For Percutaneous LVADs, Vascular Complications Decreasing but Still Common

A decade’s worth of data point to some reduction in vascular complications among US patients receiving percutaneous left ventricular assist devices (LVADs). Still, by 2015, around one in nine experienced such an event, most commonly acute limb thromboembolism and bleeding requiring transfusion, according to numbers from the National Inpatient Sample (NIS).

Describing this incidence as “high,” Nilay Patel, MD (University of Kansas Medical Center, Kansas City), and colleagues point out that the complications are also tied to increases in in-hospital mortality, the length of hospital stays, and hospitalization costs. “These findings should be factored into the decision-making for percutaneous LVAD placement,” they assert in their paper published online recently in Catheterization and Cardiovascular Interventions.

Though the researchers agree that percutaneous LVADs should be considered in profound cardiogenic shock and high-risk PCI, they also note that complications do occur. Beyond vascular complications, there is the potential for infection, kidney failure, mechanical dysfunction, and hemolysis, Patel et al observe. “Both the commercially available percutaneous LVAD devices require large-bore arterial access and thus vascular complications, such as bleeding, arteriovenous fistula, arterial dissection, arterial laceration, thrombosis, etc, are expected to be higher than other percutaneous arterial procedures.”

Earlier reports on this issue mainly came from higher-volume centers adept at large-bore access, they say, adding that less is known about how things have played out as lower-volume centers have begun using percutaneous LVADs.

Srihari Naidu, MD (Westchester Medical Center, Valhalla, NY), who commented on the findings for TCTMD, said the fact that complications didn’t increase during the wider rollout of these devices is good news.

“The numbers are pretty much in line with what we’ve seen, [and] the overall complication rates have come down despite the fact that the availability has really skyrocketed to the point that it’s hitting the real world and hitting a lot more learning curves,” he said, noting that it’s reassuring to see this pattern “when you go from tens to hundreds to thousands of people now being implanted.”

The data will show evidence of this improvement as experience grows, Naidu explained. “We’re still in the time where there’s incorporation into the marketplace, so you have to understand that there are going to be hospitals with much higher complication rates than others because of the newness of the device.” And indeed, the current study bears this out by showing a link between volume and outcome, he noted.

Overall complication rates have come down despite the fact that the availability has really skyrocketed to the point that it’s hitting the real world and hitting a lot more learning curves. Srihari Naidu

Patel et al used procedure codes to identify 31,263 percutaneous LVAD placements—specifically Impella (Abiomed) and TandemHeart (LivaNova)—in the NIS data set between 2005 and 2015. Nearly three-quarters of the treated patients were men, 64% were white, and the mean age was 64.7 years. Three-quarters had a Charlson Comorbidity Index score of ≥ 2.

In all, 13.5% of the patients experienced a vascular complication, for which 56% required surgery (7.55% of the group as a whole). However, the frequency of these complications dropped from 21.6% in 2005 to 13.3% in 2015. The most common events were bleeding requiring transfusion and atheroembolism of the lower extremity, seen in 3.7% and 2.4% of LVAD recipients, respectively.

On multivariate analysis, the odds of experiencing a vascular complication were higher among patients who presented with cardiogenic shock, had a greater comorbidity burden, and were treated at a teaching hospital. Also noteworthy is that hospitals that placed more than 30 percutaneous LVADs per year had lower in-hospital mortality than those with fewer than 15 cases (OR 0.78; 95% CI 0.66-0.91).

Patients who developed a vascular complication were more likely to die in the hospital (37.8% vs 30.0%), tended to have longer stays (mean 22.7 vs 12.2 days), and had higher hospitalization costs (mean $161,923 vs $95,547; P ≤ 0.01 for all).

Strategies Needed

Worth remembering, the researchers say, is that percutaneous LVADs “provide robust short-term mechanical circulatory support and play a critical role in the care of hemodynamically unstable cardiac patients.”

But as use continues to rise, the NIS numbers “call for caution with the use of these devices in situations where indications are not absolutely compelling. These findings also again bring to focus a need to implement strategies to minimize these complications,” Patel and colleagues stress.

“Such strategies include more attention to the vascular-access techniques such as using ultrasound guidance and micropuncture needles. Similarly, in cases where the percutaneous LVAD is only used to support a coronary intervention, use of suture-mediated closure devices (preclose technique) could be used,” they suggest. Other measures include training staff in how to achieve hemostasis by using manual compression and avoiding the use of percutaneous LVADs in patients who have vascular disease at the access site.

Naidu emphasized that the focus should be on preventing both bleeding and ischemia to the leg, rather than withholding therapy.

In addition to the strategies above, he said, fluoroscopy and angiography can help guide access. “There are also evolving techniques to maintain perfusion. For example, you can do what is called an ‘antegrade stick’ in that leg, where you put another catheter past the Impella down the leg and then hook up blood flow, so that even though the Impella is occluding flow you can push arterial blood into that leg [and prevent ischemia]. . . . The problem is that skill set is in development [and] very few people know how to do it, but it’s something we need to teach,” Naidu urged.