William Boden, MD, on Revascularization for Stable Ischemic Heart Disease

 

In this podcast, William Boden, MD, talks about the data around the use of revascularization for patients with stable angina, other medical therapies that can prevent or manage stable angina, and his best practices for managing this patient population.

Additional Resources:

  • Conservative approach to managing chest pain and abnormal diagnostic test results in a patient with stable ischemic heart disease (SIHD). Talk presented at: American Heart Association Scientific Sessions 2020; November 13-17, 2020; Virtual. 
  • Ferraro R, Latina JM, Alfaddagh A, et al. Evaluation and management of patients with stable angina: beyond the ischemia paradigm: JACC State-of-the-Art Review. J Am Coll Cardiol. 2020;76(19):2252-2266. https://doi.org/10.1016/j.jacc.2020.08.078
  • Fuster V. Evaluation and management of patients with stable angina: beyond the ischemia paradigm: JACC State-of-the-Art Review. JACC Podcast. November 2, 2020. Accessed November 10, 2020. https://www.jacc.org/do/10.1016/podcast-jacc-76-19-7/full/

 

William Boden, MD, is the director of the clinical trials network at the VA Boston Healthcare System and a professor of medicine at Boston University School of Medicine.


 

TRANSCRIPT:

Amanda Balbi: Hello everyone, and welcome to another installment of Podcasts360—your go-to resource for medical news and clinical updates. I’m your moderator, Amanda Balbi with Consultant360 Specialty Network.

My guest today is Dr Bill Boden, who is the director of the clinical trials network at the VA Boston Healthcare System and a professor of medicine at Boston University School of Medicine. He will be presenting on stable ischemic heart disease at the American Heart Association’s 2020 Scientific Sessions.

Today he’ll be answering my questions about his session and this very important topic.

Thank you so much for joining me today, Dr Boden. To start, can you give us an overview of your presentation at the AHA Scientific Sessions?

Bill Boden: Sure. The topic of discussion at the AHA will really center on the management of patients with stable ischemic heart disease or SIHD. This is a large subset of patients, well over half of all the patients, with coronary heart disease have the stable variety of SIHD.

Altogether latest estimates from the American Heart Association are about 17 million adults in the US have ischemic heart disease or SIHD. So this is a large group of patients for whom there has been controversy over the last 20 years in terms of what's the best management.

By contrast, patients who've had a heart attack or an ST segment elevation, the data from many randomized trials demonstrate that there's benefit to undertaking revascularization. We typically, for those patients, would have them go to the CATH lab to get percutaneous coronary intervention, or PCI, and a stent. That's been proven to be a benefit.

However, in this other subset of patients—again, the stable ischemic heart disease patients, which again account for a half to maybe even two-thirds of all the patients with coronary disease—there hasn't been proven benefit from multiple randomized trials over the last 15 to 18 years. And so, this has created the conundrum in terms of management.

Broadly speaking, there are 2 approaches. One of which is what we refer to as the invasive strategy, which means the patients go to the CATH lab, have a coronary angiogram to elucidate the presence or absence of coronary obstructions, and then they would proceed on to get either a PCI procedure and a stent, or potentially bypass surgery.

The other approach is one that embodies the use of what we refer to as optimal medical therapy or, for short, OMT. This includes a combination of both lifestyle intervention plus multiple medications that they've been proven individually and placebo-controlled trials to essentially reduce death or myocardial infarction.

The OMT approach embodies intensive pharmacotherapy lifestyle interventions such as weight loss, diet, exercise, good blood pressure control, and management of dyslipidemia with statins. So those are the two approaches, and essentially during my presentation at the AHA, I'll be focusing on the more conservative approach or the management of patients with optimal medical therapies.

Amanda Balbi: What does the data say about the use of revascularization among patients with stable angina?

Bill Boden: Well, the data, at least in terms of how we would use revascularization, there are essentially 2 goals of revascularization. (1) Can you demonstrate that it will prolong life or increase survival, or will it reduce myocardial infarction? As I mentioned, in the patients with acute MI or acute coronary syndrome, that has been proven to be a benefit.

(2) The other goal or objective of revascularization is symptom relief or improving quality of life. There have been at least 16 randomized trials since roughly 2000 and notably 5 big trials since 2007, which have shown that in patients with stable ischemic heart disease, there is no benefit of revascularization on reducing death or myocardial infarction.

In fact, the only benefit that one sees is an improvement of symptoms. But in many of these trials that have followed patients for many years, it's observed that the benefit in terms of revascularization on symptom relief decreases over time.

In the biggest trial, just published this past year called the ISCHEMIA trial, over 5179 patients—and this has been a big focus of the AHA presentation—only in the patients who had really frequent symptoms, that is to say they had daily or weekly angina, could you demonstrate that there was really improvement in terms of revascularization.

