Efficacy and safety of antiarrhythmic therapy in dogs with naturally acquired tachyarrhythmias treated with amiodarone or sotalol: a retrospective analysis of 64 cases

INTRODUCTION/OBJECTIVE

Studies on the use of amiodarone or sotalol are limited in dogs. Therefore, this study aimed to provide data on the efficacy and safety of these drugs in dogs with ventricular tachyarrhythmia (VT) and/or supraventricular tachyarrhythmia (SvT).

ANIMALS, MATERIALS, AND METHODS

Dogs with VT and/or SvT treated with amiodarone or sotalol as a first-line therapy were retrospectively evaluated. Signalment, clinical, diagnostic, therapeutic, and outcome data were retrieved. For VT, efficacy was demonstrated through a decrease of the Lown-Wolf grade to less than five or a reduction of at least 85% in the number of ventricular premature complexes observed on Holter monitoring. For SvT, efficacy was represented by cardioversion or a reduction in the mean heart rate on Holter monitoring ≤140 beats/min. Treatment-related side effects (TRSEs) were classified as clinically relevant and irrelevant. Statistical analysis was performed to compare data before and after antiarrhythmic prescription.

RESULTS

Sixty-four dogs were included. Amiodarone and sotalol were efficacious in treating both VT (85.7% and 90.0% of cases, respectively) and SvT (75% and 71.4% of cases, respectively). No significant differences were found when comparing their efficacy rates in dogs with VT and SvT (P=0.531 and 0.483, respectively). Clinically relevant TRSEs were rare with both amiodarone and sotalol (8.3% and 5% of cases, respectively), while clinically irrelevant TRSEs occurred more frequently with amiodarone (29.2%) than with sotalol (10%).

DISCUSSION

In dogs with tachyarrhythmias, amiodarone and sotalol are generally efficacious and safe, as clinically relevant TRSEs seem rare.

CONCLUSIONS

This study provides novel data on the effects of amiodarone and sotalol in dogs with tachyarrhythmias.

Relationship between anal cancer recurrence and cigarette smoking

BACKGROUND

The incidence of anal cancer has been increasing in the United States. Smoking is a well-established risk factor; however, the impact of smoking on disease re-currence and outcome has not been well studied. The aim of this study was to assess the association between anal cancer recurrence and cigarette smoking.

AIM

To investigate the relationship between cigarette smoking status and anal cancer treatment outcome.

METHODS

The cancer registry from a single, community hospital was screened for patients with anal cancer between 2010 and 2021. The following characteristics were gathered from the database: Age; sex; cigarette smoking history; American Joint Committee on Cancer Clinical Stage Group; response to therapy; recurrence; time to recurrence; mortality; time to death; and length of follow-up. Patients were divided into the following groups: Current smokers; former smokers; and never smokers. SPSSv25.0 software (IBM Corp., Armonk, NY, United States) was used for statistical analysis.

RESULTS

A total of 95 patients from the database met the screening criteria. There were 37 never smokers, 22 former smokers, and 36 current smokers. There was no difference between groups in regards to race or sex. There was no difference in the American Joint Committee on Cancer Clinical Stage Group between groups. The former smokers were significantly older when compared to never smokers and current smokers (66.5 ± 13.17 vs 57.4 ± 7.82 vs 63.7 ± 13.80, P = 0.011). Former smokers and current smokers had a higher recurrence rate compared to never smokers (30.8% and 20.8% compared to zero, P = 0.009). There was not a significant difference in recurrence between former smokers and current smokers. There was no difference in the mortality, non-response rate, or time to death between the groups.

CONCLUSION

Our data contributes evidence that cigarette smoking status is associated with increased recurrence for patients with anal cancer.