Heart disease remains the leading cause of death in the United States and is responsible for more than 600,000 mortalities each year, according to data from the National Center for Health Statistics. About half of these mortalities are classified as sudden cardiac death (SCD). Of these deaths, about half occur as a victim’s first recognized cardiac event. Research suggests that only a small number of those suffering out-of-hospital cardiac arrests will ultimately survive these events. “SCD is a high priority public health problem that requires multipronged treatment and prevention approaches,” explains Jeffrey J. Goldberger, MD, a professor at Northwestern University’s Center for Cardiovascular Innovation.

Recent reports indicate that the incidence of ventricular fibrillation as a cause of out-of-hospital cardiac arrest has been declining but continues to be a leading cause of SCD. Implantable cardioverter-defibrillators (ICDs) are effective but costly and have had a meaningful but, so far, limited impact on SCD. As a result, there are opportunities for new approaches to address SCD (Figure).

Risk-SCD-Future-Callout

Approximately $2.4 billion is spent each year on ICDs, but the medical community still has yet to identify the optimal method for determining which patients need these devices most. “Conducting research initiatives to improve our ability to predict risk would enable providers to target ICD use to the most appropriate recipients,” says Dr. Goldberger. “Under current prediction protocols, ICDs are not systematically reaching many patients who can benefit from receiving these devices. By assembling the right resources, there is hope that we can establish risk stratification standards that use medical resources wisely while saving the most lives.”

Stratifying Sudden Cardiac Death Risk

Developing effective strategies for preemptive risk stratification for SCD has substantial implications. Accurate assessment of risk for SCD can be instrumental in helping clinicians make decisions about the prescription of preventive therapies to reduce mortality. Several factors are often taken into consideration when deciding on therapies for patients at risk for SCD, including adherence to standard medical therapies—often in conjunction with tailored medications—implantable devices, catheter ablation, or other untested treatments, such as spinal cord stimulation. In cases in which therapies are invasive or carry risk, each decision should be based on the reliability of added benefit to patients.

Procedural, statistical, and financial issues have been obstacles to developing risk stratification strategies for SCD. “As of now, there is no adequate tool or test to predict the ideal heart patients who are good candidates for devices like ICDs,” Dr. Goldberger says. “We need new approaches to provide a basis for better risk stratification.” Several domains should be considered, including basic epidemiologic approaches to modeling risk, identifying candidate risk markers that merit further evaluation in risk assessment, ethical and regulatory considerations, and funding and policy issues.

Outlining a Plan With ICDs

In an article published in Circulation, 20 of the most prominent cardiologists and medical specialists in the U.S. developed an action plan that is intended to save lives and healthcare spending dollars associated with the use of ICDs to prevent SCD. Specifically, the group calls on clinicians, patient advocacy groups, payers, industry, and government agencies to unite behind a coordinated, six-step program to ensure that only patients who stand to derive benefit from ICDs receive implants (Table).

Dr. Goldberger and colleagues addressed several elements to improve risk prediction. These included establishing baseline risk models for key patient groups, compiling and assessing current risk stratification techniques, and evaluating emerging risk marker strategies. They also recommended using randomized clinical trials, increasing the efficiency of data collection, and creating a process for promoting properly funded clinical trials that are supported by all stakeholders. “With a concerted effort toward enhancing risk stratification techniques,” says Dr. Goldberger, “we can save more lives while simultaneously conserving medical resources for cases in which ICDs are likely to be most effective.”

“The suggestions here could save hundreds of millions of dollars,” said co-author Alan H. Kadish, MD, a cardiologist who also serves as president and CEO of the Touro College and University System. “We cannot afford ever-increasing healthcare costs, and the research dollars allocated by the Affordable Care Act and from other sources are inadequate to fund the work needed for cost-effective ICD implantation.”

Reaping Potential Benefits

A sustained and substantial investment—from both a financial and infrastructural standpoint—will be necessary to gain a better understanding of the pathophysiology of SCD and identify risk predictors, especially among special populations. “Our healthcare system can reap massive cost savings by better identifying patients who will gain the most from ICDs,” Dr. Goldberger says. “The costs of not addressing these issues will far exceed those of obtaining the data we would need to advance risk stratification. By undertaking the six-step program we developed, we will have an opportunity to truly deliver better care at a lower cost. Taking advantage of this opportunity will help the U.S. invest more wisely into research that will demonstrate which treatments are beneficial and which are extraneous.”

References

Goldberger JJ, Basu A, Boineau R, et al. Risk stratification for sudden cardiac death: A plan for the future. Circulation. 2014;129:516-526. Available at: http://circ.ahajournals.org/content/129/4/516.extract.

Goldberger JJ, Buxton AE, Cain M, et al. Risk stratification for arrhythmic sudden cardiac death: identifying the roadblocks. Circulation. 2011;123:2423-2430.

Fishman GI, Chugh SS, Dimarco JP, et al. Sudden cardiac death prediction and prevention: report from a National Heart, Lung, and Blood Institute and Heart Rhythm Society Workshop. Circulation. 2010;122:2335-2348.

Hlatky MA, Greenland P, Arnett DK, et al; American Heart Association Expert Panel on Subclinical Atherosclerotic Diseases and Emerging Risk Factors and the Stroke Council. Criteria for evaluation of novel markers of cardiovascular risk: a scientific statement from the American Heart Association. Circulation. 2009;119:2408-2416.