Continuation of mortality reduction after the end of randomized therapy in clinical trials of lipid-lowering therapy

Limitations of Randomized Clinical Trials

Randomized clinical trials are essential for determining the efficacy of interventions, but have limitations. The types of limitations discussed in this review may be grouped in 11 categories including incorrect statistical inference, low internal or external validity, misinterpretation of the difference between frequentist and Bayesian statistical approaches, publication bias, that healthy persons with a given condition participate in clinical trials although they are not representative of the population as a whole, the rather short duration (3 to 5 years) that does not give correct estimates of the lifetime effects of the interventions or the legacy effect when participants who receive active therapy derive residual benefit after the end of the study when all participants receive active medication and the tension between the generalizability of the evidence versus the reliability of the findings of different types of clinical trials and the difficulty in applying the findings of randomized clinical trials to individual patients. These limitations are described and illustrated by examples and figures from the literature. In conclusion, this review will be useful to clinical trialists, clinical trial participants and regulatory agents.

The Legacy Effect in Treating Hypercholesterolemia

Background:

The duration of randomized controlled clinical trials usually is approximately 3 to 5 years although hypercholesterolemia and other risk factors for atherosclerotic cardiovascular disease (ASCVD) are lifelong conditions.

Objectives:

The legacy effect, defined as the persistence of benefit of pharmacologic interventions in clinical trials after the end of the randomized phase when all participants receive active therapy, is used to examine the long-term benefit. We summarize the evidence for the existence of the legacy effect as it pertains to hypercholesterolemia, describe underlying mechanisms, and discuss its relevance to clinical practice.

Methods:

We examined all published (n = 13) randomized clinical trials of lipid-lowering agents compared to placebo or usual care with follow-up after the randomized phase for the presence or absence of a legacy effect.

Results:

A legacy effect was demonstrated in all studies. The current US and European guidelines recommend treatment with high-intensity statins for patients with manifest ASCVD and that individualized approach be used for primary prevention.

Conclusion:

The legacy effect results in significant long-term clinical benefits by preventing fatal and nonfatal events. This implies that early therapy would result in lower event rates. Long-term follow-up should be a part of clinical trial design in order to evaluate the presence or absence of a legacy effect.

Therapeutic Inertia: Still a Long Way to Go That Cannot Be Postponed

In the context of type 2 diabetes, the definition of therapeutic inertia should include the failure not only to intensify therapy, but also to deintensify treatment when appropriate and should be distinguished from appropriate inaction in cases justified by particular circumstances. Therapy should be intensified when glycemic control deteriorates to prevent long periods of hyperglycemia, which increase the risk of complications. Strategic plans to overcome therapeutic inertia must include actions focused on patients, prescribers, health systems, and payers. Therapeutic inertia affects the management of glycemia, hypertension, and lipid disorders, all of which increase the risk for cardiovascular diseases. Thus, multifactorial interventions that act on additional therapeutic goals beyond glycemia are needed.

The risk factors of glycemic control, blood pressure control, lipid control in Chinese patients with newly diagnosed type 2 diabetes _ A nationwide prospective cohort study

Nationwide data on glycemic control, blood pressure (BP) control and lipid control in patients with newly diagnosed type 2 diabetes were vacant in China. The aim of this study was to assess the clinical outcomes for these patients. This is an observational prospective cohort study with 12 months of follow up. Patients with a diagnosis of type 2 diabetes less than 6 months were enrolled. Hemoglobin A1c (HbA1c) levels, BP levels and lipid levels were collected at baseline and the follow-ups. This study was registered at www.clinicaltrials.gov (NCT01525693). A total of 5770 participants from 79 hospitals across six geographic regions of China were recruited. After 12 months of treatment, 68.5% of these patients achieved HbA1c <7.0%; 83.7% reached BP <140/90 mmHg; 48.2% met low density lipoprotein cholesterol (LDL-c) <2.6 mmol/L; and 29.5% of patients reached the combined three therapeutic targets. Compared to those patients with baseline HbA1c <7.0%, patients with baseline HbA1c ≥7.0% had higher failure rate to reach glycemic control (relative risk (RR) = 2.04, p < 0.001), BP control (RR = 1.21, p < 0.001) and LDL-c control (RR = 1.11, p < 0.001). Obese patients had higher possibilities of failure in glucose control (RR = 1.05, p = 0.004), BP control (RR = 1.62, p < 0.001) and lipid control (RR = 1.09, p = 0.001) than patients with normal weight. The active smokers were more likely to fail in glycemic control than non-smokers (RR = 1.06, p = 0.002), and patients with physical activities were less likely to fail in lipid control than patients without exercises (RR = 0.93, p = 0.008). This study outlined the burdens of glycemic control, blood pressure control, lipid control in newly diagnosed type 2 diabetic patients in China, identified gaps in the quality of care and risk-factor control and revealed the factors influencing these gaps.

