Comparing Analytical Methods for Composite End Points in Clinical Trials: Insights from the Vericiguat Global Study in Subjects with Heart Failure With Reduced Ejection Fraction Trial

BACKGROUND

In VICTORIA (Vericiguat Global Study in Subjects with Heart Failure with Reduced Ejection Fraction), participants with heart failure (HF) and reduced ejection fraction, vericiguat decreased the primary composite outcome (time to first HF hospitalization [HFH] or cardiovascular death [CVD]) (897 events) compared with placebo (972 events) (hazard ratio, 0.90; 95% confidence interval [CI], 0.82-0.98; P = .02). In this prespecified secondary analysis, we applied the weighted composite end point (WCE) and the win ratio (WR) methods to provide complementary assessments of treatment effect.

METHODS AND RESULTS

The WCE method estimated the mean HFH-adjusted survival based on prespecified weights from a Delphi panel of the VICTORIA executive committee and national leaders: mild (weight per event, 0.39), moderate (0.5), or severe (0.67) HFH, and CVD (1.0). The unmatched WR was estimated for the descending hierarchy of CVD, then recurrent HFH. The WCE used all 3412 primary clinical events: 875 severe HFH (vericiguat, 416/ placebo, 459), 1614 moderate HFH (767/847), 68 mild HFH (38/30), and 855 CVD (414/441). Improved HFH-adjusted survival occurred with vericiguat (mean 78.2% vs 75.6%, difference 2.4%, 95% CI, 1.7%-3.2%, P < .0001). Based on a comparison of 6,375,624 pairs, the WR of 1.13 (95% CI 1.03-1.24, P = .01) also indicated improved clinical outcomes with vericiguat.

CONCLUSIONS

The results of the WCE and WR methods were consistent with the primary analysis of the time to first HFH or CVD. Although both WCE and WR assessed recurrent events, the WCE allowed inclusion of all recurrent events, insights on the severity of HFH events, and an absolute measure of the participant-treatment experience. This approach complements conventional assessment, better informing consumers of new therapeutics and future trial designs.

Clinical trial design, end-points, and emerging therapies in pulmonary arterial hypertension

Clinical trials in pulmonary arterial hypertension (PAH) have led to the approval of several effective treatments that improve symptoms, exercise capacity and clinical outcomes. In phase 3 clinical trials, primary end-points must reflect how a patient "feels, functions or survives". In a rare disease like PAH, with an ever-growing number of treatment options and numerous candidate therapies being studied, future clinical trials are now faced with challenges related to sample size requirements, efficiency and demonstration of incremental benefit on traditional end-points in patients receiving background therapy with multiple drugs. Novel clinical trial end-points, innovative trial designs and statistical approaches and new technologies may be potential solutions to tackle the challenges facing future PAH trials, but these must be acceptable to patients and regulatory bodies while preserving methodological rigour. In this World Symposium on Pulmonary Hypertension task force article, we address emerging trial end-points and designs, biomarkers and surrogate end-point validation, the concept of disease modification, challenges and opportunities to address diversity and representativeness, and the use of new technologies such as artificial intelligence in PAH clinical trials.

Application of the Win Ratio Method in the ENGAGE AF-TIMI 48 Trial Comparing Edoxaban With Warfarin in Patients With Atrial Fibrillation

BACKGROUND

Cardiovascular trials often use a composite end point and a time-to-first event model. We sought to compare edoxaban versus warfarin using the win ratio, which offers data complementary to time-to-first event analysis, emphasizing the most severe clinical events.

METHODS

ENGAGE AF-TIMI 48 (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48) was a double-blind, randomized trial in which patients with atrial fibrillation were assigned 1:1:1 to a higher dose edoxaban regimen (60/30 mg daily), a lower dose edoxaban regimen (30/15 mg daily), or warfarin. In an exploratory analysis, we analyzed the trial outcomes using an unmatched win ratio approach. The win ratio for each edoxaban regimen was the total number of edoxaban wins divided by the number of warfarin wins for the following ranked clinical outcomes: 1: death; 2: hemorrhagic stroke; 3: ischemic stroke/systemic embolic event/epidural or subdural bleeding; 4: noncerebral International Society on Thrombosis and Haemostasis major bleeding; and 5: cardiovascular hospitalization.

RESULTS

21 105 patients were randomized to higher dose edoxaban regimen (N=7035), lower dose edoxaban regimen (N=7034), or warfarin (N=7046), yielding >49 million pairs for each treatment comparison. The median age was 72 years, 38% were women, and 59% had prior vitamin K antagonist use. The win ratio was 1.11 (95% CI, 1.05-1.18) for higher dose edoxaban regimen versus warfarin and 1.11 (95% CI, 1.05-1.18) for lower dose edoxaban regimen versus warfarin. The favorable impacts of edoxaban on death (34% of wins) and cardiovascular hospitalization (41% of wins) were the major contributors to the win ratio. Results consistently favored edoxaban in subgroups based on creatine clearance and dose reduction at baseline, with heightened benefit among those without prior vitamin K antagonist use.

CONCLUSIONS

In a win ratio analysis of the ENGAGE AF-TIMI 48 trial, both dose regimens of edoxaban were superior to warfarin for the net clinical outcome incorporating ischemic and bleeding events. As the win ratio emphasizes the most severe clinical events, this analysis supports the superiority of edoxaban over warfarin in patients with atrial fibrillation.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT00781391.

Making Sense of Composite Endpoints in Clinical Research

Multiple drugs currently used in clinical practice have been approved by regulatory agencies based on studies that utilize composite endpoints. Composite endpoints are appealing because they reduce sample size requirements, follow-up periods, and costs. However, interpreting composite endpoints can be challenging, and their misuse is not uncommon. Incorrect interpretation of composite outcomes can lead to misleading conclusions that impact patient care. To correctly interpret composite outcomes, several important questions should be considered. Are the individual components of the composite outcome equally important to patients? Did the more and less important endpoints occur with similar frequency? Do the component endpoints exhibit similar relative risk reductions? If these questions receive affirmative answers, the use and interpretation of the composite endpoint would be appropriate. However, if any component of the composite endpoint fails to satisfy the aforementioned criteria, interpretation can become difficult, necessitating additional steps. Regulatory agencies acknowledge these challenges and have specific considerations when approving drugs based on studies employing composite endpoints. In conclusion, composite endpoints are valuable tools for evaluating the efficacy and net clinical benefit of interventions; however, cautious interpretation is advised.

Assessment of Nonfatal Bleeding Events as a Surrogate for Mortality in Coronary Artery Disease

Background

Bleeding events are frequently applied as safety end points for randomized controlled trials (RCTs) investigating the effect of antithrombotic agents in patients with coronary artery disease. However, whether a bleeding event is a valid surrogate for death remain uncertain.

