Prognostic impact of previous and new myocardial infarction in patients with infectious endocarditis

Abstract Background Infective endocarditis (IE) is a life-threatening condition with high in-hospital mortality rates. The influence of previous and new myocardial infarction (MI) in these patients is unknown. Our aim was to evaluate the prevalence and prognostic impact of previous and new myocardial infarction in a national cohort of IE. Methods Our data come from the Spanish endocarditis registry. We included 6392 patients diagnosed with IE between 2008 and 2023. Results A total of 568 patients (8.8%) had a previous MI and 83 (1.3%) presented an acute MI (61 without MI history and 22 with reinfarction). Compared to patients without a previous MI, patients with a previous MI had a more advanced age (71 vs. 69 years, p 0.001), were more frequently male (80.4% vs. 66.4%, p 0.001), had higher Charlson age-adjusted comorbidity index (7 vs. 4, p 0.001), and higher mortality (in-hospital death 29.4% vs. 24.9%, one-year mortality 35.4% vs. 30.7%, both p values 0.001). However, in multivariate analyses previous MI was not and independent predictor of mortality (inhospital death odds ratio 0.90, 95% confidence interval 0.70-1.12, p=0.42 and one-year death hazard ratio 0.81, 95% confidence interval 0.64-1.02, p=0.08). On the other hand, new acute MI was an independent predictor of mortality (inhospital death odds ratio 1.9, 95% confidence interval 1.11-3.32, p=0.402 and one-year death hazard ratio 2.26, 95% confidence interval 1.32-3.89, p=0.08). Conclusion The presence of a previous MI is associated with a poor prognosis in patients with IE, although this is mainly due to advanced age and comorbidity. A new acute MI has a significant impact in IE prognosis, duplicating in-hospital and one-year mortality.