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Circulation on the Run


Jan 25, 2021

Dr. Carolyn Lam:

Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. We're your co-hosts, I'm Dr. Carolyn Lam, associate editor from the National Heart Center and Duke National University of Singapore.

Dr. Greg Hundley:

And I'm Dr. Greg Hundley, associate editor, director of the Pauley Heart Center at VCU health in Richmond, Virginia. Well, Carolyn, our feature discussion, actually our whole issue, is going to involve the flozins, empa, dapa, et cetera, but that feature discussion will get some results from the EMPEROR-Reduced trial. Well Carolyn, how about we grab a cup of coffee and this is your area, so we're going to let you run with it today.

Dr. Carolyn Lam:

Man, and I can't wait to talk about this. Yes, the sodium-glucose cotransporter 2 inhibitors or SGLT2 inhibitors, are indeed now the foundational therapies for patients with heart failure with reduced ejection fraction. Initially developed to improve glucose control in patients with type II diabetes, SGLT2 inhibitors have beneficial cardiovascular and renal effects in patients with diabetes, HFrEF, chronic kidney disease. Well, today's issue contains two pre-specified subgroup analyses from DAPA-HF and EMPEROR-Reduced, both trials evaluating SGLT2 inhibitor effects on renal outcomes, as well as cardiovascular outcomes, by baseline renal function in patients with HFrEF. The first paper comes from Dr. Jhund and colleagues from the University of Glasgow and it is revolving around the DAPA-HF trial.

Dr. Greg Hundley:

Ah Carolyn, tell us a little bit about DAPA-HF.

Dr. Carolyn Lam:

Gladly. In DAPA-HF, the SGLT2 inhibitor, dapagliflozin, reduced the incidence of the primary composite outcome of cardiovascular death or worsening heart failure in patients with HFrEF, with and without diabetes and an estimated GFR of greater or equal to 30. Of more than 4,700 patients with a baseline GFR, 41% had a GFR less than 60. The effect of dapagliflozin on the primary and secondary outcomes did not differ by GFR category or examining GFR as a continuous variable. The pre-specified composite renal outcomes, which in DAPA-HF was a more than 50% sustained decline in GFR, end stage renal disease or renal death. Now this composite renal outcome was not reduced by dapagliflozin, but the rate of decline of GFR between days 14 and 720 was less with dapagliflozin.

Dr. Greg Hundley:

Carolyn, what's the take home message here?

Dr. Carolyn Lam:

Dapagliflozin slowed the rate of decline in GFR in patients with HFrEF, both in patients with and without diabetes. There was no difference in the efficacy of dapagliflozin by baseline renal function in preventing the risk of cardiovascular death or worsening heart failure.

Dr. Greg Hundley:

Okay, well now how about the EMPEROR-Reduced trial?

Dr. Carolyn Lam:

All right. Well, let me remind you first that in EMPEROR-Reduced the SGLT2 inhibitor empagliflozin also reduced cardiovascular death or heart failure hospitalization and total heart failure hospitalization and slowed the progressive decline in kidney function in patients with heart failure with reduced ejection fraction with and without diabetes. Now, more than 3,700 patients were randomized, of whom 53% had chronic kidney disease, defined as a GFR less than 60 or a urinary albumin to creatinine ratio above 300 milligrams per gram. Empagliflozin reduced the primary outcome and total heart failure hospitalizations in patients with and without chronic kidney disease. Empagliflozin also slowed the slope of GFR decline and the risk of the pre-specified composite kidney outcome, now defined as a sustained, profound decline in GFR, chronic dialysis or transplant, was reduced similarly in patients with and without chronic kidney disease.

Dr. Carolyn Lam:

The effect of empagliflozin on the primary composite outcome of cardiovascular death and heart failure hospitalization, as well as the key secondary outcomes of total heart failure hospitalization and GFR slope, were consistent across the broad range of baseline kidney function measured by clinically relevant GFR subgroups or by albuminuria and including patients with a GFR as low as 20. Above all, empagliflozin was well tolerated in these patients with chronic kidney disease. All of this is discussed in a beautiful editorial by doctors Carnicelli and Robert Mintz.

Dr. Carolyn Lam:

Now, can I tell you about yet another paper with the SGLT2 inhibitors? This time a pre-specified comparison of the effect of empagliflozin in patients with and without diabetes.

Dr. Greg Hundley:

Ah, great Carolyn. What did this study find?

