Long-term cardiovascular safety of salmeterol powder pharmacotherapy in adolescent and adult patients with chronic persistent asthma: a randomized clinical trial.

STUDY OBJECTIVES

This study investigates the long-term cardiovascular safety of salmeterol powder vs placebo in adolescent and adult patients with mild persistent asthma.

DESIGN

Multicenter, randomized, double-blind, placebo-controlled, parallel-group study.

SETTING

Eighteen US clinical centers.

PATIENTS

Three hundred fifty-two patients (> or = 12 years) with mild persistent asthma (duration > or = 6 months) requiring pharmacotherapy; with FEV1 of 70 to 90% of predicted and without abnormal ECG/continuous ambulatory ECG (Holter).

INTERVENTIONS

Randomized to twice-daily salmeterol powder (50 microg) or placebo via breath-actuated device for 52 weeks. Backup albuterol was available to control asthma symptoms.

MEASUREMENTS AND RESULTS

Cardiovascular safety was regularly assessed by 12-lead ECG with a 15-s lead II rhythm strip, 24-h continuous ambulatory ECG (Holter) monitoring, serial vital sign measurements, and review of adverse cardiovascular events. No deaths occurred during the study. No clinically significant between-group differences were observed in pulse rate, ECG QTc interval, median number of ventricular or supraventricular ectopic events, incidence of ventricular ectopic couplets and runs, or incidence of > 100 ventricular or supraventricular ectopic events in 24 h. No clinically significant between-group differences were observed in arterial BP or incidence of adverse cardiovascular events. Salmeterol was well tolerated throughout the 52-week study period, with a cardiovascular safety profile similar to that of placebo.

CONCLUSIONS

Long-term, twice-daily pharmacotherapy with salmeterol powder is safe and is not associated with unfavorable clinically significant changes in cardiac function or increases in cardiovascular adverse effects.