CABG patients with IMA graft likely to require revascularization, study says

December 16, 2015 – Renato Lopes, MD, MHS, PhD, said the study could change how clinicians make decisions about patients who undergo the procedure.

Patients who undergo coronary artery bypass grafting (CABG) via the internal mammary artery (IMA) are more likely to require revascularization, according to a new study by DCRI researchers.

The study appears online in the journal Circulation.

The IMA conduit is widely used as a means of bypassing the left anterior descending (LAD) coronary artery during CABG procedures. Earlier research has shown the IMA-to-LAD graft to be more durable than other arterial and vein grafts, and improved patient outcomes may owe something to the procedure’s reliability. Yet until now there have been few high-quality studies of IMA graft failure rates.

renato-lopesIn this study, DCRI researchers sought to identify the factors associated with IMA graft failure and study the association between graft failure and patients outcomes. To do so, they analyzed patient data from the PREVENT IV trial. That trial was a double-blind, multicenter, randomized clinical trial that was designed to assess the effectiveness and safety of edifoligide on angiographic vein graft failure after CABG, as well as the effect of edifoligide on major adverse cardiac events (MACE) following CABG. The trial enrolled 3,014 participants at 107 U.S. sites between 2002 and 2003.

The current analysis included 1,539 patients who underwent IMA-LAD revascularization and had 12-18-month angiographic follow-up. The researchers found that IMA failure occurred in 132 participants (8.6 percent) of the study population. Factors associated with IMA graft failure included LAD stenosis less than 75 percent, additional bypass graft to diagonal branch, and not having diabetes.

LAD stenosis and additional diagonal graft were also associated with IMA failure in an alternative model that included angiographic failure or death before angiography as the outcome.

IMA failure was also associated with a significantly higher incidence of subsequent acute clinical events, a relationship that was  attributed to a higher rate of repeat revascularization, according to Renato D. Lopes, MD, MHS, PhD (pictured), the study’s senior author.

“This study represents the first robust assessment of IMA graft failure and long-term clinical outcomes in a large cohort of patients undergoing coronary artery bypass grafting surgery with systematic angiographic follow-up, regardless of symptom status,” Lopes said. “Our findings raise concerns about the performance of coronary artery bypass grafting with the use of IMA in the treatment of native vessels with only mild or moderate stenosis, as well as the use of an additional bypass graft to the diagonal branch, confirming that the severity of LAD stenosis and competitive flow are of key importance for patency of the IMA-LAD graft. This information might help physicians on decision-making and likely change practice among patients undergoing CABG surgery.”

In addition to Lopes, the study’s DCRI and Duke authors included Ralf E. Harskamp, MD; John H. Alexander, MD, MHS; Brian Englum, MD; Daniel Wojdyla, MS; Phillip J. Schulte, PhD; Eric D. Peterson, MD, MPH; and Peter K. Smith, MD.

Cancer risk relatively low with DAPT regardless of drug used

December 14, 2015 – The DCRI’s Matthew Roe, MD, MHS, found that few acute coronary syndrome patients develop neoplasms while on dual antiplatelet therapy.

Relatively few acute coronary syndrome (ACS) patients develop neoplasms while on dual antiplatelet therapy (DAPT), and the frequency of neoplasm detection was similar regardless of which antiplatelet agents were used, according to a new study by DCRI researchers.

The study is the latest analysis of results from the Targeted Platelet Inhibition to Clarify the Optimal Strategy to Medically Manage Acute Coronary Syndromes (TRILOGY ACS) study led by the DCRI’s Matthew Roe, MD, MHS (pictured), and E. Magnus Ohman, MD. The results were published online this month in the European Heart Journal.

matthew-roe-newsThe interaction between cancer and cardiovascular disease is complex and only partially understood. Earlier studies have arrived at different conclusions about the risk of cancer associated with long-term cardiovascular therapies.

