWV (β = 0.23,
P
= 0.02), whereas SDC-1 was independently inversely related to skin microvascular function, (β= − 0.27,
P
= 0.042) and was independently related to resistance artery endothelial function (β = 0.29,
P
= 0.026). All circulating biomarkers were unrelated to physiologically measured large artery endothelial function, and with echocardiographic parameters. The glycocalyx markers were associated with physiological vascular measures independent of eGFR but should not be considered as a proxy for these measures, due to the weak relations. However, combining circulating markers with physiological measures might give additional information about vascular function.
Journal Article
24-hour ambulatory blood pressure telemonitoring in patients at risk of atrial fibrillation: results from the TEMPLAR project
by
Omboni, Stefano
,
Panzeri, Edoardo
,
Kahan, Thomas
in
Blood pressure
,
Cardiac arrhythmia
,
Home medical tests
2022
Hypertension is the most common risk factor for atrial fibrillation (AF). The ability to screen for potential AF during blood pressure (BP) measurement may be a valuable tool for early AF detection. This study evaluated the frequency of irregular pulse rates suggestive of AF in subjects undergoing ambulatory BP monitoring (ABPM) and compared the characteristics of patients at low risk of presumed AF vs. those at high risk. ABPM recordings were obtained in 4419 subjects aged ≥65 years visiting 304 community pharmacies, with clinically validated automated monitors equipped with an algorithm for detecting possible AF episodes during BP measurement. Subjects with <30% of the readings suggestive of AF were categorized as having a low risk of AF, and those with ≥30% of readings were classified as high risk. A total of 531 subjects (12.0%) were categorized as having a high risk of AF, with the risk increasing with advancing age. Subjects at high risk of AF had lower average systolic BP, higher average diastolic BP and pulse rate (PR), increased BP and PR variabilities, and blunted sleep-associated reductions in BP and PR. In repeated recordings, the reliability of the AF detection algorithm per se was good (kappa 0.476, p = 0.0001; intraclass correlation coefficient 0.56, p = 0.0001). Simultaneous BP measurement and screening for potential AF by ABPM in elderly people in clinical practice may help improve BP control and the detection of subjects at high risk of AF. However, a finding of presumed AF must always be confirmed by an electrocardiogram (ECG).
Journal Article
ESC Council on hypertension position document on the management of hypertensive emergencies
by
Amraoui, Fouad
,
Kahan, Thomas
,
Williams, Bryan
in
Angiotensin II
,
Antihypertensive Agents - administration & dosage
,
Antihypertensive Agents - adverse effects
2019
Abstract
Hypertensive emergencies are those situations where very high blood pressure (BP) values are associated with acute organ damage, and therefore, require immediate, but careful, BP reduction. The type of acute organ damage is the principal determinant of: (i) the drug of choice, (ii) the target BP, and (iii) the timeframe in which BP should be lowered. Key target organs are the heart, retina, brain, kidneys, and large arteries. Patients who lack acute hypertension-mediated end organ damage do not have a hypertensive emergency and can usually be treated with oral BP-lowering agents and usually discharged after a brief period of observation.
Journal Article
Computerized history-taking improves data quality for clinical decision-making—Comparison of EHR and computer-acquired history data in patients with chest pain
by
Zakim, David
,
Kahan, Thomas
,
Nifakos, Sokratis
in
Biology and Life Sciences
,
Chest
,
Clinical decision making
2021
Patients’ medical histories are the salient dataset for diagnosis. Prior work shows consistently, however, that medical history-taking by physicians generally is incomplete and not accurate. Such findings suggest that methods to improve the completeness and accuracy of medical history data could have clinical value. We address this issue with expert system software to enable automated history-taking by computers interacting directly with patients,
i
.
e
. computerized history-taking (CHT). Here we compare the completeness and accuracy of medical history data collected and recorded by physicians in electronic health records (EHR) with data collected by CHT for patients presenting to an emergency room with acute chest pain. Physician history-taking and CHT occurred at the same ED visit for all patients. CHT almost always preceded examination by a physician. Data fields analyzed were relevant to the differential diagnosis of chest pain and comprised information obtainable only by interviewing patients. Measures of data quality were completeness and consistency of negative and positive findings in EHR as compared with CHT datasets. Data significant for the differential of chest pain was missing randomly in all EHRs across all data items analyzed so that the dimensionality of EHR data was limited. CHT files were near complete for all data elements reviewed. Separate from the incompleteness of EHR data, there were frequent factual inconsistencies between EHR and CHT data across all data elements. EHR data did not contain representations of symptoms that were consistent with those reported by patients during CHT.
