NOACs and Risk for Heart Failure in Older Patients With AF and DM

Older patients with atrial fibrillation (AF) and diabetes mellitus (DM) who use non-vitamin K antagonist oral anticoagulants (NOACs) have a lower risk for incident heart failure (HF) compared with patients who use warfarin, researchers reported in Cardiovascular Diabetology.

The nationwide retrospective cohort study evaluated the risk for HF in older patients with AF and DM who were taking NOACs vs warfarin with use of data from the National Health Insurance Research Database (NHIRD) in Taiwan.

Participants were aged 65 years or older, were diagnosed with AF and DM, and had been treated with oral anticoagulants from 2012 to 2019, with at least 1 year of follow-up per patient. The primary outcome was incident HF diagnosed in an inpatient service or 3 times or more in an outpatient service.

The propensity score was calculated using multivariable logistic regression models, including covariates, for each patient to estimate the probability of initiating NOACs.

The cohort initially included 24,835 patients (19,710 taking NOACs and 5125 taking warfarin). Their mean age was 76.6 years, 47% were women, and the mean follow-up duration was 3.0 years. Secondary cohorts were created for additional analyses after applying propensity score-based fine stratification weighting. These secondary cohorts contained 19,591 patients receiving NOACs and 5117 patients receiving warfarin.

NOAC use was significantly associated with a lower risk for HF compared with warfarin use (hazard ratio [HR], 0.80; 95% CI, 0.74-0.86, P <.001) in the analysis with propensity score-based fine stratification weighting for estimation of the average treatment effect in the whole population.

For the average treatment effect in the whole population estimation analyses for each NOAC, dabigatran (HR, 0.86; 95% CI, 0.80-0.93, P <.001), rivaroxaban (HR, 0.80; 95% CI, 0.74-0.86, P <.001), apixaban (HR, 0.78; 95% CI, 0.68-0.90, P <.001), and edoxaban (HR, 0.72; 95% CI, 0.60-0.86; P <.001) were associated with a decreased risk for HF vs warfarin.

Consistent results were found in analyses stratified by age, sex, and hospital levels, and the significantly decreased risk for HF associated with NOAC use occurred in all of these stratified groups.

In analysis that was limited to participants who had a high medication possession ratio (≥80%), NOAC use and lower HF risk had a stronger association (HR, 0.47; 95% CI, 0.40-0.56, P <.001).

When the analysis incorporated propensity score matching or multivariable regression models to adjust for covariates without propensity score methods, NOAC users still had a lower HF risk compared with warfarin users.

Among several limitations, data are not available on lifestyle, smoking and drinking history, and detailed laboratory examination results such as blood glucose and renal function. Also, the investigators were unable to confirm diagnostic accuracy owing to the patient anonymity policy in the NHIRD, and so misclassification errors may have occurred. In addition, some patients could have changed the types of oral anticoagulants that they used during follow-up, and it is unclear whether the observed lower HF risk in NOAC users can be generalized to younger or healthier patients.

“Our findings suggest that NOACs may be the preferred oral anticoagulant treatment to reduce the risk of HF in elderly AF patients with DM,” wrote the study authors. “Future research is warranted to elucidate causation and investigate the underlying mechanisms of our findings.”