Revascularization rates with coronary angioplasty and mortality in type 2 myocardial infarction: A meta-regression analysis

Background: Percutaneous coronary intervention (PCI) represents the best therapeutic option for type-1 myocardial infarction (T1MI) in the majority of clinical settings; its role in the treatment of type-2 myocardial infarction (T2MI), however, remains unclear. We therefore sought to assess in a meta-regression analysis the impact of PCI rates on mortality in patients with T2MI according to available observational studies. Methods: We performed a meta-regression analysis including all the studies involving in-patients affected by T2MI. We excluded studies not reporting the rate of T2MI patients undergoing PCI and not specifying absolute in-hospital or 1-year all-cause mortality. In the meta-regression analysis we used the in-hospital mortality and 1-year mortality as dependent variables and the rate of PCI as independent; regression was weighted for studies' size. Results: After careful examination, 8 studies were selected for the assessment of in-hospital mortality and 8 for 1-year-mortality. We included 3155 and 3756 in-patients for in-hospital and 1-year mortality respectively. At meta-regression analysis, a borderline correlation between PCI rate and in-hospital mortality (p 0.05) and a statistically significant correlation with 1-year mortality (p < 0.01) in T2MI patients were found. Conclusions: In a meta-regression analysis higher rates of PCI on T2MI in-patients were associated with lower mortality rates both in-hospital and at 1 year. Whether this association is related to the direct effect of PCI or better general conditions of T2MI patients undergoing a PCI still remains unclear.