So, the patients who had more minimal symptoms or infrequent symptoms, it didn't really seem to show that there was a justification for undertaking revascularization unless the symptoms were unacceptable to the patient.

Amanda Balbi: What other medical therapies are preferred now for either the prevention or management of stable angina?

Bill Boden: Great question. I will say that over the last 10 or 15 years, we've had many new classes of therapies that have been available to clinicians. We hear incessantly about the fact that procedural cardiology and, in particular, stents and angioplasty and so forth, have evolved with advancing technology.

That's obviously true, but what often gets lost in the shuffle here is the fact that there has also been a profound evolution in pharmacotherapies over the last roughly 10 to 15 years. For example, it's only been since around the beginning of the Millennium that we really had convincing evidence that using statins to lower LDL cholesterol has been proven to be of benefit. And that has been shown in many, many trials in both primary and secondary prevention.

There's also, within the last few years, a new class of medication referred to as the PCSK9 inhibitors, which are generally administered as either a biweekly or a monthly injection—very effective treatment for further reducing LDL cholesterol on top of a statin.

Just the last few years alone, there's also been an explosion in the availability of new drugs to treat diabetes. So 2 broad classes of these drugs are called the SGLT-2 inhibitors and the GLP-1 agonists.

And together, these agents when combined with statins, blood pressure lowering medications like ACE inhibitors and ARBs, anti-platelet agents such as aspirin and clopidogrel, or other agents. So, we now have very powerful drugs to treat dyslipidemia, powerful drugs to treat diabetes, and we have very effective drugs to reduce thrombotic risk, that is to say the use of aspirin and anti-platelet action.

In the aggregate, our portfolio of medications has expanded significantly to benefit patients.

Amanda Balbi: What are the best practices for managing a patient with chronic stable angina, a positive stress test, and evidence of obstructive coronary artery disease?

Bill Boden: Right, so it's going to depend on a few factors, the first of which would be to look at whether the patient’s anatomic burden of disease is significant. What I think came out of the ISCHEMIA trial is that there seems to be less and less benefit to looking at ischemia as a marker of potential risk.

Therefore, I think physicians—cardiologists in particular—are no defaulting to undertaking coronary CTA, a noninvasive anatomic assessment of anatomic disease burden.

If patients are found to have left main coronary disease or a significant or extensive multivessel coronary disease, and especially if they're diabetic, in that context, then I think there is evidence to support the role of revascularization. And I think that's become increasingly clear.

But I think what's also increasingly clear is that, despite the availability and the effectiveness of many of the medications in classes that we talked about, this is still woefully underutilized. So, for example, in the ISCHEMIA trial that I alluded to earlier, only 41% of the patients, but we're really taking all 4 drug classes that would otherwise allow them to have the most benefit in terms of event reduction.

We have a major challenge in terms of getting our physicians and clinicians to embrace the benefits of all OMT, if you will, and to really double down on medical therapy. Fundamentally, vascular disease, whether it occurs in the coronary arteries or in the carotid arteries, is a systemic vascular disease. The only way to impact outcomes is to treat this disease systemically, which you can do best with optimal medical therapy, lifestyle intervention, and intensive secondary prevention.

Amanda Balbi: What you say is the overall to take-home message from your session?

Bill Boden: I think the key take-home message for the session is that we do have subsets of patients for whom revascularization is beneficial and appropriate. Again, these would be principally patients who have extensive anatomic coronary disease who have failed optimal medical therapy.

In the larger subgroup of patients, in my view, who either have infrequent or milder symptoms of angina who do not have significant left main coronary disease or extensive anatomic coronary disease, then I think the data are overwhelming on the basis of multiple trials in the last 10 to 15 years that really support the benefits of using optimal medical therapy and lifestyle intervention as the first and preferred approach.

Just to reiterate the point I made earlier, I think the challenge is to find strategies that would allow us to more effectively utilize these medications more broadly across the population who are most likely to benefit.

Amanda Balbi: Thank you so much for speaking with me today.

Bill Boden: Amanda, it's been a pleasure to speak with you and thank you for the opportunity of having the ability to discuss this important topic with you today and our listeners. This will be a valuable resource for physicians to consider looking at this paper.

There's also an incredible podcast that Dr Valentin Fuster, who is the editor in chief of the Journal of the American College of Cardiology, has undertaken as part of the discussion of this paper. And so I would urge all of the listeners to this podcast to really take an opportunity to listen to Dr Fuster’s wonderful podcast, because he really highlights all of these various issues in terms of the importance of both revascularization, where it's appropriate, where it's not appropriate, and of course optimal medical therapy as well.