Left ventricular endocardial pacing found to be effective, safe

SAN FRANCISCO – Lead pacing from inside the heart’s left ventricle – an alternate site compared with traditional implants – was successful in 89% of implant attempts, results from a multicenter study of 138 patients showed.

"The difficulty with conventional coronary sinus pacing is that we are limited by coronary sinus anatomy," Dr. John M. Morgan said in a press briefing at the annual scientific sessions of the Heart Rhythm Society. "But with the ability to get to inside the left ventricle, we have the landscape to choose the most appropriate pacing site. The reason that this outcome is important is that many patients who currently get cardiac pacing therapy do not benefit from it. About 10% of patients don’t get an implant because there is failure to achieve a pacing site with the conventional coronary sinus approach, and roughly one-third of patients, even when they have their implant, do not respond."

Courtesy Medtronic

In a trial known as ALSYNC (Alternate Site Cardiac Resynchronization), Dr. Morgan and his associates at 18 centers in Europe and Canada investigated the safety and efficacy of left ventricular endocardial pacing using a Medtronic Model 3830 lead delivered using a novel transseptal system. The system is not currently available for investigational or commercial use in the United States.

The 138 study participants were indicated for cardiac resynchronization therapy (CRT) but were unable to receive a conventional system or did not respond to the therapy at least 6 months post implant. "This so-called nonresponder group has been steadily present over the last decade and a half in all of the evaluations of this otherwise valuable therapy," he said. "We believe that we may be able to address those issues by offering patients who are very sick with heart failure the benefit of cardiac resynchronization by placing the device inside the left ventricle."

The potential downside of this technique, he continued, "is that it’s perhaps slightly more technically challenging, so we need good tools to do that. The other downside is that there is a risk of perhaps developing blood clots in the left side of the heart because we’re putting tools into the left side of the heart, and therefore exposing the circulation to potential development of blood clots that can cause stroke. That has been a major concern for clinicians. The other issue is that, with this technology, we are putting a pacing lead across the mitral valve. There is a possibility that the mitral valve would in some way be impeded or interfered with by this pacing lead."

The ALSYNC system consists of a deflectable catheter, a preshaped inner catheter, and radiofrequency-powered transseptal puncture guidewire/dilator, enabling a subclavian approach and targeted LVE lead delivery. The primary study objective was to show that the complication rates were less than 30% at 6 months in patients with an implant attempt.

The mean age of the patients in the study was 68 years, 78% were male, and 40% had ischemic disease. Dr. Morgan, a cardiologist at the University of Southampton (England), reported that, at 6 months’ follow-up, LVE pacing was successful in 118 out of 133 (89%) implant attempts. The study objective was met with an observed complication rate of 17.7%, which is comparable to the complication rates of conventional CRT implants, he said.

Based on the study results to date, "there is no unexpected adverse complication rate that bothers us about the procedure in clinical terms," Dr. Morgan said.

Concerns about stroke risk "are unfounded as long as our patients are anticoagulated in order to reduce thromboembolic risk. The ALSYNC study offers the potential for us to use this new tool and this new set of technologies to give cardiac resynchronization to patients who either don’t respond or who are not able to have conventional coronary sinus-placed pacing, and thereby should extend the reach and the benefit of cardiac resynchronization therapy to many patients," he said.

The learning curve for the ALSYNC system, he estimated, is "a few cases" for clinicians who have experience with transeptal puncture procedures. "Most interventional electrophysiologists will have that experience," Dr. Morgan said, but "doctors who implant devices may not. We do have some suggestion from the trial data that the higher-volume implanting centers in the trial were getting faster procedure times."

The study was funded by Medtronic. Dr. Morgan disclosed that he is a paid consultant to the company.

dbrunk@frontlinemedcom.com

SAN FRANCISCO – Lead pacing from inside the heart’s left ventricle – an alternate site compared with traditional implants – was successful in 89% of implant attempts, results from a multicenter study of 138 patients showed.

"The difficulty with conventional coronary sinus pacing is that we are limited by coronary sinus anatomy," Dr. John M. Morgan said in a press briefing at the annual scientific sessions of the Heart Rhythm Society. "But with the ability to get to inside the left ventricle, we have the landscape to choose the most appropriate pacing site. The reason that this outcome is important is that many patients who currently get cardiac pacing therapy do not benefit from it. About 10% of patients don’t get an implant because there is failure to achieve a pacing site with the conventional coronary sinus approach, and roughly one-third of patients, even when they have their implant, do not respond."

Courtesy Medtronic

In a trial known as ALSYNC (Alternate Site Cardiac Resynchronization), Dr. Morgan and his associates at 18 centers in Europe and Canada investigated the safety and efficacy of left ventricular endocardial pacing using a Medtronic Model 3830 lead delivered using a novel transseptal system. The system is not currently available for investigational or commercial use in the United States.

The 138 study participants were indicated for cardiac resynchronization therapy (CRT) but were unable to receive a conventional system or did not respond to the therapy at least 6 months post implant. "This so-called nonresponder group has been steadily present over the last decade and a half in all of the evaluations of this otherwise valuable therapy," he said. "We believe that we may be able to address those issues by offering patients who are very sick with heart failure the benefit of cardiac resynchronization by placing the device inside the left ventricle."

The potential downside of this technique, he continued, "is that it’s perhaps slightly more technically challenging, so we need good tools to do that. The other downside is that there is a risk of perhaps developing blood clots in the left side of the heart because we’re putting tools into the left side of the heart, and therefore exposing the circulation to potential development of blood clots that can cause stroke. That has been a major concern for clinicians. The other issue is that, with this technology, we are putting a pacing lead across the mitral valve. There is a possibility that the mitral valve would in some way be impeded or interfered with by this pacing lead."

