Author + information
- Received May 20, 1994
- Revision received September 29, 1994
- Accepted October 5, 1994
- Published online March 1, 1995.
- Richard F. Davies, MD, PhD, FACC*,
- Habibullah Habibi, MD,
- W. Peter Klinke, MD, FACC,
- Pierre Dessain, MD,
- Claude Nadeau, MD, FACC,
- Denis C. Phaneuf, MD, FACC,
- Serge Lepage, MD, FACC,
- Sankaranarayanan Raman, PhD,
- Margaret Herbert, BSc,
- Kathy Foris, MD,
- Wolfgang Linden, PhD,
- Jennifer A. Buttars, BSc,
- For the Canadian Amlodipine/atenolol In Silent Ischemia Study (CASIS) Investigators
- ↵*Address for correspondence: Dr. Richard F. Davies, Room H147, University of Ottawa Heart Institute, 1053 Carling Avenue, Ottawa, Ontario K1Y 4E9, Canada.
Objectives. This study compared the effects of amlodipine, atenolol and their combination on ischemia during treadmill testing and 48-h ambulatory monitoring.
Background. It is not known whether anti-ischemic drugs exert similar effects on ischemia during ambulatory monitoring and exercise treadmill testing.
Methods. Patients with stable coronary artery disease and ischemia during treadmill testing and ambulatory monitoring were randomized to receive amlodipine (n = 51) or atenolol (n = 49). Each group underwent a counterbalanced, crossover evaluation of single drug and placebo, followed by evaluation of the combination.
Results. Amlodipine and the combination prolonged exercise time to 0.1-mV ST segment depression by 29% and 34%, respectively (p < 0.001) versus 3% for atenolol (p = NS). During ambulatory monitoring, the frequency of ischemic episodes decreased by 28% with amlodipine (p = 0.083 [NS]), by 57% with atenolol (p < 0.001) and by 72% with the combination (p < 0.05 vs. both single drugs; p < 0.001 vs. placebo). Suppression of ischemia during exercise testing and ambulatory monitoring was similar in patients with and without exercise-induced angina. Exercise time to angina improved by 29% with amlodipine (p < 0.01), by 16% with atenolol (p < 0.05) and by 39% with the combination (p < 0.005 vs. placebo, atenolol and amlodipine). In patients with angina, total exercise time improved by 16% with amlodipine (p < 0.001), by 4% with atenolol (p = NS) and by 19% with the combination (p < 0.05 vs. placebo and either single drug). In those patients without angina, no therapy significantly improved total exercise time.
Conclusions. Ischemia during treadmill testing was more effectively suppressed by amlodipine, whereas ischemia during ambulatory monitoring was more effectively suppressed by atenolol. The combination was more effective than either single drug in both settings.
This study was funded by grants from Pfizer Canada Inc., Pointe Claire, Quebec and the British Columbia Heart and Stroke Foundation, Vancouver, British Columbia. A complete list of the CASIS Investigators and their affiliated institutions appears in the Appendix.
- Received May 20, 1994.
- Revision received September 29, 1994.
- Accepted October 5, 1994.
- American College of Cardiology