Periprocedural cardiac troponin elevation: a potential indicator of enhanced ventricular threshold in permanent pacemaker recipients

Background and aim: Permanent cardiac pacing is the most efficient treatment for patients with symptomatic bradycardia and high-degree atrioventricular (AV) block. For effective pacing, sensing and pacemaker battery longevity; ventricular pacing threshold (VPT) levels, lead impedance levels and Rwave amplitude levels must be desirable. We aimed to search the association between elevated serum troponin levels and VPT values in patients who has implanted single chamber permanent pacemaker. Materials and methods: We retrospectively analyzed a total of 109 patients (mean age: 78 ± 7.1 years, 53.6% male) who underwent single chamber permanent pacemaker implantation for indications such high-degree atrioventricular block and sick sinus syndrome. Hematological and biochemical parameters were measured prior to pacemaker implantation. Additionally troponin I and high-sensitivity C-reactive protein (hs-CRP) were sampled about 12 hours after pacemaker implantation. Results: Over a median follow-up period of 17.3 months, 32 (29.3%) patients has positive troponin I levels after implantation. Troponin positive group has higher VPT values at the time of implantation (0.94 ± 0.33 vs. 0.71 ± 0.19, p<0.001) and at 30th day of implantation (0.69 ± 0.16 V vs. 0.91 ± 0.31 V, p<0.001). To identify in dependent risk factors for ventricular threshold values, a multivariate linear regression model was conducted and after implantation having positive troponin value (β=0.337, p=0.01) and troponin elevation ratio (β=0.365, p<0.001) were found to be independent risk factors for ventricular threshold. Conclusion: Our results indicate that troponin I elevation after pacemaker implantation is associated with higher VPT values at the time of and the 30th day of implantation. For longevity of pacemaker batteries, low threshold values are preferable. To further extend the life of pacemakers, we recommend following patients more closely who has high troponin levels after permanent pace replacement.