Timing of cardiac resynchronization therapy implantation

Aims: The optimum timing of cardiac resynchronization therapy (CRT) implantation is unknown. We explored long-term outcomes after CRT in relation to the time interval from a first heart failure hospitalization (HFH) to device implantation.

Methods and results: A database covering the population of England (56.3 million in 2019) was used to quantify clinical outcomes after CRT implantation in relation to first HFHs. From 2010 to 2019, 64 968 patients [age: 71.4 ± 11.7 years; 48 606 (74.8%) male] underwent CRT implantation, 57% in the absence of a previous HFH, 12.9% during the first HFH, and 30.1% after ≥1 HFH. Over 4.54 (2.80-6.71) years [median (interquartile range); 272 989 person-years], the time in years from the first HFH to CRT implantation was associated with a higher risk of total mortality [hazard ratio (HR); 95% confidence intervals (95% CI)] (1.15; 95% CI 1.14-1.16, HFH (HR: 1.26; 95% CI 1.24-1.28), and the combined endpoint of total mortality or HFH (HR: 1.19; 95% CI 1.27-1.20) than CRT in patients with no previous HFHs, after co-variate adjustment. Total mortality (HR: 1.67), HFH (HR: 2.63), and total mortality or HFH (HR: 1.92) (all P < 0.001) were highest in patients undergoing CRT ≥2 years after the first HFH.

Conclusion: In this study of a healthcare system covering an entire nation, delays from a first HFH to CRT implantation were associated with progressively worse long-term clinical outcomes. The best clinical outcomes were observed in patients with no previous HFH and in those undergoing CRT implantation during the first HFH.

Condensed abstract: The optimum timing of CRT implantation is unknown. In this study of 64 968 consecutive patients, delays from a first heart failure hospitalization (HFH) to CRT implantation were associated with progressively worse long-term clinical outcomes. Each year from a first HFH to CRT implantation was associated with a 21% higher risk of total mortality and a 34% higher risk of HFH. The best outcomes after CRT were observed in patients with no previous HFHs and in those undergoing implantation during their first HFH.