In this study, the researchers collected data on cancer history and pre- and post-randomization cancer-screening procedures for ACS patients who were randomized to DAPT (aspirin plus either prasugrel or clopidogrel) from the original TRILOGY ACS trial. That trial was a double-blind, randomized trial that compared prasugrel to clopidogrel in ACS patients with unstable angina or non-ST elevation myocardial infarction managed without revascularization.

Over three years, the trial enrolled 9,326 patients from 52 countries. Of these patients, 9,240 received at least one dose of the study drug and were analyzed for this study. Median treatment exposure was 15 months; median follow-up was 17 months.

In the current study, the researchers looked at each patient’s history of prior neoplasm occurrence and any cancer-screening tests or procedures performed before and after randomization.

“We found that cancer screening rates were much higher in North America and Western Europe compared with other regions, a finding that we believe confounded the ascertainment of neoplasm events given that geographic region was one of the strongest predictors of neoplasm development,” Ohman said.

The researchers found 187 distinct new, non-benign neoplasm events in 170 participants who received at least one dose of study drug (1.8 percent incidence rate). There was no statistical difference in neoplasm development observed between patients who received prasugrel versus those who received clopidogrel.

The researchers also found that rates of cardiovascular death, myocardial infarction, or stroke were higher among those patients who experienced a neoplasm event (18.2 percent) versus those who did not (13.5 percent). Additionally, the detection of new, non-benign neoplasm events was also associated with high rates of permanent study drug discontinuation and bleeding events (both before and after neoplasm detection).

“We implemented a novel data collection and ascertainment process for neoplasm events in a global cardiovascular outcomes trials on a scale that had never been done beforehand,” Roe said. “These findings are groundbreaking and will inform future efforts to understand the potential cancer risks of long-term cardiovascular drug therapies.”

ROCKET AF Clinical Trial Executive Committee releases secondary analysis

December 7, 2015 – The analysis was prompted by a December 2014 FDA recall of the Alere INRatio and INRatio2 PT/INR Monitor system.

The ROCKET AF Clinical Trial Executive Committee today announced its secondary analysis of the phase III trial (ROCKET AF) of the oral anticoagulant rivaroxaban. The analysis was prompted by a December 2014 FDA recall of a device used in the study.

From 2006 to 2010, the ROCKET AF trial studied rivaroxaban as compared with warfarin for the prevention of stroke and systemic embolism in patients with atrial fibrillation and at increased risk for stroke. Following completion of the trial and rivaroxaban’s initial FDA approval in 2011, the FDA issued a recall of the Alere INRatio and INRatio2 PT/INR Monitor system used in the trial to measure INR blood clotting levels for certain patient populations.

In order to understand the effect the possible malfunctioning of the device might have had in specific patient groups, the ROCKET AF Executive Committee and the Duke Clinical Research Institute conducted a secondary analysis of the trial findings.

The findings from the analysis are consistent with the results from the original trial and do not alter the conclusions of ROCKET AF—rivaroxaban is a reasonable alternative to warfarin and is non-inferior for the prevention of stroke and systemic embolism with less intracranial hemorrhage and fatal bleeding.

The ROCKET AF Executive Committee intends to publish a full description of this analysis and results as rapidly as possible.

This news may raise questions from patients who are currently prescribed rivaroxaban. It is important to recognize that there are risks with abruptly stopping any anticoagulant. Patients should discuss any questions with their physician.

Building better heart care in Kenya

December 4, 2015 – DCRI and Duke researchers are working to build stronger systems of cardiovascular care in Kenya and other developing nations.

DCRI and Duke researchers are working with Kenyan partners to build stronger systems of cardiovascular care in the African country.  Together they hope the lessons learned can be applied to other developing nations.

The partnership between the DCRI, Moi University and Moi Teaching and Referral Hospital cynthia-binanay-newsin Eldoret, Kenya, is described in a new article published this month in the Journal of the American College of Cardiology.