Objectives

This study aimed to assess the correlation between the treatment effect on bleeding events and mortality.

Methods

Multiple databases were searched to identify RCTs studying antithrombotic agents for patients with coronary artery disease through August 2022. Major and minor bleeding events were defined in included trials, mostly defined with BARC (Bleeding Academic Research Consortium) or TIMI (Thrombolysis In Myocardial Infarction) criteria. Trial-level correlations between nonfatal bleeding events and mortality were assessed. We performed subgroup analyses by the definitions of bleeding (BARC vs TIMI criteria), study year, and follow-up duration. We used a cutoff with a lower limit of 95% confidence interval of R2 >0.72 as a strong correlation and with an upper limit of 95% confidence interval of R2 <0.50 as a weak correlation.

Results

A total of 48 RCTs with 181,951 participants were analyzed. Overall, trial-level R2 for major and minor bleeding were 0.09 (95% CI: 0.00-0.26) and 0.09 (95% CI: 0.00-0.27) for all-cause or cardiovascular death, respectively. When confined to major bleeding, R2 were 0.03 (95% CI: 0.00-0.13) and 0.01 (95% CI: 0.00-0.05), respectively. All of the subgroup analyses did not show any significant correlations.

Conclusions

We demonstrated a trial-defined bleeding event may not be a valid surrogate for mortality in RCTs investigating the effect of antithrombotic agents for coronary artery disease.

Phenotyping for percutaneous coronary intervention and long-term recurrent weighted outcomes

INTRODUCTION

Percutaneous coronary interventions (PCI) are often performed in multimorbid patients with heterogeneous characteristics and variable clinical outcomes. We aimed to identify distinct clinical phenotypes utilizing machine learning and explore their relationship with long-term recurrent and weighted outcomes.

METHODS

This prospective observational cohort study enrolled all-comer PCI patients in 2020-2021. Multiple imputation k-means clustering was utilized to detect specific phenotypes. The study endpoints were patient-oriented and device oriented composite endpoints (POCE, DOCE), its individual components, and major bleeding. We applied semiparametric regression models for recurrent and weighted endpoints.

RESULTS

The study included a total of 643 patients. We unveiled three phenotype clusters: 1) inflammatory (n = 44, with high white blood cell counts, high values of C-reactive protein (CRP) and neutrophil-to-lymphocyte ratio), 2) high erythrocyte sedimentation rate (ESR) (n = 204), and 3) non-inflammatory (n = 395). For ACS-only population, we four distinct phenotypes (high-CRP, high-ESR, high aspartate-aminotransferase, and normal). For all-comer PCI patients, identified phenotypes had a higher risk of POCE (mean ratio (MR) 1.42 (95% confidence interval (CI) 1.11-1.81) and MR 2.01 (95% CI 1.58-2.56), respectively), DOCE (MR 1.61 (95% CI 1.20-2.16), MR 2.60 (95%CI 1.94-3.48), respectively), and stroke (hazard ratio (HR) 2.86 (95% CI 1.10-7.4), 6.83 (95% CI 2.01-23.2)). Similarly, high-ESR and high-CRP phenotypes of ACS patients were significantly associated with the development of clinical composite outcomes.

CONCLUSION

Machine learning unveiled three distinct phenotype clusters in patients after PCI that were linked with the risk of recurrent and weighted clinical endpoints. German Clinical Trial Registry number: DRKS00020892.

The empirical estimate of the survival and variance using a weighted composite endpoint

BACKGROUND

Composite endpoints for estimating treatment efficacy are routinely used in several therapeutic areas and have become complex in the number and types of component outcomes included. It is assumed that its components are of similar asperity and chronology between both treatment arms as well as uniform in magnitude of the treatment effect. However, these assumptions are rarely satisfied. Understanding this heterogeneity is important in developing a meaningful assessment of the treatment effect.

METHODS

We developed the Weighted Composite Endpoint (WCE) method which uses weights derived from stakeholder values for each event type in the composite endpoint. The derivation for the product limit estimator and the variance of the estimate are presented. The method was then tested using data simulated from parameters based on a large cardiovascular trial. Variances from the estimated and traditional approach are compared through increasing sample size.

RESULTS

The WCE method used all of the events through follow-up and generated a multiple recurrent event survival. The treatment effect was measured as the difference in mean survivals between two treatment arms and corresponding 95% confidence interval, providing a less conservative estimate of survival and variance, giving a higher survival with a narrower confidence interval compared to the traditional time-to-first-event analysis.

CONCLUSIONS

The WCE method embraces the clinical texture of events types by incorporating stakeholder values as well as all events during follow-up. While the effective number of events is lower in the WCE analysis, the reduction in variance enhances the ability to detect a treatment effect in clinical trials.

The win ratio: A novel approach to define and analyze postoperative composite outcomes to reflect patient and clinician priorities

BACKGROUND

The "win ratio" (WR) is a novel statistical technique that hierarchically weighs various postoperative outcomes (eg, mortality weighted more than complications) into a composite metric to define an overall benefit or "win." We sought to use the WR to assess the impact of social vulnerability on the likelihood of achieving a "win" after hepatopancreatic surgery.

METHODS

Individuals who underwent an elective hepatopancreatic procedure between 2013 and 2017 were identified using the Medicare database, which was merged with the Center for Disease Control and Prevention's Social Vulnerability Index. The win ratio was defined based on a hierarchy of postoperative outcomes: 90-day mortality, perioperative complications, 90-day readmissions, and length of stay. Patients matched based on procedure type, race, sex, age, and Charlson Comorbidity Index score were compared and assessed relative to win ratio.

RESULTS

Among 32,557 Medicare beneficiaries who underwent hepatectomy (n = 11,621, 35.7%) or pancreatectomy (n = 20,936, 64.3%), 16,846 (51.7%) patients were male with median age of 72 years (interquartile range 68-77) and median Charlson Comorbidity Index of 3 (interquartile range 2-8), and a small subset of patients were a racial/ethnic minority (n = 3,759, 11.6%). Adverse events associated with lack of a postoperative optimal outcome included 90-day mortality (n = 2,222, 6.8%), postoperative complication (n = 8,029, 24.7%), readmission (n = 6,349, 19.5%), and length of stay (median: 7 days, interquartile range 5-11). Overall, the patients from low Social Vulnerability Index areas were more likely to "win" with a textbook outcome (win ratio 1.07, 95% confidence interval 1.01-1.12) compared with patients from high social vulnerability counties; in contrast, there was no difference in the win ratio among patients living in average versus high Social Vulnerability Index (win ratio 1.04, 95% confidence interval 0.98-1.10). In assessing surgeon volume, patients who had a liver or pancreas procedure performed by a high-volume surgeon had a higher win ratio versus patients who were treated by a low-volume surgeon (win ratio 1.21, 95% confidence interval 1.16-1.25). In contrast, there was no difference in the win ratio (win ratio 1.01, 95% confidence interval 0.97-1.06) among patients relative to teaching hospital status.

