I am certain the new guidelines that we will be
seeing soon will also emphasize the importance of coronary CTA.
– Malissa Wood, Massachusetts General Hospital, Session 805 @ ACC.21
The recently completed ACC.21 and EuroPCR 2021 conferences provided an amazing opportunity to understand where cardiovascular care stands today. But beyond that, I was struck that while advances from decades ago still influence us today, there remain significant opportunities for patient-care breakthroughs ahead.
The DISCOVER-FLOW 10-year Outcomes presentation allowed us to revisit the first study ever to assess accuracy and feasibility of a coronary CTA + FFRCT pathway. The original publication from 2011 found FFRCT to be an accurate tool to non-invasively assess lesion-specific physiology in patients with coronary artery disease (CAD). Through remarkable diligence, near universal 10-year follow up was acquired in >100 patients, providing clinicians with high confidence that clinical treatment decisions informed by FFRCT will lead to improved patient outcomes over both the short and long term.
While this 10-year follow-up period is longer than any we have seen before, the finding that the coronary CTA + FFRCT pathway can effectively stratify patient risk is of course not without precedent. During ACC.21, Dr. David Maron (Prof. of Medicine at Stanford University) highlighted that an important and unexpected finding from the ISCHEMIA trial, on which he served as the PI, was that “CCTA can be used to assess prognosis because anatomic burden predicts risk whereas ischemia severity does not.”
He was one of many during the meetings to voice the need to elevate the role of coronary CTA in daily clinical work to identify and diagnose CAD. Over and over, presenters alluded to the fact that US guidelines have not yet embraced coronary CTA as others around the world have:
“[Today’s US approach] is an outdated evaluation strategy. There has been a substantial amount of evidence, particularly with noninvasive anatomic testing, which has been published since 2012, and it's time for us to redesign and put forth more novel approaches which reflect contemporary evidence.” - Dr. Leslee Shaw, Prof. of Health at Weill Cornell Medicine, ACC Session 677
“Another implication may be a decline in future use of stress testing vs CTA+FFR… The reason for elevating CTA way up in the hierarchy of diagnostic testing [in Europe] is a question about the future use of stress testing: In ISCHEMIA, 14% of patients screened had no obstructive disease and left-main disease was missed in 5.1% of patients, and then picked up on the routine CTA.” - Dr. Bernard Gersh, Prof. of Medicine at Mayo Clinic, ACC Session 805
While this consistent push to apply the lessons from many premier trials regarding coronary CTA + FFRCT for the evaluation and diagnosis of CAD was exciting to see, even more exciting were presentations indicating where this modality can go in the future, as seen in the P3 study.
The Precise PCI Plan (P3) study evaluated the accuracy of the HeartFlow Planner in calculating physiology (FFRCT) after modeling the elimination of coronary narrowings to understand the potential impact of a PCI. Through the ability to non-invasively model different potential treatment strategies, the investigators were able to understand in advance which approaches might allow them to achieve complete functional revascularization, which has been associated with improved clinical outcomes. The P3 study showed that the HeartFlow Planner was “accurate and precise” when using invasive post-PCI physiology as the gold standard, regardless of the pattern of CAD(whether focal or diffuse) or coronary calcification. Principal Investigator Dr. Carlos Collet stated that the HeartFlow Planner “expands the use of CCTA from a diagnostic method to a planning tool for revascularization.”
While there were many other impactful clinical presentations at ACC.21 and EuroPCR, these studies and presentations highlight the constant and healthy tension present when we are forced to assess today’s clinical cardiovascular care in light of where we have been and where we need to go.
The view of the future seen in these data during these conferences is truly exciting. There is an opportunity before each of us to advocate within our own sphere of influence to ensure that the next cardiovascular breakthrough transitions from conference presentation to clinical practice faster than those in the past.