Trends and determinants of calcium antagonist usage after acute myocardial infarction (the GISSI experience)

In the last decade, several clinical trials in patients with, or recovering from, acute myocardial infarction (AMI) have evaluated the role of calcium antagonists in affecting patientsʹ prognosis. Results have been disparate, with evidence of possible harm, no effect, or some benefit, depending on the agent used. We evaluated how the evidence from these trials has influenced the pattern of prescription of calcium antagonists and assessed the important determinants of use of these agents in patients after AMI. We analyzed retrospectively the prescription of calcium antagonists at discharge in all patients recovering from AMI enrolled in 3 large randomized clinical trials (Gruppo Italiano per lo Studio della Sopravvivenza nellʹInfarto-1 [GISSI-1], GISSI-2, and GISSI-3) during the last 10 years. A progressive decrease in prescriptions for calcium antagonists was evident, from 47.2% in GISSI-1 to 35.1% in GISSI-2 to 19.0% in GISSI-3 (p < 0.001). The presence of post-AMI angina, history of hypertension, and occurrence of reinfarction were associated with a higher usage of calcium antagonists, whereas the use of β blockers at discharge was a major independent negative determinant. Use of calcium antagonists for secondary prevention after AMI (i.e., without specific clinical indications for their use) decreased by approximately 60% (from 26.1% to 10.3%). The data indicate that the usage of calcium antagonists in GISSI studies has been strongly affected by the results of other large multicenter trials evaluating calcium antagonists. These agents are now prescribed in patients after AMI almost exclusively in the presence of specific indications such as systemic hypertension or angina.