Sheba Medical Center in Tel Hashomer.
(photo credit: Eli Libenson)
Implanting an automatic cardiac pacemaker/defibrillator in people at an early stage of a common type of heart failure could extend their lives significantly, according to an international study that was published on Sunday night in the New England Journal of Medicine.
The study, led by Sheba Medical Center cardiologist Prof. Ilan Goldenberg, was accompanied by a two-page editorial written by Prof. Jeffrey Goldberger of Northwestern University in Chicago, which testified to the importance of the research.
Heart failure, or cardiac insufficiency, does not mean that the heart fails and the patient immediately dies. It means the heart is unable to provide enough pumping action to maintain the flow of oxygen-rich blood throughout the body.
The resulting symptoms include: Shortness of breath that minimizes their mobility, swollen legs and tiring easily.
Cardiac insufficiency usually follows a heart attack that kills some of the heart muscle, but it can also result from chronic illness that weakens the heart.
Treatment usually consisted of lifestyle changes when it is was not very serious and medications when it was a chronic or deteriorating condition.
In rare cases, the patient underwent a human heart transplant or temporarily received an artificial heart.
Studying 1,820 heart patients under treatment at 112 medical centers in North America, Europe and Israel, the researchers found that giving cardiac-resynchronization therapy with a defibrillator (CRT-D) to patients with left bundle-branch block can significantly extend and improve their lives.
In LBBB, activation of the left ventricle is delayed, causing this chamber of the heart to contract after the right ventricle.
CRT resynchronizes the contractions of the heart’s ventricles by sending tiny electrical pulses to the heart muscle, which can help the heart pump blood throughout the body more efficiently.
When the device includes a defibrillator, it automatically slows a frantic heartbeat that could otherwise result in a quick death.
The research included only those patients who did not yet show any of the early signs of coronary insufficiency.
Goldenberg, who heads Sheba’s Leviev cardiology department and chairs the Israel Society for Cardiovascular Research, presented his team’s findings at the conference of the American College of Cardiology now taking place in Washington.
If the CRT-D device is implanted, the death rate – after seven years of follow-up – was 18 percent, compared to 29% among patients who had only a plain defibrillator.
The analysis in the study showed that there was a 41% reduction in the long-term risk of death among patients with LBBB treated with CRT-D therapy compared with those who underwent ordinary defibrillator therapy.
Besides the 41% reduction, there was a more-than 60% reduction in the number of hospitalizations for advanced coronary insufficiency.
Patients who had a different kind of heart failure – involving right-sided or bi-ventricular failure rather than LBBB – did not improve, and some even declined with this therapy.
In the editorial, Goldberger suggested the NEJM article serves as a strong impetus to pursue CRT in relevant patients with mild heart failure.
“All those responsible for pursuing and supporting long-term follow-up should be congratulated for this effort,” he said.