CONCLUSION

Using a novel statistical approach, the win ratio ranked outcomes to create a composite measure to assess a postoperative "win." The WR demonstrated that social vulnerability was an important driver in explaining disparate postoperative outcomes.

Antiplatelet agents for chronic kidney disease

BACKGROUND

Antiplatelet agents are widely used to prevent cardiovascular events. The risks and benefits of antiplatelet agents may be different in people with chronic kidney disease (CKD) for whom occlusive atherosclerotic events are less prevalent, and bleeding hazards might be increased. This is an update of a review first published in 2013.

OBJECTIVES

To evaluate the benefits and harms of antiplatelet agents in people with any form of CKD, including those with CKD not receiving renal replacement therapy, patients receiving any form of dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 July 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We selected randomised controlled trials of any antiplatelet agents versus placebo or no treatment, or direct head-to-head antiplatelet agent studies in people with CKD. Studies were included if they enrolled participants with CKD, or included people in broader at-risk populations in which data for subgroups with CKD could be disaggregated.

DATA COLLECTION AND ANALYSIS

Four authors independently extracted data from primary study reports and any available supplementary information for study population, interventions, outcomes, and risks of bias. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from numbers of events and numbers of participants at risk which were extracted from each included study. The reported RRs were extracted where crude event rates were not provided. Data were pooled using the random-effects model. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 113 studies, enrolling 51,959 participants; 90 studies (40,597 CKD participants) compared an antiplatelet agent with placebo or no treatment, and 29 studies (11,805 CKD participants) directly compared one antiplatelet agent with another. Fifty-six new studies were added to this 2021 update. Seven studies originally excluded from the 2013 review were included, although they had a follow-up lower than two months. Random sequence generation and allocation concealment were at low risk of bias in 16 and 22 studies, respectively. Sixty-four studies reported low-risk methods for blinding of participants and investigators; outcome assessment was blinded in 41 studies. Forty-one studies were at low risk of attrition bias, 50 studies were at low risk of selective reporting bias, and 57 studies were at low risk of other potential sources of bias. Compared to placebo or no treatment, antiplatelet agents probably reduces myocardial infarction (18 studies, 15,289 participants: RR 0.88, 95% CI 0.79 to 0.99, I² = 0%; moderate certainty). Antiplatelet agents has uncertain effects on fatal or nonfatal stroke (12 studies, 10.382 participants: RR 1.01, 95% CI 0.64 to 1.59, I² = 37%; very low certainty) and may have little or no effect on death from any cause (35 studies, 18,241 participants: RR 0.94, 95 % CI 0.84 to 1.06, I² = 14%; low certainty). Antiplatelet therapy probably increases major bleeding in people with CKD and those treated with haemodialysis (HD) (29 studies, 16,194 participants: RR 1.35, 95% CI 1.10 to 1.65, I² = 12%; moderate certainty). In addition, antiplatelet therapy may increase minor bleeding in people with CKD and those treated with HD (21 studies, 13,218 participants: RR 1.55, 95% CI 1.27 to 1.90, I² = 58%; low certainty). Antiplatelet treatment may reduce early dialysis vascular access thrombosis (8 studies, 1525 participants) RR 0.52, 95% CI 0.38 to 0.70; low certainty). Antiplatelet agents may reduce doubling of serum creatinine in CKD (3 studies, 217 participants: RR 0.39, 95% CI 0.17 to 0.86, I² = 8%; low certainty). The treatment effects of antiplatelet agents on stroke, cardiovascular death, kidney failure, kidney transplant graft loss, transplant rejection, creatinine clearance, proteinuria, dialysis access failure, loss of primary unassisted patency, failure to attain suitability for dialysis, need of intervention and cardiovascular hospitalisation were uncertain. Limited data were available for direct head-to-head comparisons of antiplatelet drugs, including prasugrel, ticagrelor, different doses of clopidogrel, abciximab, defibrotide, sarpogrelate and beraprost.

AUTHORS' CONCLUSIONS

Antiplatelet agents probably reduced myocardial infarction and increased major bleeding, but do not appear to reduce all-cause and cardiovascular death among people with CKD and those treated with dialysis. The treatment effects of antiplatelet agents compared with each other are uncertain.

Trade-off of major bleeding versus myocardial infarction on mortality after percutaneous coronary intervention

Background

The choice of antithrombotic therapy after percutaneous coronary intervention (PCI) is heavily dependent on the relative trade-off between major bleeding (MB) and myocardial infarction (MI). However, the mortality trade-off was mostly described in Western populations and remained unknown in East Asians.

Method

This was a retrospective cohort study from 14 hospitals under the Hospital Authority of Hong Kong between 2004 and 2017. Participants were patients undergoing first-time PCI and survived for the first year. Patients were stratified by the presence of MB and MI during the first year. The primary endpoint was all-cause mortality between 1 and 5 years after PCI. The secondary endpoint was cardiovascular mortality.

Results

A total of 32 180 patients were analysed. After adjustment for baseline characteristics and using patients with neither events as reference, the risks of all-cause mortality were increased in patients with MI only (HR, 1.63; 95% CI 1.45 to 1.84; p<0.001), further increased in those with MB only (HR, 2.11, 95% CI 1.86 to 2.39; p<0.001) and highest in those with both (HR, 2.92; 95% CI 2.39 to 3.56; p<0.001). In both Cox regression and propensity score analyses, MB had a stronger impact on all-cause mortality than MI, but similar impact on cardiovascular mortality.

Conclusions

Both MB and MI within the first year after PCI were associated with increase in all-cause and cardiovascular mortality in Chinese patients, but the impact was stronger with MB.

Mortality after bleeding versus myocardial infarction in coronary artery disease: a systematic review and meta-analysis

BACKGROUND

Bleeding is the principal safety concern of antithrombotic therapy and occurs frequently among patients with coronary artery disease (CAD).

AIMS

We aimed to evaluate the prognostic impact of bleeding on mortality compared with that of myocardial infarction (MI) in patients with CAD.

METHODS

We searched Medline and Embase for studies that included patients with CAD and that reported both the association between the occurrence of bleeding and mortality, and between the occurrence of MI and mortality within the same population. Adjusted hazard ratios (HRs) for mortality associated with bleeding and MI were extracted and ratios of hazard ratios (rHRs) were pooled by using inverse variance weighted random effects meta-analyses. Early events included periprocedural or within 30-day events after revascularisation or acute coronary syndrome (ACS). Late events included spontaneous or beyond 30-day events after revascularisation or ACS.

