Next Gen Innovators expound on highlights from TCT
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Much cutting-edge research in interventional cardiology was presented at TCT. Cardiology Today obtained insights from Next Gen Innovators who attended the meeting on the implications of some of the presentations that most interested them. Weighing in were Suzanne V. Arnold, MD, MHA, clinical scholar and cardiologist at Saint Luke’s Mid-America Heart Institute and research assistant professor in the department of biomedical and clinical informatics at the University of Missouri–Kansas City; Jay Giri, MD, MPH, FAHA, director of peripheral intervention at the Hospital of the University of Pennsylvania and assistant professor of medicine at the Perelman School of Medicine at the University of Pennsylvania; and Dharam J. Kumbhani, MD, SM, FACC, section chief/director of interventional cardiology and associate professor of medicine at UTSouthwestern Medical Center.
Dharam J. Kumbhani, MD, SM, FACC
The 3-year results of COAPT were not surprising and were reassuring. It is good that the benefits of transcatheter mitral valve repair (MitraClip, Abbott) in patients with HF and moderate or worse mitral regurgitation continue to accrue, but the main message is that the 2-year results were sustained.
At 3 years, in the intention-to-treat population, the primary outcome of all-cause mortality or HF hospitalization occurred in 88.1% of those assigned guideline-directed medical therapy compared with 58.8% of those assigned device therapy plus guideline-directed medical therapy (HR = 0.48; 95% CI, 0.39-0.58).
The crossover data were very interesting. It was, to me, a good biological experiment. The people assigned to the medical therapy group who later received the device therapy ended up doing as well as the people who got it earlier. That’s an internal validation of what the investigators saw. However, the decision of who received subsequent device therapy was not randomized. Perhaps the patients who got it were different from those who did not. They had to survive for 2 years, and many of those who did not cross over died. But there may have been other factors that prompted the investigators to offer the device therapy.
Overall, we do have to be careful about how to interpret these data. The patient population with HF and mitral regurgitation is very large. The group of patients enrolled in COAPT was very well-selected and well-defined. As long as we can find the same phenotype of patients in clinical practice, and are careful about who we implant these clips in, and are able to achieve the same procedural success rates seen in this trial, I think this treatment could be a very good solution for our patients. However, we should be cautious about interpreting these results broadly.
In addition, the 5-year results of the EXCEL trial comparing PCI with CABG in patients with left main CAD were interesting. There was enthusiasm in the intervention community with the early results showing that at 2 to 3 years you were doing as well with PCI as CABG. You kind of still see that with the 5-year results. The primary outcome of death, MI or stroke occurred in 22% of those assigned PCI compared with 19.2% of patients assigned CABG (difference, 2.8 percentage points; 95% CI, – 0.9 to 6.5; P = .13).
If you look at the entire time horizon, the two strategies are similar, but the fact that once you landmark it at 1 year, and certainly at 2 years where the lines seem to cross, does dampen my enthusiasm a bit for use in all patients with left main disease.
EXCEL looked at true hard endpoints. Many other trials have been criticized when they have compared PCI and CABG because they included revascularization as an endpoint, and that’s stacked against PCI. At the end of the day, these results will help us with shared decision-making with our patients. There will not be longer-term follow-up beyond 5 years. If a 65-year-old male comes in, he’s not necessarily only looking at a 5-year horizon; he’s looking at a long-term horizon. You can speculate that maybe the lines will continue to diverge or maybe they will cross again. Unfortunately, we won’t know that with this trial.
Jay Giri, MD, MPH, FAHA
One interesting development that people have not talked much about was the 5-year data from IVUS-XPL. At 5 years in patients undergoing PCI, those assigned IVUS guidance had fewer major adverse cardiac events than those assigned angiography guidance (HR = 0.5; 95% CI, 0.34-0.75). The researchers performed a landmark analysis and the curves continued to separate between 1 and 5 years.
This was fascinating for a key reason: Restenosis is most likely to occur between 3 months and 12 months. Then there is a long tail of later restenosis and thrombotic events. IVUS, and other kinds of intravascular imaging, seems to reduce these risks because patients end up receiving larger stents safely. If you start off with a larger luminal diameter, you are less likely to get restenosis. And now we know this is still true after 1 year. This strategy is paying pathophysiological dividends beyond the typical time point associated with neointimal hyperplasia and smooth muscle hypertrophy, the characteristic pathophysiologic findings from in-stent restenosis.
I was happy to see that vascular biology was relevant in a clinical study that should affect our clinical practice. It behooves us to be getting optimal results on these longer stents. But it’s hard to tell whether a study like this will move the needle. I have been moved by findings such as these and have been progressively using more IVUS, especially in cases which require long stents, over the last several years.
Suzanne V. Arnold, MD, MHA
A patient-level economic analysis of the COAPT trial was of great interest. The researchers projected therapy with the MitraClip device to increase life expectancy by 1.13 years and quality-adjusted life-years by 0.82 years at a cost of $45,648. They calculated a lifetime incremental cost-effectiveness ratio of $40,361 per life-year gained and $55,600 per quality-adjusted life-year gained. With MitraClip having indication creep, when it’s being used in patients in whom it will not be as effective as it was in COAPT, what amount of benefit would you have to get before you would have that acceptable threshold? The researchers explained that they performed a sensitivity analysis looking at decreasing benefit over time and found that if the benefit of the MitraClip extended out to 7 years, an ICER of $50,000 per QALY or more would be achieved.
There were two things I found remarkable about the PARTNER 3 health status outcomes analysis of low-risk patients who underwent transcatheter aortic valve replacement with a balloon-expandable valve (Sapien 3, Edwards Lifesciences) or surgical AVR. The first is that the patients were not particularly symptomatic going in to the trial, and yet the TAVR group still had a nearly 20-point improvement in Kansas City Cardiomyopathy Questionnaire overall summary score at 1 month. We expect a “ceiling effect” in which if you start with a good score, it may not get much better. Yet, there were large health status improvements regardless of baseline score. That is remarkable and may be specific to this cohort; these patients don’t have a lot of comorbidities that will impact their health status other than the aortic stenosis. If you fix the aortic stenosis, some of these patients will have a score of 100. Also of interest was the health status benefit was much smaller at 6 months and 12 months than it was at 1 month. That may reflect a small percentage of patients who seem to get a larger benefit. Are there complications that are driving this?
Disclosures: Arnold, Giri and Kumbhani report no relevant financial disclosures.