Nonfatal MIs associated with increased risk for events long-term
MedWire News: Nonfatal myocardial infarctions (MIs) occurring in the first few months after a diagnostic catheterization are associated with an increased risk for clinical events over long-term follow-up, research shows.
The study, published in the American Heart Journal, showed that nonfatal MIs within 6 months after the intervention were associated with reduced survival, survival free of MI, and survival free of MI or revascularization.
In clinical trials, studies with short follow-ups likely underestimate the benefits of reducing MI, "as the differences between the MI and non-MI groups continue to expand over time," say Eric Eisenstein (Duke Clinical Research Institute, Durham, North Carolina) and colleagues.
Nonfatal MIs are regarded differently from other clinical outcomes. While nonfatal MIs adversely affect short-term clinical outcomes, the impact on longer-term clinical outcomes is less clear.
In this study, the researchers evaluated 14,890 patients with coronary artery disease (CAD) undergoing diagnostic catheterization to estimate the clinical implications of a nonfatal MI occurring within the subsequent 6 months.
A total of 669 and 804 patients had a nonfatal MI in the first 3 and 6 months after diagnostic catheterization, respectively.
Having a nonfatal MI within the first 3 months after the procedure was associated with reduced survival at 4 years (77.1% among nonfatal MI patients vs 83.5% among non-MI patients; hazard ratio [HR]=1.40, p<0.001).
Similarly, nonfatal MI within the first 3 months was associated with reduced survival free of MI (68.4 vs 78.5%, HR=1.50; p<0.001) and reduced survival free of MI or revascularization (59.7% vs 68.5%; HR=1.34; p<0.001).
Similar results were observed among patients who had a nonfatal MI within 6 months of the diagnostic catheterization.
These results, state Eisenstein and colleagues, suggest that therapies that reduce MI rates have downstream benefits that accrue over time.
Clinical trials with limited follow-up might be insufficient to detect the full benefits of treatment, especially studies with composite clinical endpoints, add the researchers.
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