RESULTS

A total of 141,059 patients were included across 16 studies; 128,660 (91%) underwent percutaneous coronary intervention. Major bleeding increased the risk of mortality to the same extent as MI (rHRsbleedingvsMI 1.10, 95% CI: 0.71-1.71, p=0.668). Early bleeding was associated with a higher risk of mortality than early MI (rHRsbleedingvsMI 1.46, 95% CI: 1.13-1.89, p=0.004), although this finding was not present when only randomised trials were included. Late bleeding was prognostically comparable to late MI (rHRsbleedingvsMI 1.14, 95% CI: 0.87-1.49, p=0.358).

CONCLUSIONS

Compared with MI, major and late bleeding is associated with a similar increase in mortality, whereas early bleeding might have a stronger association with mortality.

Win odds: An adaptation of the win ratio to include ties

The win ratio, a recently proposed measure for comparing the benefit of two treatment groups, allows ties in the data but ignores ties in the inference. In this article, we highlight some difficulties that this can lead to, and we propose to focus on the win odds instead, a modification of the win ratio which takes ties into account. We construct hypothesis tests and confidence intervals for the win odds, and we investigate their properties through simulations and in a case study. We conclude that the win odds should be preferred over the win ratio.

Statistical methods for composite endpoints

Composite endpoints are commonly used in clinical trials, and time-to-first-event analysis has been the usual standard. Time-to-first-event analysis treats all components of the composite endpoint as having equal severity and is heavily influenced by short-term components. Over the last decade, novel statistical approaches have been introduced to overcome these limitations. We reviewed win ratio analysis, competing risk regression, negative binomial regression, Andersen-Gill regression, and weighted composite endpoint (WCE) analysis. Each method has both advantages and limitations. The advantage of win ratio and WCE analyses is that they take event severity into account by assigning weights to each component of the composite endpoint. These weights should be pre-specified because they strongly influence treatment effect estimates. Negative binomial regression and Andersen-Gill analyses consider all events for each patient -rather than only the first event - and tend to have more statistical power than time-to-first-event analysis. Pre-specified novel statistical methods may enhance our understanding of novel therapy when components vary substantially in severity and timing. These methods consider the specific types of patients, drugs, devices, events, and follow-up duration.

Prioritised endpoints for device-based hypertension trials: the win ratio methodology

AIMS

Multiple endpoints with varying clinical relevance are available to establish the efficacy of device-based treatments. Given the variance among blood pressure measures and medication changes in hypertension trials, we performed a win ratio analysis of outcomes in a sham-controlled, randomised trial of renal denervation (RDN) in patients with uncontrolled hypertension despite commonly prescribed antihypertensive medications. We propose a novel prioritised endpoint framework for determining the treatment benefit of RDN compared with sham control.

METHODS AND RESULTS

We analysed the SPYRAL HTN-ON MED pilot study data using a prioritised hierarchical endpoint comprised of 24-hour mean ambulatory systolic blood pressure (SBP), office SBP, and medication burden. A generalised pairwise comparisons methodology (win ratio) was extended to examine this endpoint. Clinically relevant thresholds of 5 and 10 mmHg were used for comparisons of ambulatory and office SBP, respectively, and therefore to define treatment "winners" and "losers". For a total number of 1,596 unmatched pairs, the RDN subject was the winner in 1,050 pairs, the RDN subject was the loser in 378 pairs, and 168 pairs were tied. The win ratio in favour of RDN was 2.78 (95% confidence interval [CI]: 1.58 to 5.48; p<0.001) and corresponding net benefit statistic was 0.42 (95% CI: 0.20 to 0.63). Sensitivity analyses performed with differing blood pressure thresholds and according to drug adherence testing demonstrated consistent results.

CONCLUSIONS

The win ratio method addresses prior limitations by enabling inclusion of more patient-oriented results while prioritising those endpoints considered most clinically important. Applying these methods to the SPYRAL HTN-ON MED pilot study (ClinicalTrials.gov Identifier: NCT02439775), RDN was determined to be superior regarding a hierarchical endpoint and a "winner" compared with sham control patients.

Relationship between classic vascular risk factors and cumulative recurrent cardiovascular event burden in patients with clinically manifest vascular disease: results from the UCC-SMART prospective cohort study

OBJECTIVE

The aim of the current study was to assess the relationship between classic cardiovascular risk factors and risk of not only the first recurrent atherosclerotic cardiovascular event, but also the total number of non-fatal and fatal cardiovascular events in patients with recently clinically manifest cardiovascular disease (CVD).

DESIGN

Prospective cohort study.

SETTING

Tertiary care centre.

PARTICIPANTS

7239 patients with a recent first manifestation of CVD from the prospective UCC-SMART (Utrecht Cardiovascular Cohort - Second Manifestations of ARTerial disease) cohort study.

OUTCOME MEASURES

Total cardiovascular events, including myocardial infarction, stroke, vascular interventions, major limb events and cardiovascular mortality.

RESULTS

During a median follow-up of 8.9 years, 1412 patients had one recurrent cardiovascular event, while 1290 patients had two or more recurrent events, with a total of 5457 cardiovascular events during follow-up. The HRs for the first recurrent event and cumulative event burden using Prentice-Williams-Peterson models, respectively, were 1.36 (95% CI 1.25 to 1.48) and 1.26 (95% CI 1.17 to 1.35) for smoking, 1.14 (95% CI 1.11 to 1.18) and 1.09 (95% CI 1.06 to 1.12) for non-high-density lipoprotein (HDL) cholesterol, and 1.05 (95% CI 1.03 to 1.07) and 1.04 (95% CI 1.03 to 1.06) for systolic blood pressure per 10 mm Hg.

CONCLUSIONS

In a cohort of patients with established CVD, systolic blood pressure, non-HDL cholesterol and current smoking are important risk factors for not only the first, but also subsequent recurrent events during follow-up. Recurrent event analysis captures the full cumulative burden of CVD in patients.

The win ratio approach for composite endpoints: practical guidance based on previous experience

The win ratio was introduced in 2012 as a new method for examining composite endpoints and has since been widely adopted in cardiovascular (CV) trials. Improving upon conventional methods for analysing composite endpoints, the win ratio accounts for relative priorities of the components and allows the components to be different types of outcomes. For example, the win ratio can combine the time to death with the number of occurrences of a non-fatal outcome such as CV-related hospitalizations (CVHs) in a single hierarchical composite endpoint. The win ratio can provide greater statistical power to detect and quantify a treatment difference by using all available information contained in the component outcomes. The win ratio can also incorporate quantitative outcomes such as exercise tests or quality-of-life scores. There is a need for more practical guidance on how best to design trials using the win ratio approach. This manuscript provides an overview of the principles behind the win ratio and provides insights into how to implement the win ratio in CV trial design and reporting, including how to determine trial size.

