When is it too late for cardiac resynchronization therapy?

Lehmann et al.1 pointed out that taken together, the large cardiac resynchronization therapy (CRT) trials included 10,803 patients, the majority of who were in congestive heart failure (CHF) New York Heart Association (NYHA) class III, but only 451 patients (4.2%) were class IV. The role of CRT in NYHA class IV patients remained uncertain until recently when Lindenfeld et al.2 reported the results of CRT in 217 such ambulatory patients (on no intravenous inotrope therapy) after a median follow-up of 14 months. Death or hospitalization for any cause was significantly improved in both CRT and CRT-defibrillator patients. The time to all-cause death and heart failure (HF) hospitalization was also significantly improved in the same groups.2 However, the large CRT trials have generally excluded patients with refractory class IV CHF on intravenous inotropic therapy.3–5 Although cardiac resynchronization has revolutionized the treatment of CHF, its use in end-stage patients whose prognosis is poor and who are dependent on intravenous drugs has remained controversial and poorly defined. Furthermore, scientific guidelines have not addressed the role of CRT in this group of patients.6–7 The question arises as to whether the recent documentation of CRT benefit for NYHA class IV ambulatory patients can be extended to the much sicker group of class IV patients on inotropic support.