Dr. Carolyn Lam:

Well, this is from Dr. Stefan Anker from Berlin and colleagues, including myself and of the more than 3,700 patients enrolled in EMPEROR-Reduced, 50% had diabetes, 34% had pre-diabetes and 16% had normal glycemia. Empagliflozin reduced the risk of the primary outcome similarly in patients with and without diabetes. Patients with and without diabetes also did not differ with respect to the effect of empagliflozin on total heart failure hospitalizations, on the decline in EGFR over time or on the risk of serious adverse renal outcomes. Among these end points, the effects of the drug did not differ in patients with pre-diabetes or normal glycemia. When analyzed as a continuous variable, baseline HbA1c did not significantly modify the benefits of empagliflozin on the primary outcome. Empagliflozin also did not lower HbA1c in patients with pre-diabetes or normal glycemia and was not associated therefore with an increased risk of hypoglycemia.

Dr. Greg Hundley:

Carolyn what's the take home message here?

Dr. Carolyn Lam:

Well, empagliflozin significantly improved cardiovascular and renal outcomes in patients with HFrEF, independent of baseline diabetes status and across the continuum of HbA1c.

Dr. Greg Hundley:

Very nice Carolyn. Well, my paper comes from professor Wai Ho Tang and it's a basic science paper. Carolyn, aberrant expression of circular RNA or CircRNA, contributes to human diseases. CircRNAs regulate gene expression by sequestering specific microRNAs. In this study, the authors investigated whether CircMAP3K5 could act as a competing endogenous microRNA-22-3p sponge and regulate neointimal hyperplasia.

Dr. Carolyn Lam:

Wow, that's interesting. And what were the results?

Dr. Greg Hundley:

Carolyn, the authors identified that CircMAP3K5 is a master regulator of TET2-mediated, vascular smooth muscle differentiation. Targeting CircMAP3K5, microRNA-22-3p and the TET2 axis, may provide a potential therapeutic strategy for diseases associated with intimal hyperplasia, including restenosis as well as atherosclerosis.

Dr. Carolyn Lam:

Oh, nicely summarized. Thanks Greg. Well, we've got other papers in today's issue. There's an ECG challenge by Dr. Frész on acute coronary syndrome with tall R waves and inverted T waves in the precordial leads, an ignored entity. We have an exchange of letters between Drs. Vandecasteele and Zhao regarding the article, Cardiac Over Expression of PDE4B Blunts β-Adrenergic Response and Maladaptive Remodeling in Heart Failure.

Dr. Greg Hundley:

Thanks Carolyn. I have some Research Letters. The first Research Letter is entitled, “Cardiovascular Toxicities Associated with Loperamide: An Analysis of the World Health Organization Pharmacovigilance Database,” and the corresponding author is Dr. Pierre Ollitrault. The second Research Letter is entitled, “Incessant Pericarditis as a Risk Factor for Complicated Pericarditis and Hospital Admission,” and it comes from Professor Massimo Imazio. And then finally, there's a White Paper (Frontiers) for atrial fibrillation screening research priorities from the NHLBI workshop with the corresponding author being Dr. Emelia Benjamin from Boston University School of Medicine. Well Carolyn, how about we jump in to more SGLT2 and another feature discussion?

Dr. Carolyn Lam:

Yes, can't wait. Thanks Greg.

Dr. Greg Hundley:

Well listeners, we're now to our feature discussion and we have with us today, Dr. Milton Packer from Baylor University Heart Vascular Center in Dallas and also our own associate editor, Dr. Justin Ezekowitz from Edmonton. Milton, welcome and wanted to ask you first off, tell us a little bit about the background that got you to want to perform this study. And what hypothesis did you want to address?

Dr. Milton Packer:

Greg, first of all, I'm delighted to be here with you and Justin. And as everyone knows, SGLT2 inhibitors have had a remarkable track record in trials of type II diabetes, trials of chronic kidney disease and now trials of patients with heart failure and a reduced ejection fraction. And in these trials, SGLT2 inhibitors have had two important benefits. The first benefit has been a reduction in serious heart failure events, primarily a reduction in heart failure hospitalizations. And the second has been a reduction in serious adverse renal outcomes. And that has been now shown consistently in trial after trial in diverse populations.

