S-ICD, the new implanted defibrillator, offers alternative for heart beat regulation

A new ground-breaking technology was recently used at the University of Ottawa Heart Institute (UOHI).

Two UOHI cardiologists, Dr. David Birnie and Dr. Pablo Nery, implanted a new innovative leadless defibrillator, the subcutaneous implantable cardioverter defibrillator (S-ICD), to a 18 year-old patient.

Under Health Canada’s special access program, this was only the third time this new type of ICD had been implanted in Canada.

Conventional defibrillators, known as transvenous defibrillators, are implanted with wires, called the leads, that snake through veins into the heart.

When the defibrillator identifies any dangerous heartbeat, it delivers a shock through the wires to return the heart to its normal rhythm and allow it to get back to pumping blood steadily throughout the body.

Not all patients are suitable for a conventional defibrillator. In some with congenital heart problems, there is no way to advance the leads into the heart through the veins.

Dr. Pablo Nery and Dr. David Birnie

Also, those wires may pose a danger due to the risk of blood clots or infection.

Patients often have to undergo a more complex and invasive surgery to attach the leads to the outer layer of the heart muscle to benefit from the use of a defibrillator

Conventional ICDs use leads that run from the device through major veins to an anchor point in the heart.

These transvenous leads can cause problems in the long term.

Despite decades of design improvements, leads can malfunction, break or stop working.

This is known as lead failure, and results in either inappropriate shocks or lack of proper regulation of the heartbeat.

What’s worse is that failed leads often must be removed, which poses serious risks to the patient.

What makes the new device special is that it is entirely subcutaneous. No part of it actually touches the heart. Instead, an electrode is implanted just under the skin near the heart.

The defibrillator is connected to the electrode, and monitors the heartbeat at all times. If needed, it delivers a shock to the heart muscle to restore its normal rhythm.

The goal of the subcutaneous ICD is to potentially reduce or eliminate these problems. “The subcutaneous ICD provides effective therapy for patients who are either not eligible for or are at high risk with a traditional ICD.

Such patients may now be able to receive protection from a subcutaneous ICD without the risks associated with the standard leads,” explained Dr. Nery.

That made the 18-year-old recipient of the S-ICD at the Heart Institute a perfect candidate. “The S-ICD offers advantages for particular patient sub-groups,” said Dr. Nery.

“This technology is now an alternative for young patients, in part because lead extraction can be avoided down the road.”

Depression linked to acute Kidney Disease

Depression was linked to a higher rate of hospitalization for acute kidney injury (formerly known as acute kidney failure), even after adjusting for heart disease, inflammatory markers, and lifestyle factors such as body mass index (BMI), smoking, alcohol consumption and physical activity, according to the investigators.

The study, led by Dr. Willem Kop of the Department of Medical Psychology and Neuropsychology at the University of Tilburg, the Netherlands, included 5,785 people in the United States who were followed for 10 years. 

At the start of the study, the participants were 65 years and older and were not on kidney dialysis.

The researchers found that depression was also associated with a higher prevalence of chronic kidney disease (CKD) at baseline. It was 20% more common in people with chronic kidney disease than in those without the disease.

The study appears online March 10 in the Clinical Journal of the American Society of Nephrology.

"People with elevated depressive symptoms have a higher risk of subsequent adverse kidney disease outcomes.

This is partially explained by other medical factors related to depression and kidney disease. But the association with depression was stronger in patients who were otherwise healthy compared to those who had co-existing medical disorders such as diabetes or heart disease," the researchers wrote in a journal news release.

The researchers are currently examining factors that may explain the link between depression and kidney disease and failure. These could include delays in seeking medical care, the effect that depression has on the immune and nervous systems, and miscommunication between patients and doctors.

Coronary Imaging helps identify cause of heart disease

Results from the PROSPECT clinical trial shed new light on the types of vulnerable plaque that are most likely to cause sudden, unexpected adverse cardiac events, and on the ability to identify them through imaging techniques before they occur.

The trial, Providing Regional Observations to Study Predictors of Events in the Coronary Tree (PROSPECT), is the first prospective natural history study of atherosclerosis using multi-modality imaging to characterize the coronary tree. The study findings were published in the January 20, 2011 issue of the New England Journal of Medicine.

“As a result of the PROSPECT trial, we are closer to being able to predict — and therefore prevent — sudden, unexpected adverse cardiac events,” said principal investigator Gregg W. Stone, MD. Dr. Stone is Professor of Medicine at Columbia University College of Physicians and Surgeons, Director of Cardiovascular Research and Education at the Center for Interventional Vascular Therapy at NewYork-Presbyterian Hospital/Columbia University Medical Center and Co-Director of the Medical Research and Education Division at the Cardiovascular Research Foundation (CRF).

The multi-center trial studied 700 patients with acute coronary syndromes (ACS) using three-vessel multimodality intra-coronary imaging — angiography, grayscale intravascular ultrasound (IVUS), and radiofrequency IVUS — to quantify the clinical event rate due to atherosclerotic progression and to identify those lesions that place patients at risk for unexpected adverse cardiovascular events (sudden death, cardiac arrest, heart attacks and unstable or progressive angina).