Trial registration:
This study is registered at
https://www.clinicaltrials.gov
(unique identifier:
NCT03439449
).
Journal Article
Use of Self-Reported Computerized Medical History Taking for Acute Chest Pain in the Emergency Department – the Clinical Expert Operating System Chest Pain Danderyd Study (CLEOS-CPDS): Prospective Cohort Study
2021
Chest pain is one of the most common chief complaints in emergency departments (EDs). Collecting an adequate medical history is challenging but essential in order to use recommended risk scores such as the HEART score (based on history, electrocardiogram, age, risk factors, and troponin). Self-reported computerized history taking (CHT) is a novel method to collect structured medical history data directly from the patient through a digital device. CHT is rarely used in clinical practice, and there is a lack of evidence for utility in an acute setting.
This substudy of the Clinical Expert Operating System Chest Pain Danderyd Study (CLEOS-CPDS) aimed to evaluate whether patients with acute chest pain can interact effectively with CHT in the ED.
Prospective cohort study on self-reported medical histories collected from acute chest pain patients using a CHT program on a tablet. Clinically stable patients aged 18 years and older with a chief complaint of chest pain, fluency in Swedish, and a nondiagnostic electrocardiogram or serum markers for acute coronary syndrome were eligible for inclusion. Patients unable to carry out an interview with CHT (eg, inadequate eyesight, confusion or agitation) were excluded. Effectiveness was assessed as the proportion of patients completing the interview and the time required in order to collect a medical history sufficient for cardiovascular risk stratification according to HEART score.
During 2017-2018, 500 participants were consecutively enrolled. The age and sex distribution (mean 54.3, SD 17.0 years; 213/500, 42.6% women) was similar to that of the general chest pain population (mean 57.5, SD 19.2 years; 49.6% women). Common reasons for noninclusion were language issues (182/1000, 18.2%), fatigue (158/1000, 15.8%), and inability to use a tablet (152/1000, 15.2%). Sufficient data to calculate HEART score were collected in 70.4% (352/500) of the patients. Key modules for chief complaint, cardiovascular history, and respiratory history were completed by 408 (81.6%), 339 (67.8%), and 291 (58.2%) of the 500 participants, respectively, while 148 (29.6%) completed the entire interview (in all 14 modules). Factors associated with completeness were age 18-69 years (all key modules: Ps<.001), male sex (cardiovascular: P=.04), active workers (all key modules: Ps<.005), not arriving by ambulance (chief complaint: P=.03; cardiovascular: P=.045), and ongoing chest pain (complete interview: P=.002). The median time to collect HEART score data was 23 (IQR 18-31) minutes and to complete an interview was 64 (IQR 53-77) minutes. The main reasons for discontinuing the interview prior to completion (n=352) were discharge from the ED (101, 28.7%) and tiredness (95, 27.0%).
A majority of patients with acute chest pain can interact effectively with CHT on a tablet in the ED to provide sufficient data for risk stratification with a well-established risk score. The utility was somewhat lower in patients 70 years and older, in patients arriving by ambulance, and in patients without ongoing chest pain. Further studies are warranted to assess whether CHT can contribute to improved management and prognosis in this large patient group.
ClinicalTrials.gov NCT03439449; https://clinicaltrials.gov/ct2/show/NCT03439449.
RR2-10.1136/bmjopen-2019-031871.
