A comparative study of ivabradine and atenolol in patients with moderate mitral stenosis in sinus rhythm.

BACKGROUND: Beta-blockers are frequently used in patients with mitral stenosis to control the heart rate and alleviate exercise-related symptoms. The objective of our study was to examine whether ivabradine was superior to atenolol for achieving higher exercise capacity in patients with moderate mitral stenosis in sinus rhythm. We also evaluated their effects on left ventricular myocardial performance index (MPI).

METHODS AND RESULTS: Eighty-two patients with moderate mitral stenosis in sinus rhythm were randomized to receive ivabradine (n=42) 5mg twice daily or atenolol (n=40) 50mg daily for 6 weeks. Transthoracic echocardiography and treadmill test were performed at baseline and after completion of 6 weeks of treatment. Mean total exercise duration in seconds markedly improved in both study groups at 6 weeks (298.57±99.05s vs. 349.12±103.53s; p=0.0001 in ivabradine group, 290.90±92.42s vs. 339.90±99.84s; p=0.0001 in atenolol group). On head-to-head comparison, there was no significant change in improvement of exercise time between ivabradine and atenolol group (p=0.847). Left ventricular MPI did not show any significant change from baseline and at 6 weeks in both drug groups (49.8%±8% vs. 48.3%±7% in ivabradine group, 52.9%±10% vs. 50.9%±10% in atenolol groups; p=0.602).

CONCLUSION: Ivabradine or atenolol can be used for heart rate control in patients with moderate mitral stenosis in sinus rhythm. Ivabradine is not superior to atenolol for controlling heart rate or exercise capacity. Left ventricular MPI was unaffected by either of the drugs.