Despite the advances in cardiac care made in recent decades, developing nations still struggle to provide adequate cardiovascular care to their citizens. Approximately 80 percent of deaths from noncommunicable diseases, including cardiovascular disease, now occur in low- and middle-income countries. Healthcare resources in these nations are often limited, and those that are available are most frequently deployed to combat infectious diseases such as HIV and malaria.

“The need for cardiovascular care in these countries is great,” said the DCRI’s Gerald Bloomfield, MD, MPH (pictured left), senior author of the article. “There just aren’t enough people to provide the care that’s needed.”

To address this problem, the National Heart, Lung, and Blood Institute and the UnitedHealth Group launched the Collaborating Centers of Excellence (COE) program in 2009 to establish cardiovascular and pulmonary disease clinical research centers in low- and middle-income countries in partnership with institutions in high-income countries. The DCRI and Moi University received funding to create the first of 11 COEs in Kenya.

Applying the experience of similar work to control infectious disease in developing nations, the DCRI/Moi partnership began to build the infrastructure for a more robust cardiovascular care system in Kenya. The process included construction of a new cardiac care unit in Eldoret as well as creation of new models for leadership and governance, workforce training, care delivery, financing, supply chain management, and health information systems.

gerald-bloomfield-news“One of the biggest problems is training,” said Cynthia Binanay, MA, BSN (pictured right), lead author of the article. “It is a constant struggle to train new staff members while still providing needed care to patients.”

Despite challenges, the DCRI/Moi partnership has made a significant improvement in cardiovascular care in Kenya. The cardiac care unit has grown consistently in volume since 2011. COE Kenyan and North American trainees and faculty have led numerous projects to address local cardiovascular issues, including hypertension in rural populations, peripheral arterial disease among diabetics, and task shifting the use of hand-held cardiac ultrasound.

They have also received awards from institutions including the Fogarty International Center of the National Institutes of Health, Fulbright Program, and Doris Duke Foundation.

The primary lesson of the DCRI/Moi partnership is that building relationships is essential to the success of any collaborative, global venture. Where bonds of trust and respect are established, the researchers concluded, public-private projects designed to deliver robust cardiac services can succeed in low- and middle-income countries.

“I would hope that people could use this partnership as a road map,” Bloomfield said. “We think this approach to building sustainable cardiovascular care opens up a sea of possibilities.”

In addition to Binanay and Bloomfield, Duke authors of the article include G. Ralph Corey, MD; John E. Lawrence, MD; and principal investigator Eric J. Velazquez, MD.

In Honor of World AIDS Day 2015

December 1, 2015 – Over the years, some of the work of DCRI’s researchers has been directly related to or touched on the topic of HIV. To recognize World AIDS Day 2015, we are highlighting how our researchers are helping to improve the lives of people around the world living with HIV.

world-aids-day-news

Drug combination shows promise for hepatitis C/HIV patients

Between 4 and 5 million people around the world are infected with both the hepatitis C virus (HCV) and HIV. These patients have more complications and worse outcomes than those infected with HIV alone, and clearing HCV infection in this population has been shown to reduce the likelihood of death from liver disease. Until now, however, clinicians have had only limited success in eliminating HCV infections with existing drug combinations.

A regimen of ledipasvir/sofosbuvir shows promise for treating patients infected with both HCV and HIV, according to a study led by the DCRI’s Susanna Naggie, MD, MHS. The study showed that 96 percent of HCV patients achieved a sustained virologic response 12 weeks (SVR12) after completing therapy. Patients who reach this benchmark are considered cured of HCV infection.

DCRI faculty present research at Conference on Retroviruses and Opportunistic Infections (CROI) 2015

The DCRI’s Susanna Naggie, MD, and Andrew Muir, MD, MHS, presented some of their latest research at the 22nd Conference on Retroviruses and Opportunistic Infections (CROI), which was held in Seattle.

Naggie presented the results of a phase III trial evaluating a regimen of ledipasvir/sofosbuvir for the treatment of chronic hepatitis C virus (HCV) in patients co-infected with HIV. The results of that study showed that 96 percent of HCV patients achieved a sustained virologic response 12 weeks (SVR12) after completing therapy. Patients who reach this benchmark are considered cured of HCV infection.

