Objective: To determine observed and RS after CRT in a nationwide cohort undergoing CRT.
Methods: A national administrative database was used to quantify observed mortality for patients undergoing CRT. Relative survival (RS) was quantified using life tables.
Results: In 50,084 patients (age: 72.1±11.6 years [mean ± SD]) undergoing with (CRT-D) (n=25,273) or without (CRT-P) defibrillation (n=24,811) over 8.8 years (median follow-up 2.7 years (interquartile range [IQR]: 1.3-4.8), expected survival decreased with age. Device type, male sex, ischaemic heart disease, diabetes and chronic kidney disease predicted excess mortality. In multivariate analyses, excess mortality (analogue of RS) was lower after CRT-D than after CRT-P in all patients (adjusted hazard ratio [aHR]: 0.80; 95% confidence interval [C.I] 0.76-0.84) as well as in subgroups with (aHR:0.79;95% C.I. 0.74-0.84) or without (aHR:0.82;95% C.I. 0.74-0.91) ischaemic heart disease. A Charlson co-morbidity index (CCI) =3 portended a higher excess mortality (aHR: 3.04; 95% C.I. 2.76-3.34). RS was higher in 2015-2017 than in 2009-2011 (aHR:0.64;95%C.I. 0.59-0.69).
Conclusions Reference RS data after CRT is presented. Sex, ischaemic heart disease, diabetes, chronic kidney disease and CCI were major determinants of RS after CRT. CRT-D was associated with a higher RS than CRT-P in patients with or without ischaemic heart disease. RS after CRT improved from 2009 to 2017.