Trial Design Principles for Patients at High Bleeding Risk Undergoing PCI: JACC Scientific Expert Panel

Investigating the balance of risk for thrombotic and bleeding events after percutaneous coronary intervention (PCI) is especially relevant for patients at high bleeding risk (HBR). The Academic Research Consortium for HBR recently proposed a consensus definition in an effort to standardize the patient population included in HBR trials. The aim of this consensus-based document, the second initiative from the Academic Research Consortium for HBR, is to propose recommendations to guide the design of clinical trials of devices and drugs in HBR patients undergoing PCI. The authors discuss the designs of trials in HBR patients undergoing PCI and various aspects of trial design specific to HBR patients, including target populations, intervention and control groups, primary and secondary outcomes, and timing of endpoint reporting.

Comparative Methodological Assessment of the Randomized GLOBAL LEADERS Trial Using Total Ischemic and Bleeding Events

BACKGROUND

Time-to-first-event analysis considers only the first event irrespective of its severity. There are several methods to assess trial outcomes beyond time-to-first-event analysis, such as analyzing total events and ranking outcomes. In the GLOBAL LEADERS study, time-to-first-event analysis did not show superiority of ticagrelor monotherapy following one-month dual antiplatelet therapy (DAPT) after percutaneous coronary intervention to conventional 12-month DAPT followed by aspirin monotherapy in the reduction of the primary composite end point of all-cause mortality or new Q-wave myocardial infarction. This study sought to explore various analytical approaches in assessing total ischemic and bleeding events after percutaneous coronary intervention in the GLOBAL LEADERS study.

METHODS AND RESULTS

Total ischemic and bleeding events were defined as all-cause mortality, any stroke, any myocardial infarction, any revascularization, or Bleeding Academic Research Consortium grade 2 or 3 bleeding. We used various analytical approaches to analyze the benefit of ticagrelor monotherapy over conventional DAPT. For ischemic and bleeding events at 2 years after percutaneous coronary intervention, ticagrelor monotherapy demonstrated a 6% risk reduction, compared with conventional 12-month DAPT in time-to-first-event analysis (hazard ratio, 0.94 [95% CI, 0.88-1.01]; log-rank P=0.10). In win ratio analysis, win ratio was 1.05 (95% CI, 0.97-1.13; P=0.20). Negative binomial regression and Andersen-Gill analyses which include repeated events showed statistically significant advantage for ticagrelor monotherapy (rate ratio, 0.92 [95% CI, 0.85-0.99; P=0.020] and hazard ratio, 0.92 [95% CI, 0.85-0.99; P=0.028], respectively), although in weighted composite end point analysis, the hazard ratio was 0.93 (95% CI, 0.84-1.04; log-rank P=0.22).

CONCLUSIONS

Statistical analyses considering repeated events or event severity showed that ticagrelor monotherapy consistently reduced ischemic and bleeding events by 5% to 8%, compared with conventional 1-year DAPT. Applying multiple statistical methods could emphasize the multiple facets of a trial and result in accurate and more appropriate analyses. Considering the recurrence of ischemic and bleeding events, ticagrelor monotherapy appeared to be beneficial after percutaneous coronary intervention. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01813435.

Pharmacological interventions for heart failure in people with chronic kidney disease

BACKGROUND

Approximately half of people with heart failure have chronic kidney disease (CKD). Pharmacological interventions for heart failure in people with CKD have the potential to reduce death (any cause) or hospitalisations for decompensated heart failure. However, these interventions are of uncertain benefit and may increase the risk of harm, such as hypotension and electrolyte abnormalities, in those with CKD.

OBJECTIVES

This review aims to look at the benefits and harms of pharmacological interventions for HF (i.e., antihypertensive agents, inotropes, and agents that may improve the heart performance indirectly) in people with HF and CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies through 12 September 2019 in consultation with an Information Specialist and using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials of any pharmacological intervention for acute or chronic heart failure, among people of any age with chronic kidney disease of at least three months duration.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the records to identify eligible studies and extracted data on the following dichotomous outcomes: death, hospitalisations, worsening heart failure, worsening kidney function, hyperkalaemia, and hypotension. We used random effects meta-analysis to estimate treatment effects, which we expressed as a risk ratio (RR) with 95% confidence intervals (CI). We assessed the risk of bias using the Cochrane tool. We applied the GRADE methodology to rate the certainty of evidence.

MAIN RESULTS

One hundred and twelve studies met our selection criteria: 15 were studies of adults with CKD; 16 studies were conducted in the general population but provided subgroup data for people with CKD; and 81 studies included individuals with CKD, however, data for this subgroup were not provided. The risk of bias in all 112 studies was frequently high or unclear. Of the 31 studies (23,762 participants) with data on CKD patients, follow-up ranged from three months to five years, and study size ranged from 16 to 2916 participants. In total, 26 studies (19,612 participants) reported disaggregated and extractable data on at least one outcome of interest for our review and were included in our meta-analyses. In acute heart failure, the effects of adenosine A1-receptor antagonists, dopamine, nesiritide, or serelaxin on death, hospitalisations, worsening heart failure or kidney function, hyperkalaemia, hypotension or quality of life were uncertain due to sparse data or were not reported. In chronic heart failure, the effects of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB) (4 studies, 5003 participants: RR 0.85, 95% CI 0.70 to 1.02; I2 = 78%; low certainty evidence), aldosterone antagonists (2 studies, 34 participants: RR 0.61 95% CI 0.06 to 6.59; very low certainty evidence), and vasopressin receptor antagonists (RR 1.26, 95% CI 0.55 to 2.89; 2 studies, 1840 participants; low certainty evidence) on death (any cause) were uncertain. Treatment with beta-blockers may reduce the risk of death (any cause) (4 studies, 3136 participants: RR 0.69, 95% CI 0.60 to 0.79; I2 = 0%; moderate certainty evidence). Treatment with ACEi or ARB (2 studies, 1368 participants: RR 0.90, 95% CI 0.43 to 1.90; I2 = 97%; very low certainty evidence) had uncertain effects on hospitalisation for heart failure, as treatment estimates were consistent with either benefit or harm. Treatment with beta-blockers may decrease hospitalisation for heart failure (3 studies, 2287 participants: RR 0.67, 95% CI 0.43 to 1.05; I2 = 87%; low certainty evidence). Aldosterone antagonists may increase the risk of hyperkalaemia compared to placebo or no treatment (3 studies, 826 participants: RR 2.91, 95% CI 2.03 to 4.17; I2 = 0%; low certainty evidence). Renin inhibitors had uncertain risks of hyperkalaemia (2 studies, 142 participants: RR 0.86, 95% CI 0.49 to 1.49; I2 = 0%; very low certainty). We were unable to estimate whether treatment with sinus node inhibitors affects the risk of hyperkalaemia, as there were few studies and meta-analysis was not possible. Hyperkalaemia was not reported for the CKD subgroup in studies investigating other therapies. The effects of ACEi or ARB, or aldosterone antagonists on worsening heart failure or kidney function, hypotension, or quality of life were uncertain due to sparse data or were not reported. Effects of anti-arrhythmic agents, digoxin, phosphodiesterase inhibitors, renin inhibitors, sinus node inhibitors, vasodilators, and vasopressin receptor antagonists were very uncertain due to the paucity of studies.

