Background: The aim of the analysis was to compare the outcome of heart failure patients in New York Heart Association (NYHA) class IV to that of NYHA class III patients 1 year after implantation of a CRT device.
Methods: The analysis was based on the 405 CRT patients enrolled in the MASCOT trial. At enrollment, 350 patients (86%) were in NYHA class III and 55 (14 %) were in NYHA class IV.
Results: At 1-year follow-up, the improvement of the ejection fraction was not statistically significantly different between NYHA class III (+7.6 ± 11.7%) and NYHA class IV patients (+9.2 ± 14.2 %; p = 0.78). NYHA class IV patients had a better mean NYHA class reduction with -1.93 ± 0.83 than NYHA class III patients with -0.93 ± 0.70 (p < 0.0001). There was a greater mean quality of life improvement in NYHA class IV (-27.2 ± 20.9) compared to NYHA class III (-17.7 ± 23.9; p = 0.02). All-cause mortality as well as cardiac mortality remained higher in NYHA class IV with 25.5 and 16.4% than in NYHA class III with 7.1 and 3.1% (p < 0.0001).
Conclusions: In this study, 14% of all patients receiving a CRT device had NYHA class IV at implantation. The data support the concept to implant a CRT device in NYHA class IV patients, because at 1 year after implantation, they experienced better symptomatic improvement compared to NYHA class III patients. The higher cardiac as well as non-cardiac mortality resulted in a fivefold higher all-cause mortality compared to NYHA class III patients.