Leads from transvenous ICDs confer tricuspid regurgitation
Click Here to Manage Email Alerts
Key takeaways:
- Transvenous ICD leads are associated with tricuspid regurgitation compared with subcutaneous ICDs.
- More research is needed to determine the effect of this relationship on patient outcomes.
In patients with an implantable cardioverter defibrillator, those who had transvenous leads had worse outcomes related to tricuspid regurgitation than those who had subcutaneous leads, according to new data from the ATLAS trial.
As Healio previously reported, in the main results of ATLAS, a subcutaneous ICD (S-ICD; Emblem, Boston Scientific) reduced major lead-related complications by 92% with no loss in device performance compared with transvenous ICDs (TV-ICD).
Image: Adobe Stock
For the present analysis, the researchers compared the S-ICD group (n = 251; mean age, 48 years; 76% men) with the TV-ICD group (n = 252; mean age, 50 years; 72% men) to determine the effects of implantation on tricuspid regurgitation severity and right ventricle size and function at 6 months.
The S-ICD “does not have any transvenous component that could interfere with the tricuspid valve,” Jeff S. Healey, MD, FRCPC, professor in the division of cardiology at McMaster University in Hamilton, Ontario, Canada, told Healio. “We wanted to have a really good look at whether or not avoiding the lead inside the heart would have any effect on the tricuspid valve function. We often see tricuspid insufficiency in patients with transvenous pacemaker and ICD leads. The question is, is that their underlying disease or is that a consequence of the lead being there? This substudy of ATLAS is the only randomized comparison with pre- and post-implant echocardiographic images read by a core lab that allows us to unpack that question.”
The primary endpoint was tricuspid regurgitation, categorized as none/trivial, mild, moderate or severe, at 6 months.
At 6 months, compared with baseline, the S-ICD group had more patients with no or trivial tricuspid regurgitation and fewer with moderate or severe tricuspid regurgitation, but the opposite was true for the TV-ICD group (P for group/time interaction < .001), according to the researchers.
The proportion of patients with any tricuspid regurgitation declined from 26% at baseline to 19% at 6 months in the S-ICD group but increased from 32% to 42% in the TV-ICD group, whereas the proportion of those with moderate or severe tricuspid regurgitation declined from 5% to 2% in the S-ICD group but rose from 6% to 7% in the TV-ICD group, and the TV-ICD group had sevenfold increased odds of worsening tricuspid regurgitation by at least one grade (OR = 7.2; 95% CI, 3.3-15.8; P < .001), the researchers found.
“Clearly, the transvenous lead does cause tricuspid regurgitation,” Darryl P. Leong, MBBS(Hons), MPH, M.Biostat, PhD, FRACP, FESC, associate professor of medicine at McMaster University and director of the McMaster University and Hamilton Health Sciences Cardio-Oncology Program, told Healio. “We were able to quantify that for the first time. Because this was a randomized trial ... we were able to learn that the transvenous ICD lead was associated with a sevenfold higher risk of either developing new tricuspid regurgitation or worsening existing tricuspid regurgitation. As a consequence of that, at 6 months, about 7% of people who received the transvenous ICD lead had either moderate or severe tricuspid regurgitation.”
Because risks for tricuspid insufficiency associated with transvenous ICD leads are now better understood, “we can keep that as part of the discussion with patients about how we can best go about mitigating the risk of sudden death,” Healey told Healio. “There were no subgroups who were particularly predisposed [to developing tricuspid regurgitation]. It probably has to do with technical factors with how the lead goes in that can cause the regurgitation. It is one additional consideration now.”
There were no significant differences between the groups in changes in RV systolic function (P for group/time interaction = .064), changes in RV fractional area change P for group/time interaction = .73) and changes in RV basal diameter (P for group/time interaction = .83).
Leong said because the study only covered 6 months, “we weren’t able to detect whether the increase in tricuspid regurgitation from a transvenous lead leads to deleterious consequences for cardiac structure and function and differences in clinical endpoints. What’s necessary if we are going to find those kinds of differences is longer-term follow-up. The question is whether the volume load that’s imposed on the right heart for a longer period of time can eventually lead to consequences like worsening cycles of tricuspid regurgitation, right ventricular dilatation and eventually right heart failure. It is an important opportunity for us to take to follow these patients long term.”
The consequences of tricuspid insufficiency have gained more awareness from cardiologists in recent years, and treatments have been developed to combat them, Healey told Healio, but noted that “repair is great, but prevention is even better. If there are technical solutions to make ICDs less morbid, that is exciting.”
Perspective
Back to Top
Bruce L. Wilkoff, MD, FACC, FHRS, FAHA
The results are what should be expected. There is some increase in leaking of the tricuspid valve when a lead is inserted through the valve and not when a lead is not inserted through the valve. It is usually minor, but can be important at times. However, the patients with transvenous leads had slightly more tricuspid regurgitation at baseline, although the patients were not supposed to need pacing, we don’t know if there was any pacing in the transvenous systems, and this could also impact tricuspid valve and RV function.
Most importantly, this is only applicable to single-chamber ICDs, as any pacing requires a lead across the tricuspid valve. Use of a leadless device may be better, but as I said before, RV pacing can also cause this to happen. Finally, this is not only an issue for ICD patients, but pacemaker patients, and may be more significant for patients with left bundle area pacing leads.
We need to see the manuscript to really assess the findings, as the authors likely will address these questions in the manuscript.
Collapse
Leong D, et al. Late Breaking Clinical Trials and Science – Ventricular Arrhythmias. Presented at: Heart Rhythm 2023; May 19-21, 2023; New Orleans (hybrid meeting).
Click Here to Manage Email Alerts