Accuracy of event rate and effect size estimation in major cardiovascular trials

Background

During the design of a randomized controlled trial (RCT), the estimation of the expected event rate (ER) and effect size (ES) of an intervention is an essential step to calculate the sample size, which determines the scope of the trial. Overestimation of ER and ES might lead to an underpowered trial design.

Objective

To evaluate the accuracy of the estimation of ER and ES in contemporary cardiovascular RCTs.

Methods

We searched “Medline” for cardiovascular RCTs published in the New England Journal of Medicine, The Journal of the American Medical Association, or The Lancet between 2010 and 2019. Only multicenter RCTs with a dichotomous primary endpoint and with not more than 2 study arms were included. Data were extracted from the original publication or the associated study protocol. For trials that tested superiority of an intervention, the effect size measurements hazard ratio, odds ratio, or risk ratio were summarized as the effect size ratio (ESR). To determine the accuracy of estimation, we compared the observed to the hypothesized ER and ESR, respectively. The association of the accuracy of estimation with trial characteristics was determined by linear regression.

Results

Of 875 identified publications, 374 underwent full review. After exclusion of trials with insufficiently reported data for this analysis, data from 344 trials were analyzed. 145 trials (42.2%) were industry sponsored, 122 (35.5%) were investigator-initiated with industry-co funding, and 77 (22.1%) with government or public funding. The majority (186; 54.1%) tested a drug as the intervention. 263 (76.5%) were designed to test for superiority of the intervention. The primary endpoint consisted of at least 2 components in 247 (71.8%) trials. The median estimated sample size was 2386 (interquartile range [IQR] 800, 6000).

The median observed event rate was 9.0% (IQR 4.3, 21.4%) and was significantly lower compared with the estimated ER (11.0% [IQR 6.0, 25.0%]; median deviation from estimation −6.9% [95% confidence interval, CI −10.0, −3.7%]; p<0.001). 196 trials (61%) overestimated the event rate (Figure 1A). The overestimation was consistent across several subgroups (Figure 2A). The median observed ESR was 0.910 (IQR 0.740, 0.990) and was significantly higher compared with the estimated ESR (0.724 [IQR 0.600, 0.795]; median deviation from estimated effect size 26.0% [95% CI, 19.0, 33.0%]). 216 (82.1%) trials overestimated the effect size (Figure 1B). This overestimation was consistent across all analyzed subgroups (Figure 2B) and was less pronounced in trials with use of a composite primary outcome.

Conclusion

6 of 10 contemporary cardiovascular RCTs overestimated the event rate for the primary endpoint and 8 of 10 trials overestimated the effect sizes of an intervention. Overestimation may lead to inability to answer the trial hypothesis.

Funding Acknowledgement

Type of funding sources: None.

Clinical analysis on diagnostic accuracy of Bosch Vivalytic SARS-CoV-2 point-of-care test and evaluation of cycle threshold at admission for COVID-19 risk assessment

BACKGROUND

Point-of-care (POC) polymerase chain reaction (PCR) tests have the ability to improve testing efficiency in the Coronavirus disease 2019 (COVID-19) pandemic. However, real-world data on POC tests is scarce.

OBJECTIVE

To evaluate the efficiency of a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) POC test in a clinical setting and examine the prognostic value of cycle threshold (CT) on admission on the length of hospital stay (LOS) in COVID-19 patients.

METHODS

Patients hospitalised between January and May 2021 were included in this prospective cohort study. Patients' nasopharyngeal swabs were tested for SARS-CoV-2 with Allplex™2019-nCoV (Seegene Inc.) real-time (RT) PCR assay as gold standard as well as a novel POC test (Bosch Vivalytic SARS-CoV-2 [Bosch]) and the SARS-CoV-2 Rapid Antigen Test (Roche) accordingly. Clinical sensitivity and specificity as well as inter- and intra-assay variability were analyzed.

RESULTS

120 patients met the inclusion criteria with 46 (38%) having a definite COVID-19 diagnosis by RT-PCR. Bosch Vivalytic SARS-CoV-2 POC had a sensitivity of 88% and specificity of 96%. The inter- and intra- assay variability was below 15%. The CT value at baseline was lower in patients with LOS ≥ 10 days when compared to patients with LOS < 10 days (27.82 (± 4.648) vs. 36.2 (25.9-39.18); p = 0.0191). There was a negative correlation of CT at admission and LOS (r[44]s = - 0.31; p = 0.038) but only age was associated with the probability of an increased LOS in a multiple logistic regression analysis (OR 1.105 [95% CI, 1.03-1.19]; p = 0.006).

