The Particulars: Cardiac resynchronization therapy (CRT) with or without an ICD (CRT-D) is indicated for symptom improvement in patients with chronic systolic heart failure, with prolonged intraventricular conduction delay, and New York Heart Association (NYHA) class III/IV symptoms, despite optimal medical therapy. Little is known about the utility of CRT-D in reducing all-cause mortality and congestive heart failure (CHF) events in patients who meet criteria for an ICD but have NYHA class I/II symptoms.
Data Breakdown: Researchers in the United State and Europe randomized more than 1,800 patients who meet criteria for an ICD to CRT-D or ICD alone. Patients in the CRT-D arm had a 17.2% rate of death or nonfatal CHF event, compared with a rate of 22.8% in the ICD arm. All-cause mortality rates were 6.8% in the CRT-D arm and 7.3% in the ICD arm. Women, those with a QRS duration of 150 milliseconds or greater, and those with left bundle branch blocks benefited most from CRT-D. Adverse events at 30 days post-implantation, however, were numerically higher in the CRT-D arm.
Take Home Pearl: In patients who meet criteria for an ICD but have NYHA class I/II symptoms, CRT-D implantation appears to significantly reduce CHF events and mortality when compared with ICD implantation alone.