Predictors of succesfull beta-blocker dose reduction during structured cardiovascular rehabilitation in patients with dysautonomia
A Contreras Lugo, A Pacheco Bouthillier, H A Radillo AlbaAbstract
Background
Beta-blockers are the first-line treatment for postural orthostatic tachycardia syndrome (POTS) and inappropriate sinus tachycardia (IST). Unfortunately, prolonged use of treatment may decrease exercise capacity and reduce cardiopulmonary adaptability. Structured cardiovascular rehabilitation (CR) has a well established role as a non-pharmacological treatment for dysautonomia, but predictors of effective beta-blocker deprescription remain undefined.
Objective
To find independent predictors of successful high-grade beta-blocker dose reduction that occurred during a 6 month structured CR program in patients with dysautonomia.
Methods
This was an observational cohort study of 104 consecutive POTS or IST patients who were enrolled in a supervised six-month CR program. Beta-blocker tapering was done incrementally based on symptom progression and heart rate response. The definition of successful dose reduction was ≥80% reduction in beta-blocker dose without recurrence of limiting symptoms at six months. Multivariable logistic regression (age, sex, diagnosis [POTS vs IST], baseline resting heart rate, peak VO₂ baseline, percentage change in the peak VO₂, adherence rate, total amount of CR sessions) was conducted. Results are reported as odds ratios (OR).
Results
Beta-blocker reduction ≥80% success was achieved in 52.0% of patients. Adherence to the rehabilitation program was the only independent predictor of a successful dose reduction in multivariate analysis (OR 1.68, p = 0.003), indicating a 68% increase in odds of high-grade deprescription with respect to the rehabilitation program adherence. Age (OR 6.89, p = 0.15), baseline peak VO₂ (OR 3.92, p = 0.54), and diagnosis (POTS vs IST) (OR 0.91, p = 0.17) were not independently associated with outcome. Discrepancy of point estimates indicates poor precision vs. absolute absence of effect. Percentage increase in peak VO₂ had no effect beyond adherence and it shows that pharmacological optimization is driven by behavioral participation and long-term program exposure, not baseline functional capacity or degree of physiological improvement.
Conclusion
Program adherence to a structured CR program in patients with dysautonomia is the main determinant of ≥80% successful beta-blocker dose reduction, irrespective of baseline phenotype or functional status. These results lend credence to a rehabilitation-based deprescription plan and emphasize the importance of behavioral engagement in the optimal pharmacotherapy of dysautonomia.Independent predictors of BB dose reductionROC curve of beta-blocker dose reduction