The ALSYNC system consists of a deflectable catheter, a preshaped inner catheter, and radiofrequency-powered transseptal puncture guidewire/dilator, enabling a subclavian approach and targeted LVE lead delivery. The primary study objective was to show that the complication rates were less than 30% at 6 months in patients with an implant attempt.

The mean age of the patients in the study was 68 years, 78% were male, and 40% had ischemic disease. Dr. Morgan, a cardiologist at the University of Southampton (England), reported that, at 6 months’ follow-up, LVE pacing was successful in 118 out of 133 (89%) implant attempts. The study objective was met with an observed complication rate of 17.7%, which is comparable to the complication rates of conventional CRT implants, he said.

Based on the study results to date, "there is no unexpected adverse complication rate that bothers us about the procedure in clinical terms," Dr. Morgan said.

Concerns about stroke risk "are unfounded as long as our patients are anticoagulated in order to reduce thromboembolic risk. The ALSYNC study offers the potential for us to use this new tool and this new set of technologies to give cardiac resynchronization to patients who either don’t respond or who are not able to have conventional coronary sinus-placed pacing, and thereby should extend the reach and the benefit of cardiac resynchronization therapy to many patients," he said.

The learning curve for the ALSYNC system, he estimated, is "a few cases" for clinicians who have experience with transeptal puncture procedures. "Most interventional electrophysiologists will have that experience," Dr. Morgan said, but "doctors who implant devices may not. We do have some suggestion from the trial data that the higher-volume implanting centers in the trial were getting faster procedure times."

The study was funded by Medtronic. Dr. Morgan disclosed that he is a paid consultant to the company.

dbrunk@frontlinemedcom.com

SAN FRANCISCO – Lead pacing from inside the heart’s left ventricle – an alternate site compared with traditional implants – was successful in 89% of implant attempts, results from a multicenter study of 138 patients showed.

"The difficulty with conventional coronary sinus pacing is that we are limited by coronary sinus anatomy," Dr. John M. Morgan said in a press briefing at the annual scientific sessions of the Heart Rhythm Society. "But with the ability to get to inside the left ventricle, we have the landscape to choose the most appropriate pacing site. The reason that this outcome is important is that many patients who currently get cardiac pacing therapy do not benefit from it. About 10% of patients don’t get an implant because there is failure to achieve a pacing site with the conventional coronary sinus approach, and roughly one-third of patients, even when they have their implant, do not respond."

Courtesy Medtronic

In a trial known as ALSYNC (Alternate Site Cardiac Resynchronization), Dr. Morgan and his associates at 18 centers in Europe and Canada investigated the safety and efficacy of left ventricular endocardial pacing using a Medtronic Model 3830 lead delivered using a novel transseptal system. The system is not currently available for investigational or commercial use in the United States.

The 138 study participants were indicated for cardiac resynchronization therapy (CRT) but were unable to receive a conventional system or did not respond to the therapy at least 6 months post implant. "This so-called nonresponder group has been steadily present over the last decade and a half in all of the evaluations of this otherwise valuable therapy," he said. "We believe that we may be able to address those issues by offering patients who are very sick with heart failure the benefit of cardiac resynchronization by placing the device inside the left ventricle."

The potential downside of this technique, he continued, "is that it’s perhaps slightly more technically challenging, so we need good tools to do that. The other downside is that there is a risk of perhaps developing blood clots in the left side of the heart because we’re putting tools into the left side of the heart, and therefore exposing the circulation to potential development of blood clots that can cause stroke. That has been a major concern for clinicians. The other issue is that, with this technology, we are putting a pacing lead across the mitral valve. There is a possibility that the mitral valve would in some way be impeded or interfered with by this pacing lead."

The ALSYNC system consists of a deflectable catheter, a preshaped inner catheter, and radiofrequency-powered transseptal puncture guidewire/dilator, enabling a subclavian approach and targeted LVE lead delivery. The primary study objective was to show that the complication rates were less than 30% at 6 months in patients with an implant attempt.

The mean age of the patients in the study was 68 years, 78% were male, and 40% had ischemic disease. Dr. Morgan, a cardiologist at the University of Southampton (England), reported that, at 6 months’ follow-up, LVE pacing was successful in 118 out of 133 (89%) implant attempts. The study objective was met with an observed complication rate of 17.7%, which is comparable to the complication rates of conventional CRT implants, he said.

Based on the study results to date, "there is no unexpected adverse complication rate that bothers us about the procedure in clinical terms," Dr. Morgan said.

Concerns about stroke risk "are unfounded as long as our patients are anticoagulated in order to reduce thromboembolic risk. The ALSYNC study offers the potential for us to use this new tool and this new set of technologies to give cardiac resynchronization to patients who either don’t respond or who are not able to have conventional coronary sinus-placed pacing, and thereby should extend the reach and the benefit of cardiac resynchronization therapy to many patients," he said.

The learning curve for the ALSYNC system, he estimated, is "a few cases" for clinicians who have experience with transeptal puncture procedures. "Most interventional electrophysiologists will have that experience," Dr. Morgan said, but "doctors who implant devices may not. We do have some suggestion from the trial data that the higher-volume implanting centers in the trial were getting faster procedure times."

The study was funded by Medtronic. Dr. Morgan disclosed that he is a paid consultant to the company.

dbrunk@frontlinemedcom.com