Feature | Cath Lab | March 27, 2017

Benefits Shown for Treating All Clogged Arteries After a Heart Attack

Use of FFR to identify and treat secondary blockages lowers risk, helps avoid subsequent procedures 

Philips Azurion angiography system, FFR for STEMI

March 27, 2017 — Patients experiencing a major heart attack often have more than one clogged artery, but under current guidelines doctors typically only clear the blockage responsible for the heart attack. Assessing and, when warranted, treating the additional blockages can improve patient outcomes and reduce the need for subsequent invasive procedures, according to research presented at the American College of Cardiology (ACC) 2017  Annual Scientific Session. 

The COMPARE-ACUTE study findings are in line with previous studies pointing to benefits of a more comprehensive treatment approach after a major heart attack, but it is the first randomized clinical trial in which doctors have used the newer diagnostic tool fractional flow reserve (FFR) to precisely assess secondary blockages. Compared with patients in whom doctors treated only the blockage that caused the heart attack, patients who received FFR-guided evaluation and treatment of all arteries were 65 percent less likely to experience the trial’s primary endpoint, a composite of all-cause mortality, non-fatal heart attack, stroke and subsequent revascularization (such as angioplasty or bypass surgery to clear blocked arteries) at 12 months. 

“Our study shows you can optimize treatment with this approach and potentially also have economic benefits by reducing the need for extra procedures,” said Pieter Smits, M.D., a cardiologist at Maasstad Ziekenhuis, Rotterdam, the Netherlands, and the study’s lead author. “For the patient, it’s a tremendous advantage to know that you have been treated for the artery that brought you to the hospital but also that any other issues have already been investigated and treated if needed. This way the patient won’t need to be brought back to the hospital later on and again be put at risk with an invasive procedure or additional diagnostics.” 

The study focused on patients experiencing ST-elevated myocardial infarction (STEMI), the most serious type of heart attack. To treat STEMI, doctors typically clear the infarct-related artery with percutaneous coronary intervention (PCI) and sometimes also a stent, to open the artery and restore blood flow. 

Medical guidelines currently recommend performing PCI on the infarct-related artery after STEMI and leaving the other arteries alone, treating them later if subsequent tests or symptoms indicate they are substantially blocked by areas of plaque buildup, known as atherosclerotic lesions. Smits and his colleagues sought to investigate whether FFR could offer an opportunity to improve outcomes by refining doctors’ ability to identify problematic lesions immediately after successful initial PCI. Because it is based on precise measures of blood pressure near lesions, FFR provides a much more accurate assessment of blockages than was previously possible with angiogram alone. 

The researchers enrolled 885 STEMI patients at 24 sites in 12 countries in Europe and Asia. Immediately after the infarct-related artery was cleared using PCI, stable patients were randomly assigned to receive FFR-guided assessment of other arteries but no additional PCI (infarct-only revascularization, performed in 590 patients) or FFR-guided assessment and, when indicated by an FFR score of 0.80 or lower, PCI to clear additional lesions (complete revascularization, performed in 295 patients). The primary composite endpoint occurred in 20.5 percent of patients receiving infarct-only revascularization and 7.8 percent of patients receiving FFR-guided complete revascularization, a difference that was statistically significant. When the components of the composite primary endpoint were analyzed separately, there was no significant difference in the rates of all-cause mortality, non-fatal heart attack or stroke; however, there was a significant reduction in the incidence of subsequent revascularization procedures among patients randomized to receive complete revascularization. All nonurgent revascularization procedures performed within the first 45 days after the initial PCI based on symptoms or stress tests were excluded from this analysis to avoid biasing the results in favor of complete revascularization. 

When assessing the lesions other than the one responsible for the heart attack, the researchers found that only about half of these lesions were constricted enough to require treatment. Together, these results suggest that treating non-infarct related lesions is beneficial and that FFR can help clinicians to precisely identify those lesions in need of treatment. 

“The results show that using FFR in the acute phase of STEMI, which was never done before, is feasible and safe,” Smits said. “Furthermore, FFR-guided complete revascularization allows you to fine-tune the treatment and get better outcome results.” 

One downside of performing complete revascularization after initial PCI is that doing so increases the complexity of the procedure. However, the results showed that procedures in the complete revascularization arm were on average just six minutes longer than the procedures in the infarct-only revascularization arm, a difference Smits said is relatively minor and likely outweighed by the increased need for subsequent revascularization among those receiving infarct-only revascularization in the initial procedure. One limitation is that the study struggled with slow enrollment, in part because some participating centers were only able to enroll patients during certain hours of the day or week and because the trial excluded patients who were in shock or unstable, a relatively frequent occurrence with STEMI. The study enrolled patients from 2011 through 2015. 