CONCLUSION

Our data indicate that POC testing with Bosch Vivalytic SARS-CoV-2 is a valid strategy to identify COVID-19 patients and decrease turnaround time to definite COVID-19 diagnosis. Also, our data suggest that age at admission possibly with CT value as a combined parameter could be a promising tool for risk assessment of increased length of hospital stay and severity of disease in COVID-19 patients.

Medical history of coronary artery disease and time to electrocardiogram in the emergency department: a real-life, single-center, retrospective analysis

Background

Timely acquisition of 12-lead Electrocardiogram (ECG) in the emergency department (ED) is crucial and recommended by current guidelines.

Objectives

To evaluate the association of medical history of coronary artery disease (hCAD) on door-to-ECG time in the ED.

Methods

In this single center, retrospective cohort study, patients admitted to ED for cardiac evaluation were grouped according to hCAD and no hCAD. The primary outcome was door-to-ECG time. A multivariate analysis adjusted for the cofounders sex, age, type of referral and shift was performed to evaluate the association of hCAD with door-to-ECG time.

Results

1101 patients were included in this analysis. 362 patients (33%) had hCAD. Patients with hCAD had shorter door-to-ECG time (20 min. [Inter Quartile Range [IQR] 13–30] vs. 22 min. [IQR 14–37]; p < 0.001) when compared to patients with no hCAD. In a multivariable regression analysis hCAD was significantly associated with a shorter door-to-ECG time (− 3 min [p = 0.007; 95% confidence Interval [CI] − 5.16 to − 0.84 min]).

Conclusion

In this single center registry, hCAD was associated with shorter door-to-ECG time. In patients presenting in ED for cardiac evaluation, timely ECG diagnostic should be facilitated irrespective of hCAD.

[Aspiration-based endocarditis debridement of a competent tricuspid valve in a high-risk case of tricuspid valve endocarditis secondary to cardiac device-related infective endocarditis]

INTRODUCTION

The incidence of tricuspid valve endocarditis secondary to cardiac device-related infective endocarditis is rising, probably due to an increasing number of implantations. We describe a novel therapy approach using standard cardiology diagnostic catheter guided by periinterventional transesophageal echocardiographic imaging for aspiration-based endocarditis debridement of the tricuspid valve in a high-risk-patient.

HISTORY

A 65-year-old patient presented with right-heart endocarditis associated with cardiac device-related infective endocarditis. He had a history of ischemic cardiomyopathy, 3-vessel coronary artery disease and was successfully resuscitated one year ago with subsequent implantation of an implantable cardioverter-defibrillator (ICD).

FINDINGS AND DIAGNOSIS

Echocardiography revealed typical endocarditis vegetations on the defibrillator lead and the tricuspid valve. Moreover peripheral septic embolism was suspected.

THERAPY AND COURSE

The cardioverter-defibrillator was explanted and extensive antiinfective therapy was established as the patient was in a state of persistent bacteremia and prolonged septic shock. Open heart surgery was dismissed due the patient´s increased risk of mortality. After interdisciplinary consensus an aspiration-based endocarditis debridement of the tricuspid valve with maintained valve-functionality using a standard cardiology was carried out.

CONCLUSION

Aspiration-based endocarditis debridement in right-heart endocarditis in high-risk patients using a standard cardiology diagnostic catheter can be an alternative to open heart surgery. However, larger clinical studies are needed to define the safety and prognostic benefit of an interventional catheter approach in infective endocarditis.

Dual-Pathway Antithrombotic Therapy in Patients With Atrial Fibrillation After Percutaneous Coronary Intervention in Stable Coronary Artery Disease: A Single-Center, Single-Operator, Retrospective Cohort Study

Background: There is limited data evaluating the prescription practices for antithrombotic therapy in patients with atrial fibrillation (AF) following elective percutaneous coronary intervention (PCI).

Objective: This single-center, single-operator, retrospective cohort study aimed to evaluate trends of antithrombotic treatment strategies in patients with AF undergoing elective PCI.

Methods: Patients with AF who electively underwent PCI performed by a single interventionalist between April 2013 and May 2018 were identified. The primary outcome was the antithrombotic therapy at discharge assessed by chart review: triple (TAT, triple antithrombotic therapy) or dual (DAT, dual antithrombotic therapy) antithrombotic therapy and vitamin K antagonist (VKA) or non-vitamin K antagonist oral anticoagulant (NOAC), respectively.