AUTHORS' CONCLUSIONS

The effects of pharmacological interventions for heart failure in people with CKD are uncertain and there is insufficient evidence to inform clinical practice. Study data for treatment outcomes in patients with heart failure and CKD are sparse despite the potential impact of kidney impairment on the benefits and harms of treatment. Future research aimed at analysing existing data in general population HF studies to explore the effect in subgroups of patients with CKD, considering stage of disease, may yield valuable insights for the management of people with HF and CKD.

Days Alive and Out of Hospital: Exploring a Patient-Centered, Pragmatic Outcome in a Clinical Trial of Patients With Acute Coronary Syndromes

Background Cardiovascular clinical trials have traditionally incorporated separate time-to-first-event analyses for their primary efficacy and safety comparisons, but this framework has a number of limitations, including limited patient-centeredness and a traditional requirement for central adjudication. Days alive and out of the hospital (DAOH) has the potential to provide additional insight. Methods and Results TRILOGY ACS (Targeted Platelet Inhibition to Clarify the Optimal Strategy to Medically Manage Acute Coronary Syndromes) was a randomized, multinational clinical trial that compared the effect of prasugrel versus clopidogrel in patients stabilized after non-ST segment elevation acute coronary syndrome treated without revascularization; the trial had a neutral result. DAOH was calculated for each patient using site-submitted adverse event reporting data. We described patterns of DAOH overall, and among younger adults (<75 years old), older adults (≥75 years old), and frail/prefrail patients over 12 months follow-up and used Poisson regression to compare DAOH for patients randomized to prasugrel versus clopidogrel. Of 9249 patients in the overall trial population, 500 (5.4%) died, and 2504 (27.1%) were hospitalized 4150 times over 12 months' follow-up; the mean±SD DAOH was 317±86. The distribution of DAOH over 12 months was left-skewed, with median DAOH 363 days. Among younger adults, older adults, and frail/prefrail patients, mean DAOH were 323, 293, and 304 days, respectively. There were no differences in DAOH by treatment arm in the overall population (rate ratio, 1.00; 95% CI, 0.99-1.01) or any subgroup. Conclusions These results support the feasibility of determining DAOH, a patient-centered outcome that can potentially overcome many of the disadvantages of the traditional time-to-composite-event framework in the clinical trial setting. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT00699998.

A win ratio approach to the re-analysis of Multiple Risk Factor Intervention Trial

Background:

Composite outcomes, which combine multiple types of clinical events into a single outcome, are common in clinical trials. The usual analysis considers the time to first occurrence of any event in the composite. The major criticisms of such an approach are (1) this implicitly treats the outcomes as if they were of equal importance, but they often vary in terms of clinical relevance and severity, (2) study participants often experience more than one type of event, and (3) often less severe events occur before more severe ones, but the usual analysis disregards any information beyond that first event.

Methods:

A novel approach, referred to as the win ratio, which addresses the aforementioned criticisms of composite outcomes, is illustrated with a re-analysis of data on fatal and non-fatal cardiovascular disease time-to-event outcomes reported for the Multiple Risk Factor Intervention Trial. In this trial, 12,866 participants were randomized to a special intervention group ( n = 6428) or a usual care ( n = 6438) group. Non-fatal outcomes were ranked by risk of cardiovascular disease death up to 20 years after trial. In one approach, participants in the special intervention and usual care groups were first matched on coronary heart disease risk at baseline and time of enrollment. Each matched pair was categorized as a winner or loser depending on which one experienced a cardiovascular disease death first. If neither died of cardiovascular disease causes, they were evaluated on the most severe non-fatal outcome. This process continued for all the non-fatal outcomes. A second win ratio statistic, obtained from Cox partial likelihood, was also estimated. This statistic provides a valid estimate of the win ratio using multiple events if the marginal and conditional survivor functions of each outcome satisfy proportional hazards. Loss ratio statistics (inverse of win ratios) are compared to hazard ratios from the usual first event analysis. A larger 11-event composite was also considered.

Results:

For the 7-event cardiovascular disease composite, the previously reported first event analysis based on 581 events in the special intervention group and 652 events in the usual care group yielded a hazard ratio (95% confidence interval) of 0.89 (0.79–0.99), compared to 0.86 (0.77–0.97) and 0.91 (0.81–1.02) for the severity ranked estimates. Results for the 11-event composite also confirmed the findings of the first event analysis.

Conclusion:

The win ratio analysis was able to leverage information collected past the first experienced event and rank events by severity. The results were similar to and confirmed previously reported traditional first event analysis. The win ratio statistic is a useful adjunct to the traditional first event analysis for trials with composite outcomes.

Effects of Icosapent Ethyl on Total Ischemic Events: From REDUCE-IT

BACKGROUND

In time-to-first-event analyses, icosapent ethyl significantly reduced the risk of ischemic events, including cardiovascular death, among patients with elevated triglycerides receiving statins. These patients are at risk for not only first but also subsequent ischemic events.

OBJECTIVES

Pre-specified analyses determined the extent to which icosapent ethyl reduced total ischemic events.

METHODS

REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial) randomized 8,179 statin-treated patients with triglycerides ≥135 and <500 mg/dl (median baseline of 216 mg/dl) and low-density lipoprotein cholesterol >40 and ≤100 mg/dl (median baseline of 75 mg/dl), and a history of atherosclerosis (71% patients) or diabetes (29% patients) to icosapent ethyl 4 g/day or placebo. The main outcomes were total (first and subsequent) primary composite endpoint events (cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, or hospitalization for unstable angina) and total key secondary composite endpoint events (cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke). As a pre-specified statistical method, we determined differences in total events using negative binomial regression. We also determined differences in total events using other statistical models, including Andersen-Gill, Wei-Lin-Weissfeld (Li and Lagakos modification), both pre-specified, and a post hoc joint frailty analysis.

