Objective:

We conducted a systematic meta-analysis of individual data from 98,496 patients enrolled in large scale randomized trials in which ACE-inhibitor treatment started in acute phase of myocardial infarction and continued for a short period of time (CCS-1, CONSENSUS-2, GISSI-3, ISIS-4 trials).

Methods:

A protocol pre-specifying the required data and the planned analyses was agreed and adopted by a Collaborative Group including the Principal Investigators of each trial.

Results:

The effects of ACE-i therapy on the odds of death calculated from this meta-analysis (IPD MA) were similar to those calculated using the published reports (PR MA).


Source events/patients OR 95% CI
IPD MA 7241/98496 0.93 0.89-0.98
PR MA 7271/96669 0.93 0.89-0.98

However, with respect to PR MA, IPD MA showed a number of advantages such as possibility of checking data consistency, use of continuous variables, conduction of time-dependent analyses on main outcomes and clinical events, evaluation of treatment effect among subgroups of patients, and multivariate analyses to calculate prognostic indexes. Exemplification of these advantages will be provided.

Discussion:

Despite its well known disadvantages, as the need of willingness of investigators to collaborate, the time and the amount of resources required, meta-analysis using individual patient data remains the gold standard, mainly when continuous data are used and time-dependent analyses are the main end-point.