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Does QTc interval predict the response to beta-blockers and calcium channel blockers in hypertensives?
Maxime Lamarre-Cliche1, Yves Lacourcière, Jacques de Champlain
1Department of Clinical Pharmacology, Centre hospitalier de l'Université de Montréal-Hôtel-Dieu, Montréal, Qc, Canada. lamarm@ircm.qc.ca
Insights
The corrected QT (QTc) interval, heart rate, and heart rate changes do not predict blood pressure reduction from beta-blockers or calcium channel blockers in hypertensive patients.
Area of Science:
- Cardiology
- Pharmacology
- Autonomic Nervous System
Background:
- The corrected QT (QTc) interval is a marker of cardiac repolarization and reflects sympathovagal balance.
- Beta-blockers and dihydropyridine-type calcium channel blockers (DHPCCB) impact the autonomic nervous system.
- Understanding predictors of antihypertensive response is crucial for personalized medicine.
Purpose of the Study:
- To investigate if QTc interval length predicts blood pressure reduction from beta1-selective beta-blockers or DHPCCB.
- To evaluate the predictive value of pretreatment heart rate and heart rate changes with therapy.
Main Methods:
- Historical reanalysis of 5 clinical trials involving beta-blockers (nebivolol) and DHPCCB (amlodipine, felodipine, isradipine, nifedipine).
- Correlation and quintile analyses were used to assess associations between QTc interval, heart rate, heart rate change, and blood pressure response.
- Separate analyses were conducted for beta-blocker and DHPCCB treatment groups.
Main Results:
- No significant association was found between QTc interval length and blood pressure response to either beta-blockers or DHPCCB.
- Pretreatment heart rate did not predict therapeutic blood pressure response.
- Heart rate changes during therapy were not associated with blood pressure reduction.
Conclusions:
- QTc interval length is not a reliable predictor of blood pressure response to beta1-selective beta-blockers or DHPCCB in hypertensive patients.
- Pretreatment heart rate and heart rate changes also lack predictive value for the antihypertensive efficacy of these drug classes.
- Current markers of autonomic function may not be useful for predicting treatment outcomes with these specific antihypertensive agents.
Abstract:
The QT interval corrected for heart rate (QTc) is believed to reflect sympathovagal balance. It has also been established that beta-blockers and dihydropyridine-type calcium channel blockers (DHPCCB) influence the autonomic nervous system. This study tested the hypothesis that QTc interval length is a predictor of the blood pressure reduction induced by beta1-selective beta-blockers or DHPCCB. The predictive values of pretreatment heart rate and of the heart rate change with therapy were also evaluated. The authors conducted an historical reanalysis of 5 clinical trials that looked at the antihypertensive effects of beta-blockers (nebivolol) or DHPCCB (amlodipine, felodipine, isradipine, nifedipine). Correlation and quintile analyses were performed to measure the association between QTc interval, heart rate, or heart rate change and therapeutic blood pressure response. Separate analyses were undertaken for beta-blockers and DHPCCB. Seventy-three and 98 hypertensive subjects respectively were included in the beta-blocker and DHPCCB analyses. QTc interval, pretreatment heart rate, and heart rate change with therapy were not associated with therapeutic blood pressure response. In this study, QTc interval length, pretreatment heart rate, and heart rate change with therapy were not good predictors of the blood pressure response to beta1-selective beta-blockers or DHPCCB in hypertensive subjects.