Discrepancies in autologous bone marrow stem cell trials and enhancement of ejection fraction (DAMASCENE): weighted regression and meta-analysis

Objective To investigate whether discrepancies in trials of use of bone marrow stem cells in patients with heart disease account for the variation in reported effect size in improvement of left ventricular function. Design Identification and counting of factual discrepancies in trial reports, and sample size weighted regression against therapeutic effect size. Meta-analysis of trials that provided sufficient information. Data sources PubMed and Embase from inception to April 2013. Eligibility for selecting studies Randomised controlled trials evaluating the effect of autologous bone marrow stem cells for heart disease on mean left ventricular ejection fraction. Results There were over 600 discrepancies in 133 reports from 49 trials. There was a significant association between the number of discrepancies and the reported increment in EF with bone marrow stem cell therapy (Spearman’s r=0.4, P=0.005). Trials with no discrepancies were a small minority (five trials) and showed a mean EF effect size of −0.4%. The 24 trials with 1-10 discrepancies showed a mean effect size of 2.1%. The 12 with 11-20 discrepancies showed a mean effect of size 3.0%. The three with 21-30 discrepancies showed a mean effect size of 5.7%. The high discrepancy group, comprising five trials with over 30 discrepancies each, showed a mean effect size of 7.7%. Conclusions Avoiding discrepancies is difficult but is important because discrepancy count is related to effect size. The mechanism is unknown but should be explored in the design of future trials because in the five trials without discrepancies the effect of bone marrow stem cell therapy on ejection fraction is zero

Difficulty in detecting discrepancies in a clinical trial report: 260-reader evaluation

Background: Scientific literature can contain errors. Discrepancies, defined as two or more statements or results that cannot both be true, may be a signal of problems with a trial report. In this study, we report how many discrepancies are detected by a large panel of readers examining a trial report containing a large number of discrepancies. Methods: We approached a convenience sample of 343 journal readers in seven countries, and invited them in person to participate in a study. They were asked to examine the tables and figures of one published article for discrepancies. 260 participants agreed, ranging from medical students to professors. The discrepancies they identified were tabulated and counted. There were 39 different discrepancies identified. We evaluated the probability of discrepancy identification, and whether more time spent or greater participant experience as academic authors improved the ability to detect discrepancies. Results: Overall, 95.3% of discrepancies were missed. Most participants (62%) were unable to find any discrepancies. Only 11.5% noticed more than 10% of the discrepancies. More discrepancies were noted by participants who spent more time on the task (Spearman’s ρ = 0.22, P < 0.01), and those with more experience of publishing papers (Spearman’s ρ = 0.13 with number of publications, P = 0.04). Conclusions: Noticing discrepancies is difficult. Most readers miss most discrepancies even when asked specifically to look for them. The probability of a discrepancy evading an individual sensitized reader is 95%, making it important that, when problems are identified after publication, readers are able to communicate with each other. When made aware of discrepancies, the majority of readers support editorial action to correct the scientific record

Effects of percutaneous coronary intervention on death and myocardial infarction stratified by stable and unstable coronary artery disease: a meta-analysis of randomized controlled trials