Dr. Milton Packer:

Now we carried out a trial called EMPEROR-Reduced with was the trial in patients with heart failure and a reduced ejection fraction. It was a sister study, so to speak, with a very parallel trial called DAPA-HF, which was carried out with dapagliflozin. And both DAPA-HF and EMPEROR-Reduced were studies, were trials of SGLT2 inhibitors, dapagliflozin and empagliflozin in people with heart failure and a reduced ejection fraction. And they produced remarkably consistent results. And specifically a reduction in serious heart failure events and serious adverse renal events.

Dr. Milton Packer:

But the trial studied complimentary patient populations. We studied patients that were a bit sicker than patients in DAPA-HF. And Greg, what's really fun is that each trial designed its own case report forms so that we collected information that the investigators were really interested in and they were not necessarily the same types of information across the two trials. One of the things that was really interesting about EMPEROR-Reduced was we were really interested in these heart failure events. We wanted to understand them. We wanted to understand whether they occurred as outpatients, inpatients. If they occurred as inpatients, what kind of hospitalizations were these? Were these serious hospitalizations? Were these short term, very mild hospitalizations? This paper, the hypothesis in this paper was to take a look at what empagliflozin did in patients with heart failure and reduced ejection fraction, specifically with respect to outpatient and inpatient worsening heart failure events.

Dr. Greg Hundley:

Very nice. How many patients did you include? What were the characteristics of the study population? And what was the design?

Dr. Milton Packer:

We enrolled, randomized 3,730 patients. All patients had heart failure with a reduced ejection fraction. All were receiving all appropriate treatments for heart failure. Interestingly, 20% were receiving nephrolysin inhibitors, which is really a very high percentage, but they were also receiving inhibitors, renin-angiotensin system beta blockers, mineralocorticoid receptor antagonists and they were patients who had an average ejection fraction of about 27%, which is much lower than most heart failure trials recently. They also had meaningfully elevated levels of natriuretic peptides. These were sicker patients and they had a much higher placebo event rate. They were randomized double-blind, one to one ratio to either placebo or empagliflozin. Dose was 10 milligrams once daily. And this was added to all previously existing therapy and patients were followed for double-blind therapy for an average duration of 16 months and we recorded prospectively information on outpatient and inpatient heart failure events.

Dr. Greg Hundley:

Very nice. What did you find, Milton?

Dr. Milton Packer:

We originally reported that in this trial, there was a reduction with empagliflozin on heart failure hospitalizations and that reduction was about 30%. We wanted to know, well, what else was going on with respect to these heart failure events? And so we asked the question, well, did empagliflozin reduce urgent and emergency room visits for heart failure? Did empagliflozin change the types of hospitalizations? We recorded the use of positive inotrophic drugs, vasopressor drugs, vasodilator drugs, cardiac devices, intervention, surgical interventions. And we found out that across the entire spectrum of heart failure outcomes, there was a reduction in serious outcomes with empagliflozin and they all were around a 30% reduction in risk. They varied a little bit from about 28 to 33, but approximately all were in the same ballpark. And what was really interesting was we had a fair number of hospitalizations where patients required IV inotropic drugs, vasopressors, mechanical intervention, they were reduced by 30% with empagliflozin. Hospitalizations associated with intensive care reduced by 30% with empagliflozin.

Dr. Milton Packer:

And then we looked at outpatient events. Outpatient intensification of diuretics reduced by 30, 33% with empagliflozin. We looked at New York heart class. And what was really interesting was that patients treated with empagliflozin had a 20 to 40% greater likelihood of showing improvement in New York heart class and a 20 to 40% lower likelihood of showing worsening in New York heart class. And those benefits, we're seeing within 28 days after randomization. This early effect is really interesting and it's generated a lot of discussion. And so we looked at our Kaplan Meier curves for the composite of cardiovascular death, heart failure hospitalizations, urgent care, emergent care visits, and we found that the two curves separated quite early and reached statistical significance only 12 days after randomization. This is a very early effect. I want to add that this early separation of curves has been reported previously with beta blockers, with mineralocorticoid receptor antagonists, with neprilysin inhibitors and now we can add this early separation with SGLT2 inhibitors.

Dr. Greg Hundley:

Very nice, Milton. Well, I'd like to turn now to our associate editor, Dr. Justin Ezekowitz. and Justin you've seen a lot manuscripts come pass through your hands. What attracted you to this manuscript? And then how do you put the findings that Milton has just described in the context with the other results that we have been witness to regarding SGLT2 inhibitors?

