[Cardiac resynchronization therapy: is there always a need for the adjunctive ICD therapy?]

Chronic postinfarction patients with an ejection fraction ≤ 30% and heart failure patients in NYHA classes II and III with an ejection fraction ≤ 35% due to ischemic or dilated cardiomyopathy meet current indications for ICD therapy. There is significant overlap with patients in NYHA class III also exhibiting a wide QRS complex (>120 ms), who commonly benefit from resynchronization therapy. Although a combination of ICD and CRT seems reasonable in many patients, one should be aware of subtle distinctions regarding selection criteria for either therapy. There is no clear ICD indication for heart failure patients in NYHA class IV or even III, taking subclass analysis of SCD-HeFT [4] into account. Uncertainty still exists for the subacute postinfarction phase (4 weeks to 6 months), whereas the early postinfarction phase should clearly not be considered for ICD evaluation. No randomized data exist for heart failure due to other etiologies. CRT, on the other hand, is not only helpful regarding symptom relief and quality of life, but also with respect to life expectancy. The additive value of adjunctive ICD therapy has not yet been proven in a randomized comparison. Finally, particularly in elderly patients, quality of life might seem more desirable than prevention of sudden cardiac death. Thus, combination of ICD and CRT is not always a "must". Instead, ICD guidelines still leave room for a patient specific decision, with "stand-alone" CRT still providing a very helpful, prognostically significant therapy.