Screening for Serious Cardiovascular Diseases in Children and Adolescents: Does the evidence Support Going Forward AND Are We Able to "Pull It Off"?

There is a growing interest in screening approaches for neonates, infants, children and adolescents in order to unmask serious, life-threatening undiagnosed cardiovascular diseases. Identification of individuals who either have critical congenital heart disease or who are at risk for sudden cardiac death, before a catastrophic presentation occurs, has the potential to reduce morbidity and mortality. This assumes that an intervention could be instituted prior to the catastrophic event but also that key concepts are met in the screening process. The very important AHA Science Advisory entitled “Key Concepts in the Evaluation of Screening Approaches for Heart Disease in Children and Adolescents” addresses these very issues.¹

The AHA statement¹ is an important summary statement with regard to where we are in 2012 in screening patients for serious cardiovascular diseases. The controversy with regard to ECG screening as a supplement to the physical examination in order to diagnose occult anatomic and electrical substrates for sudden cardiac death still exists. Several scientific statements and advisory groups have weighed-in on this topic,² as discussed in the AHA Science Advisory Statement.¹ Yet the data with regard to the effectiveness of mass ECG screening are not entirely clear. Though seemingly more sensitive and specific than the pre-participation history and physical examination,³ the screening ECG did reduce sudden cardiac death in athletes in Italy⁴ but not in Minnesota⁵ or in Israel.⁶ Logistic issues related to mass ECG screening will continue to require assessment and creative solutions. The logistic issues include cost, establishment of normal ECG values in a multi-ethnic population, the variable rate of false positives and its costs, both financial and psychological and assuring the accuracy of the interpretation of the studies. And we should make it very clear, as has the AHA Scientific Advisory Statement,¹ that we should not focus the screening process on competitive athletes only but rather on all children and adolescents. Interestingly the recent meta-analysis published by Rodday, et al⁷ suggested an evidence-basis for evaluating pediatric screening with ECG, alone or with ECHO. This study concluded that ECG was a sensitive test for mass screening, with a negative predictive value that was high, but with a variable positive predictive value and false-positive rate. This study suggested that, on this basis, that mass ECG screening may not be “ready for prime time.”

This AHA Science Advisory Statement¹ also elucidated the importance of pulse oximetry in the timely diagnosis of critical congenital heart disease in the newborn. Multiple studies have provided insight into the strengths and weaknesses of pulse oximetry with the conclusion that this technique indeed is an important and effective methodology for screening for critical congenital heart disease in the newborn.^8-11

Perhaps as importantly, this AHA Science Advisory¹ has discussed the importance of ongoing evidence-based research in order to monitor the outcomes of new and existing screening strategies. A rigorous assessment of these approaches is critical. New screening programs, including mass ECG screening, must be based on sound and evidence-based principles rather than a reaction to catastrophic events. One would certainly encourage pilot screening programs in order to establish a database to collect comprehensive information. The comprehensive collection of data would allow for a better understanding of many of the facets related to sudden cardiac death including a better understanding of the true incidence, as well as the incidence and impact of false positives, for example. So, although mass ECG screening may indeed not be “ready for prime time” in 2012, perhaps a mandatory registry with the comprehensive collection of selected data would allow us to answer many unanswered questions with regard to sudden cardiac death. In so doing, additional data might not only allow for an understanding of the true incidence of congenital heart disease but also allow us to understand other nuances with regard to the successes or failures of the various screening strategies heretofore.

This paper also briefly discusses the optimal role of governmental agencies in this arena. As the paper has stated, the role of government in mandatory resource-consuming programs in which costs may not be shared equally amongst beneficiaries is somewhat controversial. Most importantly the advocacy for a comprehensive, science-based preliminary analysis of screening hypotheses and analyses is critical. The example of the expansion of the newborn program with the addition of pulse oximetry screening for critical congenital heart disease fulfills the criteria of science-based preliminary analysis and appropriately won the endorsement at the federal government level, after an extended deliberate and evidence-based process.

This AHA Science Statement is beautifully written and gets to the crux of many of the key concepts in the evaluation of screening approaches targeted towards children and adolescents. The mutual goal is the prevention of morbidity and mortality. In the evaluation of screening methodologies it is critical to assess the data as well as the feasibility of the approach at hand in an evidence-based manner. Such is where we currently are with regard to ECG screening for sudden cardiac death. Though the data does not yet exist to support mass ECG screening this could change in the future but only via an evidence-based process that analyzes the data much like the process that was carried forth with regard to pulse oximetry for critical congenital heart disease. We look forward toward this future of evidence-based analyses and strategies to reduce morbidity and mortality including secondary prevention strategies. Two final separate but related important points:

1. If an evidence-based analysis ultimately will support the effectiveness of mass ECG screening, the logistic barriers, as discussed above and elsewhere, must still be conquered. These barriers include costs, establishment of normal values, a system of accurate analysis of the studies by the appropriate workforce and a system for dealing with the logistics and financial and psychological costs of false positives. Therefore this logistic framework in the United States must be established if the evidence-based data ultimately supports this strategy. Currently, neither clear-cut evidence in support of the efficacy of mass ECG screening nor a system to carry this out in the United States exists.
2. This author believes that a mandatory registry, requiring the reporting of all cases of sudden cardiac arrest, and its details, is important and will allow us to answer many of the currently unanswered questions with regard to sudden cardiac arrest and sudden cardiac death in children and adolescents.¹²