Another limitation is that the study was not large enough to reveal statistically significant differences in all-cause mortality or subsequent heart attacks. A larger study, currently underway, is expected to shed light on these outcomes. In addition, Smits and his colleagues plan to conduct a further analysis of the cost implications of performing infarct-only revascularization versus complete revascularization after STEMI. 

The trial was funded by two unrestricted grants from Abbott Vascular and St. Jude Medical. This study was simultaneously published online in the New England Journal of Medicine (NEJM) at the time of presentation.

Read the abstract for the study in the NEJM “Fractional Flow Reserve–Guided Multivessel Angioplasty in Myocardial Infarction.”

Watch a VIDEO interview about the iFR vs. FFR trials at ACC.17 that showed iFR to equal in outcomes.


Related Content

The American College of Cardiology (ACC) released a list of the latest practice-changing presentations at the ACC.20 annual meeting March 28-30, 2020, in Chicago. This includes five late-breaking clinical trial (LBCT) sessions and three featured clinical research sessions. There also are two LBCT deep-dive sessions where the experts will break down the hottest trials and attendees can find out what the impact might be on the practice of cardiology and patients.
Feature | ACC | April 09, 2020 | Dave Fornell, Editor
Here is the list of American College of Cardiology (ACC) practice-
ACC Cancels 2020 Conference Amid Coronavirus Concerns. #COVID19 #coronavirus #2019nCoV
Feature | ACC | March 09, 2020 | Dave Fornell, Editor
March 9, 2020 — Less than week after the American College of Cardiolog...
American College of Cardiology Names Douglas Drachman Next Annual Scientific Session Vice Chair

Image courtesy of Massachusetts General Hospital

News | ACC | October 08, 2019
Douglas Drachman, M.D., FACC, has been selected as the next vice chair of the American College of Cardiology’s (ACC)...
SyncVision iFR Co-registration from Philips Healthcare maps pressure readings onto angiogram. Results from an international study presented at ACC 2019 indicates pressure readings obtained using iFR (instantaneous wave-free ratio, also referred to as instant wave-free ratio or instant flow reserve) in coronary arteries may localize stenoses that remain after interventions. FFR in the cath lab.

SyncVision iFR Co-registration from Philips Healthcare maps pressure readings onto angiogram. Results from an international study presented at ACC 2019 indicates pressure readings obtained using iFR (instantaneous wave-free ratio, also referred to as instant wave-free ratio or instant flow reserve) in coronary arteries may localize stenoses that remain after interventions.

Feature | ACC | March 27, 2019 | Greg Freiherr, Contributing Editor
The fingerprints of value-added medicine were all over products and works-in-progress on the exhibit floor of the a

The opening late-breaking trial at ACC 2019 is the Apple Heart Study, a large-scale, app-based study to identify atrial fibrillation using a smartwatch. Earlier, smaller trials showed this approach might be used in a population health application to proactively identify AFib patients earlier.

Feature | ACC | March 19, 2019
The American College of Cardiology (ACC) released a list of the late
A patient who received HeartMate III LVAD system at ACC.18. The HeartMate 3 was the topic of of the the key late-breaking trials at #ACC18

A patient who received the HeartMate III LVAD system showing off his external battery pack. He served as a patient ambassador in the Abbott booth at ACC.18. The HeartMate III, with its magnetic levitated pump, showed a big reduction in clotting over previous LVADs in a key late-breaking trial at this year's conference.

Feature | ACC | March 27, 2018 | Dave Fornell
There were several notable presentations of new data on cardiovascular technologies at the recent 2018 American Colle
Drug Stops Dangerous Bleeding in Patients Taking Factor Xa Inhibitors


News | ACC | March 22, 2018
March 22, 2018 — The experimental drug...
Videos | ACC | March 21, 2018
DAIC Editor Dave Fornell takes a tour of some of the most interesting new technologies on the expo floor at
ACC 2018 Late-Breaking Trials Announced
News | ACC | March 21, 2018
Here is a list of the American College of Cardiology (ACC) 2018 annual meeting late-breaking clinical trials presente
Inhaled Therapy Ineffective in Difficult-to-Treat Heart Failure at ACC 2018.

Image from presentation, "Inorganic Nitrite Delivery to Improve Exercise Capacity in HFpEF: The INDIE-HFpEF Trial," Borlaug

News | ACC | March 20, 2018
March 20, 2018 — Four weeks of treatment with a novel inhaled medication failed to improve exercise capacity, daily a