Abstract Body (Do not enter title and authors here): Background
New-onset heart block (NOHB) is a frequent early complication following transcatheter aortic valve intervention (TAVI), partially driven by mechanical edema. Colchicine, known for its anti-inflammatory properties and efficacy in reducing myocardial infarction in coronary artery disease, has never been studied for its effects on NOHB post-TAVI.

Methods
This study used the TriNetX database (January 2013 to May 2024) to compare patients receiving colchicine (at least one dose within two days before and up to 12 days after their first TAVI) with those never exposed to colchicine up to one year after the procedure. A propensity score-matched (PSM) analysis controlled for baseline demographic and clinical characteristics (figure 1A). Outcomes included NOHB in addition to all-cause hospitalizations, all-cause mortality, new-onset atrial fibrillation (NOAF), acute coronary syndrome (ACS), and stroke at one and six months post-TAVI and were assessed through the risk ratio (RR) and 95% confidence interval (CI).

Results
The control group included 49,384 patients, while the colchicine group included 725. After PSM, 712 patients were included in each group; 36.1% and 40.3% were females. The mean age was 77.8 (±8.9) and 78.1 (±8.8) years, respectively. Colchicine was associated with a significant reduction of NOHB at one month (RR= 0.64, 95% CI [0.49; 0.83], p=0.001) and six months (RR= 0.61, 95% CI [0.48; 0.78], p<0.0001) post-TAVI. Similarly, all-cause hospitalizations and mortality were significantly lower in the colchicine group at one month (RR= 0.65, 95% CI [0.60; 0.71], p<0.0001; RR= 0.41, 95% CI [0.21; 0.80], p=0.007, respectively) and six months (RR= 0.96, 95% CI [0.64; 0.74], p<0.0001; RR= 0.67, 95% CI [0.46; 0.97], p=0.03, respectively). Other postprocedural complications were comparable between the groups at one and six months (figure 1B). Sensitivity analysis revealed an E-value of 2.26 at one month and 2.4 at six months for the RR of NOHB.

Conclusion
Perioperative colchicine was associated with reduced risk of NOHB, all-cause hospitalization, and all-cause mortality at one and six months after TAVI. However, it was not associated with reduced postoperative risk of NOAF, ACS, or stroke at one or six months.