Journal Article
The effects of alpha 1-adrenoceptor blockade and angiotensin converting enzyme inhibition on central and brachial blood pressure and vascular reactivity: the doxazosin–ramipril study
by
Jekell, Andreas
,
Kahan, Thomas
,
Kalani, Majid
in
Acetylcholine
,
Adrenergic alpha-1 Receptor Antagonists - administration & dosage
,
Adrenergic receptors
2017
We aimed to study whether inhibition of the renin–angiotensin–aldosterone system has effects on vascular structure and function beyond the effects on blood pressure reduction alone. Patients with mild-to-moderate hypertension (
n
= 61, age 54 ± 12 years, 34% women) received the angiotensin converting enzyme inhibitor ramipril 10 mg or the alpha 1-adrenoceptor blocker doxazosin 8 mg double-blind for 12 weeks. Aortic blood pressure, pulse wave velocity, and augmentation index were assessed by applanation tonometry. Endothelial function was studied by forearm post-ischemic flow mediated vasodilatation and by pulse wave analysis with beta 2-adrenoceptor agonist stimulation. Skin microvascular reactivity was assessed by laser Doppler fluxmetry and iontophoresis. Treatment with doxazosin or ramipril reduced aortic and brachial blood pressures (all
P
< 0.001), with greater reductions in aortic than brachial systolic blood pressures (
P
= 0.021) and aortic/brachial pulse pressure ratio (
P
= 0.005). Compared to doxazosin, ramipril reduced carotid-femoral and carotid-radial pulse wave velocity (both
P
< 0.05). Forearm endothelial dependent and independent vasodilatation, assessed by post-ischemic flow mediated vasodilatation and glyceryl trinitrate, and by pulse wave analysis remained unchanged by both doxazosin and ramipril. In addition, skin microvascular endothelial dependent (acetylcholine) and independent vasodilatation (sodium nitroprusside) remained unchanged. In conclusion, ramipril reduced indices of aortic stiffness, suggesting that angiotensin converting enzyme inhibitor therapy may have effects beyond blood pressure reduction. However, treatment did not appear to influence endothelial function. Evidence of endothelial dysfunction and its possible improvement by antihypertensive treatment might require more advanced hypertension.
This study is registered at ClinicalTrials.gov (NCT02901977) and at EudraCT (# 2007-000631-25).
Journal Article
Lack of associations between hospital rating and outcomes in patients with an acute coronary syndrome
by
Kahan, Thomas
,
Aspberg, Sara
,
Johansson, Fredrik
in
Acute Coronary Syndrome
,
Acute coronary syndromes
,
Cardiovascular disease
2024
BackgroundPublic reporting of performance data has become a common tool in evaluation of healthcare providers. The rating may be misleading if the association between the measured variables and the outcome is weak.Methods and resultsNationwide, register-based, cohort study. All Swedish patients hospitalised with an acute coronary syndrome during the time periods 2006–2010 and 2015–2017 were included in the study. Possible associations between cardiovascular morbidity and mortality for these patients and ranking scores for each hospital in a Swedish healthcare quality register for acute coronary syndromes were analysed. We found no association between the ranking score and mortality, and no or weak associations between the ranking score and readmissions.ConclusionsLack of associations between quality measurements and patient outcomes warrants improvement in ranking scores. Cautious use of the ranking results is necessary in comparisons between healthcare providers.
Journal Article
User experience of self‐reported computerized medical history taking for acute chest pain: The Clinical Expert Operating System Chest Pain Danderyd Study
by
Sundberg, Kay
,
Zakim, David
,
Kahan, Thomas
in
Acceptability
,
Adoption of innovations
,
Attitudes
2022
Background and Objective Chest pain is one of the most common complaints in emergency departments (EDs). Self‐reported computerized history taking (CHT) programmes can be used for interpretation of the clinical significance of medical information coming directly from patients. The adoption of CHT in clinical practice depends on reactions and attitudes to the technology from patients and their belief that the technology will have benefits for their medical care. The study objective was to explore the user experience of the self‐reported CHT programme Clinical Expert Operating System (CLEOS) in the setting of patients visiting an ED for acute chest pain. Methods This qualitative interview study is part of the ongoing CLEOS‐Chest Pain Danderyd Study. A subset (n = 84) of the larger sample who had taken part in self‐reported history taking during waiting times at the ED were contacted by telephone and n = 54 (64%) accepted participation. An interview guide with open‐ended questions was used and the text was analysed using directed content analysis. Results The patients' experiences of the CLEOS programme were overall positive although some perceived it as extensive. The programme was well accepted and despite the busy environment, patients were highly motivated and deemed it helpful to make a diagnosis. Six categories of user experience emerged: The clinical context, The individual context, Time aspect, Acceptability of the programme, Usability of the programme and Perceptions of usefulness in a clinical setting. Conclusions The programme was well accepted by most patients in the stressful environment at ED although some found it difficult to answer all the questions. Adjustments to the extent of an interview to better suit the context of the clinical use should be a future development of the programme. The findings suggest that CHT programmes can be integrated as a standard process for collecting self‐reported medical history data in the ED setting. Patient or Public Contribution In the conduct of this study, patients contributed with interviews reflecting their usage of a self‐reported medical history‐taking programme.
Journal Article