RESULTS

In 8,179 patients, followed for a median of 4.9 years, 1,606 (55.2%) first primary endpoint events and 1,303 (44.8%) subsequent primary endpoint events occurred (which included 762 second events, and 541 third or more events). Overall, icosapent ethyl reduced total primary endpoint events (61 vs. 89 per 1,000 patient-years for icosapent ethyl versus placebo, respectively; rate ratio: 0.70; 95% confidence interval: 0.62 to 0.78; p < 0.0001). Icosapent ethyl also reduced totals for each component of the primary composite endpoint, as well as the total key secondary endpoint events (32 vs. 44 per 1,000 patient-years for icosapent ethyl versus placebo, respectively; rate ratio: 0.72; 95% confidence interval: 0.63 to 0.82; p < 0.0001).

CONCLUSIONS

Among statin-treated patients with elevated triglycerides and cardiovascular disease or diabetes, multiple statistical models demonstrate that icosapent ethyl substantially reduces the burden of first, subsequent, and total ischemic events. (Reduction of Cardiovascular Events With Icosapent Ethyl-Intervention Trial [REDUCE-IT]; NCT01492361).

An introduction to multiplicity issues in clinical trials: the what, why, when and how

In clinical trials it is not uncommon to face a multiple testing problem which can have an impact on both type I and type II error rates, leading to inappropriate interpretation of trial results. Multiplicity issues may need to be considered at the design, analysis and interpretation stages of a trial. The proportion of trial reports not adequately correcting for multiple testing remains substantial. The purpose of this article is to provide an introduction to multiple testing issues in clinical trials, and to reduce confusion around the need for multiplicity adjustments. We use a tutorial, question-and-answer approach to address the key issues of why, when and how to consider multiplicity adjustments in trials. We summarize the relevant circumstances under which multiplicity adjustments ought to be considered, as well as options for carrying out multiplicity adjustments in terms of trial design factors including Population, Intervention/Comparison, Outcome, Time frame and Analysis (PICOTA). Results are presented in an easy-to-use table and flow diagrams. Confusion about multiplicity issues can be reduced or avoided by considering the potential impact of multiplicity on type I and II errors and, if necessary pre-specifying statistical approaches to either avoid or adjust for multiplicity in the trial protocol or analysis plan.

Computing Methods for Composite Clinical Endpoints in Unprotected Left Main Coronary Artery Revascularization: A Post Hoc Analysis of the DELTA Registry

OBJECTIVES

The study sought to investigate the impact of different computing methods for composite endpoints other than time-to-event (TTE) statistics in a large, multicenter registry of unprotected left main coronary artery (ULMCA) disease.

BACKGROUND

TTE statistics for composite outcome measures used in ULMCA studies consider only the first event, and all the contributory outcomes are handled as if of equal importance.

METHODS

The TTE, Andersen-Gill, win ratio (WR), competing risk, and weighted composite endpoint (WCE) computing methods were applied to ULMCA patients revascularized by percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) at 14 international centers.

RESULTS

At a median follow-up of 1,295 days (interquartile range: 928 to 1,713 days), all analyses showed no difference in combinations of death, myocardial infarction, and cerebrovascular accident between PCI and CABG. When target vessel revascularization was incorporated in the composite endpoint, the TTE (p = 0.03), Andersen-Gill (p = 0.04), WR (p = 0.025), and competing risk (p < 0.001) computing methods showed CABG to be significantly superior to PCI in the analysis of 1,204 propensity-matched patients, whereas incorporating the clinical relevance of the component endpoints using WCE resulted in marked attenuation of the treatment effect of CABG, with loss of significance for the difference between revascularization strategies (p = 0.10).

CONCLUSIONS

In a large study of ULMCA revascularization, incorporating the clinical relevance of the individual outcomes resulted in sensibly different findings as compared with the conventional TTE approach. In particular, using the WCE computing method, PCI and CABG were no longer significantly different with respect to the composite of death, myocardial infarction, cerebrovascular accident, or target vessel revascularization at a median of 3 years.

Composite End Points in Clinical Research

Advances in cardiovascular medicine fueled by innovative clinical trials have dramatically improved the lives of patients worldwide. Commensurate with this progress has been a decline in morbid and mortal events. Accordingly, an increased propensity to collate patient outcomes in clinical trials has emerged that combines death and nonfatal complications into a single composite event. Despite the acknowledged benefits in trial efficiency from such an approach, this method assumes uniform directionality of each component, does not distinguish the relative clinical significance of each, and counts only the first occurrence of any event in the final tally within a conventional time to first event analysis. In this article, we evaluate the criticisms that have been leveled at this approach and provide an overview of recently published phase III cardiovascular trials using primary composite end points. We then explore what to anticipate from the large cohort of as-yet unpublished clinical trials in this arena. Last, we propose a variety of novel approaches that use composite end points and suggest a path forward to enhancing their use in future clinical trials.

Trade-off of myocardial infarction vs. bleeding types on mortality after acute coronary syndrome: lessons from the Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRACER) randomized trial

AIMS

Dual antiplatelet therapy reduces non-fatal ischaemic events after acute coronary syndrome (ACS) but increases bleeding to a similar extent. We sought to determine the prognostic impact of myocardial infarction (MI) vs. bleeding during an extended follow-up period to gain insight into the trade-off between efficacy and safety among patients after ACS.

METHODS AND RESULTS

In 12 944 patients with non-ST-segment elevation ACS from the Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRACER) trial, we investigated the relative impact of MI and bleeding occurring >30 days post-ACS and subsequent all-cause mortality. Bleeding was graded according to Bleeding Academic Research Consortium (BARC) criteria. MI was associated with a five-fold increase in mortality. BARC type 2 and 3, but not type 1, bleeding had a significant impact on mortality. MI was associated with a greater risk of mortality compared with BARC 2 [relative risk (RR) 3.5; 95% confidence interval (CI) 2.08-4.77; P < 0.001] and BARC 3a bleeding (RR 2.23; 95% CI 1.36-3.64; P = 0.001), and a risk similar to BARC 3b bleeding (RR 1.37; 95% CI 0.81-2.30; P = 0.242). Risk of death after MI was significantly lower than after BARC 3c bleeding (RR 0.22; 95% CI 0.13-0.36; P < 0.001). MI and bleeding had similar time-associations with mortality, which remained significant for several months, still being higher early after the event.

CONCLUSION

In patients treated with antiplatelet therapy after ACS, both MI and bleeding significantly impacted mortality with similar time-dependency. Although BARC 2 and 3a bleeding were less prognostic for death than MI, the risk of mortality was equivalent between BARC 3b bleeding and MI, and was higher following BARC 3c bleeding.

Health-related quality of life outcomes with prasugrel among medically managed non-ST-segment elevation acute coronary syndrome patients: Insights from the Targeted Platelet Inhibition to Clarify the Optimal Strategy to Medically Manage Acute Coronary Syndromes (TRILOGY ACS) trial

BACKGROUND

Few studies have assessed treatment effects on health-related quality of life (HRQoL) in patients with acute coronary syndrome (ACS) treated without revascularization. The TRILOGY ACS trial randomized patients with ACS to either prasugrel or clopidogrel therapy plus aspirin. Outcomes showed a complex pattern suggestive of late benefits with respect to repeat clinical events and benefits confined to patients who underwent angiography. Here, we examine the HRQoL correlates of these patterns.

