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Archive for July, 2016

Validation Study High Sensitivity Troponin (0,3 hour) Rule In/Rule Out for Myocardial Infarction

Pickering et al report an important validation study for the ESC rule in testing for myocardial infarction for patients presenting with suspected acute coronary syndrome.
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The authors found that hs-TnI and hs-TnI had good positive predictive value (diagnosing 50% of the acute myocardial infarctions). However, the sensitivity of the 99th percentile (and hence rule out) was too low for clinical practice.

Summary

Objective

International guidelines to rule-in acute myocardial infarction (AMI) in patients presenting with chest pain to the emergency department (ED) recommend an algorithm using high-sensitivity cardiac troponin (hs-cTn) sampling on presentation and 3 h following presentation. We tested the diagnostic accuracy of this algorithm by pooling data from five distinct cohorts from three countries of prospectively recruited patients with independently adjudicated outcomes.

Method

We measured high-sensitivity cardiac troponin I (hs-cTnI) and high-sensitivity cardiac troponin T (hscTnT) on presentation (0 h) and 3 h post-presentation samples in adult patients attending an ED with possible AMI to validate the European Society of Cardiology (ESC) Working Group on Acute Cardiac Care rule-in algorithm (ESC-rule-in). Specifically, (i) in patients witha 0 h hs-cTn concentration ≤99th percentile and a 3 h hs-cTn >99th percentile, positive patients are those with an absolute change in troponin ≥50% of the 99th percentile, and (ii) in patients with a 0 and 3 h hs-cTn >99th percentile, positive patients are those with a relative change in troponin of ≥20%. We concurrently assessed the efficacy of the 0 and 3 h hs-cTn <99th percentile to rule-out AMI. Results 1061 patients with hs-cTnI and 985 with hscTnT
were included. The ESC-rule-in positive predictive value (PPV) was 83.5% (95% CI 74.9% to 90.1%) for hs-cTnI and 72.0% (95% CI 62.1% to 80.5%) for hs-cTnT. Forty-six AMIs (34.9%) were not ruled in using hs-cTnI and 62 (46.2%) using hs-cTnT. The sensitivity of the 99th percentile to rule-out AMI was 93.2% (95% CI 87.5% to 96.8%) for hs-cTnI and 94.8% (95% CI
89.5% to 97.9%) for hs-cTnT.

Conclusions

The ESC-rule-in algorithm has good PPV with hs-cTnI and reasonable with hs-cTnT and can rule in over 50% of AMIs. However, the sensitivity of the 99th percentile to rule-out AMI is too low for clinical use.

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The editorial is available here

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Body Mass Index and All Cause Mortality: Meta-analysis of Prospective Studies

The Global BMI Mortality Collaborative report a meta-analysis of 293 prospective studies from Asia, Australia and New Zealand, Europe and North America. A consistent positive relationship between body mass index and all cause mortality was observed. The relationship was observed in major underlying disease subgroups: coronary heart disease, stroke, respiratory disease and cancer.

Summary

Background

Overweight and obesity are increasing worldwide. To help assess their relevance to mortality in diff erent
populations we conducted individual-participant data meta-analyses of prospective studies of body-mass index (BMI),
limiting confounding and reverse causality by restricting analyses to never-smokers and excluding pre-existing
disease and the fi rst 5 years of follow-up.

Methods

Of 10 625 411 participants in Asia, Australia and New Zealand, Europe, and North America from 239 prospective
studies (median follow-up 13·7 years, IQR 11·4–14·7), 3 951 455 people in 189 studies were never-smokers without
chronic diseases at recruitment who survived 5 years, of whom 385 879 died. The primary analyses are of these deaths,
and study, age, and sex adjusted hazard ratios (HRs), relative to BMI 22·5–<25·0 kg/m².
Findings All-cause mortality was minimal at 20·0–25·0 kg/m² (HR 1·00, 95% CI 0·98–1·02 for BMI 20·0–<22·5 kg/m²;
1·00, 0·99–1·01 for BMI 22·5–<25·0 kg/m²), and increased significantly both just below this range (1·13, 1·09–1·17
for BMI 18·5–<20·0 kg/m²; 1·51, 1·43–1·59 for BMI 15·0–<18·5) and throughout the overweight range (1·07,
1·07–1·08 for BMI 25·0–<27·5 kg/m²; 1·20, 1·18–1·22 for BMI 27·5–<30·0 kg/m²). The HR for obesity grade 1
(BMI 30·0–<35·0 kg/m²) was 1·45, 95% CI 1·41–1·48; the HR for obesity grade 2 (35·0–<40·0 kg/m²) was 1·94,
1·87–2·01; and the HR for obesity grade 3 (40·0–<60·0 kg/m²) was 2·76, 2·60–2·92. For BMI over 25·0 kg/m²,
mortality increased approximately log-linearly with BMI; the HR per 5 kg/m² units higher BMI was 1·39 (1·34–1·43)
in Europe, 1·29 (1·26–1·32) in North America, 1·39 (1·34–1·44) in east Asia, and 1·31 (1·27–1·35) in Australia and
New Zealand. This HR per 5 kg/m² units higher BMI (for BMI over 25 kg/m²) was greater in younger than older
people (1·52, 95% CI 1·47–1·56, for BMI measured at 35–49 years vs 1·21, 1·17–1·25, for BMI measured at
70–89 years; p heterogeneity<0·0001), greater in men than women (1·51, 1·46–1·56, vs 1·30, 1·26–1·33; p heterogeneity<0·0001), but similar in studies with self-reported and measured BMI.

