Abstract 17337: Ivabradine and Carvedilol on Rest and Stress Coronary Diastolic Perfusion Time in Patients With Stable Coronary Artery Disease
Background: We have already demonstrated that ivabradine has a better effect on coronary flow velocity reserve (CFVR) compared with bisoprolol, in patients with stable coronary artery disease (CAD), despite a similar heart rate reduction. The aim of our study was to compare, for the first time in humans, differences between ivabradine and carvedilol on coronary diastolic perfusion time, assessed by Doppler echocardiography, both at rest and after stress test, in patients with stable CAD.
Methods: 82 patients with stable CAD were enrolled. Stress echocardiography was performed using dypiridamole (0.84 mg/kg). Coronary diastolic perfusion time (CDPT) and diastolic perfusion time to RR interval ratio (CDPT/RR) were calculated at baseline and after stress test. Patients were randomly assigned to carvedilol and ivabradine for one month and then stress echocardiography was performed again.
Results: There were no significant differences in baseline characteristics between ivabradine and carvedilol group. CFVR was successfully performed in all patients. At baseline, both CDPT and CDPT/RR significantly increased after therapy with carvedilol (486.6±52.2 ms vs. 411.1±49.6 ms; 0.52±0.05 vs. 0.48±0.05 - p<0.01) and with ivabradine (541.8±65 ms vs. 408.9±50.2; 0.58±0.03 vs 0.48±0.03 - p<0.01), but they were significantly higher in ivabradine group, despite a similar lowering of heart rate. After stress echocardiography, CDPT reduced in both carvedilol and ivabradine group, but it remained significantly higher in ivabradine group (447.1±57.1 ms vs. 415.7±49.8 - p<0.01). CDPT/RR increased to a greater extent in ivabradine group, compared with carvedilol (0.63±0.05 vs 0.56±0.04 - p<0.01). CFVR increased in both groups but it was significantly better in ivabradine group compared with carvedilol group (3.46±0.44 vs. 3.16±0.56 - p<0.01).
Conclusions: Ivabradine is able to improve coronary perfusion time, better than carvedilol, in patients with stable CAD. This effect occurs both at rest and after stress test, with a mechanism that is partially independent from heart rate reduction. These data show that ivabradine has a different effect on pathophysiology of coronary circulation, compared with beta-blockers.
Author Disclosures: E. Tagliamonte: None. F. Rigo: None. C. Astarita: None. R. Astarita: None. A. Coppola: None. M. Tagliamonte: None. N. Capuano: None.
- © 2016 by American Heart Association, Inc.