A novel method to adjust efficacy estimates for uptake of other active treatments in long-term clinical trials

Estimation of recurrent atherosclerotic cardiovascular event risk in patients with established cardiovascular disease: the updated SMART2 algorithm

AIMS

The 10-year risk of recurrent atherosclerotic cardiovascular disease (ASCVD) events in patients with established ASCVD can be estimated with the Secondary Manifestations of ARTerial disease (SMART) risk score, and may help refine clinical management. To broaden generalizability across regions, we updated the existing tool (SMART2 risk score) and recalibrated it with regional incidence rates and assessed its performance in external populations.

METHODS AND RESULTS

Individuals with coronary artery disease, cerebrovascular disease, peripheral artery disease, or abdominal aortic aneurysms were included from the Utrecht Cardiovascular Cohort-SMART cohort [n = 8355; 1706 ASCVD events during a median follow-up of 8.2 years (interquartile range 4.2-12.5)] to derive a 10-year risk prediction model for recurrent ASCVD events (non-fatal myocardial infarction, non-fatal stroke, or cardiovascular mortality) using a Fine and Gray competing risk-adjusted model. The model was recalibrated to four regions across Europe, and to Asia (excluding Japan), Japan, Australia, North America, and Latin America using contemporary cohort data from each target region. External validation used data from seven cohorts [Clinical Practice Research Datalink, SWEDEHEART, the international REduction of Atherothrombosis for Continued Health (REACH) Registry, Estonian Biobank, Spanish Biomarkers in Acute Coronary Syndrome and Biomarkers in Acute Myocardial Infarction (BACS/BAMI), the Norwegian COgnitive Impairment After STroke, and Bialystok PLUS/Polaspire] and included 369 044 individuals with established ASCVD of whom 62 807 experienced an ASCVD event. C-statistics ranged from 0.605 [95% confidence interval (CI) 0.547-0.664] in BACS/BAMI to 0.772 (95% CI 0.659-0.886) in REACH Europe high-risk region. The clinical utility of the model was demonstrated across a range of clinically relevant treatment thresholds for intensified treatment options.

CONCLUSION

The SMART2 risk score provides an updated, validated tool for the prediction of recurrent ASCVD events in patients with established ASCVD across European and non-European populations. The use of this tool could allow for a more personalized approach to secondary prevention based upon quantitative rather than qualitative estimates of residual risk.

Using marginal structural models to adjust for treatment drop-in when developing clinical prediction models

Clinical prediction models (CPMs) can inform decision making about treatment initiation, which requires predicted risks assuming no treatment is given. However, this is challenging since CPMs are usually derived using data sets where patients received treatment, often initiated postbaseline as "treatment drop-ins." This study proposes the use of marginal structural models (MSMs) to adjust for treatment drop-in. We illustrate the use of MSMs in the CPM framework through simulation studies that represent randomized controlled trials and real-world observational data and the example of statin initiation for cardiovascular disease prevention. The simulations include a binary treatment and a covariate, each recorded at two timepoints and having a prognostic effect on a binary outcome. The bias in predicted risk was examined in a model ignoring treatment, a model fitted on treatment-naïve patients (at baseline), a model including baseline treatment, and the MSM. In all simulation scenarios, all models except the MSM underestimated the risk of outcome given absence of treatment. These results were supported in the statin initiation example, which showed that ignoring statin initiation postbaseline resulted in models that significantly underestimated the risk of a cardiovascular disease event occurring within 10 years. Consequently, CPMs that do not acknowledge treatment drop-in can lead to underallocation of treatment. In conclusion, when developing CPMs to predict treatment-naïve risk, researchers should consider using MSMs to adjust for treatment drop-in, and also seek to exploit the ability of MSMs to allow estimation of individual treatment effects.

Progression-free survival as a surrogate endpoint for overall survival in modern ovarian cancer trials: a meta-analysis

Background

Progression-free survival (PFS) has been adopted as the primary endpoint in many randomized controlled trials, and can be determined much earlier than overall survival (OS). We investigated whether PFS is a good surrogate endpoint for OS in trials of first-line treatment for epithelial ovarian cancer (EOC), and whether this relationship has changed with the introduction of new treatment types.

