A cardiovascular polypill for secondary stroke prevention in a tertiary centre in Ghana (SMAART): a phase 2 randomised clinical trial

BACKGROUND

A cardiovascular polypill containing generic drugs might facilitate sustained implementation of and adherence to evidence-based treatments, especially in resource-limited settings. However, the impact of a cardiovascular polypill in mitigating atherosclerotic risk among stroke survivors has not been assessed. We aimed to compare a polypill regimen with usual care on carotid intima-media thickness (CIMT) regression after ischaemic stroke.

METHODS

In SMAART, a phase 2 parallel, open-label, assessor-masked, randomised clinical trial, we randomly allocated individuals (aged ≥18 years) who had an ischaemic stroke within the previous 2 months, using a computer-generated randomisation sequence (1:1), to either a polypill or usual care group at a tertiary centre in Ghana. The polypill regimen was a fixed-dose pill containing 5 mg ramipril, 50 mg atenolol, 12·5 mg hydrochlorothiazide, 20 mg simvastatin, and 100 mg aspirin administered as two capsules once per day for 12 months. Usual care was tailored guideline-recommended secondary prevention medications. The primary outcome was the change in CIMT over 12 months with adjustment for baseline values, compared using ANCOVA in all participants with complete data at month 12. Safety was analysed in all randomly assigned participants. This trial is registered at ClinicalTrials.gov, NCT03329599, and is completed.

FINDINGS

Between Feb 12, 2019, and Dec 4, 2020, we randomly assigned 148 participants (74 to the usual care group and 74 to the polypill group), 74 (50%) of whom were male and 74 (50%) female. CIMT was assessed in 62 (84%) of 74 participants in the usual care group and 59 (80%) of 74 participants in the polypill group; the main reason for loss to follow-up was participants not completing the study. The mean CIMT change at month 12 was -0·092 mm (95% CI -0·130 to -0·051) in the usual care group versus -0·017 mm (-0·067 to 0·034) in the polypill group, with an adjusted mean difference of 0·049 (-0·008 to 0·109; p=0·11). Serious adverse events occurred among two (3%) participants in the usual care group, and eight (11%) participants in the polypill group (p=0·049).

INTERPRETATION

The polypill regimen resulted in similar regression in subclinical atherosclerosis and many secondary and tertiary outcome measures as the tailored drug regimen, but with more serious adverse events. Larger, longer-term, event-based studies, including patients with stroke in primary care settings, are warranted.

FUNDING

US National Institutes of Health.

TRANSLATION

For the Akan (Twi) translation of the abstract see Supplementary Materials section.

Stroke Symptoms As a Surrogate in Stroke Primary Prevention Trials: The CREST Experience

BACKGROUND

and Purpose: The use of surrogate endpoints can decrease sample size while maintaining statistical power. This report considers incident stroke symptoms as a surrogate endpoint in a post-hoc analysis of asymptomatic patients from the multicenter, randomized Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST).

METHODS

CREST assessed stroke symptoms using the Questionnaire for Verifying Stroke-free Status (QVSS) at baseline and follow-up. While the primary analysis of CREST defined "asymptomatic" as having been free of stroke/TIA for 180 days, herein the population was further restricted by requiring no stroke symptoms at baseline. Incident adjudicated stroke was defined the same as for the primary analysis; incident stroke symptoms was defined as developing ≥1 stroke symptom in follow-up. Treatment differences between stenting (CAS) and endarterectomy (CEA) were assessed for three endpoints: adjudicated stroke, stroke symptoms, and adjudicated stroke or stroke symptoms.

RESULTS

The cohort included 826 of the 1181 asymptomatic patients in CREST. Adjudicated stroke events occurred in 44 patients and incident stroke symptoms occurred in 183. Analysis of adjudicated stroke endpoints demonstrated a non-significant hazard ratio (HR) for CAS compared to CEA of 1.02 (95% confidence interval [CI], 0.57-1.85). The corresponding HR for the incident stroke symptoms outcome was 1.54 (95% CI, 1.15-2.08), and the HR for the composite outcome of adjudicated stroke or incident symptoms was 1.38 (95% CI, 1.04-1.83), both significant.