Legacy effects of statins on cardiovascular and all-cause mortality: a meta-analysis

OBJECTIVES

To assess evidence for 'legacy' (post-trial) effects on cardiovascular disease (CVD) mortality and all-cause mortality among adult participants of placebo-controlled randomised controlled trials (RCTs) of statins.

DESIGN

Meta-analysis of aggregate data.

SETTING/PARTICIPANTS

Placebo-controlled statin RCTS for primary and secondary CVD prevention.

METHODS

Data sources: PubMed, Embase from inception and forward citations of Cholesterol Treatment Trialists' Collaborators RCTs to 16 June 2016.

STUDY SELECTION

Two independent reviewers identified all statin RCT follow-up reports including ≥1000 participants, and cardiovascular and all-cause mortality.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted data in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

MAIN OUTCOMES

Post-trial CVD and all-cause mortality.

RESULTS

We included eight trials, with mean post-trial follow-up ranging from 1.6 to 15.1 years, and including 13 781 post-trial deaths (6685 CVD). Direct effects of statins within trials were greater than legacy effects post-trials. The pooled data from all eight studies showed no evidence overall of legacy effects on CVD mortality, but some evidence of legacy effects on all-cause mortality (p=0.01). Exploratory subgroup analysis found possible differences in legacy effect for primary prevention trials compared with secondary prevention trials for both CVD mortality (p=0.15) and all-cause mortality (p=0.02). Pooled post-trial HR for the three primary prevention studies demonstrated possible post-trial legacy effects on CVD mortality (HR=0.87; 95% CI 0.79 to 0.95) and on all-cause mortality (HR=0.90; 95% CI 0.85 to 0.96).

CONCLUSIONS

Possible post-trial statin legacy effects on all-cause mortality appear to be driven by the primary prevention studies. Although these relative benefits were smaller than those observed within the trial, the absolute benefits may be similar for the two time periods. Analysis of individual patient data from follow-up studies after placebo-controlled statin RCTs in lower-risk populations may provide more definitive evidence on whether early treatment of subclinical atherosclerosis is likely to be beneficial.

Long-term mortality after blood pressure-lowering and lipid-lowering treatment in patients with hypertension in the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) Legacy study: 16-year follow-up results of a randomised factorial trial

BACKGROUND

In patients with hypertension, the long-term cardiovascular and all-cause mortality effects of different blood pressure-lowering regimens and lipid-lowering treatment are not well documented, particularly in clinical trial settings. The Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) Legacy Study reports mortality outcomes after 16 years of follow-up of the UK participants in the original ASCOT trial.

METHODS

ASCOT was a multicentre randomised trial with a 2 × 2 factorial design. UK-based patients with hypertension were followed up for all-cause and cardiovascular mortality for a median of 15·7 years (IQR 9·7-16·4 years). At baseline, all patients enrolled into the blood pressure-lowering arm (BPLA) of ASCOT were randomly assigned to receive either amlodipine-based or atenolol-based blood pressure-lowering treatment. Of these patients, those who had total cholesterol of 6·5 mmol/L or lower and no previous lipid-lowering treatment underwent further randomisation to receive either atorvastatin or placebo as part of the lipid-lowering arm (LLA) of ASCOT. The remaining patients formed the non-LLA group. A team of two physicians independently adjudicated all causes of death.

FINDINGS

Of 8580 UK-based patients in ASCOT, 3282 (38·3%) died, including 1640 (38·4%) of 4275 assigned to atenolol-based treatment and 1642 (38·1%) of 4305 assigned to amlodipine-based treatment. 1768 of the 4605 patients in the LLA died, including 903 (39·5%) of 2288 assigned placebo and 865 (37·3%) of 2317 assigned atorvastatin. Of all deaths, 1210 (36·9%) were from cardiovascular-related causes. Among patients in the BPLA, there was no overall difference in all-cause mortality between treatments (adjusted hazard ratio [HR] 0·90, 95% CI 0·81-1·01, p=0·0776]), although significantly fewer deaths from stroke (adjusted HR 0·71, 0·53-0·97, p=0·0305) occurred in the amlodipine-based treatment group than in the atenolol-based treatment group. There was no interaction between treatment allocation in the BPLA and in the LLA. However, in the 3975 patients in the non-LLA group, there were fewer cardiovascular deaths (adjusted HR 0·79, 0·67-0·93, p=0·0046) among those assigned to amlodipine-based treatment compared with atenolol-based treatment (p=0·022 for the test for interaction between the two blood pressure treatments and allocation to LLA or not). In the LLA, significantly fewer cardiovascular deaths (HR 0·85, 0·72-0·99, p=0·0395) occurred among patients assigned to statin than among those assigned placebo.

