Jun 29, 2016
Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. I'm doctor Carolyn Lam, Associate Editor from the National Heart Center and Duke National University of Singapore.
I am excited to be joined today by 2 guests and we will be discussing the feature paper on phenotype specific treatment of heart failure with preserve ejection fraction but first here are the highlights from 5 original papers in this week's issue.
(0:42) The first paper by first author doctor Haas, corresponding author Dr. Bidinger and colleagues from Boston Children's Hospital aim to investigate the role of PCSK9 in nephrotic syndrome associated hypercholesterolemia. The authors did this by first looking at 50 patients with nephrotic syndrome and showing that resolution of nephrotic syndrome was associated with a decrease in their plasma cholesterol, as well as a decrease in their plasma PCSK9 levels. They then looked at two mouse models of nephrotic syndrome. One using nephrotoxic serum to induce immune mediated damage of the kidney podocytes. The second, a model of genetic ablation of the kidney podocyte.
In both these models nephrotic syndrome produced hypercholesterolemia and a 7 to 24 fold induction of plasma PCSK9 levels. The authors then went on to look at the effect of knocking out PCSK9 both in the whole body as well as specifically in the liver in these mice. They showed that mice lacking PCSK9 no longer showed the increase in LDL cholesterol with nephrotic syndrome induced by nephrotoxic serum. Thus in summary, podocyte damage triggered mocked inductions in plasma PCSK9 and conversely knocking out PCSK9 in ameliorated this lepodimia in a mouse model of nephrotic syndrome. The cool thing about this data is that they now opened the door to the consideration of PCSK9 inhibitors in patients with nephrotic syndromes associated hypercholesterolemia.
(2:45) The second paper by Dr. Fortis and colleagues from Duke Clinical Research Institute aimed to address an important knowledge gap that has not yet been addressed in the pivotal noac trials or large registries. Which is whether outcomes differ among atrial fibrillation papers with worsening renal function compared with those with stable renal function while taking a noac versus warfarin. The authors looked a this by studying more than 12,600 patients who were treated with rivaroxaban compared to warfarin in the ROCKET AF trial. On treatment worsening renal function was defined as a decrease of more than 20% from screening creatinine clearance measurement any time point during the study.
The main finding was that among patients with on treatment worsening renal function, rivaroxaban was associated with lower rates of stroke and systemic embolism compared with warfarin without an increase in the composite leading end point. This is really encouraging to all of us who treat these patients, knowing that it is possible to safely anti-coagulate patients with worsening renal function without excessive bleeding and to know that rivaroxaban may be an alternative to warfarin in these patients. This paper is accompanied by a beautiful editorial on the multifaceted dilemma of renal function and atrial fibrillation by doctors Hijazi and Wellington.
(4:30) The third paper by doctor [inaudible 00:04:32] and colleagues from Massachusetts Journal Hospital describes a randomized controlled trial of an advanced care planing video decision support tool in 246 patients with advanced heart failure. Patients were randomized to an intervention arm which consisted of a six minute video as well as an advanced care planning checklist or to a control arm where patients received only a verbal description of the goals of care. This video began by first introducing to the patient the concept of advanced care planning and then using images to depict the three part goals of care namely, life prolonging care, limited medical care and comfort care. Patients in the intervention arm who were showed the video, were more likely to be informed, to select a focus on comfort and less likely to desire CPR and intubation compared to patients receiving the verbal information only. The clinical application of this finding is that advanced care planning video decision needs can stimulate and supplement patient decision communication. Indeed we need such tools to enhance patients understanding of their goals of care options and to ensure that our patients get care that reflects their well-informed wishes.
(6:10) The fourth paper is by first author Dr. [inaudible 00:06:12] and corresponding author Dr. Lloyd Jones and colleagues from the Northwestern University Feinburg school of medicine in Chicago. These authors provided the first prospective evaluation of atherosclerotic cardiovascular disease outcomes in adults with heterozygous familial hypercholesterolemia in the US population. They did this by using individual pool data from 6 epidemiologic cohorts including more than 68,500 baseline person exams and 1.2 million person years of follow up. They confirmed substantially elevated long term, meaning up to 30 year risks of coronary heart disease and total atherosclerotic cardiovascular disease including stroke in US adults with a familial hypercholesterolemia phenotype defined as LDL cholesterol above 190 milligrams per deciliter. This was associated with an acceleration of coronary heart disease risk by up to 20 to 30 years. These findings were independent of other risk factors and were consistent using various definitions of the familial hypercholesterolemia phenotype.
What are the clinical implications of these findings? This was discussed by Dr. Rodriguez and Dr. [inaudible 00:07:47] in an editorial, the take home message is that there is likely an important long term burden of atherosclerotic cardiovascular disease in phenotypic but unrecognized familial hypercholesterolemia patients in the United States. Current efforts to identify patterns and gaps in the diagnosis and management are well justified. The findings also have implications for risk communication to patients.
