Trial Outcomes & Findings for Effect of Beta-blocker Therapy on QTc Response in Exercise and Recovery in Normal Subjects (NCT NCT00588965)

Results Overview

To minimize the effect of heart rate on QT, QT was measured at heart rates between 100 and 110 beats per minute during exercise (on and off beta-blocker) and during recovery (on and off beta-blocker).

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

36 participants

Primary outcome timeframe

2 weeks on each treatment then exercise test

Results posted on

2013-07-30

Participant Flow

Participant milestones

Participant milestones
Measure	All Participants All participants were randomized to one of 2 sequences, in which they received either propranolol first, then placebo, or placebo first, then propranolol.
Overall Study STARTED	35
Overall Study COMPLETED	35
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Effect of Beta-blocker Therapy on QTc Response in Exercise and Recovery in Normal Subjects

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	All Subjects n=35 Participants Subjects will take propranolol LA 80 mg or placebo daily for one week then propranolol LA 160 mg for one week or 2 placebo pills, followed by the exercise test. The participants will be randomized to one of 2 sequences: placebo first or propranolol first.
Age, Categorical <=18 years	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	35 Participants n=5 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants
Age Continuous	32 years STANDARD_DEVIATION 12 • n=5 Participants
Sex: Female, Male Female	20 Participants n=5 Participants
Sex: Female, Male Male	15 Participants n=5 Participants
Region of Enrollment United States	35 participants n=5 Participants

PRIMARY outcome

Timeframe: 2 weeks on each treatment then exercise test

Population: Please note that this was a crossover study. There were 35 subjects and each subject completed both the placebo and beta-blocker arm.

To minimize the effect of heart rate on QT, QT was measured at heart rates between 100 and 110 beats per minute during exercise (on and off beta-blocker) and during recovery (on and off beta-blocker).

Outcome measures

Outcome measures
Measure	Placebo n=35 Participants	Propranolol n=35 Participants
QTc Response to Exercise on Versus Off Beta-blocker. During exercise	320 ms Standard Deviation 17	317 ms Standard Deviation 16
QTc Response to Exercise on Versus Off Beta-blocker. During recovery	317 ms Standard Deviation 13	315 ms Standard Deviation 14

SECONDARY outcome

Timeframe: Measured after 2 weeks on each intervention

Tpeak-end interval was measured at rest, exercise, and recovery on placebo and on propranolol.

Outcome measures

Outcome measures
Measure	Placebo n=35 Participants	Propranolol n=35 Participants
Tpeak-end Interval (Tpe) Rest	74 ms Standard Deviation 13	72 ms Standard Deviation 13
Tpeak-end Interval (Tpe) Peak Exercise	69 ms Standard Deviation 13	61 ms Standard Deviation 11
Tpeak-end Interval (Tpe) Recovery	77 ms Standard Deviation 19	68 ms Standard Deviation 14

Adverse Events

Placebo

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Propranolol

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Elizabeth Kaufman

MetroHealth Medical Center

Phone: 216-778-2349

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place