There’s good news for patients with drug-resistant, paroxysmal atrial fibrillation (AFib). A clinical trial underway at TriStar Centennial Medical Center is offering hope through the reMARQable clinical study, which will assess the safety and effectiveness of the nMARQ™ Pulmonary Vein Isolation System in treating the condition.
One of only two reMARQable trial sites in Tennessee (Vanderbilt University Medical Center is also enrolling) and only 50 nationwide, TriStar Centennial has received interest from patients and physicians across the state, said Sybil Harrelson, director of operations for Cardiovascular at Sarah Cannon Research Institute, which oversees the nMARQ trial.
Understanding AFib
Paroxysmal AFib is an episode of uncoordinated movement of the atria that occurs occasionally and then stops. Episodes can last from minutes to days before stopping and returning to normal sinus rhythm.
“In the past, conventional treatment was anticoagulation, rhythm drugs, and sometimes a patient could be shocked out of AFib,” Harrelson explained.
A newer option, catheter-based ablation can sometimes target and kill the tissue causing the irregular rhythm. However, the challenge of paroxysmal AFib, said Centennial Heart’s Gregory Bashian, MD, lies in the high probability of reconnection.
“In AFib there’s an abnormal heart rhythm coming from the top chamber,” explained Bashian, who is leading the nMARQ trial along with colleague Chris Jones, MD. “For patients with paroxysmal AFib, the focus of the ablation isn’t burning just one spot but burning a perimeter around each of the four pulmonary veins.”
Cardiologists burn a circle around each vein to create a build-up of scar tissue in hopes of preventing reconnection of the faulty electrical path. Traditional ablation utilizes a tiny, single point tool to burn multiple sites in the shape of a ring around each pulmonary vein.
“Even in the best case scenarios, the success rate for this method is far from perfect,” Bashian said. “The majority of the time a second procedure is needed because of reconnection.” He noted that’s because point-by-point burning around four separate structures creates a very real chance of the slightest missed gap, leaving room for reconnection to occur.
The nMARQ Advantage
Enter the nMARQ™ Catheter System from Biosense Webster. The fully integrated multi-ablation platform includes a ring-shaped catheter, allowing ablation with any or all of the seven to 10 catheter electrodes with the push of a button. It also enables full isolation of the catheter loop, allowing for easier and faster mapping.
“The premise of the new catheter is that it looks at and burns the tissue through a more contiguous lesion, which leaves less chance of developing gaps which would require repeat ablation down the road,” Bashian said of the investigational device.
The trial is open to patients without prior ablation and with a diagnosis of paroxysmal AFib. While it’s too early in the trial to measure nMARQ’s long-term success, Bashian said he’s been very pleased with safety outcomes to date.
“My hope is that this technology will improve both the efficacy and speed of ablation,” said Bashian.
CardioMEMS Offers Hope for Heart Failure Patients
The first wireless monitoring system approved by the Food and Drug Administration for heart failure patients is also now available at TriStar Centennial.
The CardioMEMS™ HF System, which received approval last May, has been shown to significantly reduce hospital admissions when used to manage heart failure. The device made its national debut in Nashville in 2007 when Saint Thomas West Hospital became the first program in the nation to successfully implant two patients with the monitoring system during the clinical research study.
Centennial Heart’s Thomas Johnston, MD, explained, “Patients with congestive heart failure have shortness of breath and swelling because the heart isn’t meeting the body’s needs. Some patients don’t need intensive monitoring, but others have severe swelling to where it’s difficult to manage volume status. This device allows us to monitor that.”
Such patients are prone to frequent hospitalization. The ability to monitor a patient’s status without hospitalization saves time and money and keeps the patient’s health in check before major emergencies arise. Wireless monitoring of pulmonary arterial pressure can reduce heart failure hospitalizations in high-risk populations by nearly 50 percent and 30-day readmissions by 78 percent, according to a recent trial presentation.
Smaller than a paper clip, the tiny pressure monitor is inserted through the femoral vein and implanted in the pulmonary artery. There it measures pressure and sends electrical signals to a monitoring device.
“It tells us what pulmonary artery pressures are, and an elevation suggests that the patient has volume overload and needs to increase diuretics,” Johnston explained.
Previously, physicians would rely on medical history and symptoms like shortness of breath and swelling and would then order lab work. Still, the process can be a guessing game for physicians of frequently hospitalized patients.
Johnston, who sees patients at TriStar Centennial’s Advanced Heart Failure Clinic, said the majority of heart failure patients can be managed through medication and monitoring.
“We’re using new biomarkers that didn’t exist 25 years ago; and if patients can get on the right meds, they can do very well for a long time,” Johnston said. “Most patients don’t require these devices, but it’s very beneficial to those who are chronically ill. Not only will it reduce hospitalization, but it improves the quality of life for patients.”