Lipitor (atorvastatin calcium) tablets (80mg) was more effective than simvastatin (20mg–40mg) in reducing the risk of multiple cardiovascular events in patients with a history of heart attacks in the Incremental Decreases through Aggressive Lipid Lowering (IDEAL) clinical trial, according to Pfizer.
Cardiovascular events included heart attack, stroke and cardiac revascularisation procedures such as bypass surgery and angioplasty.
All 8,888 patients enrolled in the trial had a prior heart attack and 2,546 of them experienced at least one additional cardiovascular event after entering the trial.
A new post-hoc analysis (planned after the study closed) reported that 1,048 patients had a second cardiovascular event during the course of the trial.
In those patients treated with Lipitor there was a significant 24% reduction in relative risk of having that second event than those treated with simvastatin (p<0.0001).
Analysis also found that 416 patients had a third event during the course of the trial.
In those patients treated with Lipitor there was a significant 19% reduction in the relative risk of having that third event compared to simvastatin (p=0.035).
The overall results of this analysis are even more robust in patients who were more adherent to treatment.
The results were presented at the Annual Scientific Sessions of the American Heart Association.
In the original analysis of IDEAL, the primary endpoint of the first major coronary event (non-fatal heart attack, coronary heart disease death, cardiac arrest) during the trial was reduced in the Lipitor patients compared to simvastatin patients by 11% (p=0.07), which did not reach statistical significance.
There was a significant 17% (p=0.02) reduction in risk for the first non-fatal heart attack and significant 13% (p=0.02) reduction in risk of the first major cardiovascular events, major coronary events and stroke in patients taking Lipitor.
Dr Matti Tikkanen, professor of medicine at Helsinki University, said: “Heart attack patients are extremely vulnerable to experiencing even more cardiovascular events.
“After such an event, the most important task of the treating physician is to reduce the risk of the next cardiovascular event.
“This analysis showed that Lipitor was more effective than simvastatin in reducing the risk of recurrent cardiovascular events.
“Our results provide evidence that patients who have already experienced cardiovascular events benefit from Lipitor 80mg.”
The analysis is unique because it evaluated all cardiovascular events that occurred during the five-year course of the trial, whereas analyses of most statin trials are limited usually to evaluating the occurrence of the first event only.
Dr Rochelle Chaiken, vice-president of Pfizer’s cardiovascular and metabolic medical division, said: “This unique analysis confirmed the benefit of long-term Lipitor 80mg therapy in patients who have had multiple cardiovascular events.
“When treating patients with cardiovascular disease risk it is important to take into account the clinical data for the medication so that the right medicine is chosen for the individual patient.”