INTERPRETATION

Our findings show the long-term beneficial effects on mortality of antihypertensive treatment with a calcium channel blocker-based treatment regimen and lipid-lowering with a statin: patients on amlodipine-based treatment had fewer stroke deaths and patients on atorvastatin had fewer cardiovascular deaths more than 10 years after trial closure. Overall, the ASCOT Legacy study supports the notion that interventions for blood pressure and cholesterol are associated with long-term benefits on cardiovascular outcomes.

FUNDING

Pfizer.

Legacy benefits of blood glucose, blood pressure and lipid control in individuals with diabetes and cardiovascular disease: Time to overcome multifactorial therapeutic inertia?

Cardiovascular disease is a major cause of morbidity and mortality globally and the largest contributor to healthcare costs. There is good evidence that management of risk factors such as blood pressure, dyslipidaemia and glucose can lead to improved microvascular and macrovascular complications in individuals with type 2 diabetes mellitus. Legacy effect is a phenomenon used to describe the prolonged benefits of glucose, blood pressure or lipid control in individuals with cardiovascular disease, diabetes or in primary prevention of cardiovascular disease by early risk factor control. There is now also good quality evidence on the legacy benefits of multifactorial risk factor interventions on renal, cardiovascular and mortality outcomes. Despite this robust evidence, therapeutic inertia is widespread in the management of these risk factors in clinical practice.

Cumulative in-trial and post-trial effects of blood pressure and lipid lowering: systematic review and meta-analysis

OBJECTIVE

Persistent long-term benefits after discontinuation of treatment have been suggested for blood pressure-lowering and lipid-lowering treatment. We conducted a systematic review to assess the long-term effects of blood pressure (BP) lowering (BPL) and lipid lowering on all-cause and cardiovascular mortality after discontinuation of randomized treatment.

METHODS

We systematically searched Medline, Embase, and the Cochrane Central Register of Controlled Trials. We included large-scale randomized controlled trials of BPL or lipid lowering of at least 1 year with post-trial follow-up. We identified 13 BPL trials with 48 892 participants and 10 lipid-lowering trials with 71 370 participants. Mean in-trial and post-trial follow-up was approximately 4 and 6 years, respectively.

RESULTS

BP and lipid levels tended to come together soon in the post-trial period. There was significant benefit of BPL on all-cause mortality during the in-trial period (relative risk 0.85, 95% confidence interval 0.81-0.89), and significant, but attenuated, benefit during overall follow-up (0.91, 0.87-0.94). Likewise, lipid lowering with statins reduced the risk of all-cause mortality during the in-trial period (0.88, 0.81-0.95), and this effect persisted during overall follow-up (0.92, 0.87-0.97). Similar findings were observed for cardiovascular death. In BPL trials, the cumulative reduction in all-cause mortality was significantly lower in trials with at least 5 years of post-trial follow-up compared with those with less than 5 years, and a similar tendency was observed for lipid-lowering trials.

CONCLUSION

Benefits of BPL and lipid lowering on all-cause and cardiovascular mortality were persistent, but attenuated, after discontinuation of randomized treatment, indicating the importance of continuing therapy.

How information about the time requirements and legacy effects of treatments influence decision-making in patients with diabetes and hypertension

OBJECTIVE

When deciding about diabetes treatments, patients are typically uninformed about how much time is required before (time requirements), or for how long treatments change outcomes (legacy effects). However, patients may be motivated to adopt treatments with time-related treatment information. We explored whether this information alters a patients' likelihood of starting medications.

RESEARCH DESIGN AND METHODS

We conducted semistructured interviews with 60 adults with type 2 diabetes for <10 years and hypertension on oral medications. We measured change in likelihood of starting medications after receiving time requirement (diabetes, 10 years; hypertension, 3 years) and legacy effect (diabetes, 10 additional years; hypertension, none) information. Responses were analyzed for themes about time-related treatment information.

RESULTS

At baseline, 70% of participants reported being very likely to start a recommended medication. Nearly half (40%) were less likely to start a diabetes medication after being informed of time requirements; but after being informed of legacy effects, 32% reported being more likely. Fewer participants changed likelihoods of starting antihypertensives with time-related information. Many participants expressed that medications' benefits were important to them regardless of time-related information. Participants considered time requirements for diabetes medications too long and compared them to their life expectancy. Many participants were interested in legacy effects of diabetes medications because they looked forward to discontinuing medications, although some expressed doubt that benefits could persist after stopping medications.

CONCLUSIONS

While prolonged time requirements may dissuade patients from adopting treatments, the promise of legacy effects may motivate patients to commit to diabetes treatments.

