Early Peek Hints at Safety and Utility of V-LAP Sensor for Monitoring Left Atrial Pressure

ATHENS, Greece—A very early peek at patients implanted with an investigational sensor that directly measures left atrial pressure suggests that implantation is feasible and safe. The device, known as V-LAP (Vectorious Medical Technologies), appears to pick up useful hemodynamic data and other signals that can help improve patient management.

William T. Abraham, MD (Ohio State University, Columbus), presented results for the first two patients enrolled in the VECTOR-HF trial during a late-breaking session of the European Society of Cardiology 2019 Heart Failure (ESC HF) Congress, opening with a thank you to the conference organizers for offering him the chance to showcase such preliminary results.

“This is very early stuff, this is first-in-man, and really a very small number to date,” he stressed “But I think it previews a very exciting technology that you’re going to hear a lot about in the future.”

Elaborating to TCTMD, Abraham said V-LAP is one of several “newer, next generation, implantable hemodynamic monitoring technologies” only now emerging after a number of setbacks to this field. “These are really exciting, because they get us directly into the left atrium, which is really the pressure that we want to know, and they do so with technologies that provide incredibly high-fidelity measurements of pressure,” he explained. “And from this trial, at least so far, we’ve demonstrated the early feasibility and safety of the system.”

Previous studies have established that episodes of heart failure decompensation requiring hospitalization are heralded by a rise in left atrial pressure, typically estimated by measuring pulmonary capillary wedge pressures using a pulmonary artery catheter. A flurry of device research over more than a decade has investigated both internal and external means for getting accurate, predictive pressure measurements both directly and indirectly.

The market-approved CardioMEMS (St. Jude Medical/Abbott), for example, is a pulmonary artery pressure device inserted using a right heart catheterization via the femoral vein. Where devices like V-LAP offer a hypothetical advantage is in measuring left atrial pressure directly, but in the case of V-LAP, this requires interventional cardiology know-how since the sensor is delivered via transseptal puncture and implanted in the interatrial septum in a similar fashion, said Abraham, as a percutaneous atrial septal defect closure device. Describing V-LAP as the world’s “first microcomputer in the heart,” he said the sensor is wireless, battery-free, miniaturized, and comes with an external belt, worn as a “sash around the chest,” which connects with the implant via a wireless inductive coupling protocol that in turn processes left atrial pressure readings and transmits them to a cloud-based management system.

VECTOR-HF: Early Glimpse

VECTOR-HF is a prospective, multicenter, single-arm, open-label clinical trial testing the safety, performance, and data usability of the V-LAP sensor in patients with chronic NYHA class III heart failure, left ventricular ejection fraction >15%, and a history of hospitalization for HF or elevated BNP/NT-proBNP. Eight sites in Germany, Italy, Israel, and the United Kingdom are participating in the study, aiming to enroll a total of 30 patients.

Just two patients have been implanted with the sensor to date, and Abraham offered details on these two cases in his ESC HF presentation. For both, he said, total procedure times were under an hour and deployment of the sensor itself took just 6 minutes. Since implantation, left atrial pressures have been measured successfully on a daily basis. At both the time of implantation and at 3 months, left atrial pressures measured by the implant have correlated well with pulmonary capillary wedge pressures measured via right heart catheterization.

Some additional details are also worth noting, said Abraham. In the first patient, a 52-year-old man with NYHA class III heart failure and a history of repeat hospital admissions for exacerbated heart failure, daily sensor readings showed wide variations in pressures, likely indicative of being high risk for HF hospitalizations. Because this variability is probably related to vascular factors rather than volume, said Abraham, this patient might benefit from enhanced vasodilator therapy, which has since been initiated and is now under titration. This particular patient also dozed off during one of his sensor readings, producing a tracing that suggested exaggerated respiratory variations. This prompted a trip to the sleep clinic where the patient was diagnosed with severe sleep apnea. This, Abraham noted, is “an example of the kind of comorbidity detection” made possible by the V-LAP device.

