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2 decades of intervention
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Editor’s Note: Cardiology Today celebrated its 20th anniversary in 2017. We are reaching out to experts in cardiology for their take on changes in CV medicine since the publication launched in 1997. For this article, Deepak L. Bhatt, MD, MPH, Cardiology Today Editorial Board Member, Chief Medical Editor of Cardiology Today's Intervention, executive director of interventional cardiovascular programs at Brigham and Women’s Hospital Heart & Vascular Center and professor of medicine at Harvard Medical School, focuses on intervention.
In 1997, balloon angioplasty was king and stenting was just getting off the ground. Antithrombotic regimens were extremely complex and associated with high rates of bleeding after large-bore venous and femoral access. Femoral complications were extremely common, and it was extremely challenging to take care of them. A big part of a fellow’s job at that point was managing these very common and serious complications. As well, there was a great deal of uncertainty at night of whether the procedure from the day was going to be a durable one or not. Things were very different in terms of patients having to come back to the cath lab emergently at a much higher frequency than anyone is accustomed to seeing these days.
The evolution from balloon angioplasty to bailout stenting to routine bare-metal stenting to routine drug-eluting stenting has been a dramatic change with much greater procedural stability. As a result, interventions are much more durable now, and it’s unusual to have to rush back in the middle of the night for a procedure from earlier that day.
Evolution of devices, drugs
During the past 2 decades, many devices have been evaluated. Devices for directional coronary atherectomy, for example, were very big at Cleveland Clinic, where I was at the time. The data showed that there really was no value for routine directional coronary atherectomy, although some value remains for adjunctive rotational atherectomy or orbital atherectomy prior to stenting. That evolution occurred concomitant with an evolution of the pharmacotherapies, going from the complex regimens that caused bleeding, such as aspirin, warfarin and heparin; then to ticlopidine and aspirin, so-called dual antiplatelet therapy, which helped revolutionize and facilitate the stent era. And then, the replacement of ticlopidine with the much better-tolerated clopidogrel. That enabled stenting to take off.
The move from routine arterial and also venous sheath placement to more selective venous sheath placement helped reduce complications coming from the very large 9F to 10F arterial sheaths to smaller 6F, or, very often now, 5F sheaths. This markedly reduced femoral artery complications. Then, moving to transradial access has dramatically reduced vascular bleeding complications associated with the procedure. All that evolution has made coronary intervention safer and more effective during the past 20 years.
Closure devices for femoral artery access also appeared to be associated with greater patient comfort and quicker ambulation times, and perhaps even a reduced vascular complication rate, making the procedure easier for the techs and the fellows by not having to hold the groin.
When all the changes are added up, it’s a totally different cath lab now compared with 20 years ago.
Intervention beyond the heart
Moving into other arterial, venous, and cerebral territories has been a major advance, as has moving from just coronary and vascular procedures to structural procedures. In 1997, intervention beyond the heart was much less common. Back then, there were really no data for stroke interventions. Now there are a ton of data for endovascular interventional procedures for stroke.
Another big advance in the field is moving from coronary to include also peripheral interventions right down to the toe and acute limb ischemia and amputation prevention programs, coordinated with wound-healing programs.
Imaging and contrast improvements
The imaging equipment has gotten much better in the past 20 years. There is less radiation. Although radiation is still an issue for the operator, it has dropped considerably for operators and patients. At the same time, the image quality is much better at a lower dose of radiation.
Another change, maybe not on the same scale, is moving from routine use of ionic contrast to non-ionic contrast, which made the procedure much better tolerated. Ionic contrast used to cause a lot more hypotension and allergic reactions. There was more nausea, more vomiting, and more bradycardia. All those things are markedly less now with the contrast agents we are using. Renal failure is still an issue. That has not really been improved with the change in contrast type. I remember at Cleveland Clinic, it was a big deal to use non-ionic contrast because at the time it was approximately 10 times more expensive. It could not be used in all cases despite being better tolerated. This might not have been true of every place, but we were hanging on to ionic contrast perhaps after its life span had expired. Being able to use non-ionic contrast routinely is a huge advance.
Quicker discharges
Many times back then, high risk patients would get admitted the night before for their diagnostic catheterization. That virtually never happens anymore. The idea of same-day PCI for lower-risk, elective PCI patients, would not have occurred to anyone in 1997.
I remember in the late 1990s, I did an intervention on a patient that went incredibly smoothly, and it was early in the day and he really wanted to go home. He lived locally. He had to go take care of his dog, so he wanted to go. I remember I said, “Yeah, I can’t think of a good reason to keep you when things went so smoothly.”
So, I discharged him, and it caused a controversy in the hospital because that had never happened before. Ultimately, I was not allowed to do it because there were concerns about if something happened. I countered all the safety concerns and then finally someone brought up their trump card and said, “Well, we’re not going to get reimbursed if he gets discharged.” So that ended the conversation.
It is such a different set of circumstances now, where the pressure is to get the patient out quickly. No one is telling you to admit that patient who was stented. Quite the opposite.
Looking to the future
There will be continued evolution of stent technology. But equally importantly, I hope there will be continued refinement of the antithrombotic strategies, where we can get away with shorter durations of therapy. There might be other good reasons to continue, such as the underlying disease state, but the stent itself should not mandate prolonged therapy.
Those trials are ongoing now and should help change the risk-benefit ratio of stents. If the perception is you need 1 month of DAPT instead of lifelong DAPT, that changes the economics and the overall clinical benefit of stenting. Again, we might want longer durations for other reasons — the patient has had an MI or ACS or other risk factors — but if the stent itself can mandate a shorter period, that will change our approach.
There will be continued understanding of how we can use adjunctive imaging technologies, such as OCT, to optimize interventional outcomes. Use of fractional flow reserve and instantaneous wave-free ratio are helping sort out who should even get intervention in the first place and when it can be safely deferred. I think we will see much more of that.
With regard to the first fully bioresorbable scaffold (Absorb, Abbott Vascular), which was effectively removed from the market by the manufacturer after discouraging data and slow sales, I hope that story is not over. I hope industry remains interested in exploring newer versions of that technology.
Disclosure: Bhatt reports financial ties with various device and pharmaceutical companies.