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Record W3199819696 · doi:10.1093/eurheartj/ehab552

How to identify which patients should not have a systolic blood pressure target of <120 mmHg

2021· letter· en· W3199819696 on OpenAlexaff
J. David Spence, Lucas O. Müller, Pablo J. Blanco

Bibliographic record

VenueEuropean Heart Journal · 2021
Typeletter
Languageen
FieldMedicine
TopicBlood Pressure and Hypertension Studies
Canadian institutionsWestern University
Fundersnot available
KeywordsMedicineBlood pressureCardiologyInternal medicineSystoleDiastole

Abstract

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This commentary refers to ‘On cerebrotoxicity of antihypertensive therapy and risk factor cosmetics’, by F.H. Messerli et al., https://doi.org/10.1093/eurheartj/ehaa971. and the discussion piece ‘Importance of pulse pressure at low systolic blood pressure’, by F.H. Messerli et al., https://doi.org/10.1093/eurheartj/ehab553. In their recent editorial about a UK Biobank study,1 Messerli et al.2 were right to warn that not all patients should have their systolic blood pressure lowered to <120 mmHg. However, they did not mention a subgroup of patients, who can be readily identified, in whom such low systolic targets should be avoided. Patients with stiff arteries have a wide pulse pressure, aggravated by bradycardia, and are more likely to have a large cuff artefact, with the true (intra-arterial) diastolic pressure being lower than the cuff pressure.3 Such patients are at risk from low diastolic pressure; treating patients with a pulse pressure of >60 mmHg to a systolic target of 120 mmHg would push the diastolic to < 60 mmHg. Among patients with a diastolic pressure of <60 mmHg and a pulse pressure of >60 mmHg (diastolic blood pressure (DBP) < 60/pulse pressure (PP) > 60), there were a doubling of subclinical myocardial ischaemia and a 5.85-fold increase in the risk of stroke.4 A large cuff artefact is commoner than many physicians would suppose. Spence et al. reported in 1978 that, among patients aged ≥60 years with DBP ≥100 mmHg but no hypertensive end-organ disease, half had an intra-arterial pressure that was ≥30 mmHg lower than the cuff pressure. Virtually all of myocardial perfusion, and more than half of cerebral perfusion, occur during diastole. What is little understood is that there is a large pressure gradient in the brain: based on computer simulations using an anatomically detailed cerebrovascular architecture, we estimated that ‘when the blood pressure in the brachial artery is 117/75 mmHg, it is 113/73 mmHg in the lenticulostriate artery but only 59/39 mmHg in small branches in the posterior parietal subcortex’5 (Figure 1). Detail of the peripheral beds corresponding to the lenticulostriate artery and to the posterior parietal branch of the middle cerebral artery. Pressure waveforms are shown for the normotensive (N, dashed line) and hypertensive (H, solid line) cases. Right panels (top and bottom) display the pressure waveform in the feeding artery to the corresponding arteriolar networks. Middle and left panels show the pressure level in arterioles with diameter ranges between D ∈ (190 μm, 210 μm) and D ∈ (30 μm, 50 μm), respectively; n indicates the number of vessels taken to calculate the average and standard deviation (SD) pressure waveforms (grey-shaded area). In brackets, the mean arterial pressure is reported. LsA, lenticulostriate artery; MCA, middle cerebral artery; PPB, posterior parietal branch. Reproduced by the permission of Oxford University Press from Blanco et al.5 Detail of the peripheral beds corresponding to the lenticulostriate artery and to the posterior parietal branch of the middle cerebral artery. Pressure waveforms are shown for the normotensive (N, dashed line) and hypertensive (H, solid line) cases. Right panels (top and bottom) display the pressure waveform in the feeding artery to the corresponding arteriolar networks. Middle and left panels show the pressure level in arterioles with diameter ranges between D ∈ (190 μm, 210 μm) and D ∈ (30 μm, 50 μm), respectively; n indicates the number of vessels taken to calculate the average and standard deviation (SD) pressure waveforms (grey-shaded area). In brackets, the mean arterial pressure is reported. LsA, lenticulostriate artery; MCA, middle cerebral artery; PPB, posterior parietal branch. Reproduced by the permission of Oxford University Press from Blanco et al.5 Patients with cuff DBP <60/PP >60, and in many cases an even lower intra-arterial diastolic pressure, can be expected to have diastolic pressures in the cerebral cortex that are below critical perfusion thresholds at least some of the time. This very likely accounts for the excess of white matter lesions in patients with ‘well-controlled hypertension’ reported by Messerli et al.; they were probably too well controlled. Patients with a pulse pressure of >60 mmHg should not have a systolic pressure target below 120 mmHg. Conflict of interest: none declared.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.005
metaresearch head score (Gemma)0.041
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Not applicable · Consensus signal: Not applicable
GenreCandidate signal: Commentary · Consensus signal: Commentary
Teacher disagreement score0.028
Threshold uncertainty score0.028

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0050.041
Meta-epidemiology (narrow)0.0000.001
Meta-epidemiology (broad)0.0020.001
Bibliometrics0.0010.001
Science and technology studies0.0040.002
Scholarly communication0.0030.003
Open science0.0010.001
Research integrity0.0280.021
Insufficient payload (model declined to judge)0.0070.006

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.101
GPT teacher head0.318
Teacher spread0.218 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designNot applicable
Domainnot available
GenreCommentary

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

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Citations5
Published2021
Admission routes1
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