METHODS

HRQoL was measured at baseline and 3, 12, and 24 months or end of study (EOS) in 7243 patients aged <75 years using the EuroQol 3-level, group 5-dimension index (EQ-5D). Linear mixed effects models for repeated measures were used to examine treatment differences in HRQoL overall, stratified by angiography status, and among patients who did and did not have non-fatal events.

RESULTS

No baseline differences in HRQoL were seen between patients randomized to prasugrel (n=3620) or clopidogrel (n=3623). At 24 months, remaining patients assigned to prasugrel (n=1450) vs. clopidogrel (n=1443) had higher EQ-5D index scores (86.4 vs. 84.9, P=.01). Mixed effects models found no difference in EQ-5D scores among prasugrel and clopidogrel patients overall across subgroups stratified by angiography status. However, among patients with non-fatal clinical events, patients on clopidogrel reported a larger decrement in HRQoL than patients on prasugrel (79.5±18.1 vs. 80.6±18.0; P=.02).

CONCLUSIONS

Overall, there was no difference in HRQoL outcomes among patients receiving prasugrel vs. clopidogrel. However, the differential effects of the treatments among patients with non-fatal events require further investigation.

Reduction in Total Cardiovascular Events With Ezetimibe/Simvastatin Post-Acute Coronary Syndrome: The IMPROVE-IT Trial

BACKGROUND

Intensive low-density lipoprotein cholesterol therapy with ezetimibe/simvastatin in IMPROVE-IT (IMProved Reduction of Outcomes: Vytorin Efficacy International Trial) significantly reduced the first primary endpoint (PEP) in patients post-acute coronary syndrome (ACS) compared to placebo/simvastatin.

OBJECTIVES

This analysis tested the hypothesis that total events, including those beyond the first event, would also be reduced with ezetimibe/simvastatin therapy.

METHODS

All PEP events (cardiovascular [CV] death, myocardial infarction [MI], stroke, unstable angina [UA] leading to hospitalization, coronary revascularization ≥30 days post-randomization) during a median 6-year follow-up were analyzed in patients randomized to receive ezetimibe/simvastatin or placebo/simvastatin in IMPROVE-IT. Negative binomial regression was used for the primary analysis.

RESULTS

Among 18,144 patients, there were 9,545 total PEP events (56% were first events and 44% subsequent events). Total PEP events were significantly reduced by 9% with ezetimibe/simvastatin vs placebo/simvastatin (incidence-rate ratio [RR]: 0.91; 95% confidence interval [CI]: 0.85 to 0.97; p = 0.007), as were the 3 pre-specified secondary composite endpoints and the exploratory composite endpoint of CV death, MI, or stroke (RR: 0.88; 95% CI: 0.81 to 0.96; p = 0.002). The reduction in total events was driven by decreases in total nonfatal MI (RR: 0.87; 95% CI: 0.79 to 0.96; p = 0.004) and total NF stroke (RR: 0.77; 95% CI: 0.65 to 0.93; p = 0.005).

CONCLUSIONS

Lipid-lowering therapy with ezetimibe plus simvastatin improved clinical outcomes. Reductions in total PEP events, driven by reductions in MI and stroke, more than doubled the number of events prevented compared with examining only the first event. These data support continuation of intensive combination lipid-lowering therapy after an initial CV event. (IMProved Reduction of Outcomes: Vytorin Efficacy International Trial [IMPROVE-IT]; NCT00202878).

Large sample inference for a win ratio analysis of a composite outcome based on prioritized components

Composite outcomes are common in clinical trials, especially for multiple time-to-event outcomes (endpoints). The standard approach that uses the time to the first outcome event has important limitations. Several alternative approaches have been proposed to compare treatment versus control, including the proportion in favor of treatment and the win ratio. Herein, we construct tests of significance and confidence intervals in the context of composite outcomes based on prioritized components using the large sample distribution of certain multivariate multi-sample U-statistics. This non-parametric approach provides a general inference for both the proportion in favor of treatment and the win ratio, and can be extended to stratified analyses and the comparison of more than two groups. The proposed methods are illustrated with time-to-event outcomes data from a clinical trial.

A new method of applying randomised control study data to the individual patient: A novel quantitative patient-centred approach to interpreting composite end points

BACKGROUND

Modern randomised controlled trials typically use composite endpoints. This is only valid if each endpoint is equally important to patients but few trials document patient preference and seek the relative importance of components of combined endpoints. If patients weigh endpoints differentially, our interpretation of trial data needs to be refined.

METHODS AND RESULTS

We derive a quantitative, structured tool to determine the relative importance of each endpoint to patients. We then apply this tool to data comparing angioplasty with drug-eluting stents to bypass surgery. The survey was administered to patients undergoing cardiac catheterisation. A meta-analysis comparing coronary artery bypass grafting (CABG) to percutaneous coronary interventuin (PCI) was then performed using (a) standard MACE and (b) patient-centred MACE. Patients considered stroke worse than death (stroke 102.3 ± 19.6%, p < 0.01), and MI and repeat revascularisation less severe than death (61.9 ± 26.8% and 41.9 ± 25.4% respectively p < 0.01 for both). 7 RCTs (5251 patients) were eligible. Meta-analysis demonstrated that standard MACE occurs more frequently with PCI than surgery (OR 1.44; 95% CI 1.10 to 1.87; p = 0.007). Re-analysis using patient-centred MACE found no significant difference between PCI and CABG (OR 1.22, 95% CI 0.97 to 1.53; p = 0.10).

CONCLUSIONS

Patients do not consider the constituent endpoints of MACE equal. We derive a novel patient-centred metric that recognises and quantifies the differences attributed to each endpoint. When patient preference data are applied to contemporary trial results, there is no significant difference between PCI and CABG. Responses from individual patients in clinic could be used to give individual patients a recommendation that is truly personalised.

A kinetic model for the integrated assessment of safety and efficacy in clinical trials

Regulatory agencies, professional societies, and clinical trialists commonly base judgments of treatment benefit on separate assessments of efficacy and safety. When separate assessments were compared with an integrated assessment using a kinetic model of a hypothetical randomized trial of antiplatelet agents in patients with acute coronary syndrome, the former showed treatment A to be superior to treatment B, whereas the latter showed treatment B to be superior to treatment A. In conclusion, comparative judgments regarding the balance between efficacy and safety depend on the model chosen for analysis; kinetic models are particularly suited to the integrated assessment of efficacy and safety relative to regulatory decisions, public policy, guideline development, and clinical care.