Methods

In a meta-analysis, we identified summary data [hazard ratio (HR) and median time] from published randomized controlled trials. Linear regression was used to assess the association between treatment effects on PFS and OS overall, and for subgroups defined by treatment type, postprogression survival (PPS) and established prognostic factors.

Results

Correlation between HRs for PFS and OS, in 26 trials with 30 treatment comparisons comprising 24,870 patients, was modest (r² = 0.52, weighted by trial sample size). The correlation diminished with recency: preplatinum/paclitaxel era, r²= 0.66; platinum/paclitaxel, r²= 0.44; triplet combinations, r²= 0.22; biologicals, r²= 0.30. The median PPS increased over time for the experimental (P_trend = 0.03) and control arms (P_trend = 0.003). The difference in median PPS between treatment arms strongly correlated with the difference in median OS (r² = 0.83). In trials where the control therapy had median PPS of less than 18 months, correlation between PFS and OS was stronger (r² = 0.64) than where the median PPS was longer (r² = 0.48).

Conclusions

In EOC, correlation in the relative treatment effect between PFS and OS in first-line platinum-based chemotherapy randomized controlled trials is moderate and has weakened with increasing availability of effective salvage therapies.

Triglyceride-lowering trials

PURPOSE OF REVIEW

We provide an overview of current evidence about the independent role of high triglyceride levels for cardiovascular risk and for acute pancreatitis.

RECENT FINDINGS

Natural experiments of Mendelian randomization have given us a deeper understanding about the molecular pathways involved in triglyceride metabolism. Individuals with low-triglyceride levels generally have lower rates of cardiovascular disease (CVD). There has been a significant growth in the development of new agents that modulate enzymes involved in a variety of aspects of triglyceride packaging into VLDL or chylomicron particles, and triglyceride catabolism. Antisense inhibitors of apolipoprotein CIII are being tested, as are a variety of agents designed to increase lipoprotein lipase activity. Large-scale trials are underway with purified fatty acid (FA) formulations in over 20 000 individuals in aggregate. A large study of a new fibrate is underway.

SUMMARY

A focus on patients with elevated triglyceride levels is a new paradigm not previously the focus of large trials. Clinical outcome data on cardiovascular risk reductions remains sparse. Some drugs are already approved for use in rare inherited disorders predisposing to severe hypertriglyceridaemia and acute pancreatitis. Safety and costs issues are critical.

Favourable effects of fenofibrate on lipids and cardiovascular disease in women with type 2 diabetes: results from the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study

AIMS/HYPOTHESIS

In the double-blind placebo-controlled Fenofibrate Intervention and Event Lowering in Diabetes trial (n = 9,795), fenofibrate reduced major cardiovascular events in type 2 diabetes. Sex-related differences in fenofibrate response could be clinically relevant and were pre-specified analyses.

METHODS

Women (n = 3,657) and men (n = 6,138) with type 2 diabetes not using statins were assigned fenofibrate (200 mg/day) or placebo for 5 years. Effects on lipoproteins and total cardiovascular events were evaluated by sex.

RESULTS

Baseline total, LDL-, HDL- and non-HDL cholesterol and apolipoproteins A-I and B differed between sexes, and these and triacylglycerol levels improved with fenofibrate in both sexes (all p < 0.001). Fenofibrate reduced total, LDL- and non-HDL cholesterol and apolipoprotein B more in women (all p < 0.001), independent of menopausal status and statin uptake. Adjusted for covariates, fenofibrate reduced total cardiovascular outcomes (cardiovascular death, fatal and non-fatal stroke and carotid and coronary revascularisation) by 30% in women (95% CI 8%, 46%; p = 0.008) and 13% in men (95% CI -1%, 24%; p = 0.07) with no treatment-by-sex interaction (p > 0.1). In patients with high triacylglycerol levels and low HDL-cholesterol, fenofibrate reduced total cardiovascular outcomes by 30% (95% CI -7%, 54%) in women and 24% (95% CI 2%, 42%) in men, with no treatment-by-sex interaction (p > 0.1).

CONCLUSIONS/INTERPRETATION

Fenofibrate improved the lipoprotein profile more in women than men. Cardiovascular event reductions with fenofibrate were consistently similar in women and men, both overall and among those with low HDL-cholesterol and high triacylglycerol levels. These data provide reassurance about fenofibrate efficacy in women and men. Both sexes with type 2 diabetes should be considered for fenofibrate therapy for cardioprotection.