Starting primary prevention earlier with statins

The 2013 American College of Cardiology/American Heart Association Guideline on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults was based on a systematic review of randomized trials with atherosclerotic cardiovascular disease (ASCVD) outcomes and meta-analyses of these trials published through 2011. With evidence of an ASCVD risk reduction benefit greatly outweighing the potential for adverse effects, the guideline recommends statin therapy for primary prevention in those with ≥7.5% 10-year ASCVD risk and consideration of statin therapy in those with 5% to <7.5% 10-year ASCVD risk. Subsequent meta-analyses of the statin trials support these recommendations and have additionally found a reduction in total mortality in lower-risk subjects. Additional evidence from imaging trials and epidemiologic studies suggests that initiation of statin therapy earlier in the course of ASCVD could have the potential to more effectively prevent age-related progression of atherosclerosis. Given the high levels of suboptimal risk factors in adults and the safety and availability of low-cost generic statins, a consideration of all the available evidence strongly supports earlier intervention for the primary prevention of ASCVD. In conclusion, earlier initiation of statin therapy has the potential to have a large long-term impact on the heavy burden of cardiovascular disease in the aging populations.

The evolution or revolution of statin therapy in primary prevention: where do we go from here?

CHD morbidity and mortality rates have more than halved since their peak in the 1960s and 1970s. This trend is a result of many factors; however, primary prevention provides the bulk of this benefit. Despite this tremendous progress, cardiovascular disease remains the major cause of death and this trend is projected to persist given the continuous growth in those aged 65 years or greater. Although statin therapy has been a main contributor to a primary prevention strategy, there is still controversy about exposing a large healthy population to long-term statin therapy. Advocates contend the mortality benefits from an aggressive statin approach would remove heart disease from its perch as the greatest killer of Americans and stroke mortality would drop from third to fifth place. Those advocating a much more conservative approach contend the data are not available to expose a healthy population to lifelong statin therapy given limited data on mortality, potential adverse events, and considerable costs. Given these opposing views, this summary of the evolution of statin therapy for the primary prevention of cardiovascular disease will review the major factors fueling this debate.

Cardiology for gynecologists--a minireview

Despite cardiovascular disease (CVD) being by far the most common cause of death in women worldwide, awareness is low. Myocardial infarction occurs 10 years later in women than in men. Symptoms may be atypical: dyspnea rather than chest pain. Also more women than men have myocardial infarction with normal coronary angiography, probably due to microvascular disease or coronary spasm. The prognosis of non-obstructive disease is now recognized to be the same than for obstructive disease. The conventional risk factors for CVD are the same for both genders but have a different impact for women. One example is psychosocial stress and angina pectoris can more often be induced by mental stress in women than in men. Also there are risk factors specific to women such as a history of pre-eclampsia, gestational hypertension or diabetes and polycystic ovary syndrome (PCOS). Furthermore atrial fibrillation increases the risk of stroke more in women than in men. However, 6 out of 10 deaths from CVD can be prevented by a healthy life style and dealing with preexisting risk factors. Hence it is important that gynecologists who start seeing women at an earlier age than cardiologists should be aware of cardiovascular disease.

Statin therapy and the risk of intracerebral hemorrhage: a meta-analysis of 31 randomized controlled trials

BACKGROUND AND PURPOSE

Statin therapy decreases the risk of ischemic stroke. An increased risk of intracerebral hemorrhage (ICH) has been observed in some studies. To investigate this issue, we performed a meta-analysis of randomized controlled trials using statins that reported ICH.

METHODS

We performed a literature search of Medline, Web of Science, and The Cochrane Library through January 25, 2012, and identified additional randomized controlled trials by reviewing reference lists of retrieved studies and prior meta-analyses. All randomized controlled trials of statin therapy that reported ICH or hemorrhagic stroke were included. The primary outcome variable was ICH. Thirty-one randomized controlled trials were included. All analyses used random effects models and heterogeneity was not observed in any of the analyses.

RESULTS

A total of 91,588 subjects were included in the active group and 91,215 in the control group. There was no significant difference in incidence of ICH observed in the active treatment group versus control (OR, 1.08; 95% CI, 0.88-1.32; P=0.47). ICH risk was not related to the degree of low-density lipoprotein reduction or achieved low-density lipoprotein cholesterol. Total stroke (OR, 0.84; 95% CI, 0.78-0.91; P<0.0001) and all-cause mortality (OR, 0.92; CI, 0.87-0.96; P=0.0007) were significantly reduced in the active therapy group. There was no evidence of publication bias.

CONCLUSIONS

Active statin therapy was not associated with significant increase in ICH in this meta-analysis of 31 randomized controlled trials of statin therapy. A significant reduction in all stroke and all-cause mortality was observed with statin therapy.