The new ACC/AHA/ESC guidelines for ventricular arrhythmias and prevention of sudden death appeared in my online edition of Circulation this AM and I turned with some interest to the section on prophylactic implantable defibrillator criteria. The guidelines, scripted by a committee of international experts, are supposed to represent a distillation of the best available scientific evidence. Recommendations are rated from high to low (I, IIa, IIb, and III) and by level of evidence (level A evidence from randomized clinical trials, to level C, concensus of experts). This is one of a series of similar guidelines published over the years on a variety of problems in cardiology. These guidelines are always very definitive and up to date. Thus I was curious to see what they said about ICD indications.
I hadn’t read very far before I started coming across recommendations like this: “ICD therapy is recommend for primary prevention…in patients…[who] have an LVEF less than or equal to 30% to 40%” –What? What does this mean? Is it 30%, 40%, 35%?? Does this statement have any meaning even in a mathematical sense? If there are different cases to be made for less than 30% versus less than 40%, why isn’t this reflected in the normal way in the guidelines, such as making one cutoff a Class IIa recommendation, and the other a Class IIb?
Reading the fine print, the authors explain this essentially by admitting that they could not reach a consensus. The same data is interpreted differently on either side of the Atlantic apparently. They go on to state: “Guidelines are composed of recommendations on the basis of the best available medical science; however, implementation of these recommendations will be impacted by the financial, cultural, and societal differences among individual countries.” So, in other words, in the US, where Medicare CMS guidelines for primary prevention don’t include patients with LVEF > 35%, the cutoff must be 35%. In Europe, maybe it’s 40%. Or 30%. Depending on culture, money, and society presumably.
Great! So instead of the guidelines committee of experts coming up with actual guidelines, such as making the cutoff 40% and thumbing their collective noses at CMS and saying deal with it, they bow down to local custom and preserve political correctness at the expense of scientific rigor. Presumably if an ICD implanted in a European with an EF of 40% can save his life, it could also save the life of a Medicare recipient in the US.
So which is it, ACC/AHA Task Force and the ESC Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death) Developed in Collaboration With the European Heart Rhythm Association and the Heart Rhythm Society: less than 30% or less than 40%??
(The article cited above is available at circ.ahajournals.org)