Among the discoveries of the trial are that most untreated plaques that cause unexpected heart attacks are not mild lesions, as previously thought, but actually have a large plaque burden and/or a small lumen area. These are characteristics that were invisible to the coronary angiogram but easily identifiable by grayscale IVUS.

Moreover, and perhaps most importantly, for the first time it was demonstrated that characterization of the underlying plaque composition (with radiofrequency IVUS, also known as VH-IVUS) was able to significantly improve the ability to predict future adverse events beyond other more standard imaging techniques.

“These results mean that using a combination of imaging modalities, including IVUS to identify lesions with a large plaque burden and/or small lumen area, and VH-IVUS to identify a large necrotic core without a visible cap (a thin cap fibroatheroma) identifies the lesions that are at especially high risk of causing future adverse cardiovascular events,” Dr. Stone said.

New CPR Guidelines to save lives

The American Heart Association (AHA) today issued new guidelines for cardiopulmonary resuscitation, better known as CPR, making rapid chest compressions the mainstay of basic life support for bystanders trying to revive people whose hearts have stopped.

Doctors say the AHA's change marks the end of the organization's advocacy of a practice believed for at least half a century to be essential for saving victims of cardiac arrest or heart attacks. 

"Compression is the only way to go," says AHA's Michael Sayre, an emergency physician at Ohio State University. He added that rescue breathing is still recommended for children and anyone whose cardiac arrest is likely due to oxygen deprivation.

The AHA decision was driven by a growing body of research showing that bystanders are more likely to perform compression-only CPR on strangers and that it works better than conventional CPR.

"It's a big deal," says Corey Slovis, chairman of emergency medicine at Vanderbilt University in Nashville and an early advocate of the change. "People are standing around while others are dying, when all they have to do is pump on their chests."

About 300,000 people suffer out-of-hospital cardiac arrest in the USA each year, either because they've had a heart attack or suffered a rhythm disturbance; fewer than 8% survive. An analysis of 3,700 cardiac arrests published Friday in the journal Lancet found that hands-only CPR saved 22% more lives than the conventional method. 

All told, the switch could save up to 3,000 additional lives a year in the USA and 5,000 to 10,000 in North America and Europe, says lead author Peter Nagele of Washington University in St. Louis.

A landmark study published Oct. 6 in The Journal of the American Medical Association found that bystanders who applied hands-only CPR were able to boost survival to 34% from 18% for those who got conventional CPR or none at all. In addition, the percentage of people willing to provide CPR rose from 28% in 2005 to 40% in 2009.

The new guidelines dictate that a bystander should compress the victim's chest 100 times a minute to a depth of about 2 inches. That keeps blood and oxygen flowing to the brain, sustaining it until help arrives. Stopping for rescue breaths can interrupt blood flow, AHA's Sayre says.

Studies also show that bystanders reluctant to perform mouth-to-mouth breathing often give up, thinking there's nothing they can do. "Bystanders aren't doing anything in two-thirds of cases," Sayre says. "This is not hard; it's really easy."

Slovis says it's natural to balk. "Doing artificial ventilation, risking getting infectious disease, is something that most of us are afraid of," he says.

Testosterone may help women with heart failure

Cardiologist Dr. Justin Ezekowitz, an assistant professor at the University of Alberta in Canada. "We have a hit a wall in terms of what we can do for patients with heart failure. We've made a lot of progress, but there are still patients who have symptoms despite the premium blend of medications and fancy devices."

Heart failure is most common in people who are in their 60s, 70s and beyond. Their hearts fail to pump blood properly due to factors such as previous heart attacks or high blood pressure, Ezekowitz said. The patients are often out of breath and become extremely tired, he said. "This is tiredness where they're completely out of gas even after walking a block."

Researchers have previously linked testosterone to better health in elderly men with heart failure. In the new study, researchers randomly assigned 36 women with heart failure to receive normal medical treatment by itself or with skin patches that administered testosterone to their bodies. The results appear in the Oct. 12 issue of the online Journal of the American College of Cardiology.

The researchers found that testosterone improved the women's tolerance for exercise and boosted their muscle strength, said study author Dr. Ferdinando Iellamo, a researcher at the University of Rome Tor Vergata in Italy. All of these factors "play a role in determining the prognosis and survival of female patients with chronic heart failure," Iellamo said.

Heart Attacks Down 17% After Smoking Ban

Smoking bans have an immediate and dramatic effect on reducing heart attacks, according to two new analyses of laws in the USA, Canada and Europe.

Two separate analyses released Monday each found that heart attack rates fall 17% within a year after smoking bans take effect.

One analysis, which included 13 studies, appears in Circulation: Journal of the American Heart Association. A second analysis, which considered 11 studies, appears in the Journal of the American College of Cardiology.

Cigarette smoke can trigger a heart attack in people with underlying heart disease by causing clots or spasms in the blood vessels, says David Goff, a spokesman for the American Heart Association who wasn't involved in either study.

Given that there are about 920,000 heart attacks every year, the studies suggests that public smoking bans could prevent more than 150,000 of these, according to the Cardiology paper.

Taken together, the findings provide strong, consistent evidence that the country should enact more smoke-free laws, Goff says.

"This is a huge, huge effect for a very, very low cost," says Stanton Glantz of the University of California-San Francisco, co-author of the Circulation study.