In the second patient, a 72-year-old man, sensor readings instead suggested that his left-atrial pressures were generally well-controlled, although the pressures started to increase towards the end of the 3-month period. “This may be due to some volume retention, and this will be managed with an increased diuretic dose,” Abraham said.

These first-in-human examples demonstrate the safety and feasibility of sensor implantation, ease of use of the external electronics, and a high degree of patient adherence to the daily left atrial pressure measurements, Abraham concluded, also emphasizing the diagnostic and prognostic information being captured.

“While further study is needed, heart failure patient management guided by the V-LAP system has the potential to significantly improve patient outcomes,” he said.

All 30 patients in the trial will undergo implantation and 3 months of monitoring, then at the 3-month mark physicians will be given access to left atrial pressure data to tweak patient management. The impact of this on quality of life and other measures will be tracked at 6, 12, and 24 months.

Promising, With Caveats

Commenting on the findings for TCTMD, JoAnn Lindenfeld, MD (Vanderbilt Heart and Vascular Institute, Nashville, TN), called the early peek at VECTOR-HF “very promising,” but stressed “it’s only two patients.”

Lindenfeld, like the trial discussant Finn Gustafsson, MD, PhD (Copenhagen University Hospital, Denmark), as well as Daniel Burkhoff, MD, PhD (Cardiovascular Research foundation, New York, NY), who commented the preliminary findings with TCTMD, noted that a prior device known as the HeartPOD (St. Jude Medical/Abbott) had sparked hopes for an implant that could directly measure left-atrial pressures and provide similar data.

Ultimately, LAPTOP, the trial performed to prove the device’s safety and efficacy, was stopped early due to adverse events. But as all three experts pointed out, those events were primarily related to complications with transseptal puncture back when the trial was underway; nearly 10 years later, interventional cardiologists have much more experience with transseptal procedures. “I do anticipate that the direct procedural complication rate today is going to be quite low,” Gustafsson said.

Gustafsson praised the device’s use of an integrated artificial intelligence algorithm and the “detail of the pressure curves” with the V-LAP’s tracings. “I’m sure we’re going to get more information than just average left atrial pressure from these readings and that’s going to enable us to go far with this,” he predicted.

Given that this device is solely for diagnosis and management, however, and not actually therapeutic, it will have to demonstrate that it meets a very high bar for safety, he noted. Additionally, he added, “the presence of a protruding body in the left atrium, of course, is always worrisome and definitely needs to be followed.”

Asked about this potential risk by TCTMD, Abraham called it “a small bit of protrusion.”

“It endothelializes over time, and we use antiplatelet therapy early on to try to prevent any thrombus formation or thromboembolism,” Abraham said. “In our pilot studies with earlier-generation left atrial monitoring systems, we did not see an increased risk of stroke or thromboembolism, but of course this is one of the things we’ll have to study as we go forward.”

Burkhoff, speaking with TCTMD, noted that V-LAP is just one of “multiple efforts in this field, following on what, in my mind, is the success of the CardioMEMS, and there are several more similar projects underway.”

He raised several other caveats with this type of device, however.

“This is an interventional cardiology device, and that may be actually a disadvantage in the sense that the CardioMEMS and pulmonary artery catheters can be put in by heart failure doctors, who are used to going in the pulmonary artery doing right heart catheterizations, et cetera. I think a transseptal is going to be beyond the capabilities of heart failure physicians and then we’re going to get back to those safety concerns that emerged with LAPTOP,” he said. “I don’t think a heart failure physician, unless they undergo special training, would have that expertise and maybe that could become part of interventional heart failure specialty training. But for one device, it might not happen.”

Going one step further, Burkhoff continued, is whether there are noninvasive approaches that can offer the same information. “Do you even need an implanted device? Do you need to measure this every single day? There are a lot of questions being raised about: who is the ideal patient for this and are there noninvasive ways that we can get at this? Because obviously a noninvasive way that could be cheaper would have more broad appeal,” he commented. “The penetration of the CardioMEMS, for which there’s a lot of evidence, is pretty low and there are struggles now with reimbursement for the device and the procedures.”