Aspirin for the Prevention of Recurrent Venous Thromboembolism

Background—

In patients with a first unprovoked venous thromboembolism (VTE) the risk of recurrent VTE remains high after anticoagulant treatment is discontinued. The Aspirin for the Prevention of Recurrent Venous Thromboembolism (the Warfarin and Aspirin [WARFASA]) and the Aspirin to Prevent Recurrent Venous Thromboembolism (ASPIRE) trials showed that aspirin reduces this risk, but they were not individually powered to detect treatment effects for particular outcomes or subgroups.

Methods and Results—

An individual patient data analysis of these trials was planned, before their results were known, to assess the effect of aspirin versus placebo on recurrent VTE, major vascular events (recurrent VTE, myocardial infarction, stroke, and cardiovascular disease death) and bleeding, overall and within predefined subgroups. The primary analysis, for VTE, was by intention to treat using time-to-event data. Of 1224 patients, 193 had recurrent VTE over 30.4 months’ median follow-up. Aspirin reduced recurrent VTE (7.5%/yr versus 5.1%/yr; hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.51–0.90; P =0.008), including both deep-vein thrombosis (HR, 0.66; 95% CI, 0.47–0.92; P =0.01) and pulmonary embolism (HR, 0.66; 95% CI, 0.41–1.06; P =0.08). Aspirin reduced major vascular events (8.7%/yr versus 5.7%/yr; HR, 0.66; 95% CI, 0.50–0.86; P =0.002). The major bleeding rate was low (0.4%/yr for placebo and 0.5%/yr for aspirin). After adjustment for treatment adherence, recurrent VTE was reduced by 42% (HR, 0.58; 95% CI, 0.40–0.85; P =0.005). Prespecified subgroup analyses indicate similar relative, but larger absolute, risk reductions in men and older patients.

Conclusions—

Aspirin after anticoagulant treatment reduces the overall risk of recurrence by more than a third in a broad cross-section of patients with a first unprovoked VTE, without significantly increasing the risk of bleeding.

Clinical Trial Registration—

URL: www.anzctr.org.au . Unique identifier: ACTRN12611000684921.

Low-dose aspirin for preventing recurrent venous thromboembolism

BACKGROUND

Patients who have had a first episode of unprovoked venous thromboembolism have a high risk of recurrence after anticoagulants are discontinued. Aspirin may be effective in preventing a recurrence of venous thromboembolism.

METHODS

We randomly assigned 822 patients who had completed initial anticoagulant therapy after a first episode of unprovoked venous thromboembolism to receive aspirin, at a dose of 100 mg daily, or placebo for up to 4 years. The primary outcome was a recurrence of venous thromboembolism.

RESULTS

During a median follow-up period of 37.2 months, venous thromboembolism recurred in 73 of 411 patients assigned to placebo and in 57 of 411 assigned to aspirin (a rate of 6.5% per year vs. 4.8% per year; hazard ratio with aspirin, 0.74; 95% confidence interval [CI], 0.52 to 1.05; P=0.09). Aspirin reduced the rate of the two prespecified secondary composite outcomes: the rate of venous thromboembolism, myocardial infarction, stroke, or cardiovascular death was reduced by 34% (a rate of 8.0% per year with placebo vs. 5.2% per year with aspirin; hazard ratio with aspirin, 0.66; 95% CI, 0.48 to 0.92; P=0.01), and the rate of venous thromboembolism, myocardial infarction, stroke, major bleeding, or death from any cause was reduced by 33% (hazard ratio, 0.67; 95% CI, 0.49 to 0.91; P=0.01). There was no significant between-group difference in the rates of major or clinically relevant nonmajor bleeding episodes (rate of 0.6% per year with placebo vs. 1.1% per year with aspirin, P=0.22) or serious adverse events.

CONCLUSIONS

In this study, aspirin, as compared with placebo, did not significantly reduce the rate of recurrence of venous thromboembolism but resulted in a significant reduction in the rate of major vascular events, with improved net clinical benefit. These results substantiate earlier evidence of a therapeutic benefit of aspirin when it is given to patients after initial anticoagulant therapy for a first episode of unprovoked venous thromboembolism. (Funded by National Health and Medical Research Council [Australia] and others; Australian New Zealand Clinical Trials Registry number, ACTRN12605000004662.).

