Adding troponin to EMS ambulance care reduced the time to test by 100 minutes and the total time to final disposition by 20 minutes, according to a Canadian study reported during Tuesday’s Late-Breaking Clinical Trials session.
The study, “Providing Rapid Out-of-Hospital Acute Cardiovascular Treatment (PROACT-4),” compared point-of-care troponin testing to traditional in-hospital troponin testing.
“This was a large, prognostic trial with patients enrolled by paramedics,” said lead author Justin A. Ezekowitz, MBBCh, associate professor of medicine at the University of Alberta in Canada. “The vast majority of patients with chest pain do not have cardiovascular issues. Just adding point-of-care troponin shortened the time to final disposition.”
L. Kristin Newby, MD, MHS, professor of medicine at Duke University Medical Center in Durham, North Carolina, noted that point-of-care troponin testing is less sensitive than in-hospital testing, which could delay diagnosis for patients with less severe cardiac events. And while point-of-care testing cut just 20 minutes from the typical eight-hour emergency department visit, the study suggests potential to improve workflows in other areas as well, she said.
In another late-breaking presentation, researchers unveiled a new tool to help clinicians assess which patients are more likely to benefit from extending dual antiplatelet therapy beyond 12 months after implantation of a coronary stent. Extended DAPT reduces ischemic complications, but can increase bleeding.
“These are average treatment results, but some individuals are more likely to see benefit from extended therapy and others are more likely to be harmed,” said Robert W. Yeh, MD, MSc, MBA, director of the Smith Center for Outcomes Research in Cardiology at the Beth Israel Deaconess Medical Center in Boston. “We have developed a scoring system to help individualize that determination.”
Yeh is lead author of the study “Individualizing Treatment Duration of Dual Antiplatelet Therapy after Percutaneous Coronary Intervention: An Analysis of the DAPT Study.” In the study, researchers developed predictive models for bleeding and ischemic events in patients who remained on DAPT 12 months following stent implantation, then combined them into a third model to predict the net treatment effect.
Risk factors include patient age, prior PCI or MI, stent diameter, MI at presentation, cigarette smoking, diabetes, vein graft PCI and other features. These factors were used to create a scoring system of 1 to 4. Patients with a score of less than two are more likely to bleed than see ischemic benefit, while patients with a score of two or higher are more likely to benefit from reduced ischemic events than bleed. The tool is available at www.daptstudy.org.
“The DAPT score is very similar to other clinical tools such as CH2AD2-VASC or HAS-BLED,” noted James de Lemos, MD, professor of internal medicine at the University of Texas Southwestern Medical Center in Dallas. “This study demonstrates the value of standard clinical tools in providing personalized care.”
In another presentation, researchers presented a quality-of-life analysis of the RIVER-PCI trial that echoed the study’s primary outcome, finding that ranolazine had no significant effect on angina. The study is titled “Angina and Quality of Life following PCI with Incomplete Revascularization: Results from the Ranolazine for Incomplete Vessel Revascularization (RIVER-PCI) Trial.”
Principal investigator E. Magnus Ohman, MBBS, professor of medicine at Duke University Medical Center, said the results indicate no incremental benefit from ranolazine.
“Most patients had angina going into RIVER-PCI and most were asymptomatic after their incomplete revascularization, with or without ranolazine,” Ohman said. “We need more research into the relationship between patient-reported angina and ischemia-driven events.”
John A. Spertus, MD, MPH, director of Health Outcomes Research at the Mid America Heart Institute in Kansas City, Missouri, said the trial suggests prophylactic use of ranolazine is not helpful to reduce angina after incomplete revascularization. He also noted that these patients require close follow-up for residual angina. Those with residual angina need additional treatment such as ranolazine, CTO PCI or other strategies, he said.
Results from “Long-Term Tolerability of Ticagrelor for Secondary Prevention: Insights from PEGASUS-TIMI 54 Trial” indicated that most patients who stop taking ticagrelor do so due to relatively minor side effects. Closer monitoring of these patients and better patient education and counseling could improve outcomes by improving adherence, noted Marc P. Bonaca, MD, MPH, an investigator in the TIMI study group and an associate physician in cardiovascular medicine at Brigham and Women’s Hospital in Boston.
“We found that events which clinicians characterize as mild or moderate can drive discontinuation,” Bonac said. “The majority of events leading to discontinuation are dyspnea and bleeding that require minimal or no intervention, not serious adverse events.”
Noncompliance with ticagrelor — 22.5 percent at three years in the trial — is a serious problem, agreed discussant Marco Costa, MD, PhD, professor of medicine at University Hospitals, Case Medical Center, in Cleveland, Ohio. Discontinuation is likely even higher in clinical practice, he said.
“We tend to focus on the biological aspects of our drugs and ignore the human behavior elements,” he said. “I call on our colleagues to pay more attention to these non-biological factors that lead to discontinuation.”
Another study, “Clinical Outcomes of Intravascular Ultrasound Guided Everolimus-Eluting Stents Implantation in Long Coronary Lesions,” found that intravascular ultrasound (IVUS) guidance provides better clinical outcomes than angiographic guidance for second-generation drug-eluting stents in patients with long coronary lesions. The trial followed 1,400 patients for 12 months.
“Among patients who require long coronary stents, IVUS guidance was associated with a significant 2.9 percent absolute reduction and a 48 percent relative reduction in the risk of MACE at one year,” said lead author Myeong-Ki Hong, MD, PhD, professor of medicine at Severance Cardiovascular Hospital, Yonsei University College of Medicine, in Seoul, Korea.
“We know the benefit is probably not due to operator behavior,” Costa said. “We need to better understand the mechanisms responsible.”