Does early detection of atrial fibrillation reduce the risk of thromboembolic events? Rationale and design of the Heartline study

BACKGROUND

The impact of using direct-to-consumer wearable devices as a means to timely detect atrial fibrillation (AF) and to improve clinical outcomes is unknown.

METHODS

Heartline is a pragmatic, randomized, and decentralized application-based trial of US participants aged ≥65 years. Two randomized cohorts include adults with possession of an iPhone and without a history of AF and those with a diagnosis of AF taking a direct oral anticoagulant (DOAC) for ≥30 days. Participants within each cohort are randomized (3:1) to either a core digital engagement program (CDEP) via iPhone application (Heartline application) and an Apple Watch (Apple Watch Group) or CDEP alone (iPhone-only Group). The Apple Watch Group has the watch irregular rhythm notification (IRN) feature enabled and access to the ECG application on the Apple Watch. If an IRN notification is issued for suspected AF then the study application instructs participants in the Apple Watch Group to seek medical care. All participants were "watch-naïve" at time of enrollment and have an option to either buy or loan an Apple Watch as part of this study. The primary end point is time from randomization to clinical diagnosis of AF, with confirmation by health care claims. Key secondary endpoint are claims-based incidence of a 6-component composite cardiovascular/systemic embolism/mortality event, DOAC medication use and adherence, costs/health resource utilization, and frequency of hospitalizations for bleeding. All study assessments, including patient-reported outcomes, are conducted through the study application. The target study enrollment is approximately 28,000 participants in total; at time of manuscript submission, a total of 26,485 participants have been enrolled into the study.

CONCLUSION

The Heartline Study will assess if an Apple Watch with the IRN and ECG application, along with application-facilitated digital health engagement modules, improves time to AF diagnosis and cardiovascular outcomes in a real-world environment.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04276441.

Consumer-Led Screening for Atrial Fibrillation: Frontier Review of the AF-SCREEN International Collaboration

The technological evolution and widespread availability of wearables and handheld ECG devices capable of screening for atrial fibrillation (AF), and their promotion directly to consumers, has focused attention of health care professionals and patient organizations on consumer-led AF screening. In this Frontiers review, members of the AF-SCREEN International Collaboration provide a critical appraisal of this rapidly evolving field to increase awareness of the complexities and uncertainties surrounding consumer-led AF screening. Although there are numerous commercially available devices directly marketed to consumers for AF monitoring and identification of unrecognized AF, health care professional-led randomized controlled studies using multiple ECG recordings or continuous ECG monitoring to detect AF have failed to demonstrate a significant reduction in stroke. Although it remains uncertain if consumer-led AF screening reduces stroke, it could increase early diagnosis of AF and facilitate an integrated approach, including appropriate anticoagulation, rate or rhythm management, and risk factor modification to reduce complications. Companies marketing AF screening devices should report the accuracy and performance of their products in high- and low-risk populations and avoid claims about clinical outcomes unless improvement is demonstrated in randomized clinical trials. Generally, the diagnostic yield of AF screening increases with the number, duration, and temporal dispersion of screening sessions, but the prognostic importance may be less than for AF detected by single-time point screening, which is largely permanent, persistent, or high-burden paroxysmal AF. Consumer-initiated ECG recordings suggesting possible AF always require confirmation by a health care professional experienced in ECG reading, whereas suspicion of AF on the basis of photoplethysmography must be confirmed with an ECG. Consumer-led AF screening is unlikely to be cost-effective for stroke prevention in the predominantly young, early adopters of this technology. Studies in older people at higher stroke risk are required to demonstrate both effectiveness and cost-effectiveness. The direct interaction between companies and consumers creates new regulatory gaps in relation to data privacy and the registration of consumer apps and devices. Although several barriers for optimal use of consumer-led screening exist, results of large, ongoing trials, powered to detect clinical outcomes, are required before health care professionals should support widespread adoption of consumer-led AF screening.

The All of Us Research Program: Data quality, utility, and diversity

The All of Us Research Program seeks to engage at least one million diverse participants to advance precision medicine and improve human health. We describe here the cloud-based Researcher Workbench that uses a data passport model to democratize access to analytical tools and participant information including survey, physical measurement, and electronic health record (EHR) data. We also present validation study findings for several common complex diseases to demonstrate use of this novel platform in 315,000 participants, 78% of whom are from groups historically underrepresented in biomedical research, including 49% self-reporting non-White races. Replication findings include medication usage pattern differences by race in depression and type 2 diabetes, validation of known cancer associations with smoking, and calculation of cardiovascular risk scores by reported race effects. The cloud-based Researcher Workbench represents an important advance in enabling secure access for a broad range of researchers to this large resource and analytical tools.

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The All of Us Research Program has released data for over 315,000 participants

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Demonstration projects support the utility and validity of the All of Us dataset

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The cloud-based Researcher Workbench provides secure, low-cost compute power

The engagement of participants in the research process and broad availability of data to diverse researchers are essential elements in building precision medicine equitably available for all. The NIH has established the ambitious All of Us Research Program to build one of the most diverse health databases in history with tools to support research to improve human health. Here, we present the initial launch of the Researcher Workbench with data types including surveys, physical measurements, and electronic health record data with validation studies to support researcher use of this novel platform. Broad access for researchers to data like these is a critical step in returning value to participants seeking to support the advancement of precision medicine and improved health for all.

Mobile Health-Collected Biophysical Markers in Children with Serious Illness-Related Pain

Context: There is an ongoing established need to develop engaging pain assessment strategies to provide more effective individualized care to pediatric patients with serious illnesses. This study explores the acceptability of wireless devices as one option. Objective: To evaluate the ability of wrist-wearable technology to collect physiological data from children with serious illnesses. Methods: Single-site prospective observational study conducted between September 2017 and September 2018 at Rady Children's Hospital, San Diego, California, inpatient wards. Pediatric patients with diagnoses of cancer and sickle cell disease admitted to the hospital for acute-on-chronic pain and taking opioid pain medications were asked to complete two 24-hour continuous monitoring periods with the Empatica E4 wristband. Results: Data collected from the device correlated with manually obtained vital signs. Children responded favorably to wearing the device. Participants with reported subjective pain versus no pain had average heart rate increased by 16.4 bpm, skin temperature decreased by 3.5°C, and electrodermal activity decreased by 0.27. Conclusions: This study shows the possibility of collecting continuous biophysical data in a nonobtrusive manner in seriously ill children experiencing acute-on-chronic pain using wearable devices. It provides the framework for larger studies to explore the utility of such data in relation to metrics of pain and suffering in this patient population.

Chronic kidney disease and undiagnosed atrial fibrillation in individuals with diabetes

Background

Diabetes is an independent risk factor for atrial fibrillation (AF), which is associated with increases in mortality and morbidity, as well as a diminished quality of life. Renal involvement in diabetes is common, and since chronic kidney disease (CKD) shares several of the same putative mechanisms as AF, it may contribute to its increased risk in individuals with diabetes. The objective of this study is to identify the relationship between CKD and the rates of newly-diagnosed AF in individuals with diabetes taking part in a screening program using a self-applied wearable electrocardiogram (ECG) patch.

Materials and methods

The study included 608 individuals with a diagnosis of diabetes among 1738 total actively monitored participants in the prospective mHealth Screening to Prevent Strokes (mSToPS) trial. Participants, without a prior diagnosis of AF, wore an ECG patch for 2 weeks, twice, over a 4-months period and followed clinically through claims data for 1 year. Definitions of CKD included ICD-9 or ICD-10 chronic renal failure diagnostic codes, and the Health Profile Database algorithm. Individuals requiring dialysis were excluded from trial enrollment.

Results

Ninety-six (15.8%) of study participants with diabetes also had a diagnosis of CKD. Over 12 months of follow-up, 19 new cases of AF were detected among the 608 participants. AF was newly diagnosed in 7.3% of participants with CKD and 2.3% in those without (P < 0.05) over 12 months of follow-up. In a univariate Cox proportional hazard regression analysis, the risk of incident AF was 3 times higher in individuals with CKD relative to those without CKD: hazard ratios (HR) 3.106 (95% CI 1.2–7.9). After adjusting for the effect of age, sex, and hypertension, the risk of incident AF was still significantly higher in those with CKD: HR 2.886 (95% CI 1.1–7.5).

Conclusion

Among individuals with diabetes, CKD significantly increases the risk of incident AF. Identification of AF prior to clinical symptoms through active ECG screening could help to improve the clinical outcomes in individuals with CKD and diabetes.

Activity Sensors to Evaluate the Effect of Sacubitril/Valsartan on Quality-of-Life in Heart Failure: rational and design of the AWAKE-HF study

Aims

Limited data are available regarding the ability of sacubitril/valsartan to provide clinically meaningful health‐related quality of life (HRQoL) improvements among individuals with heart failure (HF). Objective measurement of physical activity and sleep using actigraphy can provide insight into daily functioning and HRQoL.

Methods and results

We designed an 18 week, multicenter, randomized, double‐blind, double‐dummy, parallel‐group study to objectively assess changes in function and HRQoL directly after initiating sacubitril/valsartan vs. enalapril in participants with HF in their home environments. A total of 136 outpatient, ambulatory participants with New York Heart Association Class II or III HF with reduced ejection fraction (HFrEF) will be included in the study. Patients will undergo a 2 week baseline observational phase (continuing current HF treatment); data from the second week of this phase will be the baseline value for comparison with those of subsequent periods. Patients will then enter an 8 week blinded‐treatment phase (randomly assigned 1:1 to sacubitril/valsartan or enalapril), followed by an 8 week open‐label extension phase (treatment with only sacubitril/valsartan). The primary efficacy endpoint is the change in mean activity counts during the most active 30 min of the participant's day between baseline and the final randomized treatment phase measurement. Secondary endpoints include the change in mean sleep activity during the randomized and open‐label phases; questionnaires will also assess HRQoL measures. Rather than analysing pooled actigraphy data, the researchers are considering each participant to be acting as his or her own control.

Conclusions

This will be the first study to assess the effects of sacubitril/valsartan on objective measures of sleep and activity in individuals with HFrEF within the context of their daily lives. Wearable accelerometer devices will be used to gain insight into how the medication affects physical activity and sleep.

Advanced and Accurate Mobile Health Tracking Devices Record New Cardiac Vital Signs

Cardiovascular disease remains the leading cause of death and disease worldwide. As demands on an already resource-constrained healthcare system intensify, disease prevention in the future will likely depend on out-of-office monitoring of cardiovascular risk factors. Mobile health tracking devices that can track blood pressure and heart rate, in addition to new cardiac vital signs, such as physical activity level and pulse wave velocity (PWV), offer a promising solution. An initial barrier is the development of accurate and easily-scalable platforms. In this study, we made a customized smartphone app and used mobile health devices to track PWV, blood pressure, heart rate, physical activity, sleep duration, and multiple lifestyle risk factors in ≈250 adults for 17 continual weeks. Eligible participants were identified by a company database and then were consented and enrolled using only a smartphone app, without any special training given. Study participants reported high overall satisfaction, and 73% of participants were able to measure blood pressure and PWV, <1 hour apart, for at least 14 of 17 weeks. The study population's blood pressure, PWV, heart rate, activity levels, sleep duration, and the interrelationships among these measurements were found to closely match either population averages or values obtained from studies performed in a controlled setting. As a proof-of-concept, we demonstrated the accuracy and ease, as well as many challenges, of using mHealth technology to accurately track PWV and new cardiovascular vital signs at home.

Real World Home Blood Pressure Variability in Over 56,000 Individuals With Nearly 17 Million Measurements

BACKGROUND

Using the data from 56,365 individuals, from 185 countries, and a Nokia Health Wireless blood pressure (BP) monitor, we investigated real-world characteristics of BP variability (BPV).

METHODS

All included individuals self-measured and uploaded their BP using Bluetooth at least 20 times over a period of ≥1 month at a frequency and duration of their choosing. In total, 16,904,844 BP measurements were analyzed, with a median of 146 measurements per person (interquartile range [IQR] 73-321) over a median of 14 months (IQR 7-31). SD, coefficient of variation, maximum BP, and maximum minus minimum BP difference were all calculated as measures of BPV.

RESULTS

BPV showed a distinct pattern, influenced by season of year, day of week, and time of day. BPV index was higher in females compared with males (P < 0.001) and increased with age (P < 0.001). Compared to the weekend, the weekday BPV index was significantly higher, and this finding was more prominent in females (P = 0.001). In multivariate analysis, BPV index were significantly associated with age, gender, geographic location, and mean BP values.

CONCLUSION

Using the largest BP data set we are aware of, with the benefits and limitations of real-world measurement, we could show the pattern of BPV and provide reference values that may be helpful in understanding the nature of BPV as self-measurement at home becomes more common, and help guide individualized management.

Cardiovascular disease and multimorbidity: A call for interdisciplinary research and personalized cardiovascular care

In a Guest Editorial, Kazem Rahimi, Carolyn Lam, and Steven Steinhubl call for interdisciplinary research and personalized cardiovascular care to better manage patients with cardiovascular disease and multimorbidity.

Screening for Atrial Fibrillation

Approximately 10% of ischemic strokes are associated with atrial fibrillation (AF) first diagnosed at the time of stroke. Detecting asymptomatic AF would provide an opportunity to prevent these strokes by instituting appropriate anticoagulation. The AF-SCREEN international collaboration was formed in September 2015 to promote discussion and research about AF screening as a strategy to reduce stroke and death and to provide advocacy for implementation of country-specific AF screening programs. During 2016, 60 expert members of AF-SCREEN, including physicians, nurses, allied health professionals, health economists, and patient advocates, were invited to prepare sections of a draft document. In August 2016, 51 members met in Rome to discuss the draft document and consider the key points arising from it using a Delphi process. These key points emphasize that screen-detected AF found at a single timepoint or by intermittent ECG recordings over 2 weeks is not a benign condition and, with additional stroke factors, carries sufficient risk of stroke to justify consideration of anticoagulation. With regard to the methods of mass screening, handheld ECG devices have the advantage of providing a verifiable ECG trace that guidelines require for AF diagnosis and would therefore be preferred as screening tools. Certain patient groups, such as those with recent embolic stroke of uncertain source (ESUS), require more intensive monitoring for AF. Settings for screening include various venues in both the community and the clinic, but they must be linked to a pathway for appropriate diagnosis and management for screening to be effective. It is recognized that health resources vary widely between countries and health systems, so the setting for AF screening should be both country- and health system-specific. Based on current knowledge, this white paper provides a strong case for AF screening now while recognizing that large randomized outcomes studies would be helpful to strengthen the evidence base.

Digital technology to enable aging in place

Aging, both of individuals and populations, presents challenges and opportunities. The multitude of morbidities and disabilities that are a too common component of aging represent significant challenges to individuals, their families and to healthcare systems. Aging in place is the ability to safely and comfortably maintain an independent and high quality of life in one's own home and community and is a highly desirable goal of most individuals with the additional benefit of significantly impacting the impending enormous healthcare burden. In order to make this possible, new care models that take advantage of novel technologies for tracking important physiologic and safety parameters need to be developed and implemented. By thoughtfully doing so, it can be possible to seamlessly provide preventative interventions when and as needed, detect the earliest signs of aggravation of chronic conditions, or identify and respond to any emergency situations, such as falls or cardiac arrest. In contrast to current approaches, caring for elderly individuals in their homes based on a digital technology infrastructure could be effective and cost-saving. In this review, we provide an overview of the characteristics of potential digital solutions applicable to creative aging along with the existing evidence supporting their ability to improve care, increase quality of life, and substantially decrease the emotional and financial costs associated with aging.

Effectiveness of 6 months of tailored text message reminders for obese male participants in a worksite weight loss program: randomized controlled trial

Background

Worksite nutrition and physical activity interventions are important to help overweight and obese employees lose weight, but costs and insufficient sustained motivation prevent the majority of these programs from succeeding. Tailored text messaging in aiding weight management has been effective in several studies, but no studies have evaluated the effect of a tailored text message service on weight loss in a worksite health promotion program.

Objective

We studied the efficacy of a tailored text-messaging intervention for obese male participants in a worksite weight loss program of 6 months duration.

Methods

The study was an unblinded, randomized controlled trial. Men with a body mass index greater than 25 kg/m² were recruited from the Korea District Heating Corporation, the Korea Expressway Corporation, and the Korea Gas Corporation. The participants were identified by nurse managers. Participants were randomly allocated to 1 of the following 2 groups for 24 weeks: (1) intervention group, which received tailored text message reminders every other day plus 4 offline education sessions and brief counseling with monthly weight check by nurses for weight control over 6 months and (2) control group, which received the 4 offline education sessions and brief counseling with monthly weight check by nurses about weight control over 6 months. The primary outcome was the difference in weight loss at 6 months. A mixed-model repeated-measures analysis was performed to evaluate the effect of the intervention group’s weight loss compared with the control group.

Results

A total of 205 obese men were randomized into either the intervention (n=104) or the control group (n=101). At the end of 6 months, the intervention group (n=63) had lost 1.71 kg (95% CI –2.53 to –0.88) and the control group (n=59) had lost 1.56 kg (95% CI –2.45 to –0.66); the difference between the 2 groups was not significant (mean difference –0.15, 95% CI –1.36 to 1.07). At the end of the study, 60% (34/57) of the intervention group rated the message program as helpful for weight control and 46% (26/57) would recommend the text message service to their friends.

Conclusions

Tailored text message reminders did not have a significant effect on weight loss in obese men as part of a worksite weight loss program.

Trial Registration

International Standard Randomized Controlled Trial Number (ISRCTN): 39629189; http://www.isrctn.com/ISRCTN39629189?q=39629189&filters=&sort=&offset=1&totalResults=1&page=1&pageSize=10&searchType=basic-search (Archived by WebCite at http://www.webcitation.org/6VsFkwJH6).

Dynamic J-Point Elevation Associated with Epileptic Hemiplegia: The Osborn Wave of Todd's Paralysis

THIS CASE REPORT EXPOSES A PHENOMENON WHICH, ALTHOUGH PROPOSED, HAS NOT BEEN DESCRIBED IN CLINICAL LITERATURE: transient postictal hemiplegia (Todd's paralysis) with concomitant electrocardiographic J-point deflection (Osborn waves). Although typically associated with hypothermia, a prominent J-wave on the electrocardiogram (ECG) results from a transmyocardial voltage gradient during ventricular repolarization. Rarely, the Osborn wave may be observed in a non-hypothermic setting such as hypercalcemia or cerebral hemorrhage. Transient postictal hemiplegia has been attributed to localized cerebral hypoperfusion resulting from motor cortex exhaustion following an epileptic seizure. The same central nervous system autonomic dysfunction has been theorized to produce subendocardial hypoperfusion with electrocardiographic change and cardiac troponin T elevation. This is the first described ECG evidence of a dynamically displaced J-point in the setting of postictal hemiplegia.

Impact of chronic antiplatelet therapy before hospitalization on ischemic and bleeding events in invasively managed patients with acute coronary syndromes: the ACUITY trial

AIMS

Presentation with an acute coronary syndrome (ACS) on chronic aspirin therapy is an independent predictor of adverse short-term outcomes. Whether this finding applies to chronic thienopyridine use, and with the contemporary invasive management of ACS, is unknown.

METHODS AND RESULTS

In ACUITY, 13819 patients with moderate and high-risk ACS were studied; patients transferred from an outside hospital were excluded from the present analysis, given uncertain preadmission antiplatelet status. Endpoints included major adverse cardiovascular events (MACE: death, myocardial infarction, or unplanned revascularization), major bleeding, and net adverse clinical events (NACE). Among 11313 study patients, 31 % were naive for antiplatelet agent, 49% were receiving aspirin alone, and 20% were on dual antiplatelet therapy. Chronic antiplatelet users were older and had a higher risk profile. After adjusting for baseline differences, chronic antiplatelet therapy (single or dual) was not associated with an increased incidence of 30-day MACE, bleeding, or NACE. However, patients on chronic aspirin or dual antiplatelet therapy at presentation had significantly higher 1-year rates of MACE [odds ratio (95% confidence interval) = 1.17 (1.01–1.36), P = 0.03 and 1.29 (1.02–1.64), P = 0.03, respectively]. Patients presenting on dual antiplatelet therapy had significantly greater adjusted MACE at 1-year than those on aspirin alone [odds ratio (95% confidence interval) = 1.34 (1.15–1.56), P < 0.0001].

CONCLUSION

Contrary to earlier studies, prior antiplatelet therapy was not associated with an increased risk of adverse outcomes at 30 days in invasively managed patients. Such use did, however, independently predict 1-year ischemic MACE, with outcomes worse for patients presenting on chronic dual antiplatelet therapy compared with aspirin alone.

Association between inflammatory biomarkers and platelet aggregation in patients under chronic clopidogrel treatment

Inflammatory processes in the vessel wall are associated with progression of atherosclerosis and myocardial infarction. Both high levels of C-reactive protein (CRP)and high on-clopidogrel treatment platelet reactivity (HPR) have been linked to an increased risk of ischaemic events after percutaneous coronary intervention (PCI). The aim of this study was to explore the association between biomarker levels of inflammation and platelet reactivity. Stable patients (n=1,223) eligible for this study were under chronic antiplatelet treatment with aspirin and clopidogrel due to prior coronary stent placement. ADP-induced platelet aggregation (in AU*min) was measured on a Multiplate analyser. The primary outcome measure of this retrospective study was the ADP-induced platelet aggregation in patients with versus those without elevated CRP levels. Of the patients 15.5% (n=189) showed elevated CRP levels (≥5 mg/l). Platelet aggregation (median [interquartile range]) was significantly higher in patients with elevated CRP levels compared to patients with normal (<5 mg/l) CRP levels (305 [202-504] AU*min vs. 218 [144-384] AU*min; p<0.001).A multivariable linear regression model that adjusted for known predictors of HPR confirmed a significant independent association between elevated CRP levels and high ADP-induced platelet aggregation values (p=0.0002).Elevated WBC count and fibrinogen levels were also associated with higher platelet aggregation values (p<0.001 for both). In conclusion, elevated levels of CRP, WBC count and fibrinogen were significantly associated with high platelet reactivity in patients under chronic clopidogrel treatment. Whether a direct relation between platelets and inflammation exists, as well as the clinical impact of our results, warrants further investigations.

Clopidogrel pretreatment in ST-elevation myocardial infarction patients transferred for percutaneous coronary intervention

BACKGROUND

Pretreatment with clopidogrel reduces ischemic complications before percutaneous coronary intervention (PCI). Limited data exist regarding the effect of pretreatment for ST-segment elevation myocardial infarction (STEMI) patients undergoing primary PCI.

METHODS

Prospective data were analyzed from a regional STEMI system using rapid transfer for primary PCI in 30 community hospitals. Zone 1 community hospitals are <60 miles and Zone 2 hospitals are 60 to 210 miles away from the PCI hospital. Compared with 63 minutes in the PCI hospital, median door-to-balloon times were 94 minutes in Zone 1 and 123 minutes in Zone 2 hospitals. All patients received aspirin, unfractionated heparin, and clopidogrel 600 mg in the emergency department of the presenting hospital within 15 minutes of diagnosis.

RESULTS

From April 2003 through December 2008, 2,014 consecutive STEMI patients were pretreated with clopidogrel before PCI, with a median (25th-75th percentile) duration from pretreatment to PCI of 75 (58-93) minutes. Patients with longer pretreatment duration had significantly reduced reinfarction/reischemia at 30 days (Zone 1: 0.85%, Zone 2: 0.9%) compared with nontransferred patients (3.2%, P = .001) as well as reduced stent thrombosis (Zone 1: 0.6%, Zone 2: 0.6% vs Abbott Northwestern: 2.0%; P = .04). Similarly, pretreatment duration of >60 minutes before PCI had reduced 30-day reinfarction/reischemia (1.0% vs 2.9%, P = .003). There were no significant differences in mortality or major bleeding.

CONCLUSION

ST-segment elevation myocardial infarction patients undergoing primary PCI in a regional STEMI network who received earlier pretreatment with a 600-mg loading dose of clopidogrel had less ischemic complications without increased bleeding or mortality.

Relationship between baseline inflammatory markers, antiplatelet therapy, and adverse cardiac events after percutaneous coronary intervention: an analysis from the clopidogrel for the reduction of events during observation trial

BACKGROUND

We evaluated patients undergoing percutaneous coronary intervention to assess the predictive value of high-sensitivity C-reactive protein (hs-CRP) and pregnancy-associated plasma protein-A (PAPP-A) on adverse cardiac outcomes and the effect of antiplatelet therapy on these outcomes.

METHODS AND RESULTS

Baseline blood samples were available on 1468 CREDO (Clopidogrel for the Reduction of Events During Observation) patients for hs-CRP testing and 1096 patients for PAPP-A testing. The 1-year primary end point was the composite incidence of death, myocardial infarction, or stroke. Patients in the highest 2 tertiles of hs-CRP had more events compared with the lowest tertile (11.4% versus 6.4%, P=0.003). Treatment with clopidogrel reduced the 1-year composite end point for patients in the highest 2 tertiles of hs-CRP (9.1% clopidogrel versus 13.5% placebo, P=0.04) but not in the lowest tertile. Elevated PAPP-A levels were associated with a trend toward more events at 1 year that did not reach statistical significance. Patients in the highest 2 tertiles of PAPP-A randomized to clopidogrel had fewer events (7.3% clopidogrel versus 13.1% placebo, P=0.01), but no benefit was seen in the lowest tertile. A 46% risk reduction with randomization to clopidogrel was seen in patients in the highest 2 tertiles of both biomarkers (8.7% versus 16.2%, P=0.02).

CONCLUSIONS

Patients undergoing nonurgent percutaneous coronary intervention who have elevated hs-CRP and PAPP-A have an increased incidence of adverse cardiovascular events. The clinical benefit of adding clopidogrel to aspirin seems greater in those with increased levels of these inflammatory biomarkers.

Use of saliva-based nano-biochip tests for acute myocardial infarction at the point of care: a feasibility study

BACKGROUND

For adults with chest pain, the electrocardiogram (ECG) and measures of serum biomarkers are used to screen and diagnose myocardial necrosis. These measurements require time that can delay therapy and affect prognosis. Our objective was to investigate the feasibility and utility of saliva as an alternative diagnostic fluid for identifying biomarkers of acute myocardial infarction (AMI).

METHODS

We used Luminex and lab-on-a-chip methods to assay 21 proteins in serum and unstimulated whole saliva procured from 41 AMI patients within 48 h of chest pain onset and from 43 apparently healthy controls. Data were analyzed by use of logistic regression and area under curve (AUC) for ROC analysis to evaluate the diagnostic utility of each biomarker, or combinations of biomarkers, in screening for AMI.

RESULTS

Both established and novel cardiac biomarkers demonstrated significant differences in concentrations between patients with AMI and controls without AMI. The saliva-based biomarker panel of C-reactive protein, myoglobin, and myeloperoxidase exhibited significant diagnostic capability (AUC = 0.85, P < 0.0001) and in conjunction with ECG yielded strong screening capacity for AMI (AUC = 0.96) comparable to that of the panel (brain natriuretic peptide, troponin-I, creatine kinase-MB, myoglobin; AUC = 0.98) and far exceeded the screening capacity of ECG alone (AUC approximately 0.6). En route to translating these findings to clinical practice, we adapted these unstimulated whole saliva tests to a novel lab-on-a-chip platform for proof-of-principle screens for AMI.

CONCLUSIONS

Complementary to ECG, saliva-based tests within lab-on-a-chip systems may provide a convenient and rapid screening method for cardiac events in prehospital stages for AMI patients.

Variability in platelet response to a single daily dose of 150 mg enteric coated aspirin in a high risk population

PURPOSE

Previous studies have reported inadequate anti-platelet effect in 0.4-35% of patients taking aspirin. Such studies have arbitrarily defined the terms "semi-responders", "non-responders" or "resistant" to variable doses of aspirin on the basis of absolute values derived from different ex-vivo platelet aggregation (PA) methods. Our objective was to define response to 150-mg dose of aspirin in terms of normally distributed values using an ex-vivo measure of PA in a population at high risk for vascular events.

METHODS

We prospectively studied high risk patients with either established coronary artery disease (CAD) or stroke or transient ischemic attack (TIA) or peripheral vascular disease or with multiple atherothrombotic risk factors like diabetes plus one of the following-- hypertension, increased total cholesterol, cigarette smoking, micro-albuminuria, low-high density lipoprotein (HDL), family history of CAD and receiving single 150 mg dose of aspirin daily. PA was assessed by chronolog lumi-aggregometer (490-2D) using arachidonic acid (AA) reagent.

RESULTS

130 patients were studied. The response of subjects to aspirin followed a normal, bell shaped distribution curve with a mean and standard deviation (S.D.) of 13.1 +/- 4.4%. 3.1% patients had PA values more than 2 S.D. of the mean, hence termed as hypo-responders to aspirin while another 3.1% patients had PA values less than 2 S.D. of the mean, hence termed as hyper-responders to aspirin.

CONCLUSION

There is minimal inter-individual variability in the response to aspirin when tested with AA as the reagent. The response to aspirin follows a normal Gaussian distribution. The prevalence of hypo-responders to aspirin in high risk population is only 3.1%. This is the first study to document "hypo" and "hyper-responders" to single daily dose of 150 mg aspirin. The clinical relevance of these findings remains to be determined.

Efficacy of a novel procedure sheath and closure device during diagnostic catheterization: the multicenter randomized clinical trial of the FISH device

BACKGROUND

The aim of vascular closure devices is to safely secure the arterial access site at the conclusion of catheterization procedures, thereby increasing patient comfort and decreasing time to hemostasis and ambulation. The FISH (femoral introducer sheath and hemostasis) device is novel in that the access sheath and closure component are incorporated onto the same system.

METHODS

The FISH pivotal investigation was conducted at 8 catheterization laboratories throughout the United States. Eligible diagnostic patients were randomized (2 to 1) to the FISH device versus manual compression and assessed for time to hemostasis and time to ambulation. Half of the participants underwent ultrasonographic evaluation at 30-day follow up. Enrollment for an interventional cohort is ongoing and will be reported at a later date; however, the interventional patients enrolled to date were combined with the diagnostic patients to comprise the safety data of the trial.

RESULTS

Overall, 191 patients were randomized to the FISH device and 106 patients to manual compression. Most patients received a 6 Fr sheath (approximately 70%), while the remaining patients received a 5 or 8 Fr sheath. Twenty-seven patients who received the FISH device were converted to manual compression due to anticipated suboptimal hemostasis. Among the diagnostic patients, the mean time to hemostasis was 8.9 minutes for the FISH device, compared to 17.2 minutes for manual compression (p < 0.0001). Similarly, the mean time to ambulation was 2.4 hours for the FISH device, compared to 4.3 hours for manual compression (p < 0.0001). Among the total cohort, there was 1 death and 1 episode of major access-site-related bleeding that required transfusion occurred in the FISH group (1.1%), compared to no serious adverse safety events in the manual compression group (p = 1.0). For the FISH group, there were 5 minor adverse safety events; 3 access-site hematomas and 2 pseudoaneurysms treated with thrombin injection, and in the manual compression group, there was 2 access-site hematomas and 1 pseudoaneurysm treated with thrombin injection (p = 1.0).

CONCLUSION

Among diagnostic patients with good sheath placement and favorable femoral anatomy, the FISH device is superior in achieving time to hemostasis and ambulation compared to manual compression. At 30 days, there is no apparent difference in serious or minor adverse vascular events with the use of the FISH device.

Timing and correlates of very early major adverse clinical events following percutaneous coronary intervention

We attempted to determine the incidence, timing and correlates of very early (< 24 hours) major adverse clinical events in patients undergoing contemporary percutaneous coronary intervention (PCI). Early discharge following PCI may offer significant advantages to patient and practitioner, but the timing of, and risk factors for, very early (< 24 hours) major adverse clinical events following PCI are not well characterized. A retrospective analysis of the CREDO trial was performed. A total of 1,815 patients underwent a PCI procedure and 139 patients (7.7%) experienced a major adverse clinical event (death, myocardial infarction or urgent target vessel revascularization) within the first 28 days. The majority of these events (111 patients) occurred within the first 24 hours, with the greatest risk of an event within the first 6 hours. Multivariable predictors of very early events were age, AHA lesion grade, history of peripheral vascular disease, preprocedural TIMI flow grade and no. of vessels with stenosis > 50%. These data show a very low and constant risk of adverse events 6 hours following PCI.

Optimizing platelet P2Y12 inhibition for patients undergoing PCI

Guidelines recommend that dual antiplatelet therapy using aspirin and clopidogrel should be administered to the majority of patients with acute coronary syndromes, including those undergoing percutaneous coronary intervention (PCI). However, the results of a large randomized, placebo-controlled study suggest that a 300-mg loading dose of clopidogrel must be administered at least 15 h prior to PCI in order to achieve a significant reduction in peri-PCI thrombotic events. Other data suggest that 2 h of pretreatment may be sufficient if a 600-mg loading dose is used. Since it is often difficult to achieve an adequate pretreatment goal with clopidogrel in clinical practice, more rapid achievement of platelet P2Y(12) inhibition may improve patient outcomes. Prasugrel, [6-[2-(3,4-diflurophenyl) cyclopropyl1-1-y1] amino-2-propylthio-9-D-ribofuranosyl-9H-purine (AZD6140), and cangrelor are platelet P2Y(12) receptor antagonists currently in development that offer faster acting inhibition of adenosine diphosphate (ADP)--induced platelet aggregation. These agents act upon the same platelet receptor as clopidogrel, but are distinguished by their routes of administration, reversibility, and pharmacodynamic properties. Prasugrel is an orally administered agent that provides faster, higher, and more consistent inhibition of platelet aggregation than clopidogrel. The results of Phase II testing suggest that the risk of bleeding is similar in prasugrel- and clopidogrel-treated patients. AZD6140 is another orally administered platelet inhibitor with rapid and reversible action. Again, Phase II testing suggests similar bleeding risk for clopidogrel. Preliminary evidence suggests that clinical outcomes may be better in prasugrel- and AZD6140-treated patients than in clopidogrel-treated patients. Cangrelor is an intravenously administered, reversible, short-acting agent with a rapid onset of activity. Bleeding risk and clinical outcomes data are similar in cangrelor- and abciximab-treated patients. The results of ongoing Phase III clinical trials involving more than 40,000 patients will demonstrate whether these agents fulfill their potential to improve outcomes in PCI-treated patients by providing faster, higher, and more consistent inhibition of platelet aggregation.

Peroxisome proliferator-activated receptor gamma agonists for the Prevention of Adverse events following percutaneous coronary Revascularization--results of the PPAR study

BACKGROUND

Patients with metabolic syndrome are at increased risk for cardiovascular complications. We sought to determine whether peroxisome proliferator-activated receptor gamma agonists had any beneficial effect on patients with metabolic syndrome undergoing percutaneous coronary intervention (PCI).

METHODS

A total of 200 patients with metabolic syndrome undergoing PCI were randomized to rosiglitazone or placebo and followed for 1 year. Carotid intima-medial thickness (CIMT), inflammatory markers, lipid levels, brain natriuretic peptide, and clinical events were measured at baseline, 6 months, and 12 months.

RESULTS

There was no significant difference in CIMT between the 2 groups. There was no difference in the 12-month composite end point of death, myocardial infarction (MI), stroke, or any recurrent ischemia (31.4% vs 30.2%, P = .99). The rate of death, MI, or stroke at 12 months was numerically lower in the rosiglitazone group (11.9% vs 6.4%, P = .19). There was a trend toward a greater decrease over time in high-sensitivity C-reactive protein values compared with baseline in the group randomized to rosiglitazone versus placebo both at 6 months (-35.4% vs -15.8%, P = .059) and 12 months (-40.0% vs -20.9%, P = .089) and higher change in high-density lipoprotein (+15.5% vs +4.1%, P = .05) and lower triglycerides (-13.9% vs +14.9%, P = .004) in the rosiglitazone arm. There was a trend toward less new onset diabetes in the rosiglitazone group (0% vs 3.3%, P = .081) and no episodes of symptomatic hypoglycemia. There was no excess of new onset of clinical heart failure in the rosiglitazone group, nor was there a significant change in brain natriuretic peptide levels.

CONCLUSIONS

Patients with metabolic syndrome presenting for PCI are at increased risk for subsequent cardiovascular events. Rosiglitazone for 12 months did not appear to affect CIMT in this population, although it did have beneficial effects on high-sensitivity C-reactive protein, high-density lipoprotein, and triglycerides. Further study of peroxisome proliferator-activated receptor agonism in patients with metabolic syndrome undergoing PCI may be warranted.

The influence of body mass index on outcomes and the benefit of antiplatelet therapy following percutaneous coronary intervention

In general, obesity is associated with better outcome in patients undergoing percutaneous coronary interventions (PCI). One small study has suggested that these patients do not achieve adequate platelet inhibition with clopidogrel and that this may shape clinical outcomes. We evaluated the relationship between body mass index (BMI) and clinical outcomes at 1 year following PCI in patients randomized to clopidogrel or placebo in the CREDO trial.

METHODS AND RESULTS

BMI, baseline clinical characteristics and clopidogrel regimen were assessed in 2,116 patients. The primary study endpoint was the 1-year composite of death, MI or stroke. A total of 342 patients had low or normal BMI (< 25 kg per m2), 847 were overweight (25-29.9 kg per m2), 810 were obese (30-39.9 kg per m2) and 113 were very obese (greater than or equal to 40 kg per m2). Obese patients were more likely to be young males with diabetes, hypertension and hyperlipidemia (p < 0.01). Bleeding complications occurred in 38% of low BMI, 32% of overweight/obese, and 25% of very obese patients (p = 0.03). Randomization to clopidogrel was associated with a 25% risk reduction in 1-year death, MI or stroke events, as BMI increased by every 5 kg per m2 (p = 0.009).

CONCLUSION

In general, increasing BMI was associated with better efficacy and bleeding outcomes at 1 year in this nonurgent PCI population. Randomization to early- and long-term clopidogrel was associated with even further improvements in those with increasing BMI.

Long-Term Cost Effectiveness of Early and Sustained Dual Oral Antiplatelet Therapy With Clopidogrel Given for Up to One Year After Percutaneous Coronary Intervention

OBJECTIVES

This study sought to evaluate the long-term cost effectiveness of a clopidogrel loading strategy before percutaneous coronary intervention (PCI) followed by continued treatment for one year.

BACKGROUND

The Clopidogrel for the Reduction of Events During Observation (CREDO) trial, a randomized trial of 2,116 patients, showed the effectiveness of antiplatelet therapy with clopidogrel 300 mg before PCI and 75 mg daily for one year afterward compared with placebo load and placebo days 29 to 365 in reducing the combined risk of death, myocardial infarction, and stroke. All patients received clopidogrel on days 1 to 28 and aspirin on days 1 to 365.

METHODS

All hospitalizations were assigned a diagnosis-related group. Associated costs were estimated three ways (including professional costs): 1) Medicare costs, 2) MEDSTAT costs, and 3) blend with Medicare for those age > or = 65 years and MEDSTAT for those age <65 years. Clopidogrel 75 mg cost 3.22 dollars. Life expectancy in trial survivors was estimated using external data. Confidence intervals were assessed by bootstrap.

RESULTS

The primary composite end point occurred in 89 (8.45%) clopidogrel patients and in 122 (11.48%) placebo patients (relative risk reduction [RRR] 26.9%; 95% confidence interval [CI] 3.9% to 44.4%). The number of life-years gained (LYG) with clopidogrel was 0.1526 (95% CI 0.0263 to 0.2838) using Framingham data and 0.1920 (95% CI 0.054 to 0.337) using Saskatchewan data. Average total costs were 664 dollars higher for the clopidogrel arm (95% CI -461 dollars to 1,784 dollars). The incremental cost-effectiveness ratios (ICERs) based on Framingham data ranged from 3,685 dollars/LYG to 4,353 dollars/LYG, with over 97% of bootstrap-derived ICER estimates below 50,000 dollars/LYG. The ICERs based on Saskatchewan data were 2,929 dollars/LYG to 3,460 dollars/LYG, with over 98% of estimates below 50,000 dollars/LYG.

CONCLUSIONS

Platelet inhibition with clopidogrel loading before PCI followed by therapy for one year is highly cost effective.

Assessing aspirin responsiveness in subjects with multiple risk factors for vascular disease with a rapid platelet function analyzer

Aspirin, compared with placebo, reduces the risk of cardiovascular events by 25% in populations of patients with and without known arterial vascular disease. However, the phenomena of 'aspirin resistance' that has been described in 5'--50% of this population may critically reduce aspirin's efficacy. One study has suggested that aspirin-resistant patients have a 3.5 times higher risk of cardiovascular death. Presently, there are no established, simple, broadly used methods determining antiplatelet properties of aspirin, while conventional aggregometry requires special equipment and trained personnel. We sought to determine the validity of an Ultegra analyzer with the novel aspirin-sensitive cartridge before and after one pill of non-enteric coated aspirin (325 mg) in subjects with multiple risk factors for coronary artery disease. One hundred and fifty-four volunteers were enrolled into the multicenter study, but six of them were excluded. Data from 148 participants were analyzed. Platelets were assessed twice at baseline (pre-aspirin), and after 2-30 h (post-aspirin). We employed 5 micromol/l epinephrine-induced conventional aggregometry, and aspirin response units stimulated by propyl gallate with the point-of-care Ultegra analyzer. A single pill of aspirin reduced platelet-rich plasma aggregation from 72 +/- 21% to 25 +/- 10%, and diminished aspirin reduction units from 647 +/- 95 to 436 +/- 69. The overall agreement between the two methods was 87% with 85% sensitivity for Ultegra and 88% for platelet aggregation, respectively. The correlation between the two methods was 0.902. Timely determination of aspirin resistance represents an indispensable application in current medicine. The Ultegra RPFA-ASA analyzer is a novel, fast method that could be used in clinical practice for monitoring efficacy of aspirin, and for triaging the aspirin-resistant population. The clinical implications of these data need to be proven in randomized trials.

How important is preventing platelet activation in the setting of percutaneous coronary intervention?

The benefit of antithrombotic therapies is exerted primarily through inhibition of platelet activation and not solely through platelet aggregation. Inhibition of platelet activation can influence localized inflammatory processes as well as long-term clinical outcome. The combination of aspirin, adequate platelet inhibition with P2Y12-receptor inhibitors and thrombin inhibition can synergistically inhibit platelet activation, and the use of this combination may have important clinical implications for treatment of patients undergoing percutaneous coronary intervention.

What is the role for improved long-term antiplatelet therapy after percutaneous coronary intervention?

BACKGROUND

Coronary stent placement has replaced balloon angioplasty as the percutaneous coronary intervention (PCI) method of choice, primarily because of its lower restenosis rate. Compared with aspirin (ASA) monotherapy or ASA plus warfarin, the ticlopidine and ASA combination is superior in reducing thrombotic events after stenting. Clopidogrel plus ASA appears to be at least as effective as ticlopidine and ASA. Intravenous glycoprotein IIb/IIIa inhibitors effectively prevent periprocedural thrombotic complications, but their short duration of action and parenteral dosing don't allow for long-term protection. This review aimed to answer how long after PCI with a stent patients are at risk for recurrent thrombotic events and what the optimal way to prevent them is.

RESULTS

Classically, ASA has been prescribed indefinitely, whereas adenosine diphosphate receptor antagonists have been discontinued after 2 to 4 weeks. However, the Clopidogrel in Unstable Angina to Prevent Recurrent Events (CURE) trial found that long-term dual antiplatelet therapy with clopidogrel and ASA was more effective than ASA alone in preventing major cardiovascular events in patients with acute coronary syndrome, including those treated with PCI.

CONCLUSION

Results from additional ongoing studies are needed to clarify the role of long-term dual oral antiplatelet therapy in preventing ischemic events in patients who have undergone PCI.