Editor’s 2025 Top 10: Contemporary Contrast Media Dosing During Percutaneous Coronary Intervention in Patients With Pre-existing Renal Impairment

Dr Deepak L. Bhatt, editor-in-chief of the Journal of Invasive Cardiology, catches up with Dr Hitinder Gurm about his Editor’s 2025 Top 10 article, “Contemporary Contrast Media Dosing During Percutaneous Coronary Intervention in Patients With Pre-existing Renal Impairment."

Transcript:

Dr Bhatt: Hello, I'm Dr. Deepak Bhatt, the Director of the Mount Sinai Fuster Heart Hospital at the Icahn School of Medicine in Mount Sinai, New York, and the Editor-in-Chief for the Journal of Invasive Cardiology. We have been putting together a top 10 list of articles for many years at JIC, and among the top 10 articles for 2025 is a very interesting article by Dr Hitinder Gurm, a good friend and colleague whom I'm lucky to have with us.

Hitinder, could you tell the audience what your study is about?

Dr Gurm: Thank you so much for giving us this opportunity, Dr Bhatt. Our study looked at the contemporary contrast media dosing in patients with pre-existing renal impairment in the United States. I'd like to go back in time—in 2011, we published a paper showing that patients who had a contrast dose of more than 3 times the glomerular filtration rate (GFR) seemed to have a higher risk of acute kidney injury (AKI). At that time, that was a fairly prevalent practice; so, over half of the patients in our study in the state of Michigan were getting more than 3 times the contrast dose. What we proposed as part of that study was that physicians should try and limit the contrast dose to about 2 times, but definitely stay below the 3 times the GFR as a clinical approach.

Go forward about 6 to 7 years, that study changed practice in the state of Michigan. We shared that study with every hospital in the state. We have a registry called the BMC2 Registry that has participants of every nonfederal hospital, and what we found was the average contrast use in the state of Michigan in 2010 was about 200 cc. It went down to about 160 cc by 2016. The proportion of patients who got contrast more than 3 times the GFR went down significantly, and along with that, there was a reduction in the patients who had AKI.

This is an association, right? One can never assume causality, but it sort of makes practical sense. Contrast is a drug, and like every drug, the more you give of a drug, more likely you're going to have complications. So, dosing a drug that is excreted renally, based on renal function, makes elementary physiologic, biological sense. That biological plausibility makes sense, and this practice has been adopted in many hospitals outside Michigan, and almost every hospital in Michigan. What we were interested in is what is the national impact, or national practice?

And so, we use the NCDR data; we looked at about 450 000 patients with abnormal renal function. We want to focus on patients with a GFR less than 60, because in a patient with a normal GFR, you can use contrast fairly freely and not have an impact. We wanted to see, one, what was the prevalence of high contrast use—we identify high contrast use as more than 3 times the GFR—and ultra-low contrast use, which is the practice where some practitioners are using less than 1 times the GFR dose to see whether that has added benefit in really sick patients. What we were surprised by was that the use of high contrast was actually fairly prevalent in the country; over half the patients, slightly over half the patients, got more than 3 times the GFR. About 40% or so got 1 to 3 times the GFR, and there's a small number, about 2.5%, that got less than 1 times the GFR.

Now, not surprising, more contrast you got, more likely you were to have AKI. And more contrast you got, the more likely you were to have more serious AKI. So, if you look at the degree of AKI and the likelihood of dialysis, it goes up as you get more contrast.

My takeaway from this, and our study authors; takeaway from this, is that there is an association between high contrast use and AKI. This seems to match what we've found in other populations, whether it was the state of Michigan, whether it's in patients with peripheral arterial disease, and in smaller studies that have been done elsewhere. Our hope would be that this would encourage wider adoption of contrast-based dosing, and there will be a focus, and then we would see improvement.

I just want to add some other context: when we wrote this paper, we said this is not something that can be assessed in a randomized trial. Our concern was that how do you randomize patients to high dose vs low dose? You should use as little less contrast as possible in your routine practice. Well, we were proven wrong, in a way, and a few years ago, Dr Carlo Briguori from Italy published the REMEDIAL IV Trial; this trial used the divert device. That device is no longer available, but this device reduces the amount of contrast that gets to the patient, because it diverts the extra contrast; the aortic puff, essentially, goes away. In this trial, they showed you could reduce the contrast from an average of 160 to 95. So, these are patients undergoing complex procedures, and yet they were able to do that with less contrast, and they showed about a 40% reduction in the risk of AKI.

So now we have 1 study showing, in a randomized fashion, that using less contrast prevents AKI. My hope would be that this trial, combined with our data, would encourage practitioners to look at their own contrast use, and use as low as can be reasonably achieved.

Dr Bhatt: First of all, congratulations on this paper and publication in JIC, and more broadly, all your contributions to the field. I've certainly changed my practice, even based on your prior work. I've always tried to stay under the times 3 GFR, if I can, in terms of contrast use. Ideally even less than 2, but certainly less than 3. That matches some old teaching—I think it was when we were at Cleveland Clinic, a doctor told me that he'd never run into any trouble with contrast nephropathy if you kept the contrast total under 30 cc. I think that's more or less true; you can usually stay out of trouble with that, and it matches your equation pretty nicely.

It's interesting to me that in recent years, some interventionists have been putting out that theory that, oh, you know, contrast nephropathy and actual contrast use, they're just sort of happening at the same time, but not causally related. But I've always thought that just not matching what we actually see in clinical practice. You have a patient with bad kidney disease, and maybe the contrast use gets out of control a bit because it’s a complex procedure, or maybe unexpectedly complex, and then it looks like the patients have a higher risk of developing AKI, so I'm not really sure why. It seems to have come under question. But you're right, I think the observational data and the randomized data, limited though it may be, does certainly support reducing the amount of contrast one gives, especially when the kidney function's already impaired.

So really important work with implications to daily practice. Any other messages that you have for our audience about not just this paper, but more broadly, in this entire area?

Dr Gurm: Thank you, Deepak, and I agree with you. I think the fact that some practitioners question whether contrast is toxic…contrast is like any other drug; every drug can be used safely, and under certain circumstances, it'll be toxic. Renal function-based contrast dosing gives you that ability to use contrast safely. Most patients in the cath lab actually have normal renal function, and we can do caths, hopefully, not using the kind of contrast that was being used a long time ago.

As a data point, I was looking back at our paper from 2011. At that time, there were about 10% of the patients in the state of Michigan who got a contrast more than 5 times the GFR. It seems unbelievable now, but that was the practice. There were patients who got over a liter of contrast in the procedure. So my hope is that is not happening anywhere.

But the second point I want to make is that reducing contrast is not hard. It is not something that is particularly challenging, and once you pay attention to it, you can do most procedures with very little contrast and get good results. Just being practical and pragmatic can allow us to [use less contrast]. As long as you take care of patients' hydration and manage the amount of contrast, most patients can have pretty much any procedure and not have renal complications.

Dr Bhatt: I think that's really a great take-home point for the audience. Well, wonderful speaking with you, and congratulations to you and all your co-authors on this important work.

Dr Gurm: Thank you again, and thank you for the opportunity.

The transcript has been lightly edited for clarity.