“This trial provides strong evidence that people who are co-infected with HIV can achieve very high rates of hepatitis C cure with a combination direct-acting antiviral regimen,” Naggie said. “These high cure rates were observed in most of the historically difficult-to-treat sub-populations, including those who failed previous treatment and those with cirrhosis. We are greatly encouraged by these findings.”

An Update on HIV Infection: Is an AIDS-Free Generation Possible?

See video of this special research conference, which was held in honor of World AIDS Day 2014.

Northern, Southern African nations lead continent in cardiovascular research

The researchers found that nations with the highest rates of death due to HIV infection tended to have lower rates of cardiovascular publications, suggesting that competing public health priorities may affect research productivity.

Chronic kidney disease widely prevalent in Northern Tanzania, new study finds

In this study, the researchers used data from the Comprehensive Kidney Disease Assessment for Risk Factors, Epidemiology, Knowledge, and Attitudes (CKD-AFRIKA) to obtain a better picture of how CKD is affecting Northern Tanzania. Between January and June 2014, the CKD-AFRIKA researchers conducted a household survey of randomly selected adults in Northern Tanzania. Trained surveyors and field researchers administered surveys and CKD tests to 481 adults from 346 households. In addition to basic demographic information, participants were asked about any history of diabetes, hypertension, HIV, kidney disease, or heart disease.

Meningitis model shows infection’s sci-fi-worthy creep into brain

The DCRI’s John Perfect, MD, and other Duke researchers are using fish to watch in real time as Cryptococcal meningitis takes over the brain. The resulting images are worthy of a sci-fi movie teaser, but could be valuable in disrupting the real, crippling brain infection that kills more than 600,000 people worldwide each year.

Airborne cells of Cryptococcus make their way into our lungs practically every day — unwelcome guests, but of little consequence for those with healthy immune systems. But for those with compromised immunities, whether by HIV infection or cancer treatment, a resulting Cryptococcal meningitis infection can quickly become deadly.

To be able to target the infection with medications in the future, researchers need to know more about how the organism moves from the lungs into the blood stream and through the blood-brain barrier.

Lack of social support can hinder exercise programs for heart failure patients

November 19, 2015 – DCRI Fellow Lauren Cooper, MD, and her colleagues found that patients who reported more sources of social support exercised more than those who reported fewer sources of support.

Psychosocial barriers can pose a significant problem for heart failure patients who are trying to get sufficient exercise, according to a recent study by DCRI researchers.

The study, which appears in the current issue of Circulation: Heart Failure, sought to understand how these factors make it difficult for patients to adhere to regular exercise routine, and how a lack of exercise can affect outcomes for heart failure patients.

lauren-cooper-newsExercise is known to be beneficial for heart failure patients with reduced ejection fraction. Yet caregivers often find that their patients have trouble maintaining regular exercise regimens, even in a clinical setting. In this study, DCRI Fellow Lauren Cooper, MD, and her colleagues analyzed patient data from Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training (HF-ACTION), which randomized heart-failure patients to follow or not follow an exercise-training program.

For this analysis, Cooper and her team examined data from 2,279 heart failure patients enrolled in a 36-session supervised exercise program for three months, followed by two years of home exercise. These patients were also asked to complete an assessment of potential social barriers and sources of social support for their exercise programs.

Patients’ adherence to their exercise programs was measured by minutes of exercise per week. Each patient’s level of adherence was categorized as poor (less than 90 minutes per week), partial (90 or more minutes per week for three months, then  less than 120 minutes per week thereafter), or full (90 or more minutes per week for three months, then 120 or more minutes per week). Cardiopulmonary exercise testing was completed at baseline, 3 months, 12 months, and 24 months.

The researchers found that exercise adherence in general was poor. Patients who had poor adherence were more likely to be younger, female, African-American, and have higher body mass index scores.  Patients with poor adherence also had significantly worse baseline exercise capacity and reported a lower quality of life and higher levels of depression compared with patients with full adherence and partial adherence.