Results: Of 6,135 screened patients, 259 met the inclusion criteria. Among these, 133 (51%) patients received NOAC- and 126 (49%) VKA-therapy. Compared with patients on NOAC therapy, patients treated with VKA had higher bleeding risk (mean HAS-BLED-Score; 2.3 vs. 2.0; p = 0.02) and more co-morbidities (estimated glomerular filtration rate <30 ml/min, 11 vs. 4%; p = 0.04; diabetes mellitus, 33 vs. 20%; p = 0.03; history of previous PCI, 37 vs. 21%; p < 0.01). TAT was prescribed more frequently if the prescription included VKA compared with NOAC (61 vs. 41%; p < 0.01). Prescription of TAT and VKA decreased throughout the observed period (2013: 100% vs. 2018: 6%; p < 0.01 and 2013: 91% vs. 2018: 28%; p < 0.01).

Conclusion: These observational data from a single center registry show a decrease of TAT- and VKA- prescription in favor of DAT with NOAC. Whether these observations are consistent with national or global trends should to be evaluated in further studies.

Influence of extracorporeal membrane oxygenation on serum microRNA expression

Objective

To date, no biomarkers have been established to predict haematological complications and outcomes of extracorporeal membrane oxygenation (ECMO). The aim of this study was to investigate the expression of a panel of microRNAs (miRNAs), which are promising biomarkers in many clinical fields, in patients before and after initiating ECMO.

Methods

Serum miRNA levels from 14 patients hospitalized for acute respiratory failure and supported with ECMO in our medical intensive care unit were analysed before and 24 hours after ECMO. In total, 179 serum-enriched miRNAs were profiled by using a real-time PCR panel. For validation, differentially expressed miRNAs were individually quantified with conventional real-time quantitative PCR at 0, 24, and 72 hours.

Results

Under ECMO support, platelet count significantly decreased by 65 × 103/µL (25th percentile = 154.3 × 103/µL; 75th percentile = 33 × 103/µL). Expression of the 179 miRNAs investigated in this study did not change significantly throughout the observational period.

Conclusions

According to our data, the expression of serum miRNAs was not altered by ECMO therapy itself. We conclude that ECMO does not limit the application of miRNAs as specific clinical biomarkers for the patients’ underlying disease.

Expression of the oxygen-sensitive transcription factor subunit HIF-1α in patients suffering from secondary Raynaud syndrome

Anti-ischemic therapy remains a challenge due to the complexity of hypoxia response pathways. Hypoxia-inducible factor (HIF)-1 is a heterodimer transcription factor consisting of 2 subunits, HIF-1α and HIF-1β. Hypoxia-dependent activation of HIF-1α regulates cellular O₂ homeostasis. Raynaud syndrome (RS), as a comorbidity of the autoimmune disease systemic sclerosis (SS), is characterized by vasospasms that limit blood flow to the limbs, resulting in hypoxia. A single-center randomized study was conducted to compare prostaglandin E1 (PgE1) therapy with a treatment combining PgE1 and an endothelin-1 blocker, bosentan. A total of 30 patients suffering from SS with RS were enrolled. We examined the regulation of HIF-1α, its target heme oxygenase-1 (HMOX-1), and the serum levels of the HIF-1α protein in a subset of patients as well as in ten healthy individuals. The expression of HIF-1α and HMOX-1 in monocytes was measured using absolute plasmid-based quantitative real-time PCR, whereas serum HIF-1α levels were measured with ELISA. Samples were taken at the time of randomization and after 24 weeks. We found that HIF-1α and HMOX-1 mRNA expression in monocytes and serum HIF-1α protein levels were significantly higher in the SS/RS patients compared to the healthy control group. Single-drug therapy significantly increased HIF-1α and HMOX-1 mRNA expression in monocytes and serum HIF-1α protein levels in the SS/RS patients compared to those at the time of randomization, whereas combining PgE1 with an endothelin-1 blocker prevented the further increases in HIF-1α and HMOX-1 expression. We propose HIF-1α and HMOX-1 as novel markers for anti-ischemic therapy in RS.

Digital PCR for Quantifying Circulating MicroRNAs in Acute Myocardial Infarction and Cardiovascular Disease

Circulating serum microRNAs (miRNAs) have shown promise as biomarkers for the cardiovascular disease and acute myocardial infarction (AMI), being released from the cardiovascular cells into the circulation. Circulating miRNAs are highly stable and can be quantified. The quantitative expression of specific miRNAs can be linked to the pathology, and some miRNAs show high tissue and disease specificity. Finding novel biomarkers for cardiovascular diseases is of importance for medical research. Quite recently, digital polymerase chain reaction (dPCR) has been invented. dPCR, combined with fluorescent hydrolysis probes, enables specific direct absolute quantification. dPCR exhibits superior technical qualities, including a low variability, high linearity, and high sensitivity compared to the quantitative polymerase chain reaction (qPCR). Thus, dPCR is a more accurate and reproducible method for directly quantifying miRNAs, particularly for the use in large multi-center cardiovascular clinical trials. In this publication, we describe how to effectively perform digital PCR in order to assess the absolute copy number in serum samples.