(8:20) Finally, the fifth paper is by Dr. [inaudible 00:08:25] and colleagues of the TIMI study group from Brigham and Women's Hospital. These authors looked at the impact of renal function on outcomes with edoxaban and oral factor 10 A inhibitor with 50% renal clearance compared to warfarin in the ENGAGE AF-TIMI 48 trial. In the pre-specified subgroups of granting clearance 30 to 50 and more than 50 ml per minute. The higher dose edoxaban regiment was comparable to warfarin for preventing stroke or systemic embolism and resulted in significantly less major bleeding. In further exploratory analysis, there was a suggestion of lower relative efficacy for prevention of stroke or systemic embolism with the high dose edoxaban regiment, compared to warfarin in the upper range of creatinine clearance beyond 95 ml per minute. Due to lower rates of major bleeding, the net clinical benefit was more favorable with the higher dose edoxaban regiment across the range of creatinine clearance.
In summary, edoxaban demonstrated superior safety and comparable efficacy to warfarin for the prevention of thromboembolic events in many patients with atrial fibrillation. However the authors were careful to note that there was insufficient evidence to allow definitive conclusions to be drawn in patients with normal renal clearance above 95 ml per minute. The authors called for further investigation of optimal dosing of edoxaban in the higher range of creatinine clearance.
(10:14) Those were our highlights now for our feature paper of the week. Phenotype specific treatment of heart failure with preserved ejection fraction, a multi-organ road map. The first author is Dr. [inaudible 00:10:31] from Northwestern University Feinberg School of Medicine in Chicago and colleagues. To discuss this very special paper today I have two guests, one is a corresponding author, Dr. Walter Paulus from the VU, University medical center in Amsterdam as well as Dr. Jarett Berry, associate editor from UT Southwestern. Welcome Walter and Jarett.
Jarett Berry: Thanks Carolyn.
Walter Paulus: Thank you very much Carolyn.
Carolyn Lam: To start us off this is an in depth review paper and it is a really very special type of paper that it's new to Circulation. Jarett could you tell us a little bit about these reviews and how this paper came to be?
Jarett Berry: As we think about the new Circulation and our goals to really make the content of Circulation as clinically relevant as possible, as we think of the different circumstances and clinically challenges faced by practicing physicians, many different topics come to mind and one in particular, therapeutic area heart failure with preserved ejection fraction is one particular type of cardiovascular disorder that has been very difficult to find novel treatments for. As we all know there has been a number of large scale clinical trials that have failed to improve clinical outcomes in these patients, in situations like this what we really need is wisdom and a guide from those with expertise in this area so we can take that wisdom and that perspective and incorporate it into our approach to caring for these patients in a way that can provide a road map moving forward.
This particular review addressing heart failure with preserved ejection fraction was timely in that sense and the choice of author, of course, Walter and his colleagues are leaders in the field in terms of the research and our understanding of HFpEF. With that goal, we're really trying to reach out to these types of investigators for these types of reviews to provide us with a framework to help us think about charging our way forward and we couldn't think of a more appropriate choice to lead that effort other than Walter Paulus.
Carolyn Lam: Thank you so much Jarett, that's so well put and I couldn't agree more. I mean HFpEF is one of those disease syndromes were guidelines haven't changed in years and basically the first sentence is that we don't have outcome improving treatments available. Walter this must have been particularly challenging and I really congratulate you because one of the central figures that I'm so impressed with in this review is actually a clinical application figure and I'm referring to figure 2. Do you think you could tell the readers a little bit more about this?
Walter Paulus: I would like to thank first the editors of Circulation for having given us the opportunity to write this in-depth review. I must admit before answering Carolyn's question that I really enjoy this [inaudible 00:13:37]. We have a very challenging team of co-authors and the most difficult part of the enterprise was to have all the noses directed in the same direction. You have to align very many ideas and it has been a very challenging in-depth but I think it will be teamed out with a, not a compromise but something, a paper where everybody is still happy with its content. This is somehow also reflected in the figure 2 to which Carolyn is alluding.
When we start speaking about the phenotypic diversity, it's very difficult to [inaudible 00:14:13] with a conceptual theme on how we're going to organize therapy when there are many different phenotypes around. I think this is what this figure is all about, it tries to organize the phenotypic diversity and come up with a type of personalized medicine for each phenotype in a very comprehensive way. This figure, in fact, orders the phenotypes, presentation phenotypes and pre-disposition phenotypes with presentation phenotypes on the abscissa and the pre-disposition phenotypes on the ordinate. Then you get a matrix configuration, you start out in the matrix in the left hand corner for the most common phenotype which is metabolic risk combined with [inaudible 00:14:59] congestion. Then you go on and you see that you can have [inaudible 00:15:04] hypertension, then you have additional measures that need to be taken. You can go downwards in the graph and then you'll find out that it might be renal dysfunction and then you find specific measures that have to be taken when renal dysfunction is present.
