Ongoing ‘Stent Wars’ May Be Resolved by Pricing

The 30th annual Transcatheter Cardiovascular Therapeutics (TCT) conference recently took place in San Diego (Sept. 21–25). The meeting showcased several advances in interventional cardiology.

The landmark COAPT trial was very successful, demonstrating that transcatheter mitral valve approximation using the MitraClip, on a background of maximally tolerated guideline-directed medical therapy (GDMT), was superior to GDMT alone in the reduction of Heart Failure (HF) hospitalization and mortality in symptomatic heart failure patients with grade 3–4+ mitral regurgitation (MR). The MitraClip device resulted in a significantly lower rate of hospitalization for heart failure, lower mortality, and better quality of life and functional capacity within 24 months of follow-up compared to medical therapy alone.

As similar trials in Europe had been negative and the surgical literature for functional MR had also been negative, the low apriori expectation made the contrasting results appear all the more dramatic. Some interventionalists attributed these positive findings to the use of endpoints such as repeat hospitalization for heart failure and the meticulously selected population, stating effectiveness in the real world would hinge on how closely doctors could replicate the enrolled patient group. In other words, ‘MitraClip should be done for the right reasons in the right group of patients,’ was the take-home message.

Delving deep into the coronary microvasculature, the CorMicA trial paved the way for new insights into mechanisms and therapy for angina patients with no obstructive coronary artery disease (CAD). Ford et al. demonstrated how adjunctive testing of coronary vascular function during coronary angiography followed by medical therapy targeted to the findings, improved angina outcomes. While the results were only applicable to severely symptomatic patients at baseline, there was no denying the fact that microvascular angina could be extremely disabling, underlining the importance of effective therapies in afflicted patients.

ULTIMATE suggested the superiority of IVUS-guided PCI over angiography-guided PCI in the prevention of target vessel failure in an all-comers population. The findings did not seem to come as a surprise to most interventionalists. Dr. Deepak Bhatt, the executive director of interventional cardiovascular programs at Brigham and Women’s Hospital, had remarked that IVUS provides extremely useful information about edge dissection, the exact size after one post-dilates, the status of the plaque burden, and helps ensure there is good stent apposition. While it is a good idea to perform IVUS routinely, cost issues and the extra time taken may serve as drawbacks.

PREPARE-CALC was based on the concept that heavily calcified de novo coronary lesions were difficult to treat and may need debulking prior to successful stent implantation. Dr. Gert Richardt reported higher success rates with rotablation prior to stent implantation (98% versus 81%). Some patients had crossover to bailout rotablation or ‘Rota-regret’ stating, “Depending on your experience and preference, you can do the heavily calcified lesions either with upfront rotablation electively or you can start with a balloon. But if you start with the latter, you have to be prepared for a crossover or a bailout situation. Either way, you have to be trained in the technique of rotational atherectomy.”

The ABSORB IV trial demonstrated that the polymeric coronary bioresorbable vascular scaffolds (BVS) was non-inferior to cobalt-chromium-based Xience DES for cardiovascular outcomes of target lesion failure and angina in fairly simple lesion types, in a 1 year period.

Comparing the study to ABSORB III, the primary investigator, Dr. Gregg Stone commented, “It was a very, very interesting study. Better technique, better patient selection, and appropriate types of lesions do bring down this difference and I honestly believe that now all we need is a better device that will hopefully eliminate most or all of these early first 3 year differences, potentially allowing the long-term benefits of ABSORB to emerge.”

Results of the SOLVE-TAVI trial comparing self-expanding Corevalve Evolut R and balloon-expandable Edwards Sapien 3 valves revealed equivalence in Transcatheter Aortic Valve Implantation (TAVI) in a head-to-head comparison with respect to all-cause mortality, moderate, or severe prosthetic valve regurgitation, and permanent pacemaker implantation. More patients assigned the balloon-expandable valve had a stroke vs. those assigned the self-expanding valve (4.7% vs. 0.5%). While some attributed the increased risk of stroke to post-dilatation required in balloon expandable valves some thought that the finding could be due to a play by chance. It was agreed that a well-powered trial could provide further insight.

With respect to the ongoing “Stent Wars,” the ReCr8 trial demonstrated noninferiority of Polymer-free amphilimus-eluting stents (PF-AES) in comparison with permanent-polymer zotarolimus-eluting stents (PP-ZES) with respect to target-lesion failure at 12 months. SORT-OUT, also confirmed noninferiority of polymer free Biolimus A9-coated BioFreedom stent as compared to the thin strut, biodegradable polymer cobalt-chromium sirolimus-eluting Orsiro stent in an all-comers patient population, at 12 months. BIONYX, conducted by Clemens von Birgelen et al. in an all-comers population, reported non-inferiority of the novel Resolute Onyx stent versus the Orsiro stent for the primary endpoint of safety and efficacy at 1-year.

Finally, IMPERIAL comparing the Eluvia paclitaxel-eluting stent (Boston Scientific) to Zilver PTX paclitaxel-eluting stent (Cook Medical) showed that the Eluvia stent outperformed Zilver in terms of efficacy, which was defined as primary patency at 12 months.

Pondering the implications of all these studies, Dr. Roxana Mehran, the director of interventional cardiovascular research and clinical trial at Mount Sinai School of Medicine, had commented, “I don’t know what it all means. I think it probably just means that the competitive world is going to be big on which drug-eluting stent you choose and it’s going to really become all about pricing. Don’t you think that’s a good thing? If there’s a lot of competition, the driver of the prices will go down.”

The interactive training workshops also provided clinicians an exceptional and fun-filled learning experience.

Dr. C. Michael Gibson is a professor at Harvard Medical School and the Beth Israel Deaconess Medical Center. He is the CEO of the non-profit Baim Institute. He Tweets at @CMichaelGibson.

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