Dr. Justin Ezekowitz:

Thanks Greg. And also, thanks Milton for letting us look at this remarkable manuscript as I do think the clinical implications for a manuscript like this are quite profound. The first thing that really strikes me is we often get worried about looking at a number of different end points. Within a clinical trial, we often don't want to have too many looks at the data because of the risk of finding something that is spurious, is high, but in this case, the way the data was collected and the exploration is quite valuable. We can look at any one of the combinations of clinical end points that actually have direct clinical relevance for a clinician and the patient. And this paper really explored that in a lot of data, in a lot of depth and also helped us by putting the caveats around these findings that this is exploration, but it does anchor it in the SGLT2 world, but also the heart failure world.

Dr. Justin Ezekowitz:

And Milton, I think one of the striking findings that you showed and it's buried in many of the great figures and tables, is that one in two patients had something happen in the next year. In the next 12 months, that patient walking into an office for a routine followup, one in two had something and the reduction was pretty remarkable across the end point. Milton, I wanted to pick your brain on this one, just to understand when you look at the intensification of diuretics, that was anything from adding another 20 milligrams of furosemide, to doubling or tripling that. Do you think these findings are pretty ubiquitous across the patients enrolled? Or do you think they're a niche finding in only some patients at the highest risk?

Dr. Milton Packer:

Well, we actually looked at that. We actually looked at whether baseline variables influenced the effect on intensification of diuretics and it was across the board. Well, let me just say, across the board in the patients that we studied and obviously can't make reference to people we didn't study, but we didn't find any particular subgroup that responded particularly well with respect to either a hospitalizations or diuretic intensification or New York heart class changes. But Justin, there's one thing that you just said that is so important. And that is, our patient population was characterized by their physicians, 70% as having class II heart failure. And a lot of physicians think that class II heart failure represents a stable population, clinically stable population. And as you said, one in two patients in our study during followup had worsening heart failure, either represented as an inpatient or outpatient event. A class II patient with heart failure and reduced ejection fraction, even though they're getting optimal medical therapy, is not a clinically stable patient.

Dr. Greg Hundley:

Very, very interesting finding. Well, just to ask each of you, maybe Milton first and then Justin next, Milton, what do you think is the next study that we need to perform in this patient population using this class of drugs?

Dr. Milton Packer:

We're really excited about a new phase of heart failure research with SGLT2 inhibitors, which is to look at the impact of these drugs in patients with heart failure and a preserved ejection fraction. DAPA-HF and EMPEROR-Reduced were trials of inpatients with hard failure and a reduced ejection fraction. But we really, about half patients with heart failure, have an ejection fraction of greater than 40%. We really need to understand what SGLT2 inhibitors can do for these patients. And here's the good news. And there are two large scale trials that are both nearing completion. And the first of those trials will be reporting out in about nine months from now with the next trial following about six months later. We will in the next 12 to 18 months, have two major large scale trials of these drugs in a population which is highly different and yet complimentary to the patients who have been studied to date.

Dr. Greg Hundley:

Justin, how about you?

Dr. Justin Ezekowitz:

Well, to compliment what Milton is suggesting, I think that's one area. And I think the other area is in implementation science. Now that we have four big classes or groups of drugs, is to how to start these and how to optimize these efficiently in the first month to two months or even three months so the patients can get the benefit for all these medications. And I think what we need to really study is how do we do that? Because we have the drugs but the implementation is where we're not quite there yet. If we get the implementation and testing, randomized strategies and how to do it, I think we may be able to help more patients globally than with the addition of even any new drug that may come out onto the markets soon or in the future, as that remains one of our challenging topics.

Dr. Greg Hundley:

Well listeners, we want to thank Dr. Milton Packer for bringing this study to us at Circulation and also our own associate editor, Dr. Justin Ezekowitz and really highlighting how the initiation of this SGLT2 inhibitor, empagliflozin, at 10 milligrams per day, in a heart failure reduced ejection fraction population with an average left ventricular ejection fraction of 27%, resulted in a 12 day, at 12 days into therapy, a separation of the development of adverse heart failure related events that was then sustained over the next 16 months.

Dr. Greg Hundley:

Well, on behalf of Carolyn and myself, I want to wish everyone a great week and we will catch you next week on the run.

Dr. Greg Hundley:

This program is copyright of the American Heart Association, 2021.