Effects of fenofibrate on cardiovascular events in patients with diabetes, with and without prior cardiovascular disease: The Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study

BACKGROUND

In the FIELD study, comparison of the effect of fenofibrate on cardiovascular disease (CVD) between those with prior CVD and without was a prespecified subgroup analysis.

METHODS

The effects of fenofibrate on total CVD events and its components in patients who did (n = 2,131) and did not (n = 7,664) have a history of CVD were computed by Cox proportional hazards modeling and compared by testing for treatment-by-subgroup interaction. The analyses were adjusted for commencement of statins, use of other CVD medications, and baseline covariates. Effects on other CVD end points were explored.

RESULTS

Patients with prior CVD were more likely than those without to be male, to be older (by 3.3 years), to have had a history of diabetes for 2 years longer at baseline, and to have diabetic complications, hypertension, and higher rates of use of insulin and CVD medications. Discontinuation of fenofibrate was similar between the subgroups, but more patients with prior CVD than without, and also more placebo than fenofibrate-assigned patients, commenced statin therapy. The borderline difference in the effects of fenofibrate between those who did (hazard ratio [HR] 1.02, 95% CI 0.86-1.20) and did not have prior CVD (HR 0.81, 95% CI 0.70-0.94; heterogeneity P = .045) became nonsignificant after adjustment for baseline covariates and other CVD medications (HR 0.96, 95% CI 0.81-1.14 vs HR 0.78, 95% CI 0.67-0.90) (heterogeneity P = .06).

CONCLUSIONS

Our findings do not support treating patients with fenofibrate differently based on any history of CVD, in line with evidence from other trials.

Fenofibrate: a review of its use in dyslipidaemia

Fenofibrate is a fibric acid derivative indicated for the treatment of severe hypertriglyceridaemia and mixed dyslipidaemia in patients who have not responded to nonpharmacological therapies. The lipid-modifying effects of fenofibrate are mediated by the activation of peroxisome proliferator-activated receptor-α. Fenofibrate also has nonlipid, pleiotropic effects (e.g. reducing levels of fibrinogen, C-reactive protein and various pro-inflammatory markers, and improving flow-mediated dilatation) that may contribute to its clinical efficacy, particularly in terms of improving microvascular outcomes. Fenofibrate improves the lipid profile (particularly triglyceride [TG] and high-density lipoprotein-cholesterol [HDL-C] levels) in patients with dyslipidaemia. Compared with statin monotherapy, fenofibrate monotherapy tends to improve TG and HDL-C levels to a significantly greater extent, whereas statins improve low-density lipoprotein-cholesterol (LDL-C) and total cholesterol levels to a significantly greater extent. Fenofibrate is also associated with promoting a shift from small, dense, atherogenic LDL particles to larger, less dense LDL particles. Combination therapy with a statin plus fenofibrate generally improves the lipid profile to a greater extent than monotherapy with either agent in patients with dyslipidaemia and/or type 2 diabetes mellitus or the metabolic syndrome. In the pivotal FIELD and ACCORD trials in patients with type 2 diabetes, fenofibrate did not significantly reduce the risk of coronary heart disease events to a greater extent than placebo, and simvastatin plus fenofibrate did not significantly reduce the risk of major cardiovascular (CV) events to a greater extent than simvastatin plus placebo. However, the risk of some nonfatal macrovascular events and the incidence of certain microvascular outcomes were reduced significantly more with fenofibrate than with placebo in the FIELD trial, and in the ACCORD trial, patients receiving simvastatin plus fenofibrate were less likely to experience progression of diabetic retinopathy than those receiving simvastatin plus placebo. Subgroup analyses in the FIELD and ACCORD Lipid trials indicate that fenofibrate is of the greatest benefit in decreasing CV events in patients with atherogenic dyslipidaemia. Fenofibrate is generally well tolerated when administered alone or in combination with a statin. Thus, in patients with dyslipidaemia, particularly atherogenic dyslipidaemia, fenofibrate is a useful treatment option either alone or in combination with a statin.