Interpretation</h2.
The associations of both overweight and obesity with higher all-cause mortality were broadly consistent in four continents. This finding supports strategies to combat the entire spectrum of excess adiposity in many
populations.
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Meta-analysis of Peri-operative Beta-Blocker Secure Randomised Trials

Bouri et al present a very important meta-analysis of secure randomised clinical trials of peri-operative beta-blocker therapy. The authors urge retraction from guidelines (see following image) and note the 27% statistically significant increase in mortality observed in secure trials.

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Summary

Background

Current European and American guidelines recommend the perioperative initiation of a course of β-blockers in those at risk of cardiac events undergoing high- or intermediate-risk surgery or vascular surgery. The Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography (DECREASE) family of trials, the bedrock of evidence for this, are no
longer secure. We therefore conducted a meta-analysis of randomised controlled trials of β-blockade on perioperative mortality, non-fatal myocardial infarction, stroke and hypotension in non-cardiac surgery using the secure data.

Methods

The randomised controlled trials of initiation of β-blockers before non-cardiac surgery were examined. Primary outcome was all-cause mortality at 30 days or at discharge. The DECREASE trials were separately analysed.

Results

Nine secure trials totalling 10 529 patients, 291 of whom died, met the criteria. Initiation of a course of β-blockers before surgery caused a 27% risk increase in 30-day all-cause mortality ( p=0.04). The DECREASE family of studies substantially contradict the meta-analysis of the secure trials on the effect of mortality (p=0.05 for divergence). In the secure trials,β-blockade reduced non-fatal myocardial infarction (RR 0.73, p=0.001) but increased stroke (RR 1.73, p=0.05)
and hypotension (RR 1.51, p<0.00001). These results were dominated by one large trial.

Conclusions

Guideline bodies should retract their recommendations based on fictitious data without further delay. This should not be blocked by dispute over allocation of blame. The well-conducted trials indicate a statistically significant 27% increase in mortality from the initiation of perioperative β-blockade that guidelines currently recommend. Any remaining enthusiasts might best channel their energy into a further randomised trial which should be designed carefully and conducted honestly.

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Sexual Activity in Coronary Heart Disease Patients

Steptoe et al present a population based cross-sectional study to assess the relationship between sexual activity and coronary heart disease.

Abstract

Objective

Sexual activity is a central component of intimate relationships, but sexual function may be
impaired by coronary heart disease (CHD). There have been few representative population-based comparisons
of sexual behaviour and concerns in people with and without CHD. We therefore investigated these issues in a
large nationally representative sample of older people.

Methods

We analysed cross-sectional data from 2979 men and 3711 women aged 50 and older from the English Longitudinal Study of Ageing. Sexual behaviour and concerns were assessed by validated self-completion questionnaire and analyses were weighted for nonresponse. Covariates included age, partnerships status and comorbidities.

Results

There were 376 men and 279 women with CHD. Men with CHD were less likely to be sexually active (68.7% vs 80.0%, adjusted OR 0.62, 95% CI 0.47 to 0.81), thought less about sex (74.7% vs 81.9%, OR 0.72, CI 0.54 to 0.95), and reported more erectile difficulties (47.4% vs 38.1%, OR 1.46, CI 1.10 to 1.93) than men without CHD. Effects were more pronounced among those diagnosed within the past 4 years. Women diagnosed <4 years ago were also less
likely to be sexually active (35.4% vs 55.6%, OR 0.44, CI 0.23 to 0.84). There were few differences in
concerns about sexual activity. Cardiovascularshowed weak associations with erectile
dysfunction.

Conclusions

There is an association between CHD and sexual activity, particularly among men, but the impact
of CHD is limited. More effective advice after diagnosis might reverse the reduction in sexual activity, leading to
improved quality of life.
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