Pulmonary vein isolation in obese vs. non-obese patients: insights from the German national DRG-Database

Background:

Pulmonary Vein Isolation (PVI) is a well-established treatment for atrial fibrillation (AF). Obesity is one of the predisposing risk factors for AF, and PVI is performed in an increasing number of obese patients. Catheter ablation of AF in obese patients is challenging due to higher incidence of comorbidities, difficult periprocedural sedation and perioperative management. 

Purpose:

To assess the trends in demographics, periprocedural complications and in-hospital outcomes of PVI in obese vs. non-obese patients in Germany. 

Methods:

This study was conducted as a retrospective observational analysis of all German in-hospital PVI cases from 2013 to 2022 using the Diagnosis-Related Groups statistics database of the Research Data Center of the Federal Statistical Office. Two groups were defined and compared: obese (BMI ≥ 30 kg/m²) and non-obese (BMI < 30 kg/m²) patients.

Results:

Over 10 years a total of 235 139 cases of PVI, 23 688 (10.07%) in obese and 211451 (89.93%) in non-obese patients were identified. Median age was 67 (59-73) years, 60% were male. 

We observed an eightfold increase in overall PVI case numbers (between 2013 (5575 cases) and 2022 (45799 cases). The percentage of obese patients remained stable (8.8-10.9%) (Fig. 2A). Obese patients were significantly younger than non-obese (p < 0.001), had higher prevalence of persistent AF (54.9% vs. 45.3%, p < 0.001) (Fig. 2B) and underwent more often radiofrequency ablation compared to cryoballoon ablation (49.78% vs. 43.75% p < 0.001). The prevalences of comorbidities such as coronary artery disease, hypertension, vascular disease, chronic heart failure, chronic kidney disease, chronic lung disease, diabetes mellitus and hyperlipidemia were significantly higher in obese patients (p < 0.001 for each one) (Fig. 2C). CHA₂DS₂-VASc-Score was also higher in obese patients (p < 0.001).

Rate of combined major adverse cardiac events (including death) was observed to be higher in obese group (0.26% vs. 0.20%, p < 0.001). However, regarding other periprocedural complications (arteriovenous fistula, pericardial effusion, phrenic nerve paralysis and stroke), no significant differences between groups were shown.  A higher rate of acute kidney injury in obese group (1.5% vs. 0.86%, p < 0.001) was detected. 

Obese patients had a longer hospital stay (3 [2,4] vs. 2 [2,4], p < 0.001) and higher intensive care unit admission rate (2.0% vs. 1.7%, p < 0.001). Total in-hospital mortality did not differ between both groups (0.05% vs 0.06%, p = 0.48) (Fig. 2D).

Conclusion:

Obese patients undergoing PVI had a higher prevalences of comorbidities, more major adverse cardiac events and a longer hospital stay, with no differences in overall in-hospital mortality, compared to non-obese patients. These findings underscore the higher risk of obese patients undergoing PVI, emphasizing the need for a careful patient selection and a comprehensive treatment approach for this patient population.