Cryoaballoon pulmonary vein isolation in patients with atrial fibrillation and diabetes – preliminary results of the SUGAR-AF study

Background

Diabetes mellitus is an important risk factor for the occurrence of atrial fibrillation (AF) and appears to negatively influence the outcome of rhythm control at higher HbA1c values. It is already known that cryoballoon pulmonary vein isolation (CryoPVI) allows modulation of autonomic structures/ganglion plexuses located in the area of the posterior atrial wall, which can have a pro-arrhythmic effect in diabetics due to the accompanying autonomic neuropathy. However, there is no large-scale prospective study evaluating efficacy and safety of single-shot pulmonary vein isolation without any further ablation in patients with AF and diabetes. 

Methods

SUGAR-AF trial is an ongoing investigator-initiated, single-center, prospective, non-inferiority study. Follow-up was performed at 3, 6, 12, 24 and 36 months after ablation. Endpoints were: symptomatic atrial arrhythmia recurrence for efficacy and death, stroke, bleeding or procedure-related complications for safety. 

Results

We analyzed 1236 consecutive patients who underwent CryoPVI. Of these, 153 patients (12.4%) suffered from diabetes. Diabetic patients were younger (67.8 vs. 69.6 years; P=0.04), had higher CHA₂DS₂-VASc Score (4.0 vs. 2.6; P<0.0001) and BMI (30.1 vs. 27.4; P<0.0001) and were more likely to suffer from hypertension (84% vs. 64%; P<0.0001) and coronary heart disease (35% vs. 18%; P<0.0001). At 36 months occurrence of primary efficacy endpoint was similar between diabetic and non-diabetic patients (41.6% vs. 47%; hazard ratio [HR] 0.96; 95% confidence interval [CI], 0.71 to 1.31; log-rank P=0.81). Nevertheless, there was a significant correlation between ablation success and the level of HbA1c.

Conclusion

The interim results of the SUGAR-AF study suggest that CryoPVI is an effective ablation method for patients with atrial fibrillation and diabetes.