Patients who reported having more sources of social support exercised more than those who reported fewer sources of support. Similarly, patients with fewer barriers to exercise exercised more than those with more barriers to exercise. Higher reported sources of social support were not associated with all-cause death or hospitalization or with cardiovascular death or heart failure hospitalization. However, the researchers reported a significant interaction between the randomization group and reported barriers to exercise adherence.

Although the researchers cautioned that this study does not establish a link between more perceived sources of social support and improved outcomes, they noted that higher levels of social support tended to be associated with higher levels of exercise adherence.

“Patients, family members, and healthcare providers should work together to find solutions to the barriers preventing a patient from participating in structured exercise programs, because exercise programs can help patients manage their condition,”  Cooper said in a journal news release.

In addition to Cooper, other Duke authors included Robert J. Mentz, MD; Jie-Lena Sun, MS; Phillip J. Schulte, PhD; and William E. Kraus, MD.

Rewards may outweigh risks for stroke patients on tPA, antiplatelet therapy

November 18, 2015 – Stroke patients on antiplatelet therapy who are treated with intravenous tPA have a slightly higher risk of bleeding, but better overall outcomes.

Stroke patients who receive intravenous tissue plasminogen activator (tPA) as well as antiplatelet therapy are at increased risk of bleeding, but have better functional outcomes than tPA patients who do not receive antiplatelet therapy.

New research by DCRI faculty members published online this month in the journal JAMA Neurology suggests that the overall benefits of antiplatelet therapy may outweigh the risks in for such patients.

ying-xian research has established that tPA therapy improves outcomes for stroke patients. However, tPA also carries the risk for symptomatic intracranial hemorrhage (sICH), a serious complication of thrombolysis for acute ischemic stroke. Approximately 40 percent of patients receive antiplatelet therapy before their stroke, and concomitant tPA treatment increase the risk of bleeding for these patients.

To assess the relative risk for patients with intravenous tPA who also received antiplatelet therapy, the DCRI’s Ying Xian, MD, PhD, and his colleagues analyzed patient data from the American Heart Association and American Stroke Association Get With the Guidelines–Stroke (GWTG-Stroke) program. They identified 85,072 adult patients with ischemic stroke who received intravenous tPA at 1,545 U.S. hospitals between 2009 and mid-2015.

Of these patients, 38,844 (45.7 percent) were using antiplatelet therapy before admission and 46,228 (54.3 percent) were not. Patients who received antiplatelet therapy before admission tended to be older, have more cardiovascular risk factors, and were more likely to receive medications to lower cholesterol, blood pressure, or glucose levels. However, they were less likely to receive anticoagulants before admission.

Patients who received antiplatelet therapy had a higher unadjusted rate of sICH than those who did not (5.0 percent versus 3.7 percent). After risk adjustment, patients who were previously on antiplatelet therapy still had higher odds of sICH compared to those who did not, although the overall risk was small.

The risk for in-hospital mortality was similar between those who were and were not receiving antiplatelet therapy after adjustment (8.0 percent versus 6.6 percent). However, patients receiving antiplatelet therapy were more likely to achieve independent ambulation (42.1 percent versus 46.6 percent) and had better functional outcomes at discharge (24.1 percent versus 27.8 percent).

These results, the researchers concluded, demonstrate that the risk for sICH among patients with stroke who receive antiplatelet therapy before the stroke and are treated with intravenous tPA is relatively low and should be weighed against the potential benefits in terms of improved functional outcomes.

In addition to Xian, the study’s other Duke authors included Maria Grau-Sepulveda, MD, MPH; Adrian F. Hernandez, MD, MHS; Laine Thomas, PhD; Laura Webb, MS; Janet Prvu Bettger, ScD; Daniel T. Laskowitz, MD, MHS; and Eric D. Peterson, MD, MPH.