CONCLUSIONS

The low stroke event rates in asymptomatic patients challenges the assessment of CAS-versus-CEA treatment differences. Incorporating incident stroke symptoms as a surrogate outcome increased the number of events by over 4-fold. The analysis demonstrated a previously unreported significant difference in cerebrovascular risk with CAS compared to CEA. We propose that broadening the endpoints of primary stroke prevention trials to include surrogate events like incident stroke symptoms could make trials more feasible.

Non-Adherence to Antihypertensive Guidelines in Patients with Asymptomatic Carotid Stenosis

IMPORTANCE

Hypertension and carotid stenosis are both risk factors for stroke, but the presence of carotid stenosis might dampen enthusiasm for tight control of hypertension because of concerns for hypoperfusion.

OBJECTIVE

To determine the extent to which there are opportunities to potentially improve pharmacotherapy for hypertension in patients known to have asymptomatic high-grade carotid stenosis.

DESIGN

We examined anti-hypertensive medication prescription and adherence to evidence-based hypertension treatment guidelines in a cross-sectional analysis of baseline data of patients enrolled in a clinical trial.

SETTING

The Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial (CREST-2) is a multicenter prospective randomized open blinded end-point clinical trial of intensive medical management with or without revascularization by endarterectomy or stenting for asymptomatic high-grade carotid stenosis.

PARTICIPANTS

1479 participants (38.6% female; mean age 69.8 years) from 132 clinical centers enrolled in the CREST-2 trial as of April 6, 2020 who were taking ≥1 antihypertensive drug at baseline.

EXPOSURES

Pharmacotherapy for hypertension.

MAIN OUTCOME

Adherence to evidence-based guidelines for treating hypertension.

RESULTS

Of 1458 participants with complete data, 26% were on one, 31% on 2, and 43% on ≥3 antihypertensive medications at trial entry. Thirty-two percent of participants were prescribed thiazide; 74%, angiotensin converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB); 38%, calcium channel blocker (CCB); 56%, a beta blocker; 11%, loop diuretic; and 27%, other. Of those prescribed a single antihypertensive medication, the proportion prescribed thiazide was 5%; ACEI or ARB, 55%, and CCB, 11%. The prevalence of guideline-adherent regimens was 34% (95% CI, 31-36%).

CONCLUSIONS AND RELEVANCE

In a diverse cohort with severe carotid disease and hypertension, non-adherence to hypertension guidelines was common. All preferred classes of antihypertensive drug were under-prescribed. Using staged iterative guideline-based care for hypertension, CREST-2 will characterize drug tolerance and stroke rates under these conditions.

TRIAL REGISTRATION

ClinicalTrials.gov Number NCT02089217.

Abstract 70: Age and Outcomes After Carotid Stenting and Endarterectomy: A Pooled Analysis of the Crest and Act I Trials

Introduction: Using pooled data from randomized trials of symptomatic patients assigned to carotid artery stenting (CAS) versus carotid endarterectomy (CEA), we have previously shown age to be an effect modifier, with increasing risk at older ages for CAS but not for CEA. To extend assessment of age as an effect modifier to the asymptomatic population, we combined the asymptomatic patients from CREST with the patients from ACT I.

Methods: We analyzed data from 2544 subjects with >= 70% carotid stenosis randomized to CAS or CEA in addition to standard management of cardiovascular risk factors. CREST enrolled 1091 (548 CAS, 543 CEA) and ACT I enrolled 1453 (1089 CAS, 364 CEA) asymptomatic patients less than 80 years old (upper age eligibility in ACT I). We examined the impact of age on risk within CAS-treated and CEA-treated patients using Kaplan-Meier methods. Age was considered in three strata (< 65, 65 to 74, and 75+). The pre-specified, primary composite endpoint was stroke, myocardial infarction, or death during the periprocedural period or any ipsilateral stroke within 4 years after randomization.

Results: For patients assigned to CAS, risk differed between the age strata (p <0.0001) where relative to those under age 65, there was no difference in risk for those aged 65 to 74 (HR = 1.3 ; 95% CI: 0.7, 2.3, p=0.38), but those aged 75+ were at substantially higher risk (HR = 2.9; 95% CI: 1.5, 5.5, p=0.001). In contrast, risk did not differ by age strata (p = 0.80) for those assigned to CEA.

Conclusions: Age-related risk factors, e.g. carotid anatomy and underlying cerebral pathology, should be considered before selecting patients aged 75+ for CAS.

Abstract TMP96: Carotid Plaque Characteristics Correlated to Baseline Vascular Risk Factors in a Large Randomized Trial: Results from CREST-2

Objectives: Assessment of carotid disease is most commonly performed with duplex ultrasonography (DUS). Measures of plaque area and tissue composition from DUS images may identify patients at risk for future neurologic events, and may assess the effects of vascular risk-factor modification (by measuring change in plaque area and/or tissue constituents). We quantified plaque area and tissue constituents from DUS images of CREST-2 participants at baseline and correlated them with their baseline vascular risk factors.

Methods: CREST-2 consists of two multicenter, randomized trials in patients with asymptomatic ≥70% carotid stenosis comparing intensive medical management (IMM) plus endarterectomy or stenting vs IMM alone. Baseline B-mode DUS images from 500 patients underwent manual plaque outlining and automatic pixel brightness assessment. Plaque area, grayscale median (GSM), Gray-Weale score for heterogeneity, and areas for intraplaque hemorrhage and lipid were the output parameters. We computed the parameter estimates (95% confidence intervals) for baseline patient characteristics (age, sex, race, diabetes, smoking, BMI, blood pressure and LDL levels) versus plaque characteristics.

Results: High-risk plaque features (larger plaque area, lower GSM , lower Gray-Weale scores, or larger areas of hemorrhage and lipid) were present in older patients, males, and those with elevated diastolic blood pressure and LDL levels (Table).

Conclusions: In a randomized trial of asymptomatic patients with high-grade carotid stenosis, DUS-based computation of plaque geometry and tissue composition is feasible. Elevated diastolic blood pressure and LDL levels at baseline are associated with high-risk plaque characteristics. These novel findings identify potentially modifiable targets for aggressive treatment to reduce stroke-risk in patients with carotid stenosis.

Abstract TMP34: The Challenge and Yield of Racially and Ethnically Diverse Patient Populations in Low Event-Rate Clinical Trials

Background: Concern for underrepresentation of minorities in clinical trials has focused on enrollment proportions and generalizability. The interplay of trial event-rates with diversity has not been emphasized.

Methods: The Carotid Revascularization Endarterectomy vs Stent Trial (CREST) randomized 2502 patients and compared them by race, ethnicity, baseline characteristics, and primary outcome (any peri-procedural stroke, death or MI and subsequent ipsilateral stroke up to 10 years); those with unknown race or ethnicity were excluded. Proportional hazards models adjusting for age, sex, symptomatic status and treatment were used to test for a treatment by race/ethnicity interaction.

Results: One-hundred-nine patients (4.4%) were black, 32 (1.3%) Asian, 2332 (93.4%) white, 11 (0.4%) other by self-report, and 18 (0.7%) unknown; 90 (3.6%) were Hispanic, 2377 (95%) non-Hispanic, and 35 (1.4%) unknown. Compared to whites, racial minorities were younger (mean age 67±8.9 vs 69±8.8, p=0.004), more often female (44% vs 34%, p=0.01), symptomatic (63 vs 52%, p=0.01), and diabetic (51% vs 29%, p<0.0001), but less often dyslipidemic (76% vs 85%, p=0.004), current smokers (19% vs 27%, p=0.04), or had a history of cardiovascular disease (34% vs 46%, p=0.007). Hispanics were more often diabetic (48% vs 30%, p=0.0002). The rate of the primary endpoint was 10.9%±0.9% at 10 years, and did not differ by race or ethnicity (p inter >0.24). In the context of this low rate, even if minority recruitment were increased to represent 50% of study participants, and if the treatment difference in one race were a greater hazard of HR = 1.49 (anticipated alternative hypothesis), then the hazard ratio in the other group would need to be <0.73, or >3.31, to have 90% power of detection.

Conclusions: The proportion of racial and ethnicity participation in CREST was suboptimal at < 10%. Primary outcomes did not differ by minority or ethnic status. However, in low event-rate trials very high and even unrealistic enrollment goals for diversity, for example ≥50%, may still be insufficient for detection of outcome differences by race or ethnicity.

Transcranial doppler re-screening of subjects who participated in STOP and STOP II

In children with Sickle Cell Disease, the combination of risk stratification with Transcranial Doppler Ultrasound (TCD) and selective chronic red cell transfusion (CRCT-the STOP Protocol) is one of the most effective stroke prevention strategies in medicine. How fully it is being implemented is unclear. Nineteen of 26 sites that conducted the two pivotal clinical trials (STOP and STOP II) participated in Post STOP, a comprehensive medical records review assessing protocol implementation in the 10-15 years since the trials ended. Professional abstractors identified medical records in the Post STOP era in 2851 (74%) of the 3,840 children who took part in STOP and/or STOP II, and documented TCD rescreening, maintenance of CRCT in those at risk, and stroke. Among 1,896 children eligible for TCD rescreening (target group), evidence of any rescreening was found in 1,090 (57%). There was wide site variation in TCD rescreening ranging from 18% to 91% of eligible children. Both younger age and having a conditional TCD during STOP/II were associated with a higher likelihood of having a TCD in Post STOP. Sixty eight new abnormal, high risk cases were identified. Despite clear evidence of benefit the STOP protocol is not fully implemented even at experienced sites. Site variation suggests that system improvements might remove barriers to implementation and result in even greater reduction of ischemic stroke in children with SCD. Am. J. Hematol. 91:1191-1194, 2016. © 2016 Wiley Periodicals, Inc.

Abstract 17: Development of High Risk TCD in Sickle Cell Disease

Background: The Stroke Prevention Trial in Sickle Cell Anemia (STOP) and Optimizing Primary Stroke Prevention in Sickle Cell Anemia (STOP 2) established routine transcranial Doppler ultrasound (TCD) as standard of care. Some information on conversion from low to high risk was derived from the STOP/2 studies but information is needed from “real world” practice to improve TCD screening guidelines.

Subjects and Methods: During STOP and STOP2, 3,837 children, ages 2 to 16 y with SCD-SS or SCD-SBeta-0-thalassemia, underwent screening TCD. The POST-STOP study was designed to follow-up all children who participated in one or both of these trials. 19 of the 26 original study sites participated in POST-STOP, contributing a total of 3,541 (92%) of STOP/STOP2 subjects. Data abstractors visited the clinical sites to extract TCD, neuroimaging and neurological outcome information.

Results: Of the 3,541 subjects, follow-up data were available for 2834 (80%). The mean age at the last TCD STOP/2study was 9.5 years, the mean age at last follow-up in POST-STOP was 19.6 years and the mean duration of follow-up after exiting STOP/STOP2 was 9.2 years. STOP TCD risk stratification was used: normal < 170 cm/sec; conditional 170-199 cm/sec; abnormal >200 cm/sec. Subjects were classified by their highest risk TCD in STOP/STOP 2. The population was divided on this basis into normal (1813 --64%), conditional (478 --17%), abnormal (357-- 13%) or inadequate (186 --7%). Among the 478 with conditional TCD studies in STOP/STOP2, the mean age at last follow-up in POST-STOP was 19.2 years (range 4.9-33.1) and follow-up TCD was obtained on 252 (53%) from 11 months to 16 years after STOP/2 (median 10.4) . Forty three of these had an abnormal TCD (mean age at abnormal was 8.5 years from 3 months to 8.4 years after STOP/2 (median 1.97 years).

Conclusions:

1) We could find evidence of follow up TCD for about of half of these children indicating that more needs to be done to insure regular and consistent surveillance of these children who have some elevated risk.

2) Conversions to abnormal TCD were documented. Treatment decisions as well as stroke outcomes for all the 479 with conditional TCD will be derived from adjudication of the complete data set (in progress).

Metabolic syndrome, C-reactive protein, and mortality in U.S. Blacks and Whites: the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study

OBJECTIVE

We evaluate associations of metabolic syndrome (MetS), C-reactive protein (CRP), and a CRP-incorporated definition of MetS (CRPMetS) with risk of all-cause mortality in a biracial population.

RESEARCH DESIGN AND METHODS

We studied 23,998 participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort, an observational study of black and white adults ≥45 years old across the U.S. Elevated CRP was defined as ≥3 mg/L and MetS by the revised Third Report of the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III; ATP III) criteria (three of five components). CRPMetS was defined as presence of three out of six components, with elevated CRP added to ATP III criteria as a sixth component. Cox models were used to calculate hazard ratios (HRs) for all-cause mortality, and population attributable risk (PAR) was calculated. Stratified analyses based on race and diabetes status were performed.

RESULTS

There were 9,741 participants (41%) with MetS and 12,179 (51%) with CRPMetS at baseline. Over 4.8 years of follow-up, 2,050 participants died. After adjustment for multiple confounders, MetS, elevated CRP, and CRPMetS were each significantly associated with increased mortality risk (HRs 1.26 [95% CI 1.15-1.38], 1.55 [1.41-1.70], and 1.34 [1.22-1.48], respectively). The PAR was 9.5% for MetS, 18.1% for CRP, and 14.7% for CRPMetS. Associations of elevated CRP and of CRPMetS with mortality were significantly greater in whites than blacks, while no differences in associations were observed based on diabetes status.

CONCLUSIONS

By definition, CRPMetS identifies more people at risk than MetS but still maintains a similar mortality risk. Incorporating CRP into the definition for MetS may be useful in identifying additional high-risk populations to target for prevention.

The Carotid Revascularization Endarterectomy versus Stenting Trial: credentialing of interventionalists and final results of lead-in phase

The success of carotid artery stenting in preventing stroke requires a low risk of periprocedural stroke and death. A comprehensive training and credentialing process was prerequisite to the randomized Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) to assemble a competent team of interventionalists with low periprocedural event rates. Interventionalists submitted cases to a multidisciplinary Interventional Management Committee. This committee evaluated 427 applicants. Of these, 238 (56%) were selected to participate in the training program and the lead-in phase, 73 (17%) who had clinical registry experience and satisfactory results with the devices used in CREST were exempt from training and were approved for the randomized phase, and 116 (27%) did not qualify for training. At 30 days in the lead-in study, stroke, myocardial infarction, or death occurred in 6.1% of symptomatic subjects and 4.8% of asymptomatic subjects. Stroke or death occurred in 5.8% of symptomatic subjects and 3.8% of asymptomatic subjects. Outcomes were better for younger subjects and varied by operator training. Based on experience, training, and lead-in results, the Interventional Management Committee selected 224 interventionalists to participate in the randomized phase of CREST. We believe that the credentialing and training of interventionalists participating in CREST have been the most rigorous reported to date for any randomized trial evaluating endovascular treatments. The study identified competent operators, which ensured that the randomized trial results fairly contrasted outcomes between endarterectomy and stenting.

Randomized trial on sun safety education at ski and snowboard schools in western North America

The purpose of this study was to evaluate the effectiveness of Go Sun Smart, a sun safety education program, directed to parents and children enrolled in ski and snowboard schools at high altitude resorts in western North America. Twenty-six ski resorts were paired and then randomly assigned to the intervention or control condition. Three hundred fifty-seven parents were interviewed about their children's sun safety behavior and exposure to the Go Sun Smart program. More parents at the intervention resorts reported that their child was wearing sunscreen than at the control resorts (OR 2.37, 95% CI 0.93, 5.99) but this result was significant only at resorts in the Northwest region (OR 2.72, 95% CI 1.24, 5.95). Parents at intervention resorts had significantly increased odds of having seen a Go Sun Smart poster than those at the control resorts (OR=8.53, 95% CI 2.17, 33.54). No significant differences were identified between the intervention and control groups for verbal messages from ski resort employees about sun protection. Outdoor wintertime recreation venues are a potentially effective site from which to implement sun safety education programs for children and parents.