Dr. Buxton refers to the 2008 AHA/ACC/HRS Scientific Statement on Noninvasive Risk Stratification. 

Clearly, the current methods of identifying high-risk patients are being questioned.  This is where MTWA can help…

Reduced EF: The Best we Have?

“I am struck by reading this summary statement that the best test available today in patients with coronary disease or nonischemic dilated cardiomyopathy is EF. Yet, the authors of the scientific statement clearly make the point that EF bears no direct relation to the mechanisms of ventricular arrhythmias responsible for the majority of episodes of cardiac arrest.”

“Use of EF to Stratify Risk for SCA is Inappropriate”

“Another consequence of the use of low EF to guide ICD use … is the fact that at least half of the episodes of cardiac arrest occur in patients that do not meet the current definition of high-risk EF (≤30%-35%).  Thus, restricting use of ICDs to only those patients with very low EF misdirects use of this therapy.  How can it be that most sudden deaths occur in patients at ‘low risk’? The answer to this question is that use of EF to stratify risk for sudden cardiac arrest is inappropriate.  The patients that experience sudden death whose EF is greater than 35%-40% are certainly not low risk! They merely had the wrong test used to stratify risk.”

The PPV Myth: 10% Risk of SCA is not Low Risk!

“This point is exemplified by two recent observational studies of patients with recent myocardial infarction (MI) and relatively preserved EF. The first study examined the use of T-wave alternans (TWA) in patients with EF ≥ 40% after recent MI. Patients with abnormal TWA tests had a 10% incidence of arrhythmic events (sudden death or resuscitated cardiac arrest) at 2 years follow-up. The second study examined the use of baroreflex sensitivity (BRS) testing in patients with EF greater than 35% after recent MI.  The incidence of cardiovascular death at 2 years follow-up was approximately 15% in patients with an abnormal response to BRS testing. I don't believe anyone would consider patient populations with 10%-15% 2-year rates of sudden death as low risk.”