Introduction: Persistent sinus tachycardia (PST) is of-ten present in patients (pts) with mixed anxiety–depre-ssive disorder (MADD). Ivabradine, the first selective If channel inhibitor, is recognized to lower heart rate (HR) in stable angina and heart failure.
Objective: To investigate the long term impact of con-tinuous ivabradine treatment (CIT) on PST in MADD patients.
Methods: We retrospectively analysed 172 consecu-tive pts with MADD treated with CIT for PST for 48 months, starting with JAN/2011. Demography: mean age 55.7 +/- 10.2 yrs, female predominance 67.2%. The-se patients had either contraindication, or intolerance, or insufficient heart rate (HR) reduction with beta-blockers (BB). The comparator group had 344 con-temporary patients, same profiles, treated with BB. The dosages were uptitrated as much as getting the most convenient efficacy in safety terms, in both groups. The study enter date was considered the first cardiological examination after the MADD confirmatory diagnosis. The biannual visits included a psychiatrist examinati-on, ECG, and echo LVEF.
Results: After propensity matching (1:2) the 144 CIT pts were combined with 288 controls. HR dynamic va-lues in groups CIT versus control were: at onset 105.4 +/- 9.3 vs. 105.6 +/- 9.3; at 6 months 93.7 +/- 8.7 vs. 97.2 +/- 8.8; at 12 months 85.9 +/- 7.8 vs. 93.6 +/- 8.7; at 18 months 82.3 +/- 7.7 vs. 92.5 +/- 8.7; at 24 months 82.3 +/- 7.8 vs. 92.1 +/- 8.6; at 30 months 82.0 +/- 7.6 vs. 91.7 +/- 8.6; at 36 months 81.7 +/- 7.4 vs. 91.2 +/- 8.6; at 42 months 81.2 +/- 7.4 vs. 90.6 +/- 8.5; at 48 months 80.8 +/- 7.4 vs. 90.4 +/- 8,5. HR significantly lowered in CIT pts versus control group. The most spectacular decrease of HR with CIT was in the first 6 months. This effect was preserved in the long term follow-up, whi-le blood pressure, cardiac conduction, and myocardial function (LVEF) were not affected. No aggravation of MADD was observed in CIT group.
Conclusions: Taking into consideration that one of the four major mechanisms for BB depressant effects is central nervous penetration (Braunwald, 2018), CIT appears to be a safe and feasible long-term therapeutic option for treating PST in MADD pts. Thus, CIT co-uld be an alternative to BB in MADD by reducing the resting HR without impairing nor cardiac parameters, neither neuronal physiology.