By combining the ordinate and the abscissa in the matrix, you find a very personalized type of therapy for the individual phenotype. I think this to me what makes the figure that feeling is that it's structured, it's organized, it's something very complex in something which is easily comprehensible.
Carolyn Lam: Walter, I have not seen a figure like this that it's so novel and I know that clinicians will really welcome this because as Jarett so nicely put, it's wisdom and some sort of simplification and yet with in-depth understanding that we so need in the management of this syndrome. Another thing that I thought was very special about your paper is that you tackled head on the divergent results of several recent trials. You described the low nitric oxide, low cyclic guanosine monophosphate cycle that's present in HFpEF but also try to put into context the need trial, the relax trial, top cat and even mention Socrates preserved in all of this. Do you have any quick top line comments, not to give the whole story away because I'm sure readers are now encouraged to look at the paper but on how all of this actually falls into place in your schema.
Walter Paulus: I think how everything falls into place is illustrated in the figure 1. Figure 1 shows a very broad perspective on the problems of HFpEF as it shows HFpEF to be the result of systemic inflammatory state but so far we have focused only on the project manifestations of the systemic inflammatory state [inaudible 00:17:08] cardiac manifestations, which is the stiffness of the myocardium, and the [inaudible 00:17:12] of the myocardium. There are also things going in the pulmonary [inaudible 00:17:16], there are things going on in the skeletal muscle and there are things going on in the kidney. I think that if you do not take these other organs into perspective, then the image you will have from the results of your trials is getting blurred. For instance, we have so many trials about look at the exercise [inaudible 00:17:35] in terms of elevation of [inaudible 00:17:37].
It's my feeling that many patients with HFpEF just get treated diabetic. You see them afterwards again in your [inaudible 00:17:46] patient clinic and they have symptoms of nasal fatigue. They no longer being hindered by the elevation of [inaudible 00:17:52] probably because of the administration of the diabetic but they're still highly symptomatic and they have moved over to another board and that limits the [inaudible 00:18:01] mainly the skeletal muscle. It's of course nicely illustrated already for years by the work of Dalane Kitzman which is one of the co-authors, but still these issues, the same goes for the hypertension, a field in which Carolyn has been very active. There are some patients who are persistent [inaudible 00:18:18] hypertension, I'm intrigued by our classification.
It's clear that these patients have moved to a [three catalyst 00:18:24] type of hypertension and we should pay attention to this and we should try to treat it in a very specific way. Again [inaudible 00:18:33] the failure of our trials is also comprehensible. He have two, [inaudible 00:18:38] focus on the myocardium and we should try to keep a very broad perspective and look at [inaudible 00:18:43] in major broader way. Just to support this point is the result of the Socrates reserve trial which I was very intrigued by it, just listen to the results couple of days ago at the European Heart Failure Society meeting in Florence. Turns out if you give this very [inaudible 00:19:01] patients that there is no change in nature at [inaudible 00:19:05], no change in left atrial dimension, there's no single argument that something is changing in the myocardium. Nevertheless the effort tolerance of the patients was greatly increased and the question is in quality of life, how that has drastically improved? What I think is going on, is that maybe on the dose of the [inaudible 00:19:23] you are using this very [inaudible 00:19:24].
The main effect might be going on the [inaudible 00:19:27] and you just took the wrong end point, you are again focusing very narrowly on the myocardium. I think most of the patients have entered such a trial are relatively stable. You're not going to put in a trial a patient who is unstable, they must be all be treated with diabetics and you shift symptoms from the myocardium to the other organs. I think that the index review which we provide, I think has 2 main issues, that you should have a broad perspective on HFpEF with inclusion of the other organs and secondly, that we provide a matrix configuration for phenotypes specific treatment.
Carolyn Lam: Walter that is beautifully put and Jarett I think I'm speaking on behalf of you too that this paper has really accomplished what our in-depth reviews were aiming to do, which is to provide a clinical perspective and really insightful comments regarding the syndrome. Is there anything else you'd like to add Jarett?
Jarett Berry: Yeah, I just wanted to echo your congratulations and just to really highlight the importance of this figure 2. I think it is an important step for us to begin to take the concept of the heterogeneity the phenotype, whether it's something happening centrally or peripherally and take that heterogeneity and try to incorporate that into our practice pattern. I think that's obviously been discussed in length in literature before but has not been put together in a practical way for practicing clinicians. I just want to echo your comments that Walter and his coauthors have done an important service for all of us as we think about how to take care of our patients with HFpEF.
Carolyn Lam: That's awesome, I think anyone listening is really going to want to take hold of that journal and have a look at both figures, 1 and 2 and read this beautiful paper. Thank you very much Jarett and Walter for your time, today.
Jarett Berry: Thanks Carolyn.
Walter Paulus: Thank you very much Carolyn, [good night 00:21:20].
Carolyn Lam: You've been listening to Circulation on the Run, thank you for listening and don't forget to join us next week for more highlights.