The incidence and the risk of sudden death from heart failure have been on a downward trend over the years owing to the use of combination drugs.
Medical devices including implantable cardioverter-defibrillators (ICDs) are used for patients with heart failure, however, these devices are expensive and cause many adverse effects on the patients. Medications such as angiotensin-converting–enzyme (ACE) inhibitors or angiotensin-receptor blockers, beta-blockers and mineralocorticoid-receptor antagonists are currently recommended for treatment of heart failure with reduced ejection fraction (percentage of blood pumped out by the ventricles of the heart with each contraction) with evidence showing a reduction in the risk of sudden death from heart failure when these medications are used in combination.
A recent study published in The New England Journal of Medicine investigated the risk of sudden death in patients with symptomatic heart failure with reduced ejection fraction. Researchers of this study analyzed12 randomized controlled trials conducted on patients with heart failure between 1995 and 2014. They excluded patients who had an implantable cardioverter-defibrillator. They analyzed data from 40,195 patients and included calculation of the incidence rate of sudden death in each trial at 30 days, 60 days, 90 days, 180 days, 1 year, 2 years, and 3 years after randomization. They also calculated the risk of sudden death according to length of time between diagnosis of heart failure and randomization (less than 3 months,3 to 6 months,6 to 12 months,1 to 2 years,2 to 5 years, or more than 5 years) as well as according to left ventricular ejection fraction.
Of the 40,195 patients analyzed, 3,583 (8.9%) had sudden death with this proportion consisting mostly of older males with an ischemic cause of heart failure. There was a significant reduction in the annual rate of sudden death from 6.5% in the earliest trial to 3.3% in the most recent trial with only a single study (completed in 2007) that did not show the declining trend in sudden death. In all trials, the rate of sudden death was lower in the group receiving experimental therapy than in the control group. The risk of sudden death showed a dramatic 44% decline over the 19 years of patient data collected. Based on data from the duration of follow-up and time since diagnosis, a general trend in cumulative incidence and in the rate of sudden death was observed. While there was a significant increase in the cumulative risk of sudden death according to the length of time between diagnosis of heart failure and randomization, the rates showed a general lower trend. A general downward trend was also observed in the rate of sudden death among patients in different subgroups (<30% vs. 30 to 35%, and <25% vs. 25 to 35%) of low left ventricular ejection fraction.
The decline in the rate of sudden death from heart failure is evidence of the use of medications that are known to reduce the incidence of sudden death.Based on results from this study and previous trials, one could conclude that the use of guidelines-recommended therapies is more efficient than ICDs in reducing the risk of sudden death from heart failure. Despite this evidence, there is still the need for efforts to find high-risk patients who may benefit from ICDs.One limitation of this study is the fact that it was conducted retrospectively and was based on clinical trials with mostly white male patients which may not reflect real world situations.
Written by Asongna T. Folefoc
Shen L, Jhund PS, Petrie MC, Claggett BL, Barlera S, Cleland JGF, Dargie HJ, Granger CB, Kjekshus J, Køber L, Latini R, Maggioni AP, Packer M, Pitt B, Solomon SD, Swedberg K, Tavazzi L, Wikstrand J, Zannad F, Zile MR, and McMurray JJV. (2017). “Declining Risk of Sudden Death in Heart Failure.” N Engl J Med 2017;377:41-51.DOI: 10.1056/NEJMoa1609758