Impact of frailty on in-hospital and long-term outcomes after atrial fibrillation ablation in patients aged ≥75 years

Background

Frailty is recognized as an important determinant of cardiovascular outcomes. However, its impact on in-hospital and long-term outcomes after atrial fibrillation (AF) ablation in older patients is unclear.

Methods

We conducted a retrospective observational cohort study of all consecutive patients aged ≥75 years undergoing AF ablation identified from the statewide Admitted Patient Data Collection (APDC) database (Mar 2004 and Mar 2021). Frailty status of each patient was derived from the AF ablation admission records using a validated Hospital Frailty Risk Score (HFRS) and analysed as a continuous variable.

Endpoint include in-hospital major adverse events (MAE: defined as a composite of in-hospital death, permanent pacemaker or implantable cardioverter defibrillator implantation, ischaemic stroke/transient ischaemic attack [IS/TIA], or major bleeding) during the AF ablation admission.

Long-term outcomes include: all-cause mortality and non-fatal outcomes encompassing AF readmission, heart failure (HF) or IS/TIA requiring admission during follow up. All-cause death and non-fatal outcomes requiring admission were tracked till Mar 2022 using linkage to the death registry and APDC database respectively.

Multivariable logistic and Cox regression methods analysed frailty (HFRS) association with in-hospital MAE and all-cause death during follow up adjusted for age and sex respectively, while Fine-Gray competing risk of death assessed frailty association with non-fatal outcomes during follow up adjusted for age and sex.

Results

The cohort include 2865 patients (median age 79.5 [range: 75.0-97.6yrs]; 57% male). The mean (±SD) HFRS was 0.09±0.46 (median 0; range 0-7.1), with HFRS >0 in 141 patients (4.9%).

In-hospital MAE was 4.6% and was associated with frailty (HFRS per-score: adjusted odds ratio [aOR] 2.1, 95% confidence interval [CI] 1.7-2.6, p<0.001); 2 patients died in-hospital.

During a median follow-up of 4.4 years post AF ablation (interquartile range 2.4-7.1 years), 1020 patients (35.6%) died (female 32.4% vs male 38.0%, logrank p=0.011). Age (adjusted hazard ratio [aHR] 1.13 per-year, 95%CI 1.11-1.14, p<0.001) and male sex (aHR 1.26, 95%CI 1.11-1.43, p<0.001) independently predicted mortality, whereas frailty did not (aHR 1.09, 95%CI 0.95-1.21, p=0.292).

For non-fatal long-term outcomes and accounting for death during follow up, frailty was associated with higher risk for AF readmission (HFRS per-score: adjusted subdistribution hazard ratio [adj.sHR] 1.19, 95%CI 1.05-1.35, p=0.009), but not for HF (adj.sHR 0.98, 95%CI 0.82-1.17, p=0.840) or IS/TIA (adj.sHR 1.05, 95%CI 0.81-1.37, p=0.700) admissions post AF ablation.

Conclusions

In patients aged ≥75 years undergoing AF ablation, frailty status was strongly associated with in-hospital MAE, and independently associated with higher risk of AF readmission but not with all-cause mortality, HF or stroke admission during long-term follow up.