Background: In patients presenting with ST-segment–elevation myocardial infarction, percutaneous coronary intervention (PCI) reduces mortality when compared with fibrinolysis. In other forms of coronary artery disease (CAD), however, it has been controversial whether PCI reduces mortality. In this meta-analysis, we examine the benefits of PCI in (1) patients post–myocardial infarction (MI) who did not receive immediate revascularization; (2) patients who have undergone primary PCI for ST-segment–elevation myocardial infarction but have residual coronary lesions; (3) patients who have suffered a non–ST-segment–elevation acute coronary syndrome; and (4) patients with truly stable CAD with no recent infarct. This analysis includes data from the recently presented International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) and Complete versus Culprit-Only Revascularization Strategies to Treat Multivessel Disease after Early PCI for STEMI (COMPLETE) trials. Methods and Results: We systematically identified all randomized trials of PCI on a background of medical therapy for the treatment of CAD. The ISCHEMIA trial, presented in November 2019, was eligible for inclusion. Data were combined using a random-effects meta-analysis. The primary end point was all-cause mortality. Forty-six trials, including 37 757 patients, were eligible. In the 3 unstable scenarios, PCI had the following effects on mortality: unrevascularized post-MI relative risk (RR) 0.68 (95% CI, 0.45–1.03); P=0.07; multivessel disease following ST-segment–elevation myocardial infarction (RR, 0.84 [95% CI, 0.69–1.04]; P=0.11); non–ST-segment–elevation acute coronary syndrome (RR, 0.84 [95% CI, 0.72–0.97]; P=0.02). Overall, in these unstable scenarios PCI was associated with a significant reduction in mortality (RR, 0.84 [95% CI, 0.75–0.93]; P=0.02). In unstable CAD, PCI also reduced cardiac death (RR, 0.69 [95% CI, 0.53–0.90]; P=0.007) and MI (RR, 0.74 [95% CI, 0.62–0.90]; P=0.002). For stable CAD, PCI did not reduce mortality (RR, 0.98 [95% CI, 0.87–1.11]), cardiac death (RR, 0.89 [95% CI, 0.71–1.12]; P=0.33), or MI (RR, 0.96 [95% CI, 0.86–1.08]; P=0.54). Conclusions: PCI prevents death, cardiac death, and MI in patients with unstable CAD. For patients with stable CAD, PCI shows no evidence of an effect on any of these outcomes

Percutaneous coronary intervention for stable coronary artery disease

The adverse consequences of stable coronary artery disease (CAD) are death, myocardial infarction (MI) and angina. Trials in stable CAD show that percutaneous coronary intervention (PCI) does not reduce mortality. PCI does appear to reduce spontaneous MI rates but at the expense of causing some periprocedural MI. Therefore, the main purpose of PCI is to relieve angina. Indeed, patients and physicians often choose PCI rather than first attempting to control symptoms with anti-anginal medications as recommended by guidelines. Nevertheless, it is unclear how effective PCI is at relieving angina. This is because, whereas anti-anginal medications are universally required to be tested against placebo, there is no such requirement for procedural interventions such as PCI. The first placebo-controlled trial of PCI showed a surprisingly small effect size. This may be because it is overly simplistic to assume that the presence of a stenosis and inducible ischaemia in a patient means that the clinical chest pain they report is caused by ischaemia. In this article, we review the evidence base and argue that if we as a medical specialty wish to lead the science of procedures for symptom control, we should recognise the special merit of placebo-controlled experiments

Mortality from Ischaemic Heart Disease: analysis of data from the World Health Organization and coronary artery disease risk factors from NCD-RisC

Background Ischemic heart disease (IHD) has been considered the top cause of mortality globally. However, countries differ in their rates and there have been changes over time. Methods and Results We analyzed mortality data submitted to the World Health Organization from 2005 to 2015 by individual countries. We explored patterns in relationships with age, sex, and income and calculated age-standardized mortality rates for each country in addition to crude death rates. In 5 illustrative countries which provided detailed data, we analyzed trends of mortality from IHD and 3 noncommunicable diseases (lung cancer, stroke, and chronic lower respiratory tract diseases) and examined the simultaneous trends in important cardiovascular risk factors. Russia, United States, and Ukraine had the largest absolute numbers of deaths among the countries that provided data. Among 5 illustrative countries (United Kingdom, United States, Brazil, Kazakhstan, and Ukraine), IHD was the top cause of death, but mortality from IHD has progressively decreased from 2005 to 2015. Age-standardized IHD mortality rates per 100 000 people per year were much higher in Ukraine (324) and Kazakhstan (97) than in United States (60), Brazil (54), and the United Kingdom (46), with much less difference in other causes of death. All 5 countries showed a progressive decline in IHD mortality, with a decline in smoking and hypertension and in all cases a rise in obesity and type II diabetes mellitus. Conclusions IHD remains the single largest cause of death in countries of all income groups. Rates are different between countries and are falling in most countries, indicating great potential for further gains. On the horizon, future improvements may become curtailed by increasing hypertension in some developing countries and more importantly global growth in obesity