Impact of metabolic syndrome and its components on cardiovascular disease event rates in 4900 patients with type 2 diabetes assigned to placebo in the FIELD randomised trial

Background

Patients with the metabolic syndrome are more likely to develop type 2 diabetes and may have an increased risk of cardiovascular disease (CVD) events.We aimed to establish whether CVD event rates were influenced by the metabolic syndrome as defined by the World Health Organisation (WHO), the National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III) and the International Diabetes Federation (IDF) and to determine which component(s) of the metabolic syndrome (MS) conferred the highest cardiovascular risk in in 4900 patients with type 2 diabetes allocated to placebo in the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) trial.

Research design and methods

We determined the influence of MS variables, as defined by NCEP ATPIII, IDF and WHO, on CVD risk over 5 years, after adjustment for CVD, sex, HbA_1c, creatinine, and age, and interactions between the MS variables in a Cox proportional-hazards model.

Results

About 80% had hypertension, and about half had other features of the metabolic syndrome (IDF, ATPIII). There was no difference in the prevalence of metabolic syndrome variables between those with and without CVD at study entry. The WHO definition identified those at higher CVD risk across both sexes, all ages, and in those without prior CVD, while the ATPIII definition predicted risk only in those aged over 65 years and in men but not in women. Patients meeting the IDF definition did not have higher risk than those without IDF MS.

CVD risk was strongly influenced by prior CVD, sex, age (particularly in women), baseline HbA1_c, renal dysfunction, hypertension, and dyslipidemia (low HDL-c, triglycerides > 1.7 mmol/L). The combination of low HDL-c and marked hypertriglyceridemia (> 2.3 mmol/L) increased CVD risk by 41%. Baseline systolic blood pressure increased risk by 16% per 10 mmHg in those with no prior CVD, but had no effect in those with CVD. In those without prior CVD, increasing numbers of metabolic syndrome variables (excluding waist) escalated risk.

Conclusion

Absence of the metabolic syndrome (by the WHO definition) identifies diabetes patients without prior CVD, who have a lower risk of future CVD events. Hypertension and dyslipidemia increase risk.

Cardiovascular risk scores do not account for the effect of treatment: a review

Objective

To compare the strengths and limitations of cardiovascular risk scores available for clinicians in assessing the global (absolute) risk of cardiovascular disease.

Design

Review of cardiovascular risk scores.

Data sources

Medline (1966 to May 2009) using a mixture of MeSH terms and free text for the keywords ‘cardiovascular’, ‘risk prediction’ and ‘cohort studies’.

Eligibility criteria for selecting studies

A study was eligible if it fulfilled the following criteria: (1) it was a cohort study of adults in the general population with no prior history of cardiovascular disease and not restricted by a disease condition; (2) the primary objective was the development of a cardiovascular risk score/equation that predicted an individual's absolute cardiovascular risk in 5–10 years; (3) the score could be used by a clinician to calculate the risk for an individual patient.

Results

21 risk scores from 18 papers were identified from 3536 papers. Cohort size ranged from 4372 participants (SHS) to 1591209 records (QRISK2). More than half of the cardiovascular risk scores (11) were from studies with recruitment starting after 1980. Definitions and methods for measuring risk predictors and outcomes varied widely between scores. Fourteen cardiovascular risk scores reported data on prior treatment, but this was mainly limited to antihypertensive treatment. Only two studies reported prior use of lipid-lowering agents. None reported on prior use of platelet inhibitors or data on treatment drop-ins.

Conclusions

The use of risk-factor-modifying drugs—for example, statins—and disease-modifying medication—for example, platelet inhibitors—was not accounted for. In addition, none of the risk scores addressed the effect of treatment drop-ins—that is, treatment started during the study period. Ideally, a risk score should be derived from a population free from treatment. The lack of accounting for treatment effect and the wide variation in study characteristics, predictors and outcomes causes difficulties in the use of cardiovascular risk scores for clinical treatment decision.

Sulphonylurea-metformin combination therapy, cardiovascular disease and all-cause mortality: the Fremantle Diabetes Study

AIM

To determine whether combination of metformin-sulphonylurea is associated with an increased risk of cardiovascular disease (CVD) and mortality in an urban community-based cohort of type 2 patients.

METHODS

We studied 1271 (98.2%) of 1294 type 2 participants in the observational Fremantle Diabetes Study (mean age 64.2 years, 48.8% males) who had detailed diabetes-specific therapy recorded at baseline and complete follow-up data. Mortality and hospital discharge data were collected over 13 174 patient-years (mean +/- SD: 10.4 +/- 3.9 years). Cox proportional hazards modelling was used to determine whether baseline diabetes treatments were independently associated with cardiovascular mortality, hospitalization for/death from CVD or all-cause mortality after adjustment for other explanatory variables.

RESULTS

During follow-up, 523 deaths occurred (41.1%) of which 269 (51.4%) were attributed to CVD. Hospitalization for CVD as principal diagnosis occurred at least once for 481 (37.8%) participants. In Kaplan-Meier analyses, there were significant differences in cardiovascular mortality, hospitalization for/death from CVD and all-cause mortality between diabetes therapy groups (p < 0.001). Compared with diet and metformin monotherapy, those treated with metformin-sulphonylurea had higher cardiovascular and all-cause mortality (p < or = 0.024). Insulin users had significantly higher cardiovascular mortality, hospitalization for/death from CVD and all-cause mortality than those on combination therapy (p < or = 0.016). After adjustment for significant variables in the most parsimonious models, diabetes treatment was not independently associated with any of the three study endpoints (p > or = 0.49).

CONCLUSIONS

Combination metformin-sulphonylurea appears as safe as other blood glucose-lowering therapies used for type 2 diabetes.

The effect of fibrate-statin combination therapy on cardiovascular events: a retrospective cohort analysis

OBJECTIVE

To investigate the long-term efficacy of fibrate-statin combination therapy on cardiovascular events as opposed to lipid levels.

RESEARCH DESIGN AND METHODS

A retrospective analysis was performed of patients attending metabolic clinics. Cardiovascular risk factor, baseline and final lipid data and details of concomitant drug therapies were gathered on all subjects.

OUTCOME MEASURE

The occurrence of major adverse cardiovascular events (MACE) was recorded and major prognostic factors associated with outcome determined.

RESULTS

A total of 318 patients with mixed dyslipidaemia were identified on fibrate-statin therapy. Follow-up comprised an average of 7.5 years totalling 2400 patient-years. Patients were 78% male aged 62 years and 68% had evidence of previous cardiovascular disease (CVD). Smoking was present in 17%, hypertension in 41% and 32% had established diabetes. Baseline lipid parameters were total cholesterol (TC) 6.84 mmol/L, triglycerides (TG) 6.09 mmol/L and HDL-C 1.09 mmol/L. Fibrate-statin combination reduced TC by 27% to 4.64 mmol/L, TG by a median 42% to 2.33 mmol/L and increased HDL-C by 21% to 1.22 mmol/L. Non-HDL-C was reduced by 35% and apolipoprotein B by 17%. MACE occurred in 25%. Logistic regression analysis showed that patients with MACE had higher initial TC (7.02 vs. 6.80 mmol/L; p = 0.002), established CVD (65 vs. 57%; p = 0.05) and a lesser atherogenic index response (31 vs. 38%; p = 0.008). Cox regression analysis showed that age (p = 0.002), and previous CVD (p < 0.001) were determinants of outcome allied either to reduction in TG (p = 0.009), TC (p = 0.04) and increase in HDL-C (p = 0.05) or change in TG (p = 0.002) and non-HDL-C (p = 0.01).

CONCLUSION

Fibrate-statin therapy in a population with mixed dyslipidaemia resulted in an improved lipid profile with few side-effects. Consistent with its effects, decreases in TG allied with modest decrease in cholesterol and an increase in HDL-C, were associated with better prognosis.

Statin-fibrate combination for mixed dyslipidaemia: a limited option?

Abstract A growing body of evidence suggests that targeting low-density lipoprotein cholesterol is not enough and that a substantial residual risk remains despite aggressive statin treatment, particularly in patients with mixed dyslipidemia. Statin plus fibrate combination results in a more effective control of several lipid parameters than either monotherapy with a safety profile similar to both monotherapies. Therefore, this combination might represent a therapeutic option for selected patients with mixed dyslipidemia. However, the clinical benefit of statin/fibrate combination has only been observed in small subgroup analyses and more data are needed before a wider implementation is recommended in everyday clinical practice.