AHA 2015: AF a strong independent predictor of worse outcomes for TAVR patients

November 10, 2015 – The optimal treatment for atrial fibrillation patients who have undergone transcatheter aortic valve replacement remains unclear.

Atrial fibrillation (AF) is highly common in patients who have undergone transcatheter aortic valve replacement (TAVR), and is strongly associated with worse outcomes for these patients, according to a new study.

The results of that study were presented Tuesday at the annual Scientific Sessions of the American Heart Association in Orlando, Florida.

Earlier research has established that AF is common among TAVR patients. However, it has matthew-sherwood-newsbeen unclear exactly how prevalent the condition is among this patient population. There is also little evidence on the optimal antithrombotic therapy in TAVR patients, particularly those with AF.

To address these questions, the DCRI’s Matthew Sherwood, MD, and his colleagues analyzed data from the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy (STS/ACC TVR) Registry. The registry contains data on patient demographics, procedure details, and facility and physician information related to TVT.

The final patient population for the study included more than 16,000 patients at 329 sites who underwent TAVR between 2011 and 2014.

Sherwood and his team found that almost one half of the TAVR patients (45 percent) had preoperative AF. Patients with AF were also at significantly higher risk for death and bleeding, although the risk of stroke remained similar for patients with AF and those without.

The researchers also examined the use of anticoagulant and antiplatelet agents among TAVR patients. Only 53 percent of patients with AF were discharged on oral anticoagulation. Among patients on oral anticoagulation, nearly 75 percent of patients were also discharged on antiplatelet monotherapy. A much smaller number of patients (16 percent) were discharged on triple therapy, and a minority of patients were discharged on no additional antiplatelet therapy.

For those who did not receive oral anticoagulation at discharge, 61 percent of these

patients were discharged on dual antiplatelet therapy. A quarter of patients were discharged on antiplatelet monotherapy alone, and surprisingly, 14 percent of the patients with AF who did not receive oral anticoagulation also did not receive any antiplatelet therapy.

Despite variability in use or oral anticoagulation, there were no differences in 1-year hazard for mortality, stroke, or bleeding events between patients who received anticoagulation versus those who did not. Further studies are needed to define the best antithrombotic medical treatment following TAVR, especially in AF patients, the researchers concluded.

“There is great variability in the type of medication received,” Sherwood said. “The next step would be a randomized clinical trial to determine the optimal treatment for these patients.”

In addition to Sherwood, Duke authors included Sreekanth Vemulapalli, MD; Dadi Dai, PhD; Amit N. Vora, MD, MPH; Kevin Harrison, MD; and Eric D. Peterson, MD, MPH.

AHA 2015: PCI reduces need for additional drug even when blockages remain

November 10, 2015 – Cardiac patients were followed for 12 months to determine whether they needed repeat cardiac procedures or hospitalizations.

Heart patients who had undergone an angioplasty procedure that opened only some blocked arteries tended to have a resolution of their chest pain, making it unnecessary to add another medication to treat the symptom, according to a study led by the DCRI.

karen-alexandar-aha-newsIn a finding presented Tuesday at the American Heart Association’s annual Scientific Sessions meeting, the researchers reported that patients randomly assigned to receive the drug ranolazine were as likely as those taking a mock pill to say their episodes of angina diminished after undergoing angioplasty.

Angina is chest pain, and it is a leading problem for heart patients, contributing to lower quality of life, less treatment satisfaction, and higher medical costs.

“This study does provide an important message for people who have incomplete revascularization,” said lead author Karen Alexander, MD, director of safety surveillance at the DCRI. “For patients who had angina prior to angioplasty, they were mostly asymptomatic following the angioplasty even though coronary blockages remained.”

Alexander and colleagues had set out to address whether the drug ranolazine, when added to standard medications in this population, would reduce symptoms and therefore hospitalizations and procedures over time. Ranolazine works at the heart muscle to lessen the effects of coronary blockages and to ease the pain of angina.

Patients with a history of chronic angina were enrolled in the RIVER-PCI study following percutaneous coronary intervention (PCI), which is also known as angioplasty. The patients were randomly assigned to receive either ranolazine or a placebo.

Patients were followed for a 12-month period to determine whether they needed repeat cardiac procedures or hospitalizations. For most of the 2,389 patients who completed quality-of-life questionnaires at intervals throughout the study period, angina improved markedly. In both groups, the improvement was noted within the first month and was sustained up to a year following PCI.

Consistent with the neutral primary results of RIVER-PCI study, no differences were seen across treatment groups in angina or quality of life. Marginally greater improvements in angina with ranolazine were observed for people with diabetes and those with frequent baseline angina.

“Our finding does not support prescribing ranolazine based upon coronary anatomy findings alone,” said senior author E. Magnus Ohman, MD, DCRI senior investigator and the Kent and Siri Rawson Director of the Duke Program for Advanced Coronary Disease. “This piece of the study doesn’t negate the importance of ranolazine, it just says this group of patients with incomplete PCI didn’t have angina after the procedure.”

In addition to Alexander and Ohman, study authors at DCRI include Kristi Prather, Kevin J. Anstrom, Daniel Mark and Linda Davidson-Ray; along with Ori Ben-Yehuda and Gregg Stone of Cardiovascular Research Foundation; Giora Weisz of Shaare Zedek Medical Center; Ramin Farzaneh-Far, formerly of Gilead Sciences.

Gilead Sciences, which markets ranolazine, sponsored the trial along with the Menarini Group.

AHA 2015: Drug-eluting stent use rises in heart attack patients with atrial fibrillation

November 10, 2015 – The DCRI’s Amit N. Vora, MD, MPH, and others revealed substantial hospital-level variation in practices, highlighting the lack of clear guidelines for stent use in this population.

Controversy remains around the most appropriate type of stent – drug-eluting or bare metal – to use in heart attack patients with atrial fibrillation. Stent selection for this population has important implications for duration of antithrombotic therapy. This study set out to analyze trends in practices across the United States.

amit-vora-newsCompared with bare metal stents, drug-eluting devices pose a lower risk of restenosis, where the artery narrowing recurs, but a higher risk of stent thrombosis, where a blood clot forms within the stent. To mitigate this thrombosis risk, patients with drug-eluting stents receive dual antiplatelet therapy, which prevents platelets from clumping and clots from forming and growing. This additional therapy represents an added layer of risk for those with atrial fibrillation, who already need to take anticoagulant therapy to reduce stroke risk.

The results of the study were announced Tuesday at the 2015 American Heart Association (AHA) Scientific Sessions in Orlando, Florida.

The authors found that heart attack patients with atrial fibrillation are more likely to receive a drug-eluting stent than a bare metal stent, and that use of drug-eluting stents in these patients has increased over time. This applied even to patients with both high predicted stroke risk and bleeding risk. There was also substantial variation in practices between hospitals. Patients with atrial fibrillation who received a drug-eluting stent were, however, less likely to receive warfarin therapy at discharge.

“The variation in practices between hospitals in this high-risk population reflects the current lack of clear guidance, and the need for additional research on stent selection and antithrombotic strategy,” said lead author Amit Navin Vora, MD, MPH. “As a next step, outcomes data should be examined.”

These findings were based on data from 14,427 atrial fibrillation patients presenting with acute myocardial infarction to 652 hospitals from 2008-2014. The data came from the National Cardiovascular Data Registry (NCDR) Acute Coronary Treatment and Intervention Outcomes Network Registry®-Get With the Guidelines™ (ACTION Registry-GWTG). This risk-adjusted, outcomes-based quality improvement program focuses exclusively on high-risk STEMI (ST-segment elevation myocardial infarction) and NSTEMI (non-ST-segment elevation myocardial infarction) patients.

In addition to Vora, Duke co-authors included Tracy Y. Wang, MD, MHS, MSc; Shuang Li, MS; Karen Chiswell, PhD; Sunil V